Completion Report for Well ER-EC-2A - UNT Digital Library/67531/metadc741005/... · Well ER-EC-2A is located within the Nellis Air Force Range complex, approximately 10 kilometers

DOE/NV/11718--591

Nevada EnvironmentalRestorationDivision

CompletionReport forWell ER-EC-2A

March 2002

DISCLAIMER STATEMENT

Reference herein to any specific commercial product, process, or service by tradename, trademark, manufacturer, or otherwise, does not necessarily constitute orimply its endorsement, recommendation, or favoring by the U.S. Government orany agency thereof or its contractors or subcontractors.

AVAILABILITY STATEMENT

Available to the public, in paper, from–

U.S. Department of CommerceNational Technical Information Service5285 Port Royal RoadSpringfield, VA, 22161-0002Telephone: 800.553.6847Fax: 703.605.6900E-mail: [email protected] ordering: http://www.ntis.gov/ordering.htm

Available electronically at http://www.doe.gov/bridge.

Available for a processing fee to U.S. Department of Energy and its contractors,in paper, from–

U.S. Department of EnergyOffice of Scientific and Technical InformationP.O. Box 62Oak Ridge, TN 37831-0062Telephone: 865.576.8401Fax: 865.576.5728E-mail: [email protected]

DOE/NV/11718--591

Completion Report forWell ER-EC-2A

Prepared for:U.S. Department of Energy

National Nuclear Security AdministrationNevada Operations Office

Las Vegas, Nevada

Prepared by:Bechtel Nevada

Geological and Hydrological ServicesLas Vegas, NV

March 2002

This work was supported by the U.S. Department of Energy, National Nuclear Security Administration

Nevada Operations Office, under Contract No. DE-AC08-96NV11718.

ii

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iv


v

Completion Report for Well ER-EC-2ADOE/NV/11718--591

ABSTRACT

Well ER-EC-2A was drilled for the U.S. Department of Energy, National Nuclear Security

Administration Nevada Operations Office, in support of the Nevada Environmental Restoration

Project at the Nevada Test Site, Nye County, Nevada. This well was drilled in January and

February of 2000 as part of a hydrogeologic investigation program in the Pahute Mesa - Oasis

Valley region just west of the Nevada Test Site. A 44.5-centimeter surface hole was drilled and

cased off to a depth of 412.9 meters below the surface. The hole diameter was then decreased to

31.1 centimeters for drilling to a total depth of 1,516.1 meters.

One completion string with three isolated slotted intervals was installed in the well. A

preliminary composite, static water level was measured at the depth of 228.0 meters,

approximately two months after installation of the completion string.

Detailed lithologic descriptions with preliminary stratigraphic assignments are included in this

report. These are based on composite drill cuttings collected every 3 meters, and 81 sidewall

samples taken at various depths below 212 meters, supplemented by geophysical log data.

Detailed petrographic, chemical, and mineralogical studies of rock samples were conducted on

30 samples. The well was collared in rhyolite lava and penetrated Tertiary-age lava and tuff of

the Volcanics of Fortymile Canyon and the Timber Mountain Group. The preliminary geologic

interpretation of borehole data indicates that this well was drilled within the margins of the

buried Rainier Mesa and Ammonia Tanks calderas, and that caldera collapse in this area was

deeper than expected, resulting in a section of Volcanics of Fortymile Canyon (caldera-filling

deposit) that is much thicker than expected.

vi


vii

Table of Contents

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x

List of Acronyms and Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

1.0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.1 Project Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.2 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

1.3 Project Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

1.4 Project Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

2.0 Drilling Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.2 Drilling History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.3 Drilling Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

2.4 Fluid Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

3.0 Geologic Data Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.2 Collection of Drill Cuttings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.3 Sidewall Core Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.4 Sample Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

3.5 Geophysical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

4.0 Geology and Hydrogeology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.2 Geology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.2.1 Stratigraphy and Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.2.2 Alteration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13

4.3 Predicted Versus Actual Geology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13

4.4 Hydrogeology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16

Table of Contents (Continued)

viii

5.0 Hydrology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.1 Preliminary Water-Level Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.2 Water Production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.3 Preliminary Flow Meter Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

5.4 Preliminary Groundwater Characterization Samples . . . . . . . . . . . . . . . . . . . . . . . . . 5-3

6.0 Precompletion and Open-Hole Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

7.0 Well Completion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.2 Well Completion Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.2.1 Proposed Completion Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.2.2 As-Built Completion Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5

7.2.3 Rationale for Differences between Actual and Proposed Well Design . . . . . . 7-6

7.3 Well Completion Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6

8.0 Actual versus Planned Costs and Scheduling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

9.0 Summary, Recommendations, and Lessons Learned . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

9.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

9.2 Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2

9.3 Lessons Learned . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2

10.0 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

Appendix A - Drilling Data

A-1 Drilling Parameter Logs for Well ER-EC-2A

A-2 Casing Data for Well ER-EC-2A

A-3 Well ER-EC-2A Drilling Fluids and Cement Composition

Appendix B - Well ER-EC-2A Fluid Management Data

Well ER-EC-2A Fluid Disposition Reporting Form

Preliminary Analytical Results for Fluid Management Samples from Well ER-EC-2A

Appendix C - Preliminary Detailed Lithologic Log for Well ER-EC-2A

Appendix D - Geophysical Logs Run in Well ER-EC-2A

Distribution List

ix

List of Figures

Number Title Page

1-1 Reference Map Showing Location of Well ER-EC-2A . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

2-1 Drill Site Configuration for Well ER-EC-2A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2-2 Well ER-EC-2A Drilling and Completion History . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

4-1 Map of Pahute Mesa - Oasis Valley Area Showing Theorized Locations of

Caldera Boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34-2 Surface Geologic Map of the Well ER-EC-2A Site . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

4-3 Geology and Hydrogeology of Well ER-EC-2A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

4-4 Preliminary Geologic Cross Section A-A’ Through Well ER-EC-2A . . . . . . . . . . . . 4-12

4-5 Predicted and Actual Stratigraphy at Well ER-EC-2A . . . . . . . . . . . . . . . . . . . . . . . . 4-14

4-6 Preliminary Hydrogeologic Cross Section B-B’ Through Well ER-EC-2A . . . . . . . . 4-17

7-1 As-built Completion Schematic for Well ER-EC-2A . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

7-2 Wellhead Diagram for Well ER-EC-2A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4

8-1 Planned versus Actual Construction Progress for Well ER-EC-2A . . . . . . . . . . . . . . . 8-2

8-2 Planned versus Actual Cost for Constructing Well ER-EC-2A . . . . . . . . . . . . . . . . . . . 8-3

x

List of Tables

Number Title Page

1-1 Well ER-EC-2A Site Data Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

2-1 Abridged Drill Hole Statistics for Well ER-EC-2A . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

3-1 Sidewall Samples from Well ER-EC-2A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3-2 Status of Rock Sample Analyses for Well ER-EC-2A . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

3-3 Well ER-EC-2A Geophysical Log Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

7-1 Well ER-EC-2A Completion String Construction Summary . . . . . . . . . . . . . . . . . . . . 7-3

A-2 Casing Data for Well ER-EC-2A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2-1

A-3-1 Well ER-EC-2A Drilling Fluids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3-1

A-3-2 Well ER-EC-2A Cement Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3-1

D-1 Well ER-EC-2A Geophysical Logs Presented . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D-1

xi

List of Acronyms and Abbreviations

BN Bechtel Nevada

C centigrade

cm centimeter(s)

DOE U.S. Department of Energy

DOE/NV U.S. Department of Energy, Nevada Operations Office

DRI Desert Research Institute

E east

EC Electrical Conductivity

F Fahrenheit

FMP Fluid Management Plan

ft foot (feet)

gal gallon(s)

gpm gallons per minute

in. inch(es)

IT IT Corporation

km kilometer(s)

lpm liters per minute

LANL Los Alamos National Laboratory

LiBr lithium bromide

m meter(s)

Ma million years ago

mi mile(s)

N north

NAD North American Datum

NNSA/NV U.S. Department of Energy, National Nuclear Security AdministrationNevada Operations Office

NTS Nevada Test Site

PM-OV Pahute Mesa - Oasis Valley

TD total depth

TFM Thermal Flow Meter

TMCC Timber Mountain caldera complex

TWG Technical Working Group

UGTA Underground Test Area

UDI United Drilling, Inc.

USGS United States Geological Survey

xii


1-1

1.0 Introduction

1.1 Project Description

Well ER-EC-2A was drilled for the U.S. Department of Energy, National Nuclear Security

Administration Nevada Operations Office (NNSA/NV) in support of the Nevada Environmental

Restoration Project at the Nevada Test Site (NTS), Nye County, Nevada. Well ER-EC-2A is the

eighth in a series of wells to be drilled as part of the hydrogeologic investigation well program in

the Pahute Mesa - Oasis Valley (PM-OV) region of Nye County, Nevada. This program is part

of the NNSA/NV Environmental Restoration Division’s Underground Test Area (UGTA) project

at the NTS. The goals of the UGTA project include evaluating the nature and extent of

contamination in groundwater due to underground nuclear testing, and establishing a long-term

groundwater monitoring network. As part of the UGTA project, scientists are developing

computer models to predict groundwater flow and contaminant migration within and near the

NTS. To build and test these models, it is necessary to collect geologic, geophysical, and

hydrologic data from new and existing wells to define groundwater migration pathways,

migration rates, and quality.

The goal of the PM-OV program is to collect subsurface geologic and hydrologic data in a large,

poorly characterized area down-gradient from Pahute Mesa where underground nuclear tests

were conducted, and up-gradient from groundwater discharge and withdrawal sites in Oasis

Valley northeast of Beatty, Nevada (Figure 1-1). Data from these wells will allow for more

accurate modeling of groundwater flow and radionuclide migration in the region. Some of the

wells may also function as long-term monitoring wells.

Well ER-EC-2A is located within the Nellis Air Force Range complex, approximately

10 kilometers (km) (6 miles [mi]) southwest of the Area 20 underground nuclear test area

(Figure 1-1). The elevation of the dirt-fill drill pad at the wellhead is 1,494.1 meters (m)

(4,901.9 feet [ft]) above mean sea level. The Nevada State (central zone) plane coordinates

(North American Datum [NAD] 1983) at the wellhead are North (N) 6,265,715.6 and

East (E) 508,740.7 m (N 20,556,768.7 and E 1,669,093.5 ft). Additional site data are listed in

Table 1-1.

IT Corporation (IT) was the principal environmental contractor for the project, and IT personnel

collected geologic and hydrologic data during drilling. The drilling company was United

1-2


NellisAir Force

Range

10,000 Meter UTM Tics Based on NAD83

Bureau ofLand

Management

NevadaTestSite

ThirstyMountain

ER-EC-2A

ER-EC-10

ER-EC-6

ER-EC-1

ER-18-2ER-EC-5

ER-EC-4

ER-EC-8

ER-EC-7

ER-EC-9

ER-EC-3

ER-OV-7

ER-OV-8

Area 19

Area 20

Area 18

Area 29

Area 30

Area 25

Area 17

Area 12

Area 16

Shoshone Mountain

Pahute Mesa

Ka

wic

h C

an

yo

n

TimberMountain

Oas

is V

alle

y

BeattyWash

BlackMountain

Elea

na

Ran

ge

BuckboardMesa

Redrock Valley

Fo

rty

mil

e C

an

yo

n

Rainier MesaBig Burn Valley

Yu

cca

Mtn

.

Th

irst

y C

an

yon

95

374 Beatty

116°40'0"W

116°40'0"W

116°30'0"W

116°30'0"W

37

°0

'0"N

37

°0

'0"N

37

°1

0'0

"N

37

°1

0'0

"N

37

°2

0'0

"N

37

°2

0'0

"N

520000

520000

530000

530000

540000

540000

550000

550000

40

80

00

0

40

80

00

0

40

90

00

0

40

90

00

0

41

00

00

0

41

00

00

0

41

10

00

0

41

10

00

0

41

20

00

0

41

20

00

0

41

30

00

0

41

30

00

0

PM-OV Well

Proposed PM-OV Well

Well Access Road

Proposed Well Access Road

Primary NTS Road

Highways (U.S. and State)

Nellis Air Force Range

Nevada Test Site

0 1 2 3 4 5

Miles


10 Minute Latitude / Longitude Graticule

Figure 1-1Reference Map Showing Location of Well ER-EC-2a

(Proposed wells not drilled at time Well ER-EC-2a was drilled.)

1-3

NTS/GIS: jrc erec2a.mxd

31-OCT-2000

1-4


1-5

Table 1-1Well ER-EC-2A Site Data Summary

Well Designation ER-EC-2A

Site Coordinates a

Nevada State Plane (ce ntral zone) (NAD 83):

N 6,265 ,715.6 m (N 20,55 6,768.7 ft)

E 508,7 40.7 m (E 1,669,09 3.5 ft)

Nevada State Plane (ce ntral zone) (NAD 27):

N 871 ,767.2 ft

E 528,9 37.9 ft

Universal Transverse Mercator (Zone 11)(N AD 83):

N 4,111,038.2 m

E 538,340.5 m

Surface Elevation b 1,494.1 m (4,901.9 ft)

Drilled Depth 1,516.1 m (4,974 ft)

Fluid-Level Depth c

228.0 m (747.9 ft)

Fluid-Level Elevation 1,266.1 m (4,154.0 ft)

a Measurement made by BN Survey.

b Measurement made by BN Survey. Elevation at top of construction pad. 1929 North American

Vertical D atum.

c Measured by IT on April 14, 2000, approximately two months after completion string was installed.

Drilling, Incorporated (UDI), a subcontractor to Bechtel Nevada (BN). Site supervision,

engineering, construction, inspection, and geologic support were provided by BN. The roles and

responsibilities of these and other contractors involved in the project are described in Contract

Number DE-RP-08-95NV11808, and in BN Drilling Work Plan Number D-001-002.00

(BN, 2000). The UGTA Technical Working Group (TWG), a committee of scientists and

engineers comprising NNSA/NV, Lawrence Livermore National Laboratory, Los Alamos

National Laboratory (LANL), and contractor personnel, provided additional technical advice

during drilling, design, and construction of the well. See FY99 Western Pahute Mesa-Oasis

Valley Hydrogeologic Investigation Wells Drilling and Completion Criteria (IT, 1998) for

descriptions of the general plan and goals of the PM-OV project, as well as specific goals for

each planned well.

General guidelines for managing fluids used and generated during drilling, completion, and

testing of UGTA wells are provided in the UGTA Fluid Management Plan (FMP)

(U.S. Department of Energy, Nevada Operations Office [DOE/NV], 1996a), an attachment to the

1-6

UGTA Waste Management Plan (DOE/NV, 1996b). Estimates of production of fluid and drill

cuttings for the PM-OV holes are given in Appendix N of the drilling and completion criteria

document for the PM-OV project (IT, 1998), along with sampling requirements and contingency

plans for management of any hazardous waste produced. All activities were conducted in

accordance with the Nevada Environmental Restoration Project Health and Safety Plan

(DOE/NV, 1998), and the Site-Specific Health and Safety Plan for PM-OV Investigation Wells

(BN, 1999).

This report presents construction data and summarizes scientific data gathered during drilling and

installation of the completion string. Some of the information in this report is preliminary and

unprocessed, but is being released with the drilling and completion data for convenient reference.

A well data report prepared by IT (IT, 2000) contains additional information on fluid

management, waste management, and environmental compliance. Updated geologic information

(including any changes in the geologic interpretation) will be compiled in the documentation

package for the PM-OV hydrostratigraphic framework model to be prepared by BN.

Information on well development, aquifer testing, and groundwater analytical sampling will be

compiled and disseminated separately by IT.

1.2 Objectives

The primary purpose of constructing Well ER-EC-2A was to obtain information which will help

characterize the hydrogeology of this part of the PM-OV area. Well-specific scientific

objectives, as discussed in Appendix B of the drilling criteria document (IT, 1998), include the

following:

! Explore the possibility of a deep groundwater flow regime.

! Obtain hydraulic properties for the rocks that fill the Timber Mountain caldera complexto determine how these rocks affect local groundwater flow.

! Determine groundwater levels to define the local groundwater flow system gradient.

Some of these objectives will not be met until additional work is completed, including installing

a pump and conducting hydraulic testing, and analyzing geology and hydrology data from this

and other wells in the PM-OV area.

1-7

1.3 Project Summary

This section summarizes Well ER-EC-2A construction operations; the details are provided in

Sections 2.0 through 8.0 of this report.

The surface conductor hole was constructed by augering a 121.9-centimeter (cm) (48-inch [in.])

diameter hole to a depth of 20.1 m (66 ft) and installing a string of 30-in. casing. Drilling of the

main hole with a 17½-in. rotary bit, using an air-water-foam fluid (with a polymer additive as

required) in conventional circulation, began on January 22, 2000. A suitable depth to set the

surface casing was reached at 418.2 m (1,372 ft). At this point, drilling was suspended for

geophysical logging, and then the 13d-in. surface casing string was landed at 412.9 m

(1,354.6 ft) on January 28, 2000, approximately 184.7 m (606 ft) below the static water level.

Drilling continued with a 12¼-in. bit to a total depth (TD) of 1,516.1 m (4,974 ft), which was

reached on February 6, 2000.

Water production was first noted at the depth of approximately 265.8 m (872 ft), and reached a

maximum of approximately 3,407 liters per minute (lpm) (900 gallons per minute [gpm]) near

the bottom of the hole. About two months after installation of the completion string, the fluid

level was tagged by IT at the depth of 228.0 m (747.9 ft). No radionuclides above background

levels were encountered during drilling of Well ER-EC-2A.

Composite drill cuttings were collected every 3.0 m (10 ft) from 36.6 m (120 ft) to TD, and

81 sidewall core samples were taken at various depths below 212.8 m (698.0 ft). Open-hole

geophysical logging of the well was conducted to help verify the geology and characterize the

hydrology of the rocks; some logs also aided in the construction of the well by indicating

borehole volume and condition, and cement location. The well penetrated lavas and tuffs of the

Volcanics of Fortymile Canyon and the Timber Mountain Group.

A single completion string was installed in Well ER-EC-2A on February 11, 2000. Stainless

steel, 5½-in. production casing was landed at 1,512.0 m (4,960.5 ft). The bull-nosed string has

three slotted intervals, at 1,367.7 to 1,498.3 m (4,487.2 to 4,915.8 ft), 937.8 to 1,081.6 m

(3,076.7 to 3,548.6 ft), and 520.3 to 664.1 m (1,707.1 to 2,178.8 ft). Internally epoxy-coated,

7e-in. carbon-steel casing extends from the top of the 5½-in. casing to the ground surface. The

completion string was gravel-packed across the slotted intervals and the remaining annular space

was filled with gravel, sand, and cement to the depth of 210.9 m (692 ft) on February 14, 2000.

1-8

No pump was installed at the time of completion, but will be inserted as needed for hydrologic

sampling and testing activities.

1.4 Project Manager

Inquiries concerning Well ER-EC-2A should be directed to the UGTA Project Manager at:

U.S. Department of EnergyNational Nuclear Security AdministrationNevada Operations OfficeEnvironmental Restoration DivisionPost Office Box 98518Las Vegas, Nevada 89193-8518

2-1

2.0 Drilling Summary

2.1 Introduction

This section contains detailed descriptions of the drilling process and fluid management issues.

The general drilling requirements for all PM-OV wells were provided in FY99 Western Pahute

Mesa-Oasis Valley Hydrogeologic Investigation Wells Drilling and Completion Criteria

(IT, 1998). Specific requirements for Well ER-EC-2A were outlined in Drilling Work Plan

Number D-001-002.00 (BN, 2000). Figure 2-1 shows the layout of the drill site. Figure 2-2 is a

chart of the drilling and completion history for Well ER-EC-2A. A summary of drilling statistics

for the well is given in Table 2-1. The following information was compiled primarily from BN

daily drilling reports.

2.2 Drilling History

Field operations at Well ER-EC-2A began when BN drillers using an auger rig drilled a

121.9-cm (48-in.) conductor hole in three passes to 20.1 m (66 ft). A string of 30-in. casing was

set at the depth of 19.8 m (65 ft). The bottom of the conductor casing was cemented inside to

19.2 m (63 ft), and the annulus was cemented from the bottom of the casing to ground level on

January 13, 2000.

The UDI crews rigged up the Wilson Mogul 42B rig on January 17 through 20, 2000, and tagged

cement at the depth of 19.2 m (63 ft). Drilling resumed through the cement with a center-punch

assembly consisting of a 17½-in. rotary bit mounted below a 26-in. hole opener on

January 21, 2000, using air, water, and foam (“air-foam”) in conventional circulation. When the

17½-in. bit reached a depth of 22.6 m (74 ft) and the 26-in. hole opener had cleared the bottom of

the 30-in. casing, the center-punch assembly was tripped out of the hole. The hole opener was

removed, a new 17½-in bit was tripped into the hole, and drilling resumed.

Drilling of the main hole with a 17½-in. rotary bit and air-foam began January 22, 2000.

Beginning at a depth of 38.4 m (126 ft), a polymer additive was added to the air-foam injection

mix. The first water production was noted by IT personnel at a depth of approximately 265.8 m

(872 ft).

As a precaution against sloughing of the upper section of unsaturated volcanic rocks, it was

decided to install surface casing when a competent formation for supporting the casing was

2-3


2-6


2-7

Table 2-1Abridged Drill Hole Statistics for Well ER-EC-2A

LOCATION DATA:

Coordinates: Nevada State Plane (central zone): NAD 83: N 6,265,715.6 m E 508,740.7 m NAD 27: N 871,767.2 ft E 528,937.9 ft

Universal Transverse Mercator: NAD 83: N 4,111,038.2 m E 538,340.5 mSurface Elevation a: 1,494.1 m (4,901.9 ft)

DRILLING DATA:

Spud Date: 1/21/2000 (main hole drilling with Wilson Mogul 42B rig)Total Depth (TD): 1,516.1 m (4,974 ft)Date TD Reached: 2/06/2000Date Well Completed b: 2/14/2000Hole Diameter: 121.9 cm (48 in.) from surface to 20.1 m (66 ft.); 44.5 cm (17.5 in.) from 20.1 to

418.2 m (66 to1,372 ft); 31.1 cm ( 12.25 in.) from 418.2 m (1,372 ft) to TD of1,516.1 m (4,974 ft).

Drilling Techniques: Dry-hole auger from surface to 20.1 m (66 ft.); rotary drilling with 17½-in. bitusing air-foam in direct circulation from 20.1 to 38.4 m (66 to 126 ft); rotarydrilling with 17½-in. bit using air-foam and polymer in direct circulation from38.4 to 418.2 m (126 to 1,372 ft); rotary drilling with 12¼-in. bit and air-foam/polymer to TD of 1,516.1 m (4,974 ft).

CASING DATA: 30-in. conductor casing, surface to 19.8 m (65 ft); 13d-in. surface casing, surface to412.9 m (1,354.6 ft).

WELL COMPLETION DATA:The completion string consists of 7e-in. carbon-steel casing with an internal epoxy coating, connected to5½-in. stainless-steel casing via an internally coated carbon-steel cross-over sub. The carbon-steelcasing extends through the unsaturated zone approximately 188.7 m (619 ft) into the top of the saturatedzone. The 14.13-cm (5.563-in.) outside-diameter stainless-steel casing has a 12.82-cm (5.047-in.)inside diameter, is bull-nosed, and has three slotted intervals (listed below) that each consist ofconsecutive slotted joints. Detailed data for the completion intervals are provided in Section 7.0 of thisreport.

Total Depth: 1,512.0 m (4,960.5 ft)

Depth of Slotted Sections: 520.3 to 664.1 m 937.8 to 1,081.6 m 1,367.7 to 1,498.3 m(1,707.1 to 2,178.8 ft) (3,076.7 to 3,548.6 ft) (4,487.2 to 4,915.8 ft)

Depth of Sand Packs: 498.3 to 508.4 m 922.0 to 931.8 m 1,344.2 to 1,357.6 m(1,635 to 1,668 ft) (3,025 to 3,057 ft) (4,410 to 4,454 ft)

Depth of Gravel Packs: 508.4 to 681.5 m 931.8 to 1,098.2 m 1,357.6 to 1,514.6 m(1,668 to 2,236 ft) (3,057 to 3,603 ft) (4,454 to 4,969 ft)

Depth of Pump: Not installed at time of completion.

Water Depth c: 228.0 m (747.9 ft)

DRILLING CONTRACTOR: United Drilling, Inc.GEOPHYSICAL LOGS BY: Schlumberger, Colog, Inc. Desert Research Institute, Gyrodata, Inc.

SURVEYING CONTRACTOR: Bechtel Nevada

a Elevation of ground level at wellhead. 1929 North American Vertical Datum. b Date completion string was cemented. Pump will be installed at a later date.c Measured by IT on April 14, 2000, approximately two months after completion string was installed.

2-8

reached. The decision was made to stop and set casing on January 26, 2000, at a depth of

418.2 m (1,372 ft), where water production had reached an estimated rate of 379 lpm (100 gpm).

The drillers circulated fluid to clean and condition the hole, pulled the drill string off the bottom,

and waited about 20 minutes before tagging bottom again. No fill was found, and the drillers

tripped the drill string out of the hole. Drilling activity was suspended for 14 hours during

geophysical logging, prior to installation of the surface casing.

A casing subcontractor landed 13d-in. casing that has ribbon stabilizers (centralizers) installed

above the guide shoe, at the middle and at the top of the first joint, and at the top of the second

joint. A stab-in float collar was installed between the first and second joints. Two metal-petal

cement baskets are located at 20.4 m (67 ft) below ground level. The casing was landed at a

depth of 412.9 m (1,354.6 ft) on January 28, 2000, above about 4 m (13 ft) of fill that had

accumulated in the bottom of the surface hole during geophysical logging. After the stab-in sub

was seated in the float shoe, the seal was checked by pumping air down the drill pipe. Pre-flush

clear water was pumped down the casing and the annulus prior to cementing. Type II cement

was pumped inside the casing through the stab-in sub, followed by water to displace the cement

into the annulus. The top of cement in the annulus was later determined by geophysical logs to

be at the depth of approximately 228.6 m (750 ft). After the drill pipe was tripped out of the

hole, a mix of gravel and sand was dropped on the cement baskets, and the remaining annulus

was cemented to ground level with Type II cement. Cementing of the surface casing was

completed on January 28, 2000. The top of cement inside the casing was tagged at 398.7 m

(1,308 ft) when the bottom-hole assembly was tripped back into the hole.

After drilling about 7 m (23 ft) of cement, the drillers stopped to pull the drill string out of the

hole to check the pipe tally. The tally was deemed correct, so the drillers tripped the drill string

back into the hole and resumed drilling out cement. Drilling was stopped on January 29, 2000,

just above the cement shoe, at the depth of 412.7 m (1,354 ft), because it was noted that the fluid

level in Sump #1 was approaching the overflow pipe. Discharge to the ground surface would not

be permitted if the sump fluid were found to contain contaminants. The results of the analysis of

a sample taken from the sump at the end of surface-hole drilling on January 25, 2000, had not yet

been received, so drilling was stopped until the analysis was completed. The bit was pulled up

into the casing, and drilling operations were put on standby for 10 hours. Drilling was allowed to

resume at 1400 hours on January 29, 2000, after receipt of the analysis, which indicated no

contaminant present above critical levels.

2-9

When drilling resumed, the discharge valve on the overflow pipe in Sump #1 was opened, and

drilling of cement continued to 414.2 m (1,359 ft). Fill was encountered at 414.2 to 418.2 m

(1,359 to 1,372 ft), then drilling continued into the formation, using air-foam with a polymer

additive. On February 2, 2000, at a depth of 1,100.6 m (3,611 ft), the drill string was tripped out

of the hole for a bit change. The bit was replaced with a new 12¼-in. chisel-tooth bit, and

drilling continued uninterrupted to the TD of 1,516.1 m (4,974 ft), reached on February 6, 2000.

The amounts of polymer and foaming agent in the drilling fluid, and the fluid injection rate, were

adjusted as necessary during drilling to maintain superior circulation and penetration rate, and to

minimize borehole sloughing. However, fill (due to sloughing of the borehole wall) was

encountered during drilling of some portions of Well ER-EC-2A, though it did not cause

significant delays in the drilling. Between the depths of 29.3 and 85.0 m (96 and 279 ft), 0.6 to

3.0 m (2 to 10 ft) of fill was encountered on most connections. Below this zone, fill of 1.5 m

(5 ft) or less was encountered on a few connections, and a significant amount of sloughed

material accumulated during geophysical logging. At the time the completion string was

installed, approximately 1.5 m (5 ft) of fill remained in the bottom of the hole.

The TD was reached approximately 7.9 m (26 ft) short of the planned depth of 1,066.8 m

(5,000 ft), after the rate of penetration became slow. Geologists and the TWG determined that no

further valuable stratigraphic data would be gained by drilling the last 7.9 m (26 ft). Immediately

after reaching TD, the drillers circulated fluid to condition the hole before the second phase of

geophysical logging, which took place on February 7 - 9, 2000. Installation of the completion

string began on February 10, 2000. Demobilization from the Well ER-EC-2A site began after

gravel-packing and cementing were completed on February 14, 2000.

The directional survey run in the well on August 10, 2000, indicates that at the lowest surveyed

depth of 1,499.6 m (4,920 ft) the hole had drifted 27.7 m (90.9 ft) to the east of the collar

location, and that the hole is relatively straight (no “dog legs”).

A graphical depiction of drilling parameters including penetration rate, revolutions per minute,

pump pressure, and weight on the bit is presented in Appendix A-1. See Appendix A-2 for a

listing of casing materials. Drilling fluids and cements used in Well ER-EC-2A are listed in

Appendix A-3.

2-10

2.3 Drilling Problems

No significant drilling problems were encountered at Well ER-EC-2A. Fill of generally less than

3.0 m (10 ft) was encountered periodically throughout drilling, but did not result in significant

drilling delays. The Drilling Work Plan (BN, 2000) contained provisions for setting intermediate

casing in the event that sloughing hole conditions or high water production caused drilling

difficulties; however, neither was a problem and intermediate casing was not required in

Well ER-EC-2A. The only significant delay encountered was the result of fluid-management

issues, discussed in Subsection 2.4. Drilling was stopped 7.9 m (26 ft) short of the planned TD

of 1,524.0 m (5,000 ft) due to a slowing in the rate of penetration. This is not thought to have

caused the loss of any significant data.

2.4 Fluid Management

Drilling effluent was monitored in accordance with the methods prescribed in the UGTA FMP

(DOE/NV, 1996a). The air-foam/polymer drill fluid was circulated down the inside of the drill

string and back up the hole through the annulus (conventional or direct circulation) and then

discharged into a sump. Water used to prepare drilling fluids came from the Coffer Dune Well,

located on the Coffer Ranch. Lithium bromide (LiBr) was added to the drill fluid as a tracer to

provide a means of estimating groundwater production. The rate of water inflow was estimated

from the dilution of the tracer in the drill fluid returns.

To manage the anticipated water production, two sumps were constructed prior to drilling

(Figure 2-1). No contaminants were expected during drilling at this site, so neither sump was

lined prior to drilling. Samples of drilling effluent were tested on-site hourly for the presence of

tritium, and every eight hours for lead. The on-site monitoring results indicate that tritium

remained at background levels, and lead was undetectable (less than 50 parts per billion) during

the entire drilling operation.

Before fluids are discharged from a sump through the overflow pipe, the FMP requires that a

sample be collected from the sump and analyzed off-site to verify on-site monitoring data and

demonstrate compliance with the FMP. Duplicate samples were collected from Sump #1 on

January 25, 2000, after drilling of the surface hole. While the sample was being analyzed,

geophysical logging of the surface hole was conducted, the surface casing was installed, and

drilling continued through the cement inside the casing, before being halted to wait for the

analysis results. The analytical results showed the sump fluids were within the parameters of the

2-11

FMP criteria. Samples from both sumps were also collected and analyzed at the end of drilling

operations. Water-quality data for all four sump samples are provided in Appendix B.

The results of analyses of samples of drilling fluid collected at Well ER-EC-2A during drilling

operations indicate that all fluid quality objectives were met, as shown on the fluid management

reporting form dated July 28, 2000 (Appendix B). The form lists volumes of solids (drill

cuttings) and fluids produced during well-construction operations, Stages I and II (i.e., vadose-

and saturated-zone drilling only; well development and aquifer testing will be conducted at a

later date). The volume of solids produced was calculated using the diameter of the borehole

(from caliper logs) and the depth drilled, and includes added volume attributed to a rock bulking

factor. The volumes of fluids listed on the report are estimates of total fluid production, and do

not account for any infiltration or evaporation of fluids from the sumps.

2-12


3-1

3.0 Geologic Data Collection

3.1 Introduction

This section describes the sources of geologic data obtained from Well ER-EC-2A and the

methods of data collection. Improving the understanding of the subsurface structure,

stratigraphy, and hydrogeology in the area southwest of Pahute Mesa was among the primary

objectives of Well ER-EC-2A, so the proper collection of geologic and hydrogeologic data from

Well ER-EC-2A was considered fundamental to successful completion of the project.

Geologic data collected at Well ER-EC-2A consist of drill cuttings, sidewall core samples, and

geophysical logs. Data collection, sampling, transfer, and documentation activities were

performed in accordance with applicable contractor procedures.

3.2 Collection of Drill Cuttings

Composite drill cuttings were collected from Well ER-EC-2A at 3.05-m (10-ft) intervals as

drilling progressed from the depth of 36.6 m (60 ft) to the TD of the well at 1,516.1 m (4,974 ft).

Triplicate samples were collected from 490 intervals (samples were not collected from two

intervals), and in addition, the IT field representative collected two sets of reference samples

from each of the cuttings intervals. One set was examined at the drill site for use in preparing

field lithologic descriptions, and remains in the custody of IT. The other set was sent to

R. G. Warren (LANL) where it remains. All other samples (i.e., three sets of 490 samples) are

stored under controlled conditions at the U. S. Geological Survey (USGS) Geologic Data Center

and Core Library in Mercury, Nevada. One of these sample sets was sealed with custody tape at

the rig site and remains sealed as an archive sample; one set was left unsealed in the original

sample containers; and the third set was washed and stored in accordance with standard USGS

Core Library procedures.

3.3 Sidewall Core Samples

Sidewall core samples were collected by Schlumberger from Well ER-EC-2A to verify the

stratigraphy and lithology at selected locations. Sample locations were selected by the IT Field

Representative on the basis of field lithologic logs (with consideration of borehole conditions

determined from caliper logs). A percussion gun tool was used to collect 17 sidewall cores in the

upper 413.3 m (1,356 ft) of the borehole on January 27, 2000, prior to installing surface casing.

Prior to installation of the completion string, Schlumberger collected 39 percussion and 25 rotary

3-2

sidewall cores from the lower part of the borehole. Table 3-1 1ists the recovery and stratigraphic

assignment for each sample.

3.4 Sample Analysis

Thirty samples of drill cuttings from various depths in Well ER-EC-2A were submitted to the

LANL Earth and Environmental Sciences Division - Geology and Geochemistry laboratories for

petrographic, mineralogic, and chemical analyses to aid in stratigraphic identification and for

characterization of mineral alteration. All of the planned analyses have been completed, as

shown on Table 3-2.

3.5 Geophysical Data

Geophysical logs were run in the borehole to further characterize the lithology, structure, and

water content of the rocks encountered. In addition, logs were run to evaluate borehole

conditions, to determine the fluid levels during the course of drilling, and to monitor completion

progress. Geophysical logging was conducted during three stages of drilling and completion:

prior to setting surface casing, prior to installing the completion well casing, and during well

installation (annulus investigation log). Some logs were run in both the saturated and

unsaturated zones of the borehole, while others (e.g., thermal flow log, chemistry log, ultrasonic

borehole imager log, etc.) were run only in the saturated interval. A complete listing of the logs,

dates run, depths, and service companies is provided in Table 3-3. The logs are available from

BN in Mercury, Nevada, and copies are on file at the IT office in Las Vegas, Nevada.

Preliminary geophysical data from the logs are reproduced in Appendix D.

The overall quality of the geophysical data collected was good. However, high flow velocities in

the borehole exceeded the range for the thermal flow tool run by Desert Research Institute (DRI)

personnel, so DRI ran their “spinner” tool, a full bore flow meter, to determine flow gradients.

This tool did not arrive on-site calibrated for a 12¼-in. diameter borehole, so additional time was

required for calibration in the field. Because the tool was used under conditions for which it was

not specifically designed, the resultant data set should be carefully evaluated.

3-3

Table 3-1Sidewall Samples from Well ER-EC-2A

(Page 1 of 2)

Core Depthmeters (feet)

ToolUsed a

LengthRecoveredb

cm (in.)

StratigraphicUnit c

212.8 (698) SWC 1.25

Tfbw

227.4 (746) SWC 1.25

233.8 (767) SWC 0.25

268.2 (880) SWC 0.25

335.9 (1,102) SWC 0.5

359.7 (1,180) SWC 1.5

374.0 (1,227) SWC 1.25

381.3 (1,251) SWC 1.25

385.0 (1,263) SWC 1.25

387.1 (1,270) SWC 1.5

390.1 (1,280) SWC 0.25

393.2 (1,290) SWC 0.25

399.9 (1,312) SWC 0.25

405.4 (1,330) SWC 0.5

407.8 (1,338) SWC 1.0

410.9 (1,348) SWC 0.75

413.3 (1,356) SWC 1.25

448.1 (1,470) SWC 1.5

460.9(1,512) SWC 1.0

469.1 (1,539) SWC 1.25

495.9 (1,627) SWC 0.5

509.6 (1,672) SWC 0.5

Core Depthmeters (feet) Tool

Used aLength

Recoveredb

cm (in.)

StratigraphicUnit c

556.3 (1,825) SWC 1.0

Tfbw

589.8 (1,935) SWC 0.25

615.4 (2,019) SWC 1.5

625.4 (2,052) SWC 1.5

640.4 (2,101) SWC 1.5

648.0 (2,126) SWC 1.5

656.5 (2,154) SWC 1.75

662.9 (2,175) SWC 2.0

676.7 (2,220) SWC 1.75

Tfb

687.0 (2,254) SWC 1.75

700.7 (2,299) SWC 1.75

711.7 (2,335) SWC 1.75

738.8 (2,424) SWC 1.5

778.8 (2,555) SWC 1.75

790.0 (2,592) SWC 0.5

808.0 (2,651) SWC 1.75

815.0 (2,674) SWC 1.75

862.6 (2,830) SWC 0.25

874.8 (2,870) SWC 1.5

883.9 (2,900) SWC 1.5

887.9 (2,913) SWC 1.5

900.4 (2,954) SWC 1.0

Table 3-1Sidewall Samples from Well ER-EC-2A

(Page 2 of 2)

3-4


ToolUsed a

LengthRecoveredb

cm (in.)

StratigraphicUnit c

907.4 (2,977) SWC 2.0

Tfb914.4 (3,000) SWC 1.75

929.6 (3,050) SWC 1.5

941.8 (3,090) SWC 1.0

Tf

950.4 (3,118) SWC 1.5

955.5 (3,135) MSCT .025

957.1 (3,140) MSCT 0.25

959.5 (3,148) MSCT 0.25

964.7 (3,165) MSCT 0.5

Tm

966.2 (3,170) MSCT 1.25

986.0 (3,235) MSCT 1.25

991.5 (3,253) SWC 0.25

997.6 (3,273) SWC 0.75

1,006.1 (3,301) SWC 1.0

1,012.5 (3,322) SWC 1.0

1,018.3 (3,341) SWC 1.0

1,023.8 (3,359) SWC 0.75

1,026.6 (3,368) MSCT 1.25

1,027.2 (3,370) SWC 0.5


ToolUsed a

LengthRecoveredb

cm (in.)

StratigraphicUnit c

1,086.9 (3,566) MSCT 0.5

Tm

1,136.9 (3,730) MSCT 1.5

1,160.1 (3,806) MSCT 1.25

1,210.1 (3,970) MSCT 1.25

1,266.4 (4,155) MSCT 0.5

1,285.3 (4,217) MSCT 1.0

1,309.4 (4,296) MSCT 0.5

1,316.7 (4,320) MSCT 0.75

1,345.1 (4,413) MSCT 0.25

1,383.5 (4,539) MSCT 1.25

1,385.9 (4,547) MSCT 1.25

1,393.2 (4,571) MSCT 1.0

1,403.0 (4,603) MSCT 0.75

1,405.1 (4,610) MSCT 1.5

1,417.6 (4,651) MSCT 1.25

1,439.3 (4,722) MSCT 1.0

1,466.7 (4,812) MSCT 1.25Tmar

1,508.2 (4,948) MSCT 1.25

a SWC = Percussion sidewall gun operated by Schlumberger; MSCT = rotary mechanical sidewall coring tool operated by Schlumberger.b Estimatedc Preliminary assignments: Tfbw = rhyolite of Beatty Wash; Tfb = Beatty Wash Formation (undivided); Tf = Volcanics of Fortymile Canyon (undivided);

Tm = Timber Mountain Group (undivided); Tmar = mafic-rich Ammonia Tanks Tuff. See Appendix C for more information about the stratigraphy andlithology of Well ER-EC-2A.

3-5

Table 3-2Status of Rock Sample Analyses for Well ER-EC-2A

Depth a

meters (feet)

Analyses Performed b

Petrogra phic Mine ralog ic Chemical

PS MP XRD XRF Fe+2

/Fe+3

27.4 (90) QL N/P C C C

207.3 (680) QL N/P C C C

228.6 (750) QL N/P C C C

307.8 (1,010) QL N/P C C C

384.0 (1,260) QL N/P C C C

411.5 (1,350) QL N/P C C C

457.2 (1,500) QL N/P C C C

518.2 (1,700) QL N/P C C C

597.4 (1,960) QL N/P C C C

667.5 (2,190) QL N/P C C C

725.4 (2,380) QL N/P C C C

792.5 (2,600) QL N/P C C C

847.3 (2,780) QL C C C C

902.2 (2,960) QL N/P C C C

932.7 (3,060) QL N/P C C C

954.0 (3,130) QL N/P C C C

960.1 (3,150) QL N/P C C C

966.2 (3,170) QL N/P C C C

978.4 (3,210) QL N/P C C C

1,008.9 (3,310) QL N/P C C C

1,069.8 (3,510) QL N/P C C C

1,133.9 (3,720) QL N/P C C C

1,173.5 (3,850) QL N/P C C C

1,243.6 (4,080) QL N/P C C C

1,304.5 (4,280) QL N/P C C C

1,356.4 (4,450) QL N/P C C C

1,405.1 (4,610) QL N/P C C C

1,429.5 (4,690) QL N/P C C C

1,472.2 (4,830) QL N/P C C C

1,516.1 (4,974) QL C C C C

a Depth represents base of 3.0-m (10-ft) sample interval for drill cuttings. All samples are drill cuttings thatrepresent the lithologic character of the interval.

b Status of analyses at the time of this writing: C = analysis complete; QL = qualitative analysis complete; N/P = analysis not planned. Analysis type: PS = polished thin section; MP = electron microprobe; XRD = x-raydiffraction; XRF = x-ray fluorescence; Fe

+2/Fe+3 = wet chemical analysis for iron.

3-6

Table 3-3Well ER-EC-2A Geophysical Log Summary

(Page 1 of 2)

Geophysical Log Type a Log PurposeLoggingService

DateLogged

Run Number

Bottom ofLogged

Interval b

meters (feet)

Top of LoggedInterval b

meters (feet)

* Natural Gamma Ray Spectroscopy Stratigraphic correlation,mineralogy, natural and man-maderadiation

Schlumberger01/27/2000

02/08/2000

SGR-1

SGR-2

414.8 (1,361)

1,504.5 (4,936)

0.0 (0)

371.9 (1,220)

* Four Arm Caliper/Gamma Ray Borehole conditions, cementvolume calculation /stratigraphic correlation

Schlumberger01/27/2000

02/07/2000

CA4-1/ SGR-1

CA4-2/ GR-2

414.8 (1,361)

1,515.8 (4,973)

19.8 (65)

393.2 (1,290)

* Array Induction Log/Caliper/Gamma Ray/SP

Lithologic determination /borehole conditions /stratigraphic correlation

Schlumberger 01/27/2000 IND-1/ GR-1/ CAL-1/SP-1 412.7 (1,354) 19.8 (65)

* Epithermal Neutron/Density/Gamma Ray/ Caliper

Total water content / rock porosity/ stratigraphic correlation/boreholeconditions Schlumberger

01/27/2000

02/08/2000

ENP-1/CDL-1/GR-1/CAL-1

ENP-2/CDL-2/GR-3/CAL-2

409.7 (1,344)

1,510.3 (4,955)

19.8 (65)

396.2 (1,300)

* Dual Laterolog/ *SpontaneousPotential/Gamma Ray

Saturated zone: water saturation /stratigraphic correlation Schlumberger 02/08/2000 DLL-1/ SP-3 /GR-3 1,510.3 (4,955) 396.2 (1,300)

Gamma Ray/Digital Array SonicA. Wave-form and variable densitypresentations* B. Sonic porosity and travel time(STC) computations

Saturated zone:A. Porosity, lithologic determination

B. Fracture identificationSchlumberger 02/08/2000 AC-1/ GR-4 1,511.8 (4,960) 335.3 (1,100)

Ultrasonic Borehole Imager Saturated zone: lithologiccharacterization, fracture and voidanalysis.

Schlumberger 02/08/2000 BHTV-1 1,513.0 (4,964) 396.2 (1,300)

Temperature/Gamma Ray Saturated zone: groundwatertemperature / stratigraphiccorrelation

Schlumberger 02/07/2000 TL-1/GR-2 1,505.1 (4,938) 140.2 (460)

Chronological SidewallCores/Spontaneous Potential

Geologic samplesSchlumberger

01/27/2000

02/08/2000

SGUN-1/SP-2

SGUN-2/SP-5

412.1 (1,352)

1,027.2 (3,370)

32.3 (106)

448.1 (1,470)

Mechanical Sidewall CoringTool/Gamma Ray

Geologic samples Schlumberger 02/08/2000 MSCT-1/GR-5 1,508.2 (4,948) 955.5 (3,135)

Ambient Full-Bore Flowmeter /Temperature Log

Rate and direction of groundwaterflow in borehole / groundwatertemperature

DesertResearchInstitute

02/09/2000 SPINR-1/TL-2 1,513.3 (4,965) 369.2 (1,300)

Table 3-3Well ER-EC-2A Geophysical Log Summary

(Page 2 of 2)

3-7

Geophysical Log Type a Log PurposeLoggingService

DateLogged

Run Number

Bottom ofLogged

Interval b

meters (feet)

Top of LoggedInterval b

meters (feet)

* Thermal Flow Log Rate and direction of groundwaterflow in borehole


02/09/2000 1 1,082.0 (3,550) 502.9 (1,650)

* Chemistry/Temperature Log Groundwater chemistry andtemperature, formationtransmissivity


02/09/2000 1 1,515.8 (4,973) 257.3 (844)

Nuclear Annulus Investigation Log Well construction monitoring Colog 02/11-14/2000 AIN-1 1,511.8 (4,960) 178.6 (586)

Gyroscopic Directional Survey Borehole deviation Gyrodata 08/10/2000 1 1,499.6 (4,920) 0

a Logs presented in geophysical log summary, Appendix D, are indicated by *.

b Depth below ground surface.

3-8


4-1

4.0 Geology and Hydrogeology

4.1 Introduction

This section summarizes the geology and hydrogeology of Well ER-EC-2A. Bechtel Nevada

geologists prepared the detailed lithologic descriptions presented in Appendix C, incorporating

information from field lithologic descriptions by IT well-site geologists and geophysical log data.

Stratigraphic assignments and identification of alteration mineralogy presented here are based

primarily on mineralogic and chemical data and interpretations provided by R. G. Warren of

LANL (Warren, 2000). See Table 3-2 for a list of laboratory analyses conducted at LANL on

samples from Well ER-EC-2A.

4.2 Geology

This section is subdivided into discussions of the stratigraphic section and structural features

interpreted from Well ER-EC-2A data, followed by a discussion of alteration noted in samples

from the well.

4.2.1 Stratigraphy and Structure

Well ER-EC-2A is located within the northwestern moat area of the Timber Mountain caldera

complex (TMCC) (Figure 4-1), which consists of several “nested” calderas. Analysis of the data

from Well ER-EC-2A and regional geologic and geophysical data suggest that the well is located

within both the Rainier Mesa and Ammonia Tanks calderas, two of the calderas in the TMCC.

The formation of these calderas is the result of the eruption of the Rainier Mesa Tuff (erupted

11.6 million years ago [Ma] [Sawyer, et al., 1994]) and the Ammonia Tanks Tuff (erupted

11.45 Ma [Sawyer, et al., 1994]); both tuffs are considered stratigraphically to be part of the

Timber Mountain Group. Following the collapse of the Ammonia Tanks caldera, resurgence of a

central dome created the present topographic expression of the TMCC, including Timber

Mountain and the surrounding "moat" (Figure 4-1). Younger volcanic rocks partially fill the

moat, and bury most of the Timber Mountain Group rocks within the moat. Moat-filling units

exposed at the surface near Well ER-EC-2A (Figure 4-2) include tuff and lava of the Volcanics

of Fortymile Canyon (erupted from various vents near the TMCC shortly after resurgence of the

central dome of the Ammonia Tanks caldera), ash-flow tuff of the Thirsty Canyon Group

(erupted from the Black Mountain caldera located north of Well ER-EC-2A; see Figure 4-1), and

younger colluvium and alluvium.

4-2


NellisAir Force

Range


Bureau ofLand

Management

NevadaTestSite

Black Mountain

Caldera

Tim

ber Mountain Moat

95

374

ER-EC-2A

ER-EC-10

ER-EC-6ER-EC-1

ER-18-2ER-EC-5

ER-EC-4

ER-EC-8

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ER-OV-7

ER-OV-8

Area 19

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Shoshone Mountain

Pahute Mesa

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Silent Canyon

Caldera Complex

Claim Canyon

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Timber Mountain

Caldera Complex

Beatty

116°40'0"W

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°0

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WPM-OV Well

Proposed WPM-OV Well

Well Access Road

Proposed Well Access Road

Primary NTS Road

Highways (U.S. and State)

Nellis Air Force Range

Nevada Test Site

0 1 2 3 4 5

Miles


10 Minute Latitude / Longitude Graticule

Figure 4-1Map of Pahute Mesa - Oasis Valley Area Showing

Theorized Locations of Caldera Boundaries (after Wahl et al., 1997)(Proposed wells not drilled at time Well ER-EC-2A was drilled.)

4-3

NT

S/G

IS:

jrc

ere

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-M

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ER-EC-2AER-EC-2AABAB

A'B'A'B'

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116°37'30"W

116°37'30"W

116°35'0"W

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37

°7

'30"N

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Figure 4-2Surface Geologic Map of the Well ER-EC-2A Site

4-5

NTSGIS:bma_erec2ageol.mxd

04-MAY-2001

EXPLANATONGeologic Units

QTa - Surficial deposits, undivided

QTc - Colluvium (Quaternary and Tertiary)

Qam - Middle alluvium (middle Pleistocene)

Qay - Young alluvium (Holocene & late Pleistocene)

Tfb - Beatty Wash Formation (undivided)

Tfd - Lavas of Dome Mountain

Tft - Post-Timber Mountain basaltic rocks

Tgy - Younger sedimentary deposits

Tma - Ammonia Tanks Tuff

Ttc - Comendite of Ribbon Cliff

Ttg - Gold Flat Tuff

Ttp - Pahute Mesa and Rocket Wash Tuffs

Ttt - Trail Ridge Tuff

Tyb - Thirsty Canyon and younger basalts

Typ - Pliocene and youngest Miocene basalt

Well access road

Normal fault; ball and bar on

downthrown side

Cross-section line

Geology adapted from Wahl et al., 19972,000 Meter UTM Tics Based on NAD832.5 Minute Latitude/Longitude Graticule

2,000 0 2,000 4,0001,000

Feet

500 0 500 1,000250

Meters

4-6


4-7

The stratigraphy and lithology of Well ER-EC-2A are illustrated in Figure 4-3. Well ER-EC-2A

penetrated more than 914.4 m (3,000 ft) of mainly lava and tuff of the Volcanics of Fortymile

Canyon. Below the Volcanics of Fortymile Canyon, the borehole penetrated approximately

487.7 m (1,600 ft) of tuff assigned to the Timber Mountain Group that appears to have been

erupted after the Ammonia Tanks Tuff and the formation of the Ammonia Tanks caldera. The

well reached TD in intracaldera Ammonia Tanks Tuff.

Drilling of Well ER-EC-2A began in rhyolitic lava of the rhyolite of Beatty Wash, a subunit of

the Beatty Wash Formation. The borehole penetrated approximately 209.1 m (686 ft) of lava,

including intervals of pumiceous and vitrophyric lava. The assignment of this lava unit to the

rhyolite of Beatty Wash is based mainly on the presence of significant amounts of biotite,

hornblende, and sphene, and the absence of quartz. Below the lava, the well penetrated 712.9 m

(2,339 ft) of nonwelded tuff and minor welded ash-flow tuff. The upper half of this interval is

assigned to the rhyolite of Beatty Wash because of its similarity in petrographic character to

outcrop samples of rhyolite of Beatty Wash collected within the northern Timber Mountain moat

area (Warren, 2000). The overall petrographic character of the lower half of the interval is

similar to that of the overlying interval, but the lower portion contains quartz (although in

abundances too low for Timber Mountain Group units) and has more felsic phenocrysts and

mafic minerals. Based on these characteristics, this lower interval can be assigned to the Beatty

Wash Formation, but not to any subunit of the formation.

Below the rhyolite of Beatty Wash is a complex and diverse assemblage of rocks that consist of

interbedded tuffs, fine-grained sedimentary and tuffaceous sedimentary rocks that resemble

lacustrine deposits, and possibly chemically precipitated hydrothermal deposits. This interval is

21.3 m (70 ft) thick and occurs at the base of the Volcanics of Fortymile Canyon. It is assigned

to the Volcanics of Fortymile Canyon based on the scarcity of quartz in the tuffaceous units. The

only other occurrence in the area of similar rocks in the same stratigraphic position was reported

by Fridrich et al. (1999) on Oasis Mountain, approximately 19.3 km (12 mi) southwest of

Well ER-EC-2A.

Below the Volcanics of Fortymile Canyon, Well ER-EC-2A penetrated 490.4 m (1,609 ft) of

mostly poorly welded tuff assigned to the Timber Mountain Group. The stratigraphic

assignment of this interval is based mainly on a dramatic increase in quartz, and its stratigraphic

position below Volcanics of Fortymile Canyon and above mafic-rich Ammonia Tanks Tuff. A

more precise assignment is hindered by the high degree of alteration present, but the interval

4-8


4-10


4-11

likely includes post-Ammonia Tanks Tuff units such as tuff of Crooked Canyon and tuff of

Buttonhook Wash, and/or debris flows from the lower part of the Ammonia Tanks Tuff. Visual

evaluation of samples and data from geophysical logs suggest that the interval consists of a

monotonous sequence of poorly welded tuffs. However, petrographic analyses suggest that

much of the interval may be moderately welded.

Drilling of Well ER-EC-2A was terminated in moderately welded ash-flow tuff of the mafic-rich

Ammonia Tanks Tuff. This stratigraphic assignment is based on the unit’s mafic-rich character,

high sanidine content, the presence of quartz, and the absence of monazite which is ubiquitous in

the underlying Rainier Mesa Tuff (Warren, 2000).

The relative position, extent, and thickness of the stratigraphic units near Well ER-EC-2A are

illustrated on the cross section in Figure 4-4. As shown on the cross section, Well ER-EC-2A is

interpreted to be located within the structural margins of both the Rainier Mesa and Ammonia

Tanks calderas (which are interpreted to be coincident in the northwestern region of the TMCC).

This interpretation is based on data from nearby drill holes as well as from regional analyses of

surface geology and gravity data (DOE/NV, 2000a, b, c; Mankinen et al., 1999).

Because Well ER-EC-2A was terminated in Ammonia Tanks Tuff and thus did not reach the

Rainier Mesa Tuff, data from the hole does not provide information on the location of the well

relative to the Rainier Mesa caldera. However, the unusually low elevation for the top of the

mafic-rich Ammonia Tanks Tuff in Well ER-EC-2A, and the unusually thick sequence of post-

Ammonia Tanks Tuff rocks suggest that this location is within the Ammonia Tanks caldera and

that collapse was unusually deep in this portion of the caldera. The extent of collapse is quite

evident when compared with Well ER-EC-4, located approximately 5.6 km (3.5 mi) west-

northwest of Well ER-EC-2A and outside of the TMCC (DOE/NV, 2000b). The top of the

Ammonia Tanks Tuff at Well ER-EC-2A is 815.6 m (2,676 ft) lower in elevation than the top at

Well ER-EC-4. Consequently, post-Ammonia Tanks Tuff units at Well ER-EC-2A are 858.9 m

(2,818 ft) thicker than at Well ER-EC-4. Also supporting the interpretation of unusually deep

caldera collapse in the area of Well ER-EC-2A is the presence of lacustrine deposits at the base

of the Volcanics of Fortymile Canyon that probably represent the development of a caldera lake.

As mentioned previously, the only other known occurrence in the region of similar units in a

similar stratigraphic position is on Oasis Mountain. Fridrich et al. (1999) suggested that the

4-13

lacustrine and volcanic rocks that make up Oasis Mountain were deposited within the margins of

the Rainier Mesa caldera and were later transported westward to their present location outside the

caldera along a shallow detachment fault.

4.2.2 Alteration

Alteration has a significant effect on both the general hydraulic character of volcanic rocks and

on how radionuclides migrate through these rocks. The predominant type of mineralogic

alteration observed in each stratigraphic unit encountered in Well ER-EC-2A is illustrated on

Figure 4-3. Above the depth of 227.4 m (746 ft), the rocks are mostly devitrified, with lesser

amounts of silicic alteration and unaltered (vitric) rocks. This interval corresponds to the interval

of lava assigned to the rhyolite of Beatty Wash. Below the depth of 227.4 m (746 ft), the rocks

are zeolitic to 399.3 m (1,310 ft) and consist of nonwelded tuff. All rocks below 227.4 m

(746 ft) contain a quartzo-feldspathic assemblage of alteration minerals, indicating higher-

temperature, hydrothermal alteration. This alteration interval includes nonwelded tuffs, welded

ash-flow tuffs, and tuffaceous sedimentary rocks.

4.3 Predicted Versus Actual Geology

The predicted geology for Well ER-EC-2A (IT, 1998) was based on geologic maps by O’Conner

et al. (1966), Byers et al. (1976), and Wahl et al. (1997). The geology of Well UE-18r

(Carr et al., 1968) was also evaluated, as the well was thought to be in a similar volcanic and

structural setting. A comparison of the predicted and the actual (preliminary) stratigraphy is

provided in Figure 4-5. The well was predicted to penetrate approximately 229 m (750 ft) of

rhyolite lava of the Beatty Wash Formation, overlying a minor thickness of bedded tuff also of

the Beatty Wash Formation. Well ER-EC-2A penetrated the predicted thickness of lava

(227.4 m [746 ft]), but encountered more than 734.3 m (2,409 ft) of mostly nonwelded tuff of the

Volcanics of Fortymile Canyon below the lava. The much greater than predicted thickness of

tuff below the lava appears to be the result of deposition within a deep volcanic depression

resulting from much greater collapse of the northwestern portion of the Ammonia Tanks caldera.

The occurrence of lacustrine deposits in Well ER-EC-2A was not predicted, but their presence

would be expected if a caldera lake developed within the deep depression created by the caldera

collapse. The deep collapse of the Ammonia Tanks caldera in the area of ER-EC-2A also

resulted in the accumulation of a considerable thickness of Timber Mountain rocks that post-date

the Ammonia Tanks Tuff. These rocks were not predicted to occur at the ER-EC-2A site, as

such a deep collapse was not predicted.

4-15

The Ammonia Tanks Tuff was encountered at the depth of 1,452.1 m (4,764 ft) in

Well ER-EC-2A, which is 1,208.2 m (3,964 ft) deeper than predicted prior to drilling. The well

was predicted to penetrate a complete section of the Ammonia Tanks Tuff before encountering

Timber Mountain landslide breccia and Rainier Mesa Tuff. However, because the Ammonia

Tanks Tuff was encountered so much deeper than predicted, the well was still within the

Ammonia Tanks Tuff when drilling ended at 1,516.1 m (4,974 ft) just above the planned TD of

1,524.0 m (5,000 ft).

Prior to drilling of Well ER-EC-2A, it was uncertain whether this location was within the

Ammonia Tanks caldera. Interpretation of geologic data from the well and recent gravity data

(Mankinen et al., 1999) now strongly suggest that Well ER-EC-2A was drilled within the caldera

margin. Although only 64.0 m (210 ft) of Ammonia Tanks Tuff was penetrated before drilling

was halted, the rocks encountered are strongly welded and are from the upper mafic-rich

member, indicating that only the upper portion of what is likely a very thick intracaldera

sequence of the Ammonia Tanks Tuff was penetrated. Analysis of regional gravity data suggests

that basement rocks occur at the deepest levels in the northern portion of the TMCC (Mankinen

et al., 1999), consistent with deeper collapse. However, deeper basement rocks in the northern

portion of the caldera could also be the result of less post-caldera resurgence in this area.

Landslide breccia related to caldera development was predicted to be encountered between the

Ammonia Tanks and Rainier Mesa Tuffs and within the Rainier Mesa Tuff. As discussed above,

the well reached TD in Ammonia Tanks Tuff, well above the predicted position of the landslide

breccia. However, such deep collapse of the Ammonia Tanks caldera suggested by drill hole and

geophysical data likely resulted in a very high, steep, and initially unstable Ammonia Tanks

caldera margin north and west of Well ER-EC-2A. It is likely that such a margin would generate

landslides that would result in the deposition of landslide breccia deposits within the Ammonia

Tanks caldera. Although no landslide deposits were definitively identified within the Ammonia

Tanks or post-Ammonia Tanks rocks in Well ER-EC-2A, petrographic analysis of drill cuttings

from the depth of 1,243.6 m (4,080 ft) in Well ER-EC-2A shows a mixture of lithologies which

may represent a landslide deposit originating from the lower portion of the Ammonia Tanks Tuff

(Warren, 2000).

There has been some speculation among project scientists that the interval of fine-grained

sedimentary rocks encountered at the depth of 946.1 to 961.6 m (3,104 to 3,155 ft) in

Well ER-EC-2A represents a slide block of Paleozoic rocks. However, regional geologic and

4-16

geophysical analysis indicate that it is unlikely that nearby Paleozoic rocks are at high enough

levels outside the caldera complex to provide landslide debris at the depth in question in Well

ER-EC-2A. Also, petrographic analyses of these rocks indicate that it is highly unlikely that

these rocks represent Paleozoic units (Warren, 2000).

4.4 Hydrogeology

The rocks of Well ER-EC-2A have been subdivided into hydrogeologic units, as illustrated in

Figure 4-3. A preliminary interpretation of the distribution of these units is shown in cross

section on Figure 4-6. Because of the limited amount of data from the area around

Well ER-EC-2A, and the difficulty in predicting the lateral continuity of hydraulic properties of

volcanic rocks, the cross section is rather conjectural. However, it does illustrate the

complexities associated with the distribution of hydrogeologic units in caldera settings such as

the Oasis Valley area.

The dominant hydrogeologic unit in Well ER-EC-2A is tuff confining unit, consisting of mostly

quartzo-feldspathic, poorly welded tuff, and comprising approximately 80 percent of the rocks

penetrated by the well. Analysis of water production data during drilling indicates that the rocks

assigned as tuff confining unit (based on lithology and alteration) produced water at a rate of

about 946 lpm (250 gpm) to possibly as much as 2,271 lpm (600 gpm). Fracture analysis of the

borehole image log from Well ER-EC-2A suggests that water production from tuff confining

units is confined to discrete fractured intervals. Thus, data from Well ER-EC-2A indicates that

although primary permeability is probably low in tuff confining units, these hydrogeologic units

can at times produce substantial water from fractured intervals. It should also be noted that the

high degree of alteration present obscures lithologic characteristics and makes lithologic

identification difficult and somewhat uncertain. Thus, the water production observed within the

tuff confining units may be coming from rocks that are substantially more welded (and thus more

fractured) than described. For example, water production during drilling increased from

approximately 2,271 lpm (600 gpm) to more than 3,028 lpm (800 gpm) near the bottom of the

well where strongly welded Ammonia Tanks Tuff is present.

See the discussion of the general hydraulic properties of the hydrogeologic units, including,

expected in Well ER-EC-2A in IT (1998), Section B.6.2 and Table B.6.1. Planned hydrologic

testing in the Well ER-EC-2A may verify the actual hydraulic character of the units exposed in

the screened intervals of the well.

4-18


5-1

5.0 Hydrology

5.1 Preliminary Water-Level Information

Well ER-EC-2A is located on the west flank of an apparent northeast-trending groundwater

trough that extends from the Oasis Valley discharge area through the Well ER-EC-2A area, and

beneath Pahute Mesa. Water-level data are sparse in this area, so hydrologic data from

Well ER-EC-2A are expected to aid in understanding regional groundwater flow.

The elevation of the water table at Well ER-EC-2A was projected to be approximately 1,276 m

(4,187 ft), as derived from sparse hydrologic data for this region (IT, 1998). Based on the pre-

construction estimate of surface elevation at the site, depth to water was expected at

approximately 205 m (673 ft) (IT, 1998). During drilling, water production was first noted at a

depth of approximately 265.8 m (872 ft), and fluid depths between 230.4 and 257.3 m (756 and

844 ft) were obtained from various geophysical logs run on January 27, 2000 and

February 7-8, 2000, before the completion string was installed. A preliminary composite fluid

level (depth) of 228.0 m (747.9 ft) was measured by IT on April 14, 2000 (IT, 2000), which

seems to indicate slow recovery (gradually decreasing depth to water over time). Based on this

preliminary fluid depth and the as-built surface elevation of 1,494.1 m (4,901.9 ft), the fluid level

elevation at Well ER-EC-2a is 1,266.1 m (4,154.0 ft). This is approximately 10 m (33 ft) below

the predicted elevation of 1,276 m (4,187 ft). A transducer for monitoring of the water level was

not installed at the time of completion.

5.2 Water Production

Water production was estimated during drilling of Well ER-EC-2A on the basis of LiBr dilution

data as measured by IT field personnel. Nonwelded to moderately welded ash-flow tuffs of the

Timber Mountain Group were the primary water-producing units at this location, however,

measurable water production (approximately 38 lpm [10 gpm]) began at the depth of about

265.8 m (872 ft) within nonwelded rhyolite of Beatty Wash. The production rate remained

relatively low and constant to the depth of about 399.3 m (1,310 ft) where it began to increase.

The decision was made to stop drilling and install a surface casing at the depth of about 418.2 m

(1,372 ft), where water production had reached about 379 lpm (100 gpm). When drilling

resumed, the production rate dropped back to about 95 lpm (25 gpm) but at the depth of about

464.8 m (1,525 ft) it began steadily to increase, reaching 757 lpm (200 gpm) at a depth of

approximately 556.3 m (1,825 ft), still within nonwelded tuff. Water production then increased

very gradually until, between the depths of 929.6 and 944.9 m (3,050 and 3,100 ft), near the base

5-2

of a nonwelded ash-flow tuff of the Beatty Wash Formation and within tuffaceous sedimentary

deposits of the Volcanics of Fortymile Canyon (undivided), it increased dramatically from about

1,325 lpm (350 gpm) to about 2,271 lpm (600 gpm). Water production remained fairly steady

within the underlying nonwelded tuffs of the Fortymile Canyon and Timber Mountain Groups.

At the depth of about 1,341.1 m (4,400 ft), still within the Timber Mountain Group, water

production began to increase again, reaching the maximum measured during drilling, of about

3,407 lpm (900 gpm) from the depth of 1,505.7 m (4,940 ft) to the TD in moderately welded

Ammonia Tanks Tuff. Estimated water production rates are presented graphically in

Appendix A-1.

5.3 Preliminary Flow Meter Data

Flow meter data, along with temperature, electrical conductivity (EC), and pH measurements,

can be used to characterize borehole fluid variability, which may indicate inflow and outflow

zones. The design of the completion string for Well ER-EC-2A was based in part on field

evaluation of data from these measurements.

DRI personnel made measurements with their thermal flow meter (TFM) tool at five locations

between the depths of 502.9 and 1,082.0 m (1,650 and 3,550 ft) before the completion string was

installed. Preliminary analysis of a plot of the discrete TFM data points indicates a downward

flow of water within the borehole at all stations. However, flow velocities could not be measured

because they exceeded the calibration range of the instrument, so DRI then ran an ambient full-

bore flow meter and temperature log, or “spinner” log, from 396.2 to 1,513.3 m (1,300 to

4,965 ft). This log also indicated downward flow in the borehole. Preliminary comments by

DRI on the log plot indicate inflow between the depths of 412.7 and 432.8 m (1,354 and

1,420 ft), 524.3 and 670.6 m (1,720 and 2,200 ft), and between 899.2 and 1,036.3 m (2,950 and

3,400 ft). Outflow of fluid from the hole was reported at 1,066.8 m (3,500 ft) and between

1,447.8 and 1,493.5 m (4,750 and 4,900 ft).

In addition, DRI ran a chemistry log, which included measurements of temperature, EC, and pH,

from 257.3 to 1,515.8 m (844 to 4,973 ft). Groundwater temperature gradually increased from

the minimum reading of 34.4 degrees Celsius (C) (93.9 degrees Fahrenheit [F]) at the top of the

fluid column to the depth of approximately 1,066.8 m (3,500 ft). Below that depth the

temperature increased somewhat more steeply, and continued to rise to the borehole maximum of

49.6 degrees C (121.3 degrees F) at the depth of 1,515.8 m (4,973 ft). Plots of the TFM and

chemistry log data are reproduced in Appendix D.

5-3

5.4 Preliminary Groundwater Characterization Samples

Following geophysical logging, DRI collected preliminary groundwater characterization samples

within the open borehole. Two six-liter samples were collected at the depth of 1,066.8 m

(3,500 ft). Analytical data from these initial samples, collected before formal well development,

will provide a basis for comparison with future groundwater chemistry data.

5-4


6-1

6.0 Precompletion and Open-Hole Development

The only precompletion development conducted in Well ER-EC-2A consisted of circulating fluid

for 30 minutes to clean the borehole, and developing the well by using five compressors to blow

water out of the hole. This process was conducted immediately after TD was reached and prior

to geophysical logging.

6-2


7-1

7.0 Well Completion

7.1 Introduction

Well completion refers to the installation in a borehole of a string of pipe or casing that is slotted

or screened at one or more locations along its length. The completion process also typically

includes emplacement of backfill materials around the casing, with coarse fill such as gravel

adjacent to the open intervals and impervious materials such as cement between the open

intervals to isolate them. The casing serves as a conduit for insertion of a pump in the well, for

inserting devices for measuring fluid level, and for sampling, so that accurate potentiometric and

water chemistry data can be collected from known portions of the borehole.

Completion activities at Well ER-EC-2A took place on February 10-14, 2000, though a

submersible pump was installed later for hydrologic testing. Figure 7-1 is a schematic of the

final well-completion design for Well ER-EC-2A, Table 7-1 is a construction summary for the

well, and Figure 7-2 shows a plan view and profile of the wellhead surface completion. Data for

this section were obtained from daily operations and activity reports, casing records, and

cementing records provided by the BN Drilling Department. Information from IT’s well data

report (IT, 2000) was also consulted for preparation of this section.

7.2 Well Completion Design

The final completion design differs slightly from the proposed design, as described in the

following paragraphs.

7.2.1 Proposed Completion Design

The original completion design (IT, 1998) was based on the assumption that Well ER-EC-2A

would penetrate a thick welded-tuff aquifer in the Rainier Mesa Tuff. The well was planned to

be completed with a single casing string consisting of 5½-in. stainless steel casing, with every

other joint slotted, suspended on carbon-steel 7e-in. casing. The primary goal was to obtain

satisfactory completion within this welded-tuff aquifer, but the proposed completion design also

called for the isolation (using non-slotted casing) of low transmissivity zones within the

completion interval, if such zones could be identified.

7-3

Table 7-1Well ER-EC-2A Completion String Construction Summary

Casing TypeConfiguration

mete rs (feet)Cement Sand/Gravel

7e-in. carbon-steelproduction casing withinternal epoxy coating

0 to 415.7(0 to 1,364.0)

BlankType II

210.9 to 498.3(692 to 1,635)

None7e-in. to 5½-in. cross-over sub, carbon-steel,

with stainless-steeldouble pin

415.7 to 416.5(1,364.0 to 1,366.4)

Blank

5½-in.Stainless-steel

production casing

416.5 to 1,512.0(1,366.4 to 4,960.5)

Blank416.5 to 520.3

(1,366.4 to 1,707.1)

Type II

681.5 to 788.5(2,236 to 2,587)

832.1 to 922.0(2,730 to 3,025

1,098.2 to 1,344.2(3,603 to 4,410)

20/40 Sand

498.3 to 504.7(1,635 to 1,656)

922.0 to 928.7(3,025 to 3,047)

1,344.2 to 1,353.9(4,410 to 4,442)

6-9 Sand

504.7 to 508.4(1,656 to 1,668)

928.7 to 931.8(3,047 to 3,057)

1,353.9 to 1,357.6(4,442 to 4,454)

3/8-in. x 4 Gravel

508.4 to 681.5(1,668 to 2,236)

788.5 to 832.1(2,587 to 2,730) a

931.8 to 1,098.2(3,057 to 3,603)

1,357.6 to 1,514.6(4,454 to 4,969)

11 consecutive slotted joints520.3 to 664.1

(1,707.1 to 2,178.8)

Blank664.1 to 937.8

(2,178.8 to 3,076.7)

11 consecutive slotted joints

937.8 to 1,081.6(3,076.7 to 3,548.6)

Blank 1,081.6 to 1,367.7(3,548.6 to 4,487.2)

10 consecutive slotted joints

1,367.7 to 1,498.3 (4,487.2 to 4,915.8)

Blank and bull-nosed1,498.3 m to 1,512.0( 4,915.8 to 4,960.5)

a Gravel section not adjacent to slotted interval

7-5

7.2.2 As-Built Completion Design

The design of the Well ER-EC-2A completion was determined through consultation with

members of the UGTA TWG, on the basis of on-site evaluation of data such as lithology and

water production, drilling data (lost circulation, etc.), data from various geophysical logs, and

from flow meter and water chemistry logs.

The as-built completion design for Well ER-EC-2A provides access to three aquifers

(Figure 7-1). The composition of the string summarized here is detailed on Table 7-1, and the

casing materials are listed in Appendix A-2. The lower section of the completion string, from

1,512.0 to 416.5 m (4,960.5 to 1,366.4 ft), is type SSTP304 stainless-steel casing with an outside

diameter of 14.13 cm (5.563 in.) and an inside diameter of 12.82 cm (5.047 in.). The top of the

5½-in. casing is approximately 101 m (331 ft) below the static fluid level. The bottom 0.67-m

(2.2-ft) joint is a blank bull-nose to serve as a sediment sump. Above the 5½-in. casing, a

0.73-m (2.4-ft) long cross-over sub serves as the transition to the upper part of the string, which

is 7e-in. carbon-steel production casing with an internal epoxy coating.

The lowest slotted interval, 1,367.7 to 1,498.3 m (4,487.2 to 4,915.8 ft), is open to mainly

welded-tuff aquifer lithologies of the Timber Mountain Group. (See Figure 4-3 for an

illustration of gravel-pack locations relative to hydrogeologic units.). This casing interval

consists of 10 consecutive slotted joints. The second slotted interval, 937.8 to 1,081.6 m

(3,076.7 to 3,548.6 ft), consists of 11 consecutive slotted joints. It is open to tuff confining unit

lithologies consisting of nonwelded tuff and an interval of reworked tuff with tuffaceous siltstone

and reworked tuff that seemed to be a significant water producer during drilling. The uppermost

slotted interval, 520.3 to 664.1 m (1,707.1 to 2,178.8 ft), also consists of 11 consecutive slotted

joints and is open to tuff confining unit lithologies of the Volcanics of Fortymile Canyon.

The openings in each slotted casing joint are 0.198 cm (0.078 in.) wide and 5.1 cm (2 in.) long,

cut in rings of 18 slots (spaced 20 degrees apart around the joint). The rings are spaced 15.2 cm

(6 in.) apart, and the longitudinal centers of the slots in each ring are staggered 10 degrees from

the slot centers in the next ring. No slots are cut within 0.6 m (2 ft) of the ends of the slotted

joints to assure that the strength of the pipe near the connections is not degraded.

7-6

7.2.3 Rationale for Differences between Actual and Proposed Well Design

The proposed well design was based on an expected geologic setting in which a thick welded-

tuff aquifer in the Ammonia Tanks Tuff would be present in the upper part of the hole. Below

the Ammonia Tanks Tuff, two intervals of welded-tuff aquifer of the Rainier Mesa Tuff were

expected, separated by a section of Timber Mountain landslide breccia. The proposed well

design included the construction of one completion zone that encompassed both expected

intervals of welded Rainier Mesa Tuff in the lower fifth of the borehole.

Rainier Mesa Tuff was not encountered in Well ER-EC-2A, which reached TD in the upper part

of the Ammonia Tanks Tuff. However, several water-producing units were encountered,

including nonwelded to moderately welded tuff, tuffaceous siltstone, and reworked tuff of the

Volcanics of Fortymile Canyon Group, and nonwelded and welded tuff of the Timber Mountain

Group. The completion design was modified to include completion zones in these aquifers, and

intervening intervals were isolated by blank sections. However, the basic plan of installing a

single string consisting of larger diameter carbon-steel casing above the water table and smaller

diameter stainless-steel casing in the saturated zone was accomplished.

7.3 Well Completion Method

A “tremie” line and the completion string were landed after a brief period of circulation and

conditioning of the hole. The three completion zones were gravel-packed and isolated from each

other with sand and cement barriers. One additional gravel layer (instead of cement) was placed

adjacent to a blank interval (Figure 7-1; Table 7-1) to save time waiting for cement deliveries.

Caliper logs were used to calculate the volumes of stemming materials needed during well

completion. Well-construction materials were inspected in accordance with relevant procedures;

standard decontamination procedures were employed to prevent the introduction of contaminants

into the well.

The filter pack around each open interval consists of 0.95-cm (d-in.) by 4-mesh washed pea

gravel, with 6-9 Colorado silica sand directly above the gravel, and 20/40 sand on top of the

6-9 sand. In this stemming design, developed by the UGTA program at the NTS, the layer of

20/40 sand serves as a barrier to any fluids that might seep from the cement above, preventing

cement fluids from contaminating the groundwater (fluids from the cement would have the effect

of drastically raising the pH of the groundwater). The underlying layer of 6-9 sand prevents the

20/40 sand from infiltrating the gravel-packed interval. All cement used in stemming the

completion string was Type II Portland cement with no additives. A clear-water pre-flush and

7-7

back-flush were made at each stage of emplacement. Gravel, sand, and cement were emplaced

through a 2f-in. Hydril® tremie line that was withdrawn as the completion process progressed.

A Nuclear Annulus Investigation Log (“NAIL”) was used to monitor the emplacement of

stemming materials. As-built positions of the well materials are shown on Figure 7-1 and listed

in Table 7-1.

Stemming of the hole began with the first stage of gravel emplaced from 1,514.6 to 1,357.6 m

(4,969 to 4,454 ft) on top of 1.5 m (5 ft) of fill at the bottom of the hole, and adjacent to the

lowest slotted interval. This gravel pack is topped by a sand barrier to the depth of 1,344.2 m

(4,410 ft), followed by cement, poured in two stages up to 1,098.2 m (3,603 ft). A second layer

of gravel was placed between the depths of 1,098.2 and 931.8 m (3,603 and 3,057 ft), adjacent to

the middle slotted interval; this gravel was topped with sand to the depth of 922.0 m (3,025 ft),

and cement, poured in two stages, to the depth of 832.1 m (2,730 ft). The next gravel section,

adjacent to a blank casing interval, is located between 832.1 and 788.5 m (2,730 and 2,587 ft),

and is capped by cement, poured in two stages, to 681.5 m (2,236 ft). The last gravel-packed

zone was placed outside the uppermost slotted interval between the depths of 681.5 and 508.4 m

(2,236 and 1,668 ft), and was capped with sand to the depth of 498.3 m (1,635 ft). The final

cemented section extends to the depth of 210.9 m (692 ft).

The drill rig was released after cementing was completed. Hydrologic testing was planned as a

separate effort, so a pump was not installed in the well and no well-development or pumping

tests were conducted immediately after completion.

7-8


8-1

8.0 Actual versus Planned Costs and Scheduling

The BN cost model developed for Well ER-EC-2A was based on drilling to the planned TD of

1,524.0 m (5,000 ft). The drilling program baseline projected that it would require 36 days to

accomplish drilling of the surface and main holes, logging, and completion for the well,

assuming the conductor hole would already have been constructed by BN. The actual time spent

to drill the main and surface holes, and install the completion string in Well ER-EC-2A was

25 days. Drilling of the surface hole and installation of the 13d- casing proceeded as expected.

However, drilling of the production hole and installation of the completion casing took

approximately 11 days less time than predicted. A graphical comparison, by day, of planned and

actual well-construction activities is presented in Figure 8-1.

The cost analysis for Well ER-EC-2A begins with construction of the conductor hole by BN and

the cost of mobilizing the UDI drill rig to the Well ER-EC-2A site. The cost of building roads,

the drill pad, and sumps is not included, and the cost of well-site support by IT is not included.

The total construction cost for Well ER-EC-2A includes all drilling costs: charges by the drilling

subcontractor; charges by other support subcontractors (including compressor services, drilling

fluids, bits, casing services, down-hole tools and, and geophysical logging); and charges by BN

for mobilization and demobilization of equipment, partial construction of the conductor hole,

cementing services, completion materials, radiation technicians, inspection services, and

geotechnical consultation.

The total planned cost for Well ER-EC-2A was $2,307,869. The actual cost was $1,848,201, or

20 percent less than the planned cost. Figure 8-2 presents a comparison of the planned

(“baseline”) and actual costs, by day, for drilling and completing Well ER-EC-2A. The quicker

than expected drilling time for construction of the production hole was main source of the cost

savings realized on this well.

74

4,201

4,676

4,9744,915

65 226403

620

1,0511,372

1,926

2,626

3,190

3,5483,794

0

1,000

2,000

3,000

4,000

5,000

6,000

20-Jan 21-Jan 22-Jan 23-Jan 24-Jan 25-Jan 26-Jan 27-Jan 28-Jan 29-Jan 30-Jan 31-Jan 1-Feb 2-Feb 3-Feb 4-Feb 5-Feb 6-Feb 7-Feb 8-Feb 9-Feb 10-Feb 11-Feb 12-Feb 13-Feb 14-Feb 15-Feb 16-Feb 17-Feb 18-Feb 19-Feb 20-Feb 21-Feb 22-Feb 23-Feb 24-Feb 25-Feb

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

Sequential Day Number and Date

Dep

th in

Fee

t

Planned Actual

Drill 17-1/2 inch Hole

Run Geophysical Logging Services

Run and Cement13-3/8 inch Casing

Drill 12-1/4 inchProduction Hole

Run Geophysical Logging Services Install Production

CasingStem and Cement Casing

`

8-2

Figure 8-1 Planned versus Actual Construction Progress for Well ER-EC-2A

$2,307,869

$1,848,201

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

20-Jan

21-Jan

22-Jan

23-Jan

24-Jan

25-Jan

26-Jan

27-Jan

28-Jan

29-Jan

30-Jan

31-Jan

1-Feb

2-Feb

3-Feb

4-Feb

5-Feb

6-Feb

7-Feb

8-Feb

9-Feb

10-Feb

11-Feb

12-Feb

13-Feb

14-Feb

15-Feb

16-Feb

17-Feb

18-Feb

19-Feb

20-Feb

21-Feb

22-Feb

23-Feb

24-Feb

25-Feb

26-Feb

27-Feb

28-Feb

29-Feb

30-Feb

31-Feb

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

Date and Sequential Day Number

Cos

t in

Dol

lars

PLANNED ACTUAL

Actual cost for installation of conductor casingand mobilization, as of beginning of work bydrilling subcontractor, 01/20/2000

$441,651

Actual Costs

Baseline Task Plan Costs

8-3

Figure 8-2 Planned versus Actual Cost for Constructing Well ER-EC-2A

8-4


9-1

9.0 Summary, Recommendations, and Lessons Learned

9.1 Summary

Subcontractor activities at Well ER-EC-2A commenced on January 21, 2000, and concluded on

February 14, 2000, when the TD of 1,516.1 m (4,974 ft) was reached. After geophysical

logging, the completion string was installed and gravel-packed, and the hole was stemmed to the

depth of 210.9 m (692 ft) on February 11-14, 2000. Crews worked on a 7-days-per-week,

24-hours-per-day schedule for most of the operation. Twenty-five working days were expended

to drill the surface and main holes, conduct geophysical logging, and install the completion

string. The only problem encountered during construction of Well ER-EC-2A was a 10.5-hour

delay during drilling due to a fluid-management issue.

No radionuclides above background were encountered in the groundwater produced from

Well ER-EC-2A. Preliminary (field-monitoring) data indicated no lead above permitted levels

for dissolved lead in the drilling effluent.

IT personnel measured the depth to fluid at 228.0 m (747.9 ft) on April 14, 2000, two months

after the completion string was installed.

Composite drill cuttings were collected every 3 m (10 ft) from 36.6 m (120 ft) to TD. Eighty-

one sidewall samples were collected in the interval 212.8 to 1,508.2 m (698 to 4,948 ft).

Geophysical logging was conducted in the upper part of the hole before installation of the surface

casing, and in the lower part of the hole before installation of the completion string. Some of

these logs were used to aid in construction of the well, while others help to verify the geology

and determine the hydrologic characteristics of the rocks.

A single completion string with three gravel-packed, slotted intervals, was installed in

Well ER-EC-2A. A string of 5½-in. stainless-steel casing installed below the water table is

suspended from 7e-in. carbon-steel casing (with an internal epoxy coating) which extends to the

surface. The open intervals in the 5½-in. casing are centered within the gravel-pack intervals that

are located at 508.4 to 681.5 m (1,668 to 2,236 ft); 931.8 to 1,098.2 m (3,057 to 3,603 ft); and

1,357.6 to 1,514.6 m (4,454 to 4,969 ft). These intervals are open to bedded and nonwelded tuff

of the rhyolite of Beatty Wash and the Beatty Wash Formation, reworked tuff, tuffaceous

siltstone with mostly nonwelded tuff of the Timber Mountain Group, and welded-tuff aquifer

lithologies of the Ammonia Tanks Tuff.

9-2

9.2 Recommendations

The planned pump installation, well development, groundwater sampling, and hydrologic testing

must be conducted at Well ER-EC-2A to accomplish the remaining objectives for this well-

construction effort. In addition, after all the planned PM-OV wells are drilled, geologic and

hydrologic data must be evaluated and interpretations of the area hydrogeology updated and

inserted into the UGTA hydrologic model. This process, followed by analysis of the updated

model, will allow more precise characterization of groundwater flow direction and velocity in the

region between the nuclear testing areas of Pahute Mesa and the Oasis Valley discharge area.

9.3 Lessons Learned

The efficiency of drilling and constructing wells to obtain hydrogeologic data in support of the

UGTA project continues to improve as experience is gained with each new well. No new lessons

were learned during the construction of Well ER-EC-2A, which was the eighth well in this

program of drilling in the Oasis Valley area,.

10-1

10.0 References

Bechtel Nevada. 1999. Western Pahute Mesa/Oasis Valley (WPM-OV) Investigation Wells Site-Specific Health and Safety Plan (SSHASP). February 1999. Las Vegas, NV.

Bechtel Nevada. 2000. Drilling Program for Underground Test Area (UGTA) Western PahuteMesa/Oasis Valley (WPM-OV) Investigation Well ER-EC-2A - Original. Drilling Work PlanNumber D-001-002.00. January 18, 2000. Las Vegas, NV.

BN, see Bechtel Nevada.

Byers, F. M., Jr., W. J. Carr, R. L. Christiansen, P. W. Lipman, P. P. Orkild, and W. D. Quinlivan. 1976. “Geologic Map of the Timber Mountain Caldera Area, Nye County, Nevada.” U.S.Geological Survey Miscellaneous Investigations Map I-891, scale 1:48,000 Reston, VA.

Carr, W. J., F. M. Byers, and E. C. Jenkins. 1968. Geology of Drill Hole UE18r, TimberMountain Caldera, Nevada Test Site. U.S. Geological Survey Technical Letter: SpecialStudies-69. Denver, CO.

DOE/NV, see U.S. Department of Energy, Nevada Operations Office.

Ferguson, J. F., A. H. Cogbill, and R. G. Warren. 1994. “A Geophysical-Geologic Transect of theSilent Canyon Caldera Complex, Pahute Mesa, Nevada.” In Journal of Geophysical Research,v. 99, n. 33, pp. 4,323-4,339.

Fridrich, C. J., S. A. Minor, and E. A. Mankinen. 1999. Geologic Evaluation of the Oasis ValleyBasin, Nye County, Nevada. U.S. Geological Survey Open-File Report 99-533-A. Denver,CO.

IT, see IT Corporation.

IT Corporation. 1998. FY99 Western Pahute Mesa - Oasis Valley Hydrogeologic InvestigationWells Drilling and Completion Criteria, ITLV/13052-049. Las Vegas, NV.

IT Corporation. 2000. Written communication prepared for DOE/NV. Subject: “Western PahuteMesa - Oasis Valley: ER-EC-2A Well Data Report,” July 2000. Las Vegas, NV.

Mankinen, E. A., T. G. Hildenbrand, G. L. Dixon, E. H. McKee, C. J. Fridrich, and R. J. Laczniak. 1999. Gravity and Magnetic Study of the Pahute Mesa and Oasis Valley Region, Nye County,Nevada, U. S. Geological Survey Open-File Report 99-303. Menlo Park, CA

O’Connor, J. T., R. E. Anderson, and P. W. Lipman. 1966. “Geologic Map of the Thirsty CanyonQuadrangle, Nye County, Nevada.” U.S. Geological Survey Geologic Quadrangle MapGQ-524, scale 1:24,000. Washington, D.C.

10-2

Sawyer, D. A., J. J. Fleck, M. A. Lanphere, R. G. Warren, and D. E. Broxton. 1994. “EpisodicCaldera Volcanism in the Miocene Southwest Nevada Volcanic Field: Revised StratigraphicCaldera Framework, 40Ar/39Ar Geochronology, and Implications for Magmatism andExtension.” Geological Society of America Bulletin, v. 67, n. 10, pp. 1,304-1,318.

U.S. Department of Energy, Nevada Operations Office. 1996a. Attachment 1, “FluidManagement Plan for the Underground Test Area Subproject.” In Underground Test AreaSubproject Waste Management Plan, Revision 1, DOE/NV--343. Las Vegas, NV.

U.S. Department of Energy, Nevada Operations Office. 1996b. Underground Test AreaSubproject Waste Management Plan, Rev. 1, DOE/NV--343. Las Vegas, NV.

U.S. Department of Energy, Nevada Operations Office. 1998. Nevada Environmental RestorationProject Health and Safety Plan, Revision 3, February 1998. Las Vegas, NV.

U.S. Department of Energy, Nevada Operations Office. 2000a. Completion Report forWell ER-EC-6. DOE/NV/11718–360. Las Vegas, NV.

U.S. Department of Energy, Nevada Operations Office. 2000b. Completion Report forWell ER-EC-1. DOE/NV/11718–381. Las Vegas, NV.

U.S. Department of Energy, Nevada Operations Office. 2000c. Completion Report forWell-ER-EC-4. DOE/NV/11718–397. Las Vegas, NV.

Wahl, R. R., D. A. Sawyer, M. D. Carr, S. A. Minor, J. C. Cole, WC Swadley, R. J. Laczniak,R. G. Warren, K. S. Green, and C. M. Engle. 1997. Digital Geologic Map of the Nevada TestSite Area, Nevada. U.S. Geological Survey Open-File Report 97-140, scale, 1:120,000. Denver, CO.

Warren, R. G. 2000. Written communications to Lance Prothro, Bechtel Nevada, Las Vegas, NV,dated March 3, 2000, September 18, 2000, March 12, 2001, and March 13, 2001. Subject:Results of analyses on samples from Well ER-EC-2A.

Appendix A

Drilling Data

A-1 Drilling Parameter Logs for Well ER-EC-2AA-2 Casing Data for Well ER-EC-2AA-3 Well ER-EC-2A Drilling Fluids and Cement Composition

Appendix A-1

Drilling Parameter Logs for Well ER-EC-2A

A-1-1

A-1-2


Appendix A-2

Casing Data for Well ER-EC-2A

A-2-1

Table A-2Casing Data for Well ER-EC-2A

CasingDepth Interval

meters (feet)

Type Grade

OutsideDiameter

centimeters(inches)

InsideDiameter

centimeters (inches)

WallThicknesscentimeters

(inches)

Weightper foot(pounds)

ConductorCasing

0 to 19.8(0 to 65.0)

Carbon SteelPE Weld

N/A76.2(30)

74.295(29.250)

0.953(0.375)

118.65

Surface Casing0 to 412.9

(0 to 1,354.6)CarbonSteel

K5533.97

(13.375)32.042

(12.615)0.965

(0.380)54.5

CompletionCasing

(with cross-over)

0 to 416.5(0 to 1,366.4)

Carbon Steelwith internal

epoxy coatingN80

19.37(7.625)

17.701(6.969)

0.833(0.328)

26.4

CompletionCasing

416.5 to 1,512.0(1,366.4 to 4,960.5)

StainlessSteel

SSTP30414.13

(5.563)12.819(5.047)

0.655(0.258)

14.6

A-2-2


Appendix A-3

Well ER-EC-2A Drilling Fluids and Cement Composition

A-3-1

Table A-3-1Well ER-EC-2A Drilling Fluids

Typic al Air-Fo am M ix a

Typic al Air-Fo am/P olym er Mix a

11.4 liters (3 gallons) Geofoam ® b

per

7,949 liters (50 barrels) water

15.1 to 41.6 liters (4 - 11 gallons) Geofoam ®

and

3.8 to 15.1 liters (1 - 4 gallons) LP701 ® b

per

7,949 liters (50 barrels) water

a An air-foam (“soap”) mix was used as the drilling fluid in Well ER-EC-2A. No additives wereused between the depths of approximately 18.3 and 38.4 meters (60 to 126 feet). Variousproportions of polymer were added to the air-foam to suit conditions during drilling belowapproximately 38.4 meters (126 feet).

b Geofoam® foaming agent and LP701® polymer additive are products of Geo Drilling Fluids, Inc.

NOTES:1. All water used to mix drilling fluids for Well ER-EC-2A came from the Coffer Dune Well.2. A concentrated solution of lithium bromide was added to all introduced fluids to make up a final

concentration of 0.7 to 173 milligrams per liter.

Table A-3-2Well ER-EC-2A Cement Composition

Cement

Composition

30-in.a

Conductor Casing

13d-in. Surface

CasingCompletion

Type II plus2 percent CaCl

4.6 to 20.1 m b

(15 to 65 ft c)Not used Not used

Type II neat0 to 4.6 m (0 to 15 ft)

0 to 20.4 m(0 to 67 ft)

228.6 to 418.2 m(750 d to 1,372 ft)

210.9 to 498.3 m(692 to 1,635 ft)

681.5 to 788.5 m(2,236 to 2,587 ft)

832.1 to 922.0 m(2,730 to 3,025 ft)

1,098.2 to 1,344.2 m(3,603 to 4,410 ft)

a inch b meter(s) c foot (feet) d estimated

A-3-2


Appendix B

Well ER-EC-2A Fluid Management Data

B-2

Preliminary Analytical Results for Fluid Management Samples from Well ER-EC-2A

SampleNumber

Date &Time

CollectedComment

Resource Conservation Recovery Act Metals (mg/L) a GrossAlpha

(pCi/L) b

GrossBeta

(pCi/L)Tritium(pCi/L)Arsenic Barium Cadmium Chromiu

mLead Selenium Silver Mercury

EC-2A-01250-1 01/25/200012:35

Sampletaken fromunlined Sump#1

Total 0.013 0.036(B) c

0.00027(U) d

0.012 0.039(J) e

0.0066 0.01(U)

0.00011(UJ) f

Dissolved 0.0096(B)

0.002(B)

0.00018(U)

0.004(B)

0.003(UJ)

0.0042(B)

0.01(U)

0.0002(UJ)

12.2E g =4.7

15.3E=4.8

-200E=160

(U)

EC-2A-01250-2 01/25/200012:45

Duplicatesample taken from unlinedSump #1

Total 0.017 0.039(B)

0.005(U)

0.0013 0.045(J)

0.005(U)

0.01(U)

0.00015(UJ)

Dissolved 0.011 0.00078(B)

0.0005(U)

0.0036(B)

0.003(UJ)

0.005(U)

0.01(UJ)

0.00002(UJ)

12.3E=4.8

14.1E=4.7(U)

-190E=160

(U)

EC-2A-02140-1 02/14/200014:15


Total 0.0068(J) 0.029(J)

0.005(UJ)

0.017(J)

0.003(UJ)

0.005(UJ)

0.01(UJ)

5.1e-05(J)

Dissolved 0.0061(J) 0.0064(J)

0.005(UJ)

0.017(J)

0.003(UJ)

0.0038(J)

0.01(UJ)

2.5e-05(J)

7.4E=30

12.0E=2.1

-50E=170

(U)

EC-2A-02140-2 02/14/200014:30


Total 0.0096(J) 0.053(J)

0.005(UJ)

0.0047(J)

0.072(J)

0.005(UJ)

0.01(UJ)

9.5e-05(J)

Dissolved 0.0068(J) 0.0018(UJ)

0.005(UJ)

0.0036(J)

0.003(UJ)

0.005(UJ)

0.01(UJ)

5.5e-05(J)

11.0E=2.3

8.3E=6(U)

-90E=170

(U)

Contract-Required Detection Limit 0.01 0.1 0.005 0.01 0.003 0.005 0.01 0.0002 N/A h N/A N/A

Nevada Drinking Water Standard (NDWS) 0.05 2.0 0.005 0.1 0.015 0.05 0.1 0.002 15 50 20,000

5 Times NDWS 0.25 10 0.025 0.5 0.075 0.25 0.5 0.01 75 250 100,000

Data provided by IT (IT, 2000) All analyses by Paragon Analytics, Inc.

a mg/L = milligrams per literb pCi/L = picocuries per literc B = Result less than Contract-Required Detection Limit, but greater than the Instrument Detection Limitd U = Result less the Instrument Detection Limit or the Minimum Detectable Concentratione J = Estimated Valuef UJ = Estimated result less than the Instrument Detection Limit or the Minimum Detectable Concentrationg E = Errorh N/A = Not applicable

Appendix C

Preliminary Detailed Lithologic Log for Well ER-EC-2A

C-1

Preliminary Detailed Lithologic Log for Well ER-EC-2aLogged by H. M. Noto and L. B. Prothro (BN Geological and Hydrological Services)

October 2000

Depth

Interval

mete rs (feet)

Thickness

meters

(feet)

Sam ple

Type a

Labora tory

Analyses b Lithologic Description

c Stratigra phic

Unit d

0 - 31.1

(0 - 102)

12.8

(42)DA 90

Pumiceous Lava: Yellowish gray (5Y 8/1) to light brownish gray

(5YR 6/1); mostly vitric, much less devitrified and silicic;

pumiceous and perlitic; rare felsic phenocrysts of plagioclase and

sanidine; rare to minor biotite and hornblende; conspicuous

sphene; chalcedony is present as loose fragments.

Tfbw

31.1 - 61 .0

(102 - 200)

29.9

(98)DA

Lava: Mottled light brownish gray (5YR 6/1), moderate greenish

yellow (10Y 7/4), a nd pa le bro wn (5 YR 5 /2); alt eratio n is va riable

and includes devitrified, silicic, vitric, and zeolitic, with zeolitization

decreasing towards ba se; spherulitic, including distinctive dark

reddish brown (10R 3/4) spherulites; perlitic where vitric; minor

felsic phenocrysts of feldspar; minor to common hornblende and

biotite; conspicuous sphene; chalcedony occurs as coatings,

cavity fillings, and loose fragments.

61.0 - 81 .7

(200 - 268)

20.7

(68)DA

Lava: Pale red (10R 6/2) and pale brown (5YR 5/2); devitrified,

silicic , and vitric, m uch less z eolitic ; wea kly to mod erate ly

spherulitic, including distinctive dark reddish brown (10R 3/4)

spherulites; perlitic where vitric; minor felsic phenocrysts of

feldspar, inc luding ch atoyan t sanidine; m inor to com mon b iotite

and lesser hornblende; cons picuous sphene; cha lcedony occurs

as coatings, cavity fillings, and loose fragments.

81.7 - 94 .5

(268 - 310)

12.8

(42)DA

Lava: Mottled pale yellowish brown (10YR 6/2), medium light gray

(N6), grayish red (10R 4/2), and light brownish gray (5Y R 6/1);

devitrified and silicic; flow-banded; weakly pumiceous in lower

part; rare to minor felsic phenocrysts of feldspar; minor biotite and

lesser hornblende; sphene an d pseudom orphs after sphene are

presen t.

Lithologic Log for Well ER-EC-2A - October 2000 Page 2 of 10

Depth

Interval

mete rs (feet)

Thickness

meters

(feet)

Sam ple

Type a

Labora tory


c Stratigra phic

Unit d

C-2

94.5 - 16 6.7

(310 - 547)

72.2

(237)DA

Lava: Light gray (N7) and mottled light brown (5YR 6/4) and

med ium lig ht gra y (N6); de vitrified , less er silic ic; pumice ous in

some intervals; flow -bande d throug hout; m inor felsic ph enocry sts

of feldspar; minor to common biotite, and lesser hornblende;

conspicuous sphene; botryoidal chalcedony occurs as coatings

and loose fragm ents ; sec ondary q uartz -cry stal aggre gate s fill

voids.

Tfbw

166.7 - 1 76.8

(547 - 580)

10.1

(33)DA

Lava: Mottled grayish red (10R 4/2) and moderate orange pink

(10R 7/4); devitrified and silicic; flow-banded; weakly spherulitic;

minor felsic phenocrysts of feldspar, including chatoyant sanidine

and partia lly alte red fe ldspar; m inor to com mon biotite ; sphene is

presen t.

176.8 - 1 93.5

(580 - 635)

16.8

(55)DA

Lava: Moderate brown (5YR 4/4) to moderate brow n (5YR 3/4),

pale yellowish brown (10YR 6/2), medium light gray (N6), and

lesser grayish black (N2); devitrified, silicic, and lesser vitric;

spherulitic, perlitic where vitric; minor felsic phenocrysts of

feldspar; minor biotite; conspicuous sphene; chalcedony occurs as

loose fragments; numerous hairline fractures filled with silica.

193.5 - 2 07.3

(635 - 680)

13.7

(45)DA 680

Vitrophyric Lava: Mostly grayish black (N2), lesser dusky

yellowish brown (10YR 2/2); mostly vitric, much less devitrified;

perlitic; minor felsic phenocrysts of sanidine and plagioclase; minor

biotite and lesser hornblende; conspicuous sphene.

207.3 - 2 27.4

(680 - 746)

20.1

(66)DA 750

Pumiceous Lava: Pale brown (5YR 5/2) and light brown (5YR

5/2); devit rified, p artially silicic; rem nan t perlitic textu re; m inor fe lsic

phenocrysts of sanidine and plagioclase; minor biotite and lesser

hornblende; conspicuous sphene and pseudomorphs after

sphene; rare to minor dusky brown (5YR 2/2) lithic fragments;

drusy quartz lines cavities.


Depth

Interval

mete rs (feet)

Thickness

meters

(feet)

Sam ple

Type a

Labora tory


c Stratigra phic

Unit d

C-3

227.4 - 3 99.3

(746 - 1,310)

171.9

(564)DA

1,010

1,260

Nonw elded Tuff: Light b rown (5YR 6/4) a bove appr oxim ately

243.8 m (800 ft), moderate yellowish brown (10YR 5/4) and dusky

yellow (5Y 6/4) to approximately 317.0 m (1,040 ft), light brown

(5YR 6/4) to approximately 356.6 m (1,170 ft), grayish orange

(10YR 7/4) below ; zeolitic, partially silicic; com mon mod erate

yellowish brown (10YR 5/4) to light olive brown (5Y 5/6) pumice;

common felsic phenocrysts of sanidine and plagioclase, trace of

quartz; minor to common biotite and hornblende; conspicuous

sphene and pseudomorphs after sphene; common dark reddish

brown ( 10R 3 /4) and g rayish red p urple (5R P 4/2) lithic frag men ts

consisting of various volcanic lithologies; drusy quartz occurs as

coatings and cavity linings.

Tfbw

399.3 - 4 27.9

(1,310 - 1,404)

28.7

(94)DA 1,350

Nonw elded Tuff: Pale redd ish brow n (10R 5/4) to mo derate

reddish orange (10R 6/6); quartzo-feldspathic; common grayish

orange (10YR 7/4) to pale yellowish brown (10YR 6/2) pumice;

rare to minor felsic phenocrysts of sanidine and plagioclase, trace

of quartz ; rare biotite; ps eudom orphs a fter sphe ne are p resent;

rare to minor lithic fragments.

427.9 - 6 46.8

(1,404 - 2,122)

218.8

(718)DA

1,500

1,700

1,960

Nonw elded Tuff: Grayish orange (10YR 7/4), dusky yellow (5Y

6/4), and pale yellowish brown (10YR 6/2); quartzo-feldspathic;

comm on to abu ndant pu mice; m inor to com mon fe lsic phen ocrysts

of sanidine and plagioclase, some partially to strongly altered, and

much less quartz; minor to common black biotite; rare to common

lithic fragme nts with m ore lithic-rich inte rvals oc curring a t 448.1 to

457.2 m (1,470 to 1 ,500 ft) and 487.7 to 5 06.0 m (1,600 to

1,660 ft).

Ultrasonic borehole image log indicates fractures at the following

depths: 444.1; 485.9-488.9; 509.6; 512.1; 528.5; and 599.2 m

(1,457, 1,594-1,604, 1,672, 1,680, 1,734, and 1,966 ft). Most of

the fractures have dips greater than 70 degrees.


Depth

Interval

mete rs (feet)

Thickness

meters

(feet)

Sam ple

Type a

Labora tory


c Stratigra phic

Unit d

C-4

646.8 - 6 66.0

(2,122 - 2,185)

19.2

(63)DA 2,190

Nonw elded Tuff: Moderate brown (5YR 4/4) to light brown (5YR

6/4); moderately quartzo-feldspathic, with significant silicification;

common dusky yellow (5Y 6/4) pumice; minor felsic phenocrysts of

sanidine and plagioclase, both partially altered, and much less

quartz; m inor to com mon biotite and le sse r horn blend e; min or lithic

fragments.

Tfbw

666.0 - 8 30.3

(2,185 - 2,724)

164.3

(539)DA

2,380

2,600

Nonw elded Tuff: Light brown (5YR 6/4) and grayish orange

(10YR 7/4) above approximately 719.3 m (2,360 ft), l ight brown

(5YR 6/4) to pale reddish brown (10R 5/4) from 719.3 to 768.1 m

(2,360 to 2,520 ft), becoming grayish pink (5R 8/2) below;

moderately to strongly quartzo-feldspathic, degree of alteration

incre asing with depth; comm on pu mice ; rare to comm on fe lsic

phenocrysts of altered feldspar, including kaolinite pseudomorphs

after plagioclase, and lesser quartz; common biotite; one

pseudomo rph after sphene observed at depth 716.3 m (2,350 ft);

rare lithic fragments.Tfb, undivided

830.3 - 8 58.0

(2,724 - 2,815)

27.7

(91)DA 2,780

Moderately W elded Ash-F low Tuff: Pale reddish brown (10R

5/4); moderately quartzo-feldspathic, with significant silicification

near top of unit; flow-like features observed may reflect

reomorphism; common pumice; common felsic phenocrysts of

unaltered to partly altered sanidine, lesser pseudomorphs after

plagioclase, and lesser quartz; common biotite; pseudomorphs

after sphene are present; minor to common lithic fragments.

Ultrasonic borehole image log indicates fractures above 842.8 m

(2,765 ft). Fractures appear to dip more than 80 degrees.


Depth

Interval

mete rs (feet)

Thickness

meters

(feet)

Sam ple

Type a

Labora tory


c Stratigra phic

Unit d

C-5

858.0 - 8 67.5

(2,815 - 2,846)

9.4

(31)DA

Partially Welded As h-Flow Tu ff: Pale reddish brown (10R 5/4);

mode rately qua rtzo-felds pathic; co mmo n pum ice; mino r to

common felsic phenocrysts of feldspar, pseudomorphs after

feldspar, and much less quartz; minor partially altered biotite;

pseudomorphs after sphene are present; minor lithic fragments.

Ultrasonic borehole image log indicates two fractures dipping

approximately 70 degrees at 858.3 m (2,816 ft).Tfb, undivided

867.5 - 9 40.3

(2,846 - 3,085)

72.8

(239)DA

2,960

3,060

Nonw elded Tuff: Pale red (10R 6/2) and pale reddish brown

(10R 5 /4) at the top , becom ing pale red purple (5R P 6/2) to

medium light gray (N 6) lower; s trongly qu artzo-feld spathic, w ith

degree of alteration increasing towards base, weakly calcareous;

minor to common pumice; minor to common felsic phenocrysts of

pseud omorp hs after feld spar, an d muc h less qu artz; rare to

com mon biotite , with a bundance inc reas ing w ith depth; m inor lith ic

fragments.

940.3 - 9 46.1

(3,085 - 3,104)

5.8

(19)DA

Reworked Tuff and Tuffaceous Sandstone: Samples consist

mostly of grayish red (10R 4/2), light gray (N7), pinkish gray (5YR

8/1), gree nish gray (5G 6/1), a nd br own ish gr ay (5 YR 4 /1), ze olitic

to quartzo-feldspathic, and weakly calcareous, m edium- to very

fine-grained, laminated, well indurated, reworked tuff and

tuffaceous sandstone.

Samples also consist of in lesser abundance, loose pieces of

cha lcedony , and brow nish black (5YR 2/1), m oderately

calcareous, coarsely crystalline fragments of an unknown lithology

(probab ly high ly alte red w elded tuff w ith ca lcite, b ut possib ly

chemically deposited or diagenetically altered fine-grained

sedimentary rock).

Ultrasonic borehole image log shows a high degree of bedding

within this interval, with beds dipping approximately 20 degrees.

Tf, undivided


Depth

Interval

mete rs (feet)

Thickness

meters

(feet)

Sam ple

Type a

Labora tory


c Stratigra phic

Unit d

C-6

946.1 - 9 61.6

(3,104 - 3,155)

15.5

(51)DA

3,130

3,150

Tuffaceous Siltstone/Rewo rked Ash, and lesser Welded T uff

and Tufface ous Sand stone/Rew orked Tuff: Samples consist

of:

Tuffaceous Siltstone/Reworked Ash: Mostly medium dark gray

(N4 ) to bla ck (N 1) to a ppro xima tely (3 ,140 ft), becom ing m ulti-

colored (e.g. pale yellowish brown (10YR 6/2), moderate pink (5R

7/4) to moderate reddish orange (10R 6/6), dark yellowish orange

(10Y R 6/6 ), etc. ) belo w 95 7.1 m (3,14 0 ft); m ass ive to very thinly

lamin ated . Man y inte rvals are s trong ly silicif ied, obscuring grain

size . Thin -sec tion a t 954 .0 m ( 3,13 0 ft) is d esc ribed as finely

laye red lig ht-co lored chalc edony an d dar k-co lored stron gly

silicified and carbonized clay. Two lithologies are described for the

thin-section at 960.1 m (3,150 ft): (1) strongly carbonized clay

with bands of analcime interpreted as hydrothermally altered

lacustrine sedime nts, (2) m edium g rained ag gregate s of calcite

with much lesser analcime and minor clay, interpreted as

chemically precipitated hydrothermal deposits. X-ray diffraction

analyses indicate samples at 954.0 and 960.1 m (3,130 and

3,150 ft) contain 3.8% and 5.5% fluorite, respectively.

Welded Tuff (occurs m ostly above 957.1 m [3,140 ft]): Grayish

black (N2), lesser greenish gray (5GY 6/1); strongly quartzo-

feldspathic and pyritic; abundant felsic phenocrysts of

pseudomorphs after feldspar; no visible biotite.

Samples also contain lesser amounts of reworked tuff (same as

the reworked tuff described for the overlying interval).

Ultrasonic borehole image log shows a high degree of bedding

through out interva l, with beds dipping ap proxim ately 20 d egrees .

Log also indicates the presence of two generally parallel fractures

dipping approximately 75 degrees at 950.7 m (3,119 ft) depth.

Tf, undivided


Depth

Interval

mete rs (feet)

Thickness

meters

(feet)

Sam ple

Type a

Labora tory


c Stratigra phic

Unit d

C-7

961.6 - 9 68.7

(3,155 - 3,178)

7.0

(23)DA 3,170

Nonw elded Tuff: Medium gray (N5) to approximately 966.2 m

(3,170 ft) becoming partly moderate reddish orange (10R 6/6)

below ; qua rtzo- felds path ic, py ritic; co mm on to abun dan t felsic

phenocrysts of pseudomorphs after feldspar, and conspicuous

quartz; rare to common biotite; a pseudomorph probably after

sphene observed in thin section; rare to common lithic fragments.

Tm, undivided

968.7 - 9 76.6

(3,178 - 3,204)

7.9

(26)DA

Nonw elded Tuff: Dark y ellowish b rown (1 0YR 4 /2) and m oderate

reddish brown (10R 4/6); quartzo-feldspathic with significant

silicification; common to abundant felsic phenocrysts of feldspar

and conspicuous quartz; rare biotite.

976.6 - 9 79.0

(3,204 - 3,212)

2.4

(8)DA 3,210

Nonw elded Tuff: Moderate reddish orange (10R 6/6) to light

brown (5YR 6 /4); quartz o-feldspa thic; com mon fe lsic phen ocrysts

of pseudomorphs after feldspar and lesser quartz; rare altered

biotite ; a pseudomo rph p roba bly af ter sp hene obs erve d in thin

section; rare lithic fragments.

979.0 - 9 97.3

(3,212 - 3,272)

18.3

(60)DA

Nonw elded Tuff: Very pale orange (10YR 8/2) and medium light

gray (N6) to brownish gray (5YR 4/1); strongly quartzo-feldspathic,

sign ifican tly silic ic in so me in terva ls; min or to c omm on fe lsic

phenocrysts of pseudomorphs after feldspar, and conspicuous

quartz; minor, generally altered, biotite; rare lithic fragments.

997.3 - 1 ,181.1

(3,272 - 3,875)

183.8

(603)DA

3,310

3,510

3,720

3,850

Nonw elded Tuff: Light olive gray (5Y 5/2), very pale orange

(10YR 8/2), yellow ish gray (5Y 8/1), a nd very light gray (N 8) to

med ium d ark g ray (N4) ; stron gly qu artzo -felds path ic, we akly

pyritic; weakly spherulitic; rare to minor pumice; rare to common

felsic phenocrysts of quartz, pseudomorphs after feldspar, and

secon dary felds par repla ceme nts; rare to minor bio tite; minor to

common lithic fragments.

Thin sec tion analyses sugg est m uch of inte rval m ay be mod erate ly

welded tuff.


Depth

Interval

mete rs (feet)

Thickness

meters

(feet)

Sam ple

Type a

Labora tory


c Stratigra phic

Unit d

C-8

1,181.1 - 1,211.9

(3,875 - 3,976)

30.8

(101)DA

Nonw elded Tuff: Medium dark gray (N4); strongly quartzo-

felds path ic; we akly s phe rulitic; c om mo n to abundan t felsic

phenocrysts of conspicuous quartz, and pseudomorphs after

feldspar; minor biotite; rare lithic fragments.

Tm, undivided

1,211.9 - 1,400.3

(3,976 - 4,594)

188.4

(618)DA

4,080

4,280

4,450

Nonw elded Tuff: Very light gray (N8) to medium gray (N 5),

yellowish gray (5Y 8/1), and light brownish gray (5YR 6/1);

strongly quartzo-feldspathic, pyritic, and very weakly calcareous;

minor to common pumice; minor to common felsic phenocrysts of

pseudomorphs after feldspar and lesser, yet conspicuous, quartz,

including dipyramidal quartz; rare to minor biotite; rare to common

lithic fragments.

Thin section analyses suggest that the upper and lower portions of

interval m ay be m oderate ly welded tuff.

1,400.3 - 1,410.0

(4,594 - 4,626)

9.8

(32)DA 4,610

Moderately W elded Ash-F low Tuff: Medium dark gra y (N4) to

dark gray (N3) ; qua rtzo- felds path ic; min or pu mice ; abundant fels ic

phenocrysts are pseudomorphs after feldspar and lesser quartz;

common biotite; minor lithic fragments.

1,410.0 - 1,452.1

(4,626 - 4,764)

42.1

(138)DA 4,690

Nonw elded Tuff: Yellowish gray (5Y 8/1) and light brownish gray

(5YR 6/1); strongly quartzo-feldspathic, weakly calcareous; minor

to common pumice; comm on to abundant felsic phenocrysts are

pseudomorphs after feldspar and lesser quartz; minor to common

mostly altered biotite; minor lithic fragments.


Depth

Interval

mete rs (feet)

Thickness

meters

(feet)

Sam ple

Type a

Labora tory


c Stratigra phic

Unit d

C-9

1,452.1 - 1,516.1

(4,764 - 4,974)

TD

64.0

(210)DA, SC

4,830

4,974

Moderately W elded Ash-F low Tuff: Dark gray (N3) to grayish

black (N2); quartzo-feldspathic, weakly calcareous and chloritic;

common pumice; abundant felsic phenocrysts are pseudomorphs

after feldspar, a nd les ser q uartz ; com mon to abundant m afic

minerals are mostly unaltered biotite, and lesser pseudomorphs

after clinopyroxene and sphene; minor li thic fragments. No

mon azite (cha racte ristic o f the R ainier Mes a Tu ff) obs erve d in thin

section or indicated by neutron activation analysis.

Tmar

a DA = drill cuttings tha t represe nt lithologic ch aracter o f interval; SC = sidewall core.

b Notation s refer to a nalyses c onduc ted on the sam ple depth s indicated . See T able 3-2 o f this repor t for additiona l informa tion.

c Descriptions are based mainly on visual examination of lithologic samples using a 10x- to 40x-zoom binocular microscope and geophysical

logs. Additional data from laboratory analyses have been incorporated into the descriptions. Colors describe we t sample color.

Abund ances for felsic ph enocrys ts, pum ice fragm ents, and lithic fragm ents: trace = only one o r two individu als obse rved; rare = < 1%;

minor = 5%; common = 10% ; abundant = 15% ; very abundant = > 20%.

Abund ances for ma fic mine rals: trace = only one o r two individu als obse rved; rare = < 0.05% ; minor = 0.2% ; common = 0.5% ;

abundant = 1%; very abund ant = > 2%.

d Tfbw = rhyolite of Be atty W ash; Tfb = Beatty W ash Fo rma tion; Tf = Volcan ics of Fo rtymile Ca nyon; Tm = Tim ber Mo untain G roup;

Tmar = ma fic-rich Am mon ia Tank s Tuff .

C-10


Appendix D

Geophysical Logs Run in Well ER-EC-2A

D-1

Appendix D contains unprocessed data presentations of selected geophysical logs run inWell ER-EC-2A. Table D-1 summarizes the logs presented. See Table 3-3 for moreinformation.

Table D-1Well ER-EC-2A Geophysical Logs Presented

Log TypeRun

NumberDate

Log Interval

meters feet

Epithermal NeutronENP-1

ENP-2

01/27/2000

02/08/2000

19.8 - 409.7

396.2 - 1 ,510.3

65 - 1,344

1,300 - 4,955

Dens ityCDL-1

CDL-2

01/27/2000

02/08/2000

19.8 - 409.7

396.2 - 1 ,510.3

65 - 1,344

1,300 - 4,955

Array Induction and Dual Laterolog

(resistivity)

IND-1

DLL-1

01/27/2000

02/08/2000

19.8 - 41 2.7

396.2 - 1 ,510.3

65 - 1,354

1,300 - 4,955

Spontaneous PotentialSP-1

SP-3

01/27/2000

02/08/2000

19.8 - 41 2.7

396.2 - 1 ,510.3

65 - 1,354

1,300 - 4,955

Gamma RayGR-1

GR-2

01/27/2000

02/07/2000

19.8 - 41 2.7

393.2 - 1 ,515.8

65 - 1,354

1,290 - 4,973

Digita l Array Sonic

(delta T and sonic porosity)AC-1 02/08/2000 335.3 - 1 ,511.8 1,100 - 4,960

Spectral Gamma Ray

(potassium, thorium, uranium)

SGR-1

SGR-2

01/27/2000

02/08/2000

0 - 414.8

371.9 - 1 ,504.5

0 - 1,361

1,220 - 4,936

Thermal Flow 1 02/09/2000 502.9 - 1 ,082.0 1,650 - 3,550

Chemistry

(temperature, pH,

electrical conductivity)

1 02/09/2000 257.3 - 1 ,515.8 844 - 4,973

D-2

D-3

D-4

D-5

D-6

Distribution List

Copies

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Distribution List (continued)

Copies

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Documents

Completion Report for Well ER-EC-2A - UNT Digital Library/67531/metadc741005/... · Well ER-EC-2A is located within the Nellis Air Force Range complex, approximately 10 kilometers