ECD Reduction Tool - dea-global.orgdea-global.org/wp-content/uploads/2009/11/DEA_Bansel_4th_2008.pdf · ECD Reduction Tool ... 350 400 0 100 200 300 400 500 600 ... Extra Standpipe

1© 2007 Weatherford. All rights reserved.

ECD Reduction ToolR. K. Bansal, Brian Grayson, Jim StanleyControl Pressure Drilling & Testing

November 20, 2008Drilling Engineering Association, Fourth Quarter Meeting

© 2007 Weatherford. All rights reserved.

Description of the ECD Reduction Tool (ECD RT)

Lab test results

Field test results

Forward plan

Summary

Presentation outline


ECD Reduction Tool (ECD RT)What?

• A downhole tool for reducing the equivalent circulating density (ECD), hence the bottomhole pressure, while drilling.

Why?• Wherever high ECD is a problem:

You want to drill with a lighter mud to minimize chances for mud loss but you risk fluid influx when circulation stops. It is a common problem where difference between pore pressure and formation fracture pressure is small, orYou want to use a heavier mud to improve wellborestability but you can’t due to increased risk of mud loss, such as in ERD wells (small difference between collapse pressure and formation fracture pressure).

Where it is run?• High in the drillstring, in the vertical section of the well close

to surface.


Major benefits of ECD reduction

Improved wellbore stability by tolerating higher static mud weights

Extended hole intervals and reduced number of casing strings

Reduced impact of uncertainty on casing setting depth by widening the usable PP/FG margin

Reduced lost circulation and differential sticking


Description – 8.20” ECD RT

Modular design - 3 primary components

• Hydraulic turbine drive

• Annular pump

• Sealing element

Total Length ~ 30 feet.

Tool diameter 8.20 inch.

Applicable in 9-5/8” (47# or lighter) and 10-3/4” casing pipes.

Normal circulation rate 500-550 gpm; 600 gpm max.

TURBINE PUMP SEALS


Operational Advantages

Portable tool; Requires no rig modification

Drill string component; Quick rig-up / rig down. Only a short trip of 7 stands is required to add the tool in drill string.

For use on land and offshore applications

Use for planned and or unanticipated problematic intervals of the well

Does not impede mud pulse telemetry

Does not affect normal drilling operations


Flow loop tests

Performance characterization

The effect of LCM in the drilling fluid

The effect of reverse flow (bull heading)

The effect of gas in the return fluid

P1P3

P2

Flow


-50

0

50

100

150

200

250

300

350

400

0 100 200 300 400 500 600

Circulation rate, gpm

Ann

ulus

Pre

ssur

e R

educ

tion,

psi

Annulus pressure reduction as a function of circulation rate and mud weight

14.5 ppg

16.5 ppg

17.8 ppg

19.2 ppg

10.4 ppg

Water


0

5,000

10,000

15,000

20,000

25,000

0.0 1.0 2.0 3.0 4.0 5.0 6.0ECD Reduction, lb/gal

Verti

cal d

epth

, ft

Projected ECD reduction versus depth

14.5 ppg

16.5 ppg

12.5 ppg

10.4 ppg

PECD Reduction =

.052*Depth

Circulation rate: 525-550 gpm


Extra standpipe pressure (SPP) requirement

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Circulation rate, gpm

Extr

a St

andp

ipe

Pres

sure

, psi

19.2 ppg 17.8 ppg 16.5 ppg 14.5 ppg 10.4 ppg Water


Full scale technology tests

Primary Objectives

1.Quantify pressure reduction

2.Measure transient pressure spike at the start of rig pumps

3.Quantify Surge and Swab effects

4.Demonstrate compatibility with mud-pulse telemetry

5.Assess longevity of the tool at normal circulation rate

Rig floor

Flow line

Ground

ECDRT

Bit

Cement in lower two joints

P1

P2


ECD Reduction demonstrated in technology trial

Circulation rate

ECD


Field trials conductedRig floor

ECDRT

Annular pressure sub

Objectives Achievements

Quantify ECD reduction

Demonstrated expected ECD reduction

Evaluate operational procedures

Did not impede normal drilling operation

Cuttings flowed through the pump easily

Mud pulse telemetry worked normally

Assess reliability Reliability proved to be a weakness. Maximum drilling achieved was 500-ft of 8.75” hole. Focus of recent development was to improve longevity and reliability.

Drilling operation was monitored by standpipe pressure, hook load, real-time ECD and fluid return.


ECD reduction in Arkoma field trial

Circulation rate

ECD

Mud Weight

Normal ECD

Circulation rate

ECD


6.75" 6.75" 8.20"

44" 355.6" (29' 7.6")

UPPER GAGE CARRIER ECDRT

5.0"

LOWER GAGE CARRIER

44"

6.75"

Forward Plan - Next Field Trial Plan going forward is to run a successful field trial and we are actively looking for an opportunity.

Casing size 9-5/8” (47 lb/ft or lighter) or 10-3/4”

Circulation rate between 475-550 gpm; mud type and weight do not matter.

Ability to drill ahead 1500 to 2000 ft with the ECD RT located in the vertical hole. ECD RT starting location is 650-700 ft from surface.

Instrumentation for real time display of downhole pressure, ECD and circulation rate.


SummaryECD RT potentially offers significant benefits to drilling operations

The concept of ECD RT has been proven in field trials

The present design will function in 9-5/8” (47# or lighter) and 10-3/4” casing pipes and handle up to 600 gpm circulation rate

Looking for additional field trial opportunity to prove reliability and longevity of the tool.

Likely to develop other sizes subsequently.

Documents

ECD Reduction Tool - dea-global.orgdea-global.org/wp-content/uploads/2009/11/DEA_Bansel_4th_2008.pdf · ECD Reduction Tool ... 350 400 0 100 200 300 400 500 600 ... Extra Standpipe