The mountain is permeable and fractured: Hydrological Connectivity in the Laramie Range
1.Dept. of Geology & Geophysics, University of Wyoming 2. Dept. of Petroleum Engineering, China University of Geosciences
WyCHEG Interest Group Meeting, Oct 30, 2017, Laramie, WY
Ye Zhang1, Brad Carr1, Shuangpo Ren2, Andy Parsekian1
https://commons.wikimedia.org/w/index.php?curid=11121878
Mountain Hydrology
Laramie Range Laramie Range
Wyoming Blair Creek
wetland
Blair Creek Well field
Granite outcrop
Granite outcrop
Granite outcrop
Mapped lineaments
0 1 2 km
N
Medicine Bow National Forest
Blair Wallis
• Geology: fractured granite & metamorphic rock overlain by weathered granite;
• Hydrology: surface & subsurface hydrology dominated by snowmelt.
• Hydrological Research: SW & GW monitoring & GW well tests;
• Geophysical Research: borehole & surface (seismic, resistivity, GPR, NMR, gravity, etc.)
• Petrophysics research: extend from field to mountain scale;
Blair Wallis Fractured Rock Well Field
http://www.justtrails.com/tag/vedauwoo/
2 miles South of Blair Wallis Well Field, WYDOT
Cross-hole hydraulic communication exists among BW 6, 7, 8, 9, and BW1.
Blair Creek
wetland
0 100 200 m
N
Blair Wallis Fractured Rock Hydrology Research Well Field
Drilling at Blair
Setting surface casing made of PVC at BW6
Sulfide-Rich Sherman Cores from BW4
Classic Sherman Cores from BW5 Natural Clay from BW6 killed our pump
BW-1 BW-2 BW-3 BW-4 BW-5 BW-6 BW-7 BW-8 BW-9
Coord. 41.183939° N, 105.394125° W
41.183888° N, 105.397732° W
41.185873° N, 105.399440° W
41.184046° N, 105.393329° W
41.184099° N, 105.398273° W
41.183842° N, 105.394332° W
41.183989° N, 105.394456° W
41.183904° N, 105.394667° W
41.183753° N, 105.394551° W
TD (m) 30.27 16.03 39.10 58.61 39.02 60.76 72.83 76.2 60.96
Casing depth (m)
17 6.1 6.7 9.8 18 17.07 17.07
16.76
17.07
Casing diameter (inch)
7’’ steel casing 7’’ pvc casing 7’’ pvc casing
4’’ pvc casing
4’’ pvc casing 6’’ pvc casing 6’’ pvc casing 6’’ pvc casing
6’’ pvc casing
Borehole diameter*1 (inch)
4 7/8’’ 5.5’’ 5.5’’ ~3.8’’ ~3.8’’ 5’’ 5’’ 5’’ 5’’
Rock type Classic Sherman
Classic Sherman
Classic Sherman
Sulfide-rich Sherman
Classic Sherman
Classic Sherman
Classic Sherman
Classic Sherman
Classic Sherman
DTW (m)*2
11.8 (8/15/2015) 11.03 (11/18/2015)
5.7 (9/11/2015)
11.7 (11/18/2015)
10.9 (9/11/2015)
13.18 from toc (9/8/2016) 12.645 bgs (8/31/2016)
11.835 from toc? (9/8/2016) 11.755 bgs (9/1/2016)
13.743 (12/8/2016)
12.947 (12/8/2016)
*1 This is diameter of the open borehole beneath the casing (see the diagram on previous page; also see caliper logs); *2 From top of casing (TOC) unless it is labeled as bgs (below ground surface); continuous WL monitoring is available since May, 2015. *3 No corings for BW 6, 7, 8, and 9. Note most shallow saprolite wells (Brady’s; Austin’s) in Blair Wallis were drilled using the backpack shaw drill.
Drilling method
air/water rotary +coring; airlifted;
air/water rotary +coring; not developed
wireline+coring (drilled with water); not developed
wireline+coring (drilled with water); airlifted;
wireline+coring (drilled with water); airlifted;
air/water rotary + downhole hammer*3
airlifted;
air/water rotary + downhole hammer; airlifted;
air/water rotary + downhole hammer; airlifted;
air/water rotary + downhole hammer; airlifted;
Well Field Summary
• 9 bedrock wells completed in the saturated fractured granite; A subset of 5 wells (BW1, 6, 7, 8, 9) are hydraulically connected;
• 4 or 5 shallow wells completed in saturated weathered granite;
• 7 NMR boreholes completed in unsaturated weathered granite;
• All wells & boreholes: monitoring water pressure & temperature;
• Hydraulic tests: single well & cross-hole interference tests (hydraulic tomography);
• Numerous bedrock fractures observed in cores and wireline logs;
• Short-term pumping tests (up to 44 hr) show from very-low to moderate productivity;
• Bedrock equivalent KH: 10-7~10-4 m/s (fine to medium sand);
• Fresh water (TDS<100 mg/l); a few tests produced suspended sediments (granite minerals & clay);
Well Field Observations
BW4
• 28 hr pumping test @ 20 gpm; • Drawdown in BW4 is ~12 m; • BW1, 40 m away, had no response;
BW 7 Test • Variable fracture
connectivity: differential drawdowns in monitoring wells;
• Sediment production causes pumping rate to reduce;
• Drawdown stabilization at 3.5 gpm: water-supply BC (stream loss);
10
12
14
16
18
20
22
24
26
28
8/22/2017 0:00 8/22/2017 12:00 8/23/2017 0:00 8/23/2017 12:00 8/24/2017 0:00 8/24/2017 12:00 8/25/2017 0:00
DTW
(m)
manualmeasurementtransducer
Sediment production
Discharge: GW flow to basin is estimated at 6~19% of the total precipitation over the Laramie Range, assuming local-scale K data at Blair extends to mountain scale.
Recharge: GW level is dominated by annual spring snowmelt indicating connectivity to surface.
Recharge & Discharge
Denver Basin – Casper Aquifer
Laramie Basin: Casper Aquifer Monitoring
Taboga (2006)
Recharge to Casper Aquifer from above during annual snowmelt.
Laramie Basin: Casper Recharge Study
Artesian (~13’ ags)
Granite flow at ~2 gpm
Head (~20’ bgs)
Sept-Oct, 2017: Hydraulic gradient exists for upward flow, supplying a “sub-charge” to Casper Aquifer
• Exists between snow, streams, lakes/reservoirs, soil, & groundwater regimes;
• Degrees of connectivity varies;
• Complex interaction.
Broader Connectivity
Implications Scientific: Advance understanding of mountain hydrology & snowmelt partitioning into SW and GW;
• Opportunities (mountain block v. mountain front recharge); • Vulnerability; • Conjunctive SW/GW management;
Management:
Future Work: • Petrophysics linking aquifer properties to geophysics for mountain
scale surveys;
Extra
Blair Wallis Fractured Rock research well field
Red Buttes
Belvoir Ranch
Gov Gulch Site
Casper Aquifer Monitoring Program & UW Golf Course
High plains aquifer monitoring well network (ALTAS site)
Monitored reservoirs
6 stream sites with 12 riparian wells
Laramie Basin
Denver Basin
Laramie Range
Acknowledgement
Students: Shuangpo Ren, Sam Grag, Sam Coker; Consultants: Chris Moody, Bern Hinkeley, Mark Stacy; Funding: NSF, Wyoming Water Research Program, USGS; Cooperating Agencies: USFS, State of Wyoming DEQ, Cheyenne BOPU;
BW-1 BW-2 BW-3 BW-4 BW-5 BW-6 BW-7 BW-8 BW-9
Coord. 41.183939° N, 105.394125° W
41.183888° N, 105.397732° W
41.185873° N, 105.399440° W
41.184046° N, 105.393329° W
41.184099° N, 105.398273° W
41.183842° N, 105.394332° W
41.183989° N, 105.394456° W
41.183904° N, 105.394667° W
41.183753° N, 105.394551° W
TD (m) 30.27 16.03 39.10 58.61 39.02 60.76 72.83 76.2 60.96
Casing depth (m)
17 6.1 6.7 9.8 18 17.07 17.07
16.76
17.07
Casing diameter (inch)
7’’ steel casing 7’’ pvc casing 7’’ pvc casing
4’’ pvc casing
4’’ pvc casing 6’’ pvc casing 6’’ pvc casing 6’’ pvc casing
6’’ pvc casing
Borehole diameter*1 (inch)
4 7/8’’ 5.5’’ 5.5’’ ~3.8’’ ~3.8’’ 5’’ 5’’ 5’’ 5’’
Rock type Classic Sherman
Classic Sherman
Classic Sherman
Sulfide-rich Sherman
Classic Sherman
Classic Sherman
Classic Sherman
Classic Sherman
Classic Sherman
DTW (m)*2
11.8 (8/15/2015) 11.03 (11/18/2015)
5.7 (9/11/2015)
11.7 (11/18/2015)
10.9 (9/11/2015)
13.18 from toc (9/8/2016) 12.645 bgs (8/31/2016)
11.835 from toc? (9/8/2016) 11.755 bgs (9/1/2016)
13.743 (12/8/2016)
12.947 (12/8/2016)
*1 This is diameter of the open borehole beneath the casing (see the diagram on previous page; also see caliper logs); *2 From top of casing (TOC) unless it is labeled as bgs (below ground surface); continuous WL monitoring is available since May, 2015. *3 No corings for BW 6, 7, 8, and 9. Note most shallow saprolite wells (Brady’s; Austin’s) in Blair Wallis were drilled using the backpack shaw drill.
Drilling method
air/water rotary +coring; airlifted;
air/water rotary +coring; not developed
wireline+coring (drilled with water); not developed
wireline+coring (drilled with water); airlifted;
wireline+coring (drilled with water); airlifted;
air/water rotary + downhole hammer*3
airlifted;
air/water rotary + downhole hammer; airlifted;
air/water rotary + downhole hammer; airlifted;
air/water rotary + downhole hammer; airlifted;
BW4
Upper Lone Tree Creek watershed
Upper Duck Creek watershed
Upper Goose Creek watershed
BELVOIR RANCH
Upstream flow stations Downstream flow stations Existing monitoring wells
Casper formation outcrop
A B C
Denver Basins: Belvoir Ranch Stream, Riparian, and Casper Aquifer Study
Belvoir Ranch: SW/GW Connectivity
0
20
40
60
80
100
120
1405/
165/
195/
215/
245/
275/
29 6/1
6/4
6/6
6/9
6/12
6/14
6/17
6/20
6/22
6/26
6/29 7/
17/
47/
77/
97/
127/
157/
177/
207/
237/
257/
287/
31 8/2Pr
ecip
itatio
n an
d S
now
Wat
er
Equi
vale
nce
(mm
)
SWE (mm) Precipitation (mm)
52
54
56
58
60
62
64
66
68
70
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
5/16
5/19
5/21
5/24
5/27
5/29 6/
16/
46/
66/
96/
126/
146/
176/
206/
226/
266/
29 7/1
7/4
7/7
7/9
7/12
7/15
7/17
7/20
7/23
7/25
7/28
7/31 8/
2
Gro
und
wat
er d
epth
(m)
Wat
er d
epth
in st
ream
(m)
Stream WL, upstream siteStream WL, downstream siteGround water depth at LTC Mon #1
Laramie Basin: Casper Recharge Study Granite interval: image & flowmeter logs
bgs (m)
inflow
outflow
Artesian (~13’ ags)
Granite flow at ~2 gpm
Head (~20’ bgs)
Sept-Oct, 2017: Hydraulic gradient exists for upward flow, thus a “sub-charge” to Casper
Geology of southern Wyoming
UW GG