Hydraulic and Water-Quality Characterization of Fractured-Rock Aquifers Using Borehole Geophysics

Transcription

1 Hydraulic and Water-Quality Characterization of Fractured-Rock Aquifers Using Borehole Geophysics John H. Williams Office of Ground Water Troy, New York

2 Flow in Open Borehole Runkel and others (2003)

3 Ambient Flow Edwards carbonate-rock aquifer, Texas

4 Ambient Flow REGIONAL DENSE MEMBER Edwards carbonate-rock aquifer, Texas

5 Ambient Fluid Log and FW/SW Interface Fresh Water Saline Water Edwards carbonate-rock aquifer, Texas

6 Pumped Fluid Logs Edwards carbonate-rock aquifer, Texas

7 Pumped Fluid Logs and FW/SW Interface Fresh Water REGIONAL DENSE MEMBER Saline Water Edwards carbonate-rock aquifer, Texas

8 Flow and Fluid Logging under Ambient and Pumped Conditions Deep borehole in TCE source area, cased to 155 ft Flow zones at 201 and 312 feet Downward ambient flow Pumped flow 80% 201 feet 20% 312 feet Cretaceous sandstone aquifer, southern California

9 201 FOOT ZONE Bedding fractures Intermediate angle fractures High angle fractures Bedding fracture 312 FOOT ZONE

10 Flowmeter Detects Most Transmissive Flow Zones

11 CORE ANALYSIS MATRIX DIFFUSION - High TCE in the matrix near the 201-foot zone No TCE in the matrix near the 312-foot zone :

12 CROSS CONTAMINATION - Ambient Pumped TCE point samples :

13 CROSS CONTAMINATION - TCE Monitoring Dec Jun Jan : Sterling(1999)

14 Central New York 7-mile VOC plume in Silurian-Devonian carbonate-rock aquifer RCRA site Surface-water drainage divide Union Springs wells 1988 Detected DCE ug/l DCE RCRA site 1990s TCE in shallow bedrock 2000 Vacuum extraction Union Springs wells

15 RCRA EPA Domestic

16 Corehole 181 Stratigraphy Bentonite Phosphate clasts Characteristic gamma signature in Silurian-Devonian carbonate rocks Shaley dolomite Gypsiferous

17 Borehole-Wall Images ATV OTV BERTIE FLOW ZONE

18 Flowmeter Log Analysis Flow, in gal/min ONONDAGA FLOW ZONES BERTIE FLOW ZONE

19 SC Flow, in gal/min Corehole 219 ATV OTV Temp ONONDAGA FLOW ZONES RONDOUT FLOW ZONE BERTIE FLOW ZONE

20 Head, in Feet Discrete Zone Heads in Well 181 ONONDAGA FLOW ZONES UPPER MANLIUS CONFINING UNIT RONDOUT FLOW ZONE BERTIE FLOW ZONE

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22 Stratigraphy and Discrete Zone Heads N S ELEVATION, IN FEET HEAD, IN FEET FT

23 Recharge and Head Response Well 183- Bertie zone Well 204- Rondout zone

24 RCRA site

25 OTV Head, in Feet Discrete Zone Heads in Well 222 ONONDAGA FLOW ZONES UPPER MANLIUS CONFINING UNIT RONDOUT FLOW ZONE BERTIE FLOW ZONE

26 Advances in Flow Log Analysis

27 Flow Logging and QW Point Sampling in Production Wells Floridan carbonate-rock aquifer

28 Specific Ion logging Cal Flow Sp Cond Temp Nitrate Chloride Trans & Head Crystalline-rock aquifer, southeastern New York

29 FRACTURE GEOMETRY, TRANSMISSIVITY, AND STORAGE

30 LOCATION OF SITE AND HYDROGEOLOGIC FRAMEWORK FT North L-20 L-19 L-18 L-17 L-21 S-15 S-14 S-13 S-12 L-19 S-12 EXPLANATION Lockatong lithostratigraphic unit Stockton lithostratigraphic unit Mesozoic clastic-rock aquifer, Newark Basin

31 CROSS-HOLE FLOW TEST IN MUDSTONE 15BR 68BR FT North L-20 L-19 L-18 L-17 L-21 S-15 S-14 S-13 S-12 EXPLANATION Extraction well Corehole

32 GEOPHYSICAL LOG AND HYDRAULIC ANALYSIS 0 Gamma FWS OTV ATV Flow, in gal/min Trans, in m 2 /s Head, in ft ft 2 /d 40 Depth, in feet 80 5 ft 2 /d ft 2 /d 160 Corehole in Mesozoic mudstone, Newark Basin

33 CROSS-BOREHOLE FLOW TEST DESIGN 150 Well 15BR Corehole 68BR Altitude, in feet Carbon Rich Mudstone Laminated Dark Gray Mudstone Massive Red Mudstone Weathered Bedrock Surface Intermediate zone Closed interval Open interval & Identification A Shallow zone B C D E F L-20 L-19 L-18 L-17 Massive Light Gray Mudstone L Distance, in feet

34 5 Pump off Pumped 9.2 gal/min 30 Minutes Pump off 68BR <0.05 FT Depth to water level, in feet BR 7 FT 15 WATER-LEVEL RESPONSE

35 TRANSIENT FLOW RESPONSE IN COREHOLE 68BR 0 Change in flow, in gal/min Measured Simulated Simulated Shallow Zone Isolated and Intermediate Zone Connected Elapsed time, in minutes BETWEEN SHALLOW AND INTERMEDIATE FLOW ZONES

36 CROSS-BOREHOLE FLOW TEST RESULTS 150 Well 15BR Corehole 68BR Altitude, in feet Carbon Rich Mudstone Laminated Dark Gray Mudstone Massive Red Mudstone Weathered Bedrock Surface Intermediate zone Closed interval Open interval & Identification A Shallow zone B C D E F L-20 L-19 L-18 L-17 Massive Light Gray Mudstone L Distance, in feet

37 SUMMARY Borehole geophysics provides critical hydraulic and water quality information for fractured-rock investigations Borehole-wall images and other logs help define the lithologic, stratigraphic, and structural framework Borehole-flow logs under ambient and stressed conditions are used to estimate zone transmissivity and head Cross-borehole, transient flow tests are used to evaluate the hydraulic connectivity of the zones Borehole-fluid logs and point samples provide insights into zone water quality and cross-contamination Newly developed specific-ion tools for logging dissolved oxygen, chloride, and nitrate