2010-09-28_REVISION - M1980047 (2)

Home Browse Search

General Project Description: ExxonMobil Upstream Research Company ( "URC "), a subsidiary of Exxon Mobil Corporation, has an ongoing research program into oil shale conversion technology. This process involves fracturing the oil shale rock using conventional oil well fracturing techniques, injecting a proppant that will conduct electricity within the fractures, and establishing an electrical current within the propped fracture which may be used to heat the rock resistively. Revision Description: This Technical Revision to State of Colorado Mined Land Reclamation Board Permit No. M- 1980 -047 requests approval to: 1) Drill four (4) additional water monitoring wells, to expand ExxonMobil's existing water monitoring program. Attachment B includes survey plats, wellbore sketches and reclamation cost information. Three (3) of these water monitoring wells (EF- V2, EF -V3 & EF -V4) will be drilled from the currently unused road above the mine bench and will sample the B- Groove (assuming the presence of water). These wells will be approximately 170 feet total depth and will provide a "sampling fence" directly down - gradient of the Electrofrac experiment volume. One (1) monitoring well (EF -AW 1) will be drilled into the alluvium, down - gradient of the mine bench and will be approximately 300 feet total depth, depending on the depth of the water table. 2) Drill four (4) to eight (8) water drainage holes from the inclined shaft in the mine. These holes will drain water from the interval between the Mahogany Marker and the A- Groove. Attachment C describes the locations and lengths of four drainage holes ExxonMobil plans to drill initially. Based on the results of these drain holes, up to four additional holes may be drilled as needed. Drainage holes will be 2 -3/8 inches in diameter, and will be cased only if necessary. Drainage holes will penetrate the Mahogany Marker to A- groove interval west of the current Electrofrac experiment volume. While water mobility throughout the Mahogany zone is low, these drain holes will provide an additional preventive measure to keep water from entering the experiment volume. This is a prudent idea for both ongoing and planned experiments in the mine. Water from the drainage holes will be ducted into the mine outflow. Ground and Surface Water Monitoring: While the probability of any impact to ground or surface water from the experimental work is extremely small, ExxonMobil has nevertheless implemented a program of water monitoring to allow early detection of any impacts, should they occur. The program focuses on the Mahogany zone at and around the location of the commercial mine site. Technical Revision Submittal