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PERMIT #: M-1980-047 <br />INSPECTOR'S INITIALS: THM <br />INSPECTION DATE: October 22, 2010 <br />OBSERVATIONS <br />This inspection was conducted as part of the normal monitoring program established by the Colorado Division <br />of Reclamation, Mining and Safety (DRMS). <br />This was a partial inspection with the primary focus to observe the locations of the four proposed hydrology <br />monitoring wells associated with Technical Revision 13 and to observe the results of the Electrofrac field <br />testing which is conducted inside of the north and south drifts of the Colony Mine. No other components of the <br />mine were inspected on October 22, 2010. <br />A technical revision to expand the hydrological monitoring program was submitted to the DRMS September 28, <br />2010. The purpose of the inspection was to observe the proposed water quality monitoring well locations. <br />Three B-Groove Aquifer monitoring well locations were observed on the bench above the mine drifts. The <br />wells are located immediately downgradient of the Electrofrac experiment. A fourth monitoring location was <br />observed downgradient of the mine bench, the monitoring well will be drilled into the alluvium. All well <br />locations appeared to be appropriately placed to adequately monitor groundwater conditions. Also included in <br />TR-13 are four to eight A-Groove aquifer drain holes that are intended to divert water from the A-Groove up- <br />gradient of the Electrofrac experiment zone to the mine incline and out the existing mine drainage network. <br />Technical revision No. 13 was approved November 2, 2010. <br />During the inspection ExxonMobil was conducting mid-level testing of the EF-1 and/or EF-3 Electrofracs. The <br />approved testing temperature was increased to 300°F with the approval of TR-12 September 16, 2010. On <br />September 29, 2010 a high voltage test was conducted on the EF-1 propped fracture. The duration of the high <br />voltage test was approximately two hours. The purpose of the test was to determine if the propped fractures are <br />robust enough to endure high voltage. The EF-1 test was reported to be a success and the fractures within the <br />rock were determined to be thermally conductive to the testing limits of 300°F. The high voltage test on the <br />EF-3 propped fracture was conducted September 30, 2010. The test lasted for approximately one hour before <br />the test was cut short when a very low flow of gas was observed venting from the EF-3 casing. Carbon <br />Monoxide was detected with a gas detector and the high voltage test on EF-3 was immediately terminated. The <br />operator also stated that a minimal amount of liquid exited the EF-3 casing after the September 30,' 2010 event. <br />The liquids collected were observed during the inspection. The liquids had a slight hydrocarbon odor and a <br />yellowish color along with an oily sheen. Samples were collected from EF-3 and sent to a laboratory for <br />analysis. The results have not been provided to the DRMS as of the date of this inspection report November 5, <br />2010. It is suspected by the DRMS that a small volume of oil shale had been partially pyrolized due to a "hot <br />spot" near the EF-3 casing. It was noted that temperatures during the EF-3 high voltage test were not recorded <br />above the allowed 300°F by the temperature monitoring system. Due to temperatures not being recorded above <br />300°F, the extent of the "hot spot" is suspected to be an extremely localized event and a very low volume of oil <br />shale was potentially converted to gas and liquid hydrocarbons. It is also noted that the EF-3 propped fracture is <br />still operational and currently undergoing mid-level testing during the inspection. Furthermore, the DRMS has <br />determined that the amount of potential hydrocarbon gas and liquid released during the high voltage test was <br />apparently not released in quantities sufficient to adversely affect human health, property or the environment. <br />Responses to this inspection report should be directed to Travis Marshall at the Division of Reclamation, <br />Mining and Safety, Grand Junction Field Office, 101 South 3rd Street, Room 301, Grand Junction, Colorado <br />81501, phone no. (970) 241-2042. <br />Page 2 of 4