EPA Region 4 has been involved in plugging abandoned oil wells in and around Boyd's Creek south of Glasgow, Kentucky since 1983. The Boyd's Creek III Site consists of a karst spring that discharges oil and high-sulfur water to the creek on a 50 acre farm along Oil Well Road south of Glasgow. An oil containment and collection system was established in the mid 1990's and has been maintained through an Interagency Agreement with the Tennessee Valley Authority on a monthly basis.
The leaking wells have been the result of historically poor drilling and plugging techniques combined with the particular hydrogeologic conditions in the area. The present oil discharge appears to be the result of one, or several improperly abandoned oil wells. In August 2004, as a result of a geophysics survey conducted by EPA ERT, two additonal abandoned oil wells were discovered upgradient of the spring and successully plugged.
During 2014, the National Pollution Fund Center encouraged EPA Region 4 to conduct additional efforts at closing this Site since it has been an ongoing response since the 1995. To assist in this effort, the OSC tasked EPA ERT to conduct a second geophysics survey to further assess the area upgradient of the current oil collection system. In June 2014, EPA ERT's Greg Powell and technical contractors from SERAS conducted the survey. The primary objective of the survey was to map lateral variations of soil resistivity/conductivity to identify areas of low resistivity (high conductivity) that might be related to oil-associated brine emanating from improperly plugged oil wells. A second objective was to map the subsurface geology to identify natural conduits, such as fractures and dissolution features. A report summarizing these assessment findings was submitted to the OSC during the week of Jan 19th, 2015. (Documents Section - SERAS report and Figures Attachment)
Based on the findings of the geophysics study, two new anomalies were found which warranted further investigation. (See Figure 8 of Figures Attachment in Document Section) .
During the week of November 9th, ERRS and the oil well service subcontractor began plugging operations at the recently found subsurface oil well at Boyds' Creek, south of Glasgow, KY. As of November 11th the oil well service subcontractor successfully milled to 140 feet and the well depth was reportedly 250 to 270 feet. The contractor was initially unable to circulate drilling fluids to land surface because of Karst zones, which required the continuous milling with drilling mud (betonite clay). The OSC planned to mill to 250 feet, run a geophysical well log to identify oil producing zones, then plug and cement the well.
On November 12th and 13th, ERRS and the oil well service subcontractor continued plugging operations. The contractor drilled to a depth of 190 feet with drilling mud and observed cement shavings indicating the well had been previously cemented. No oil was observed during any phase of drilling down hole indicating the well had been properly cemented. The well was logged showing the corniferous oil producing zone at 150 feet, and the OSC directed ERRS to cement the well to land surface. The OSC will continue to assess the farm with EPA ERT for additional bore holes in an effort to find the source of crude oil.
Once that effort is completed additional geoprobing and conductivity assessment activities for the deeper anomaly near the crest of the hillside may be indicated.
After successfully plugging the new anomaly in November 2015, the OSC and TVA will continue to monitor the oil collection system for any variance in the amount of crude oil collected. Additional geoprobing and conductivity assessment activities for the deeper anomaly near the crest of the hillside may be indicated for the second anomaly found by EPA ERT and its contractor. .
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