AOGCC fines Great Bear over drilling test

The Alaska Oil and Gas Conservation Commission has proposed fining Great Bear Petroleum Operating LLC $20,000 for not correctly pressure testing the surface casing of the Alkaid No. 1 exploration well that the company drilled this winter. Great Bear is conducting a drilling program to evaluate the potential for source-rock oil development and to seek conventional oil targets near the Dalton Highway south of Prudhoe Bay.

The commission said that Great Bear did not follow the required procedure for carrying out a leak-off test after completing the surface casing of the well. A leak-off test ensures that the well structure can withstand and contain a pressure kick from an unexpected influx of gas or fluid from a rock formation.

AOGCC says that, when the drillers at the Alkaid well conducted the test, a significant change in pumping rate midway through the test impacted the quality of the test data and contradicted the validity of the test result that Great Bear reported to the commission. Moreover, Great Bear’s kick tolerance calculations were not realistic, the commission says. And the test result required in Great Bear’s permit to drill the Alkaid well was not achieved, the commission says.

The commission says that Great Bear has offered four reasons for the problems with the testing: a drilling rig crew improperly training in the test procedure; a perception by Great Bear staff that it was not necessary to notify the commission about the testing anomalies because they believed that the test results met the minimum safety margin; a belief that the test result was acceptable because the well’s total depth had been reduced; and a view that coal seams below the surface casing could explain the lower-than-expected test result.

The commission says that any changes to the parameters in a drilling permit require commission approval.

- ALAN BAILEY