DOG approves Great Bear seismic survey to cover 450 square miles

Alaska’s Division of Oil and Gas has issued a permit, approving Great Bear Petroleum Operating LLC’s 3-D seismic survey, planned to be carried out this winter on the North Slope. The survey, to be conducted by Geokinetics Inc., will cover an area of about 450 square miles immediately south and southwest of Deadhorse.

The new survey comes as part of Great Bear’s search for drilling targets in its North Slope acreage. In 2010 the company purchased a broad swathe of state leases along a fairway to the south of the central North Slope, to pursue the possibility of producing oil directly from the prolific oil source rocks of northern Alaska. The company has since expanded its lease holdings in the same general area and modified its exploration strategy, using high-resolution 3-D seismic surveying both to identify potential “sweet spots” for source rock development and to locate conventional oil prospects.

In the summer and fall of 2012 the company drilled two wells off the Dalton Highway, to the south of Deadhorse, and acquired rock core from oil source rocks penetrated by these wells. And last winter the company drilled a third well, the Alkaid No. 1 well to the west of the Dalton Highway - testing has yet to be conducted on that well.

Since the winter of 2012 Great Bear has been conducting annual seismic surveys, progressively covering its North Slope acreage as part of its exploration strategy. The company has also carried out LIDAR - light detection and ranging - surveys, to construct detailed topographic maps of its acreage, to enable the efficient planning of ground operations.

According to DOG’s permit approval documentation, this winter’s seismic survey will involve the use of 12 to 14 tracked vibrators as seismic sound sources, supported by tracked cable trucks and Tucker SnoCats. Vibrator sound source lines will run north to south in the survey area, with lines being placed 500 to 800 feet apart. At any one time, 20 to 26 seismic sound receiver lines may be place on the ground, with groups of one to three geophones placed along each line.

- ALAN BAILEY