GGS planning Schrader Bluff seismic

Global Geophysical Services Inc. plans to conduct a 3-D seismic survey this winter in the Schrader Bluff region of the North Slope on behalf of Repsol E&P USA Inc.

The proposed Schrader Bluff 3-D Seismic Survey would cover some 293 square miles of state land located immediately south of the Prudhoe Bay and Kuparuk River units.

The region is home to decades of previous drilling, including wells by ARCO, ConocoPhillips, Eni Petroleum and Mobil. Other leaseholders in the proposed coverage area include Great Bear Petroleum and the Kuparuk River unit working interest owners.

Repsol had previously said it plans to drill the Tuttu No. 1 exploration well in the Schrader Bluff region this winter, but declined to describe its target for the well.

Global Geophysical Services plans to conduct the survey using weatherized rubber-tracked vibrators and a nodal recording system to detect and record seismic waves. A technology called “slip-sweep” allows multiple vibrators to operate at the same time.

The company described the program as having “multiple reservoir targets.”

The state is taking comments through Jan. 9, 2014.

—A copyrighted oil and gas lease map from Mapmakers Alaska was a research tool used in preparing this story.

—Eric Lidji