ANWR seismic is planned
SAExploration, ASRC and KIC proposed to survey 1002 area over two winter seasons
SAExploration Inc., Arctic Slope Regional Corp. and Kaktovik Inupiat Corp. have filed with the federal Bureau of Land Management a plan for a proposed 3-D seismic survey program in the 1002 area of the Arctic National Wildlife Refuge. The program, referred to as the Marsh Creek 3-D, would encompass the entire 1002 area, an area of some 2,600 square miles in the ANWR coast plain. SAExploration, the proposed operator for the survey, anticipates the survey program taking two winter seasons to complete.
Did you find this article interesting?
BLM is in the process of developing an environmental impact statement for the conducting of oil and gas lease sales in the 1002 area. However, existing seismic data for the refuge is old, is widely spaced and is 2-D rather than 3-D. Companies interested in bidding in a lease sale would presumably want modern seismic data, to evaluate tracts to bid on. Geologists have indicated that, especially in the relatively undeformed western part of the 1002 area, high resolution seismic data would be beneficial in identifying subtle oil and gas traps in the subsurface.
Two crews over two wintersThe survey plan says that SAE anticipates supporting two seismic crews for the survey operations during each of the winter seasons that the survey program takes to complete. During each season, surveying would start about Dec. 1 and end on May 31, or at the time when winter off-road tundra operations must end. On state land on the coastal plain of the central North Slope, seismic survey operations are commonly conducted during the winter off-road tundra travel season, when the snow cover and frozen ground protect the tundra from damage. Vehicles and equipment used are of designs that can avoid impacting the tundra.
The Marsh Creek survey plan says that the survey program will minimize any impacts on the environment by using technology that can minimize the number of vehicles deployed on the tundra; the use of articulated, rubber tracked, low ground pressure vehicles; reducing vehicle sizes; and using systems that minimize the risks of hydrocarbon spills from the vehicles.
Vibrator equipmentA modern seismic survey of this type typically uses surface vibrator equipment to generate the subsurface sounds that will echo off subsurface structures. The Marsh Creek plan anticipates the use of rubber tracked or buggy vibrator equipment, together with wireless, autonomous nodes for recording the seismic signals. Vibrator source points would be located at 41.25-foot intervals on source lines, with geophone nodes located at 165-foot intervals on receiver lines running perpendicular to the source lines. The source and receiver lines would be spaced about 660 feet apart. And up to 20 receiver lines could be place on the ground at any one time.
Vibrators will only operate on snow covered tundra or grounded sea ice. And a vibrator will only have to traverse each source line once.
Crews will lay out the wireless recording nodes either by foot or through the use of rubber tracked, tundra-approved vehicles, the March Creek survey plan says. Recording operations will be conducted 24 hours per day, using two 12-hour shifts, the plan says. SAE has a wildlife interaction plan that includes protocols such as reporting the sightings of polar bears to the U.S Fish and Wildlife Service, the plan says.
A specialized vehicle or snow machines will use technology including ground penetrating radar to check for the integrity of ice in the area of a seismic operation. And the plan includes a protocol for avoiding damage to areas with willows. SAE plans to use temporary airstrips on frozen lakes or appropriate tundra for conducting crew changes, to save several hours of ground travel.
Environmental organizations opposedEnvironmental organizations are adamantly opposed to any oil and gas related activity in the 1002 area. The Alaska Wilderness League slammed the proposed seismic operations, citing still visible scars from surveying conducted in 1984 and 1985 and claiming that the surveying activities will involve “convoys of 30-ton thumper trucks and bulldozers traveling over extensive areas of fragile tundra.”
“This is the polar opposite of what was promised by drilling proponents,” said Adam Kolton, executive director of the Alaska Wilderness League. “Instead of a small footprint and a careful process, they want to deploy a small army of industrial vehicles and equipment with a mandate to crisscross every square inch of the refuge’s biological heart.”
There have been press reports that the U.S. Fish and Wildlife Service is dissatisfied with the seismic survey plan, saying that the plan does not contain sufficient specific detail for an adequate agency review. Apparently the Washington Post obtained a copy of the Fish & Wildlife response. Although BLM is administering oil and gas related activity in the 1002 area, Fish and Wildlife manages ANWR as a whole and maintains a conservation plan for the refuge. SAE will require an incidental harassment authorization from Fish and Wildlife for the unintended disturbance of polar bears. An IHA normally spells out mitigation measures required to minimize wildlife impacts.
Print this story | Email it to an associate.
Tweet it||Digg it|
Click here to subscribe to Petroleum News for as low as $89 per year.