In March/April 2011 Apache carried out an extensive series of seismicacquisition tests in Cook Inlet, Alaska, to evaluate the feasibility oflarge-scale, year-round 3D seismic acquisition in Cook Inlet, and to look atthe effectiveness of a nodal or autonomous seismic recording system compared toa conventional cable-telemetry system. An 18-mile seismic line startingonshore, crossing the tidal mudflats, and extending into the deeper water ofCook Inlet was acquired using multiple onshore and offshore source, receiver, and instrument types to establish the viability of a large-scale regional 3Dsurvey and the optimum source parameters for such a program. The location ofthe test line is shown in Figure 1.
Alaska's Cook Inlet Basin is a proven hydrocarbon-producing compressionalfore-arc basin with 1.3 billion barrels of oil and 8 TCF of gas produced, andapproximately 1 billion barrels of oil and 21 TCF of gas yet to be found, according to the USGS and BOEM. Since the expansion of exploration andproduction activity on Alaska's North Slope in the 1980's there has been littleexploration activity in Cook Inlet; small 2D and 3D seismic surveys havegenerated leads for the small number of wells drilled in the area during thistime. The majority of these seismic surveys had been either exclusively onshoreor offshore, with only a handful of transition zone surveys crossing theshoreline, and all acquired in the short window of a single season. To makelarge-scale regional seismic surveying a reality, a single crew, equipped tooperate year-round, would be needed.