Publications

A new approach to seismic acquisition has been tested in the southern Browse Basin during 2008 in an effort to remove both source ghost and receiver ghost effects from towed streamer data. Of particular relevance in the test area is the almost complete absence on conventional streamer data of coherent seismic events at depths greater than about two seconds two-way time (TWT). The new acquisition methodology has the potential to boost both low and high frequency content of seismic data and enable imaging in what has historically been considered to be one of the many “no seismic zones of the North West Shelf. A 100 km 2D line was acquired three times in a spatially-coincident manner during 2008: With a conventional source array and solid streamer, with a conventional source array and a dual-sensor streamer, and finally with a prototype “multi-level source array and a dual-sensor streamer. Receiver ghost removal arises from the dual-sensor streamer, and source ghost attenuation arises from the multilevel source array.Data in the depth range of two to at least four seconds TWT are now both coherent and strongly represented at most locations along the line on both dual-sensor streamer stacks. The most substantial improvements derive from also using the multilevel source array. The methods described have survey efficiency equivalent to “conventional towed streamer acquisition. Efforts are now ongoing to efficiently extend the methodology to 3D acquisition and processing.