The Ocean-bottom Recording Trade-off

De Kok, R.

The Leading Edge
August 2006

Abstract

Ocean bottom systems (OBS) have developed from a solution for shallow water data gathering into a versatile method, potentially solving a variety of special seismic problems. However, more than two decades later it can be stated that OBS methods have not lived up to expectations. There are two conditions that need to be satisfied before OBS can be developed into a cost effective, and more commonly accepted technique for seismic acquisition data quality and acquisition efficiency. Currently, only high accuracy, or only high efficiency can be achieved but not both. It is here proposed to solve the efficiency limitation through the deployment of streamers. Also the quality can be increased with the deployment of a higher number of receiver stations. Further the coupling may be improved by depressing the streamer onto the consolidated sediments. A speculative method for a streamer, tunneling through the unconsolidated mud-layer, is presented. Traditional OBS streamers also have the disadvantage of rotating when excited in the perpendicular direction. This causes cross-feed of wave propagation modes. In order to reduce the effect of the rotation of the streamer flat streamers may be used. Another novel and speculative concept introduced to remedy the multi component cross-feed is to measure the rotation and to compensate for its undesired effect on the lateral signal components. .