Can We Surgically Remove Swell Noise

The weather is one of the main causes of down-time in marine seismic acquisition. When the swell noise generated by a rough sea reaches a given level, acquisition has to stop. When the weather gets even rougher the cables have to be pulled out of the water to avoid losing them. There is however a range of weather conditions during which shooting is safe but not performed because the amount of noise exceeds client specifications. The surgical removal of swell noise, that is to say the total elimination of noise and the full restoration of signal, would increase the level of noise that can be accepted, possibly to the point where shooting stops only when it is unsafe. This would significantly reduce acquisition downtime and therefore cost. Known noise attenuation techniques are applied on a test data set to check whether they fulfill the > condition. Although most of them fail to pass, a recently developed method called gives results that are sufficiently close to deserve the > label. The next step is of course to install an on-board procedure that will surgically remove swell noise using this technique, possibly in real time.