Low Frequency Marine Acquisition

A low frequency marine towed streamer acquisition experiment was conducted in deep-water offshore Gabon. Data were acquired during two vessel passes along a 2D test line using a tuned and detuned source and solid streamer towed at 9m and 15m, respectively. Frequency analysis of shot records and 2D brute stacks clearly show an enhancement of low frequency reception on the receiver side by lowering the tow depth of the streamer from 9m to 15m. This result is as expected. The use of a detuned air-gun array, however, showed a significant increase of low frequency energy on the signal side, even with the streamer at a 9m tow depth. These results suggest that the source and receiver components of the towed streamer acquisition system can be “tuned” to provide the optimum signal-to-noise in areas where low frequencies are critical to the seismic imaging effort.