Fully distributed fiber-optic streamer with small channel spacing for marine seismic acquisition

In this paper, a lightweight and fully distributed fiber-optic streamer with small channel spacing based on the distributed acoustic sensing is developed and demonstrated for the marine seismic acquisition. The bendinsensitive backscattering enhanced optical fiber evenly wound around the sensitization material is employed as the sensing fiber, and a rigid mandrel with high tensile strength is applied in the center of the sensitization layer to guarantee the towed work. Through optimizing the structural parameters with the theoretical and simulation analysis, an excellent frequency response from 5 Hz to 2 kHz with high sensitivity around -137 dB re :1 rad/(mu Pa m) and slight fluctuation less than 4 dB is demonstrated in the experiment. In the sea trial, the seismic profile with a high lateral resolution of 0.5 m along the 20 km survey line is obtained, in which the continuity of the seismic event is good and the reflections of the stratum more than 1.1 s below the seabed are clearly visible. In general, the proposed novel lightweight and fully distributed fiberoptic streamer has shown immense potential to achieve the marine seismic imaging with high lateral resolution, which can provide richer information for the accurate reservoir prediction.