Marine Seismic Acquisition using Autonomous Marine Vehicles Towing 3D Sensor Arrays

Abstract

Abstract Marine seismic data is typically acquired by using towed-streamers due to their high efficiency, easy implementation, and narrow-azimuth (NAZ) acquisition geometry. This method usually results in good-quality seismic data for noncomplex geological environments and is a well-established methodology. However, this method is limited in obstructed areas or in areas with very shallow water where streamer vessels cannot be used. We present two field tests of autonomous marine vehicles (AMVs) equipped with 3D seismic sensor arrays to record marine seismic data concurrently with OBC seismic acquisition missions ongoing in the same area. The field tests evaluated the operational aspects of the AMVs and demonstrated that the vehicles equipped with 3D arrays can be used to acquire seismic data that is usable and comparable with seismic data obtained from the associated ocean-bottom cable (OBC) surveys. The vehicles proved their ability to hold station and record and transmit QC data back to the survey vessel. The ability to use the vehicles to acquire data in areas previously hard to reach opens the door to potentially deploy the vehicles during streamer surveys to acquire data with offset in excess of 20 km. Shots can be recorded by the vehicle placed at predetermined locations to record ultra-long offset data, which can assist in building velocity models with full waveform inversion. The AMV is capable of carrying out a number of functions over a longer time frame and at lower cost than when using traditional methods. Its ability to maintain position in a holding area or travel to a new location, when needed, through GPS coordinates optimizes seismic surveys without compromising results. As offshore exploration and production move into deeper and more remote areas, the seismic industry can increasingly rely on autonomous vehicles for support.