Seismic data acquisition using Ocean Bottom Seismic nodes at the Deimos Field, Gulf of Mexico

Abstract

Seismic data acquisition using Ocean Bottom Seismic (OBS) nodes was conducted over the Deimos field in the Gulf of Mexico, in about 1000m of water. The field is located under a salt overhang. Wave equation modeling was used to determine the optimal location of the nodes. The ability to acquire data at very long offsets was particularly useful. Seismic operations proved to be flexible in an area with considerable surface and subsea infrastructure, operational interference and strong currents. As the market for OBS node technology develops and more surveys get acquired in the future, it is expected that operational best practices will lead to increased efficiency in the field. Pre‐processing of the data included node positioning, timebreak alignment, and optimized wavefield separation and noise attenuation on vertical geophone data. Migration of the downgoing wavefield data proved to be successful down to the target depth. Processed results achieved to date show significant improvements in sub‐salt imaging compared to existing narrow azimuth data.