Research on improving conventional marine seismic streamer data imaging quality using OBS data from Northern South China Sea

• Using time-slice method to accurately relocate the OBS position the sea floor
• Using the RayInvr software to inverse the P wave velocity
• Using the inverted velocity to improve the imaging quality of streamer seismic data

It is very important to convert the seismic data from the time domain to the depth domain. Here we discuss the approaches of inverse modeling of travel times for determination of the P-wave velocity (Vp) using OBS data, and also using the inverted velocity to improve the conventional marine seismic streamer data imaging quality. The migration section of the single channel seismic data is used to define the model horizons and help to control their geometry. Wide angle hydrophone data of OBS are used to determine P-wave travel times. The picked travel times from various shots are inverted for P-wave interval velocities using RayInvr, which calculated theoretical travel times via ray tracing. Damped least squares optimization is performed to fine tune the fits between observed and calculated travel times. In the end, two conventional marine seismic streamer data's migration sections are compared and the result shows that the section using the inverted velocity of OBS data is much better than that using the velocity of conventional velocity analysis method to the streamer data.