Cheaper and Better Long Offset Nodal Surveys Based on Low-Frequency Enhanced Sources

Summary The recent success of long offset nodal surveys in the Gulf of Mexico (GoM) for FWI based velocity estimation and subsequent RTM based imaging has rekindled interest in OBN survey designs. A major cost component of such surveys is the size of the source halo surrounding the nodal patch. For “regular” OBN surveys in the GoM, focusing on reflection imaging, the size of this halo can vary between 4 and 10 km depending on imaging objectives. Recent long offset nodal surveys in the GoM typically acquire much larger source halos in the order of 20–30 km to enable FWI based velocity estimation utilizing refractions off basement. In this abstract we will discuss options offered by a new generation of Low Frequency (LF) enhanced marine seismic sources for the design of more efficient long offset nodal surveys. The designs will retain much of the higher low frequency output of these sources, which is crucial for the performance of FWI in salt dominated environments.