Recording of ocean‐bottom seismometer (OBS) data has several advantages over conventional near‐surface recording. Because of their deployment on the sea floor, OBS are less vulnerable to noise and disturbances in the water column and thus have a relatively higher signal‐to‐noise ratio. OBS also offers wide‐azimuth (WAZ) and full‐azimuth (FAZ) geometries, which are important for imaging the complex structures such as salt domes. Vertical seismic profile (VSP) reflection surveys help to define a salt‐sediment interface near a wellbore by using offset sources. VSP with circular shooting has been using for 3D imaging near the borehole. VSP itself, however, still has some limitations such as poor offset and angular coverage per bin and limited total bin fold. This imaging limitation in the VSP can be lessened by combining ocean‐bottom seismometers on the sea floor with the VSP borehole survey. We show a number of model examples using combined borehole and ocean‐bottom recordings to improve azimuth, offset and fold distribution. Survey designs were created in OMNI 3D to compare and examine.

We use 10 concentric circles separated by 200m and 50m shot interval to create circular shooting geometry. Same shooting geometry was used to create joint VSP and OBS survey. The results show that the joint VSP and OBS survey has better fold, offset and azimuth distribution than VSP itself.