Modelling and Imaging Through a Gas-Obscured Zone in Malaysia

Summary We demonstrate using viscoelastic modeling followed by dual velocity RTM imaging that ocean bottom node (OBN) survey is needed in a gas-obscured zone in Malaysia. Scattering caused by “geobodies” filled or partially filled with gas will distort the P-wave propagation. S-wave, on the other hand, is less sensitive to the geobodies, and therefore has a good chance for imaging through gasobscured zones. However, when intrinsic Q (or attenuation) is present in the overburden, the ability of PSconverted wave imaging will be degraded. The reliability and resolution of PS-converted wave imaging also depends on the accuracy of velocity models used for RTM imaging.