Modeling and Imaging through a Gas-Obscured Zone in Malaysia

Zhu, Xianhuai (ConocoPhillips) | Sood, Sanjay (ConocoPhillips) | McMahon, Tim (ConocoPhillips) | Brewer, Joel (ConocoPhillips) | Keys, Robert (ConocoPhillips) | Mosher, Chuck (ConocoPhillips)


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 PSconverted wave imaging also depends on the accuracy of velocity models used for RTM imaging.