Converted-wave Imaging Challenges Available to Purchase

Multi-component (MC) seismic data acquired with both P-and S-wave objectives is an expensive technology, and rarely acquired over large areas where P-wave imaging and characterization has been or is likely to be successful. Despite early success with P-to-S (PS) converted waves as recently as the mid-90s progress has been slow, and use of MC seismic is therefore not widespread. We are usually faced with the reality of applying a developing technology (and fairly immature compared with the history of P-wave applications) in the toughest areas, where other cheaper technologies have failed. Complications specific to PS propagation are varied, and not always intuitive. As the combination of issues vary from place-to-place this can result in a difficulty to compare objectively the success of MC projects in the industry. Data analysis and forward modelling from BP''s Caspian Sea MC seismic data illustrate some of the issues faced by processing and model building for converted waves in complex settings. Mud volcano-related features once thought to act like gas clouds to P-waves complicate propagation and are not invisible to PS waves.