PS-wave seismic data: A game changer in exploration and monitoring

Abstract

In this presentation we show, using field examples, that quantitative inversion for S-impedance can be substantially improved using PS-wave data in conventional PP-wave amplitude variation with angle (AVA) inversion. For exploration improvement in S-impedance or the second AVA parameter, this can better identify reservoir rock and fluid properties. However, the value of an improved S-impedance can truly be observed and appreciated on time-lapse (4D) reservoir monitoring data and how it impacts discrimination of saturation and pressure changes. We see that with joint PP/PS inversion, the 4D S-impedance is better estimated and not coupled to 4D P-impedance, compared to using PP inversion alone. These claims are demonstrated on synthetic and several field data. We conclude that joint inversion is in fact extremely valuable and can lead to a larger chance of success in placing exploration and development wells. Given this business value, we should work to develop it as a standard industry practice.