Estimating S-wave statics from a PS-receiver-stack image

Abstract

Estimating converted-wave (S-wave) statics is a tough challenge in reality but crucial for the final success of PS-wave processing and imaging. We introduce a novel and practical method to directly estimate S-wave statics from a PS-receiver-stack image. Before a PS dataset is stacked to a PS-receiver-stack image, available source-side P-wave statics and common-conversion-point normal-moveout (CCP-NMO) correction are applied, so we only need to estimate an S-wave static value for each trace in this PS-receiver-stack image. For the corresponding PP dataset, the PP-receiver stack is generated by stacking the NMO corrected gathers with both source- and receiver-side P-wave statics applied. We pick out a target event on the PP-receiver-stack image and convert it to a PS-guidance structure via available P-to-S velocity conversions. Since the target PS event on our PS-receiver-stack image only has source-side P-wave statics applied, the time differences between this PS-guidance structure and the target PS event on the PS-receiver-stack image are actually the outstanding receiver-side S-wave statics. By aligning this PS target event to its corresponding PS-guidance structure, we thus retrieve the S-wave statics for this PS dataset. We use a challenging field dataset as an example to demonstrate the robustness of our new S-wave statics estimation method.