Integrated Velocity Modeling by Water Table Imaging and Structural Smoothing in Yingxiongling, Qaidam Basin

Abstract

The Yingxiongling structural belt is located in the south of world's highest-altitude petroliferous basin, Qaidam Basin. It is well known for the extremely complicated topography and subsurface structure. Accurate velocity modeling and depth imaging is extremely difficult, as well as exploration and production in this area. Building a reliable initial model that accounts for both near-surface and subsurface structures is crucial. We first generate a geologically-guided subsurface velocity model by structural smoothing of the pre-stack time migration (PSTM) velocity guided by dip field. Furthermore, we take the water table, a typical geological phenomenon in Qaidam basin, into account for near surface modeling. With information regarding a stable and smooth water table, we achieve an optimum image predicting the trap, thus supporting exploration and production in the area.