Complex Geologic Modeling Using Walkaway-VSP Imaging: a Case Study from Jiuquan Basin,China

Complex structure, fragmentized strata and the lack of drilling data make it difficult to modeling geological structure in the complicated structural belt. Dispite some oilfield had completed the large area 3D-seismic with high-steep structures, the imaging at structural main portion still necessary to improve. In recent years, we realized that borehole seismic have the natural advantage in observation of the high-steep targets. In this paper, we implemented a synchronous dual-well acquisition Walkaway-VSP with large array geophone in Jiuquan basin. And then we studied the complex geologic modeling with Walkaway-VSP imaging. Finally, we formed a system of complicated geological modelling with overthrust nappe stratum based on high quality Walkaway-VSP imaging. It is a very useful application of borehole seismic technology in complex areas.