Joint Study of 3D-VSP and Surface Full-azimuth Seismic in Northeast China

Great progress have been made on VSP techniques in recent years, especially the improvement of downhole geophone manufacture and VSP data processing methods. In XJWZ area of Daqing oil field, the reservoir is mainly formed by volcanic and its distribution is complex due to many periods of volcanic overlap in this area. Before this project is conducted, seismic surveys are mainly 2D and narrow azimuth 3D which are not suitable for anisotropy analysis and fracture identification. Therefore, a joint survey of 3D-VSP and full-azimuth surface seismic was implemented. This project tries to combine the advantages of VSP and surface seismic by 3D-VSP and full-azimuth surface seismic simultaneous survey. Q factor and anisotropy parameter estimated from VSP are applied to 3D seismic processing. Reservoir characterization and gas saturation prediction with final images shown encouraging results. Suggested well has been drilled and wet gas has been founded, so the validity of this method has been proved.