Imaging study of shallow complex fault blocks in Xingzhuang area, Biyang sag

Xinzhuang area in Biyang sag is characterized by complex structures, well developed minor fault blocks, and shallowly buried reservoirs (only 50-800 m). Because the velocity of P-wave and S-wave changes greatly, conventional seismic imaging method can not satisfy the needs of exploration and development. Aiming at the characteristics, we have adopted the shallow seismic data processing technologies including pre-stack de-noise, high-accuracy statics, far-offset stretching, and offset division energy equalization for data process. Meanwhile, we also studied the pre-stack time migration technologies such as migration velocity field establishment, migration aperture selection, and migration dip identification. In addition, we obtained the pre-stack data volume by protecting the information of shallow layers and improving the S/N of middle and deep layers. In terms of the distribution of target formation dips, proper migration aperture and dip parameters were selected to image the pre-stack time migration on the whole data volume. After processing, the imaging accuracy was improved. The final result profiles show clear faults and abundant information. Through comprehensive interpretation, some new understandings have been acquired about the fault characteristics of Xinzhuang area, Biyang sag, some new traps discovered, and good oil/gas encountered in drilling.