Geophysical Research Progress on Tight Sandstone Reservoir in International Cooperation Block of Sulige Gas Field

The tight sandstone reservoir in the cooperation block of Sulige gas field is characterized by thin gas-bearing sand, large variation laterally and strong heterogeneity. Owing to the complex surface conditions, and particularly the thick weathered zone, the 3D seismic data presented limited frequency bandwidth. Both processing and reservoir prediction did not achieve the expected effect. To enhance the reliability of predicted results, the reprocessing data with better quality were obtained in the pilot area by using the prestack data processing procedure with wider frequency, higher fidelity, and preserved amplitude at its core. Compared to the previous results, the reprocessing data exhibited wider bandwidth, higher resolution, and better consistency. The seismic forward modeling showed that the data could be used to discriminate over 10-m-thick single sand body or sand group and over 5-m-thick gas-bearing sand. Using crossplot interpretation of selected sensitive parameters, the thickness of reservoir and effective sandstone could be estimated quantitatively. Obvious enhancements were obtained for the well-seismic match of AVO features and which of the prestack seismic inversion. The research findings in the pilot area will have an important guidance to the development of international cooperation block in Sulige gas field.