Geophysical Research Progress on Tight Sandstone Reservoir in Sulige Gas Field

DOI: 10.14800/IOGR.1147

Abstract

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. Due 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 expectation. 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 from its cores. Compared to the previous results, the reprocessing data exhibits wider bandwidth, higher resolution and better consistency. The seismic forward modelling shows that the data can be used to discriminate over 10 m single sandbody or sand group, and over 5m gas-bearing sand. Using cross-plot interpretation of selected sensitive parameters, the thickness of reservoir and effective sandstone can be estimated quantitatively. Obvious enhancements were obtained for the well-seismic match of AVO features and 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.