Study on Gas-water Distribution Law and Development Potential of Gas-water Transition Region in Shan2 gas Reservoir of Zizhou Gas Field

Abstract Gas-water relationship in Shan2 gas reservoir of Zizhou gas field is complicated, and gas-water distribution law and gas-water transition region’s development potential are unclear. To this end, the gas-water distribution law and the exploration potential of gas-water transition zone of gas reservoir are studied by using the dynamic and static data of drilling, logging and production testing accumulated over the years and the methods of geological stack map, volumetric method and dynamic reserve analysis method. The results manifest that the gas stratum of the gas reservoir develops in dendrite and continuous sheet from northwest to southeast, and four water bodies are distributed in isolated clusters at the dendrite sand body’s end in the southwest of the gas reservoir. The gas-water transition region is located in the superposition of gas layer and water body, which is controlled by many factors, such as, structure, sand body and reservoir forming, showing scattered and irregular shape. The preliminary assessment of the gas-water transition zone is 232.5km 2 , the geological reserves are 170.2×10 8 m 3 , the recoverable reserves are from 51.1×10 8 m 3 to 81.7×10 8 m 3 , and the development potential is large. This research is a basis for the follow-up exploration of the gas-water transition region of Shan2 gas reservoir in Zizhou gas field, which has important reference meaning for the study of gas-water distribution law and development potential of the gas-water transition zone in similar gas reservoirs.