Design Of Gas Storage Injection And Production Scheme Based On Fault Stability Evaluation Of LM Block

Underground gas storage plays an important role in the balance of natural gas supply and demand and peak regulation.After two cycles of operation,LM gas storage still does not reach the design index on the whole,and the storage capacity is lower than the designed working gas capacity.The phenomena such as slow capacity reaching speed and interpenetration between water and gas affect the efficient operation of gas storage.Based on dynamic analysis of production data in LM block and quantitative evaluation of fault stability,this paper established a numerical reservoir model considering fault stability evaluation,and designed the injection-production scheme of gas storage in LM block with fault activation pressure as the boundary.The results are as follows:(1)Study on multi-cycle injection and production dynamics of gas storage:Based on the actual production data,the gas injection dynamic analysis of 10 injection and production Wells in the gas storage,as well as the gas storage capacity reaching and water discharge analysis,it is pointed out that the current problems of the gas storage are as follows:under12.3MPa,the storage capacity is about 3.51×10~8m~3,which has a big gap with the designed storage capacity of 5.25×10~8m~3.According to the remaining uncontrolled reserves,two to four injection-production Wells can be arranged.(2)The dynamic analysis of the sealing property of the gas reservoir is carried out.The research results show that the ground stress of the gas reservoir cover layer is higher and the sealing property of the gas reservoir cover layer is higher.Six faults in the block,L4 showed a new understanding,and the fault was not sealed.At the same time,the fault stability of six faults in LM block was quantitatively evaluated.The minimum activation pressure of L1fault within the control circle of LM gas storage was 17.23MPa by FAST evaluation method.The minimum activation pressure of L2 fault is 16.41MPa;The minimum activation pressure of L3 fault is 17.11MPa;The minimum activation pressure of L4 fault is 16.16MPa.The minimum activation pressure of L5 fault is 16.41MPa.The minimum activation pressure of L6 fault is 21.34MPa.(3)According to the results of dynamic analysis of gas storage and quantitative evaluation of fault stability,the upper operating formation pressure of the new gas storage is determined to be 14.4MPa.Using reservoir numerical simulation software,the final solution was to adjust well patterns and deploy new injection-production Wells.Two new injection-production horizontal wells were identified,with an additional working gas capacity of 2.0450×10~8m~3At the same time,the maximum injection pressure and the reasonable injection pressure of ten injection-production wells are determined.Finally determine the LM gas storage injection and production scheme design.