Analysis On Production Law And Influencing Factors Of High-Speed Injection-Production Fluid In Gas Storage-Type Gas Storage

Underground gas storage is an important means of natural gas peaking supply,which is of great strategic significance for maintaining civil demand and protecting national energy security.At present,most of the related researches on gas reservoir-type UGS are mainly based on numerical simulation methods,but it is difficult to accurately characterize the mechanism of high-speed fluid seepage and the interaction between fluids.At the same time,due to the complex two-phase flow state of gas and water in gas storage-type gas storage,the understanding of seepage mechanism and fluid production under high-speed injection and production conditions is very limited.In view of the above problems,this paper carried out high-speed seepage of reservoir gas and high-speed injection and production of gas and water under the conditions of high speed,high temperature and high pressure by means of physical simulation experiments and long core displacement device,and revealed the operation process of the gas storage.The seepage characteristics in the gas storage;the physical simulation experimental cabin is used to periodically simulate the high-speed injection and production process of the gas storage,and the pressure changes and the dynamic characteristics of production and operation in the whole process of the first construction of the gas storage and multiple rounds of injection and production are clarified.The dynamic distribution law of the fluid in the gas storage was clarified,and the expansion mechanism of the gas storage in multiple rounds of operation was revealed.Finally,the full-diameter physical simulation experiment system was used to study and reasonably evaluate the influencing factors during the operation of the gas storage.The following understandings have been obtained from the research:(1)With the increasing gas injection rate,when the Reynolds number is greater than 0.2,the fluid changes from laminar flow to turbulent flow,and the apparent permeability of the100 m D core gradually decreases.(2)Under the conditions of high speed,high temperature and high pressure,with the increase of the injection and production times of gas and water,the injection and production capacity of the gas storage will decrease,the storage space will become smaller,and the injected gas volume will be lost.(3)Compared with the 1m D reservoir,the 100 m D reservoir has a higher degree of recovery,the injection-production pressure difference is smaller and more stable,but the time to reach capacity is longer.During the operation stage,after multiple rounds of injection and production,the cumulative gas-water exchange efficiency,gas production,and working gas proportion are higher in the 100 m D reservoir than in the1 m D reservoir,and the scope of the 100 m D reservoir is larger.(4)The lower the gas production rate,the greater the pressure difference between injection and production,and the higher the operating efficiency of the gas storage.