Exploration of Dynamic Analysis Technology to Oil-Type Underground Gas Storage - A Case Study of NanPu No.1 Gas Storage

At present, Most in-service underground gas storage are gas reservoir. Nanpu No.1 is the first gas storage reservoir in Jidong Oilfield, which develops gas reservoir, gas reservoir with oil ring and gas-top reservoir in the reservoir area. Unlike gas reservoir type gas storage, the reservoir construction process, the oil-gas-water three-phase fluid replacement, seepage mechanism is complex, the use of gas reservoir type gas storage dynamic analysis standards can no longer meet the needs of the reservoir injection and extraction phase dynamic analysis, in order to ensure capacity and production and efficient peak regulation, the reservoir type gas storage dynamic analysis technology exploration. The study shows that: (1) the reservoir will go through three stages: gas drive oil enhancement, cooperative reservoir construction, and scale peaking, and the dynamic analysis can be carried out in five aspects: dynamic sealing of the geological body, gas drive effect, gas injection and extraction capacity, reservoir capacity utilization, key index comparison and influencing factors; (2) in the evaluation of gas drive effect, the analysis of oil and fluid enhancement IFEDC-202314681 2 characteristics of neighboring wells after gas injection should be focused at the early stage of reservoir construction, and the analysis of fluid components, gas-bearing fluids, and gas-bearing fluids should be focused at the middle and late stage of reservoir construction. (3) In the evaluation of gas injection and recovery capacity, the influence of different gas saturation of the formation should be fully considered, and the changes of gas injection and recovery capacity should be tracked and evaluated; (4) In the quantitative evaluation of inventory utilization, both injection and recovery wells and drainage wells should be taken into account, and the free gas volume, the second saturation dissolved gas volume of remaining oil, and the accumulated gas volume of the cycle should be considered. The study clarifies the main contents of reservoir-type gas storage injection and extraction dynamic analysis, which can effectively promote the standardization and systematization of gas storage dynamic analysis.