The Injecting-Producing Well Completion Technology For Underground Gas Storage Based On A Depleted Sandstone Gas Reservoir

If underground gas storage is based on a depleted sandstone gas reservoir, formationpressure is low. So it has high completion technology requirements. The main problemsare:gas well productivity is how to meet the large displacement injection and production ofgas storage;it also has big reconstruct difficulty in the formation, it can not ensure gas storagerunning30to50years; reservoir protection is difficult; injected gas contain CO2,it has highsecurity requirements about the well head and string.Considering the difficulties of building gas storage in a depleted sandstone gas reservoir,the systems method must be used in analysis of different condition and study of completiontechnology. It studies the node analysis method for constructing an underground gas storagebank system. Deep penetration perforation on injecting-producing well with long intervalsmeets the safety and the designed injection-production requirement. And it design the stringof injecting-producing wells and well open and close working system. Thus, the systematicproject design mode and technology series are formed, being of guidance and reference forthe construction of underground gas storage in China.We establish the injection-production system nodal analysis model. It provided the basisfor prediction of the tubing size,wellbore pressure and temperature parameters. Consideringthe erosion erosion and liquid carrying liquid capacity, it determine the tubing inner diameteris76mm.To reduce the low-pressure reservoir pollution and improve injection-productioncapacity, it design with127deep penetrating composite perforator,90°phase,20holes/mperforation.In accordance with production ways, working conditions and gas storage runningneeds at different stages, it design the injection and production completion string, monitoringcompletion string, perforating injection and integration the completion string series, and for stress analysis results of different working conditions show that the string safety factor meetthe requirements.The injection and production system nodal analysis simulation technologyprovide theoretical support for the the gas library program design and post-operationmanagement.It consider reservoir-wellbore-ground conditions and the injection-productionenvironment conditions.By the research on matching technology of deep penetratingcompound perforating in a low-pressure reservoir and injection-production tubing string, itprovide technical support to achieve injection production index of W96depleted sandstonegas storage,efficient completion and stable operation.