| Deep petroleum reservoir is becoming a more and more important part of un-developed oil/gas reservoir, due to the continuously development of shallow-medium reservoir. A massive drilling exploration operations have been launched in countries from the world-wide, large number of deep petroleum reservoirs have been discovered, as the result, Well completion technology plays a crucial role in maximising the performance of horizontal well, enhancing the production and recovery of deep reservoir. Currently, the well completion technology in China could not meet the requirements of the development of deep reservoir, which is the major constrain on the efficiency of development of deep horizontal wells. How to develop the deep reservoirs in more scientific, more efficient ways is of great significance in addressing the energy demand issue of China. One of the most vital tasks which is confronted with Chinese petroleum engineers is how to make breakthrough of the bottleneck in the development of deep reservoirs in order to breach the technology monopoly.Yuanba Gas Field is one of the world’s super deep sea facies acid gas field. Superimposed area and beach facies are of poor reservoir property, with complicated geological characterisctics of deep depth, high pressure, strong heterogeneity of fractures and complex gas-water relationship. This paperillustrate the optimization of well completion method for Yuanba Gas Field from four aspects, including the relationship between gas well production situation, gas-water relationship, reservoir renovation requirements, project operation risk; Considering the area of Yuanba composite with beach facies reservoir (cannot be built by natural production output) requires open hole section completion for acidization and production, production difficulties of open hole section completion of Yuanba was analyzed, namely the smooth running of strings, reliability ensurance of tools, optimal design of well completion string and safety of production.In this paper, we use the software of Landmark to analyze the well completion string running. Conclusions was drawn that yuan dam open hole section completionrequired the following wellbore conditions:two open hole dogleg degree<1°/30m, measuring point for10m a point; Three, four and vertical section of the dogleg degree<3°/30m; Deflecting section dogleg degree<9°/30m, horizontal section dogleg degree<6°/30m.Keyway should be avoided in the hole well; targets ajustion for multiple times causing the well track complex should be avoided, the upturn of trajectory should beespecially avoided.On the basis of studying the tubular mechanics analysis model with packers, the different working conditions of horizontal wellbore pressure and temperature distribution are studied, and its calculating model was set up; Consideringangle, azimuth angle, lateral force and friction combination of three dimensional string axial force calculation model in crooked hole; which layed foundation for subsequent horizontal well section completion tubular optimization. Based on the above model, the design forstrings in Yuanba was optimized including chosing the length of the shorter hydraulic open hole packer, ultilizing double pressure differential sliding sleeve, adopting isolation ball seat further prevent debris such as solid phase particles from entering the pipe string, using a "permanent seal+suspension seal" double packer design to improve the inclined section after annulus isolation, anticorrosive effect. Through the strength check the use of wall thickness of9.52mm lengthtubing was further optimized. Open hole packer pressure capacity requirements was optimized. Suggestions for tool product optimization were put forward. |
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