Study On The Optimum Completion Method Of Xujiahe Deep Gas Well In Western Sichuan

West Sichuan Aoxian Xujiahe group deep formation has abundant resource with great exploratory prospect. However, due to the complication of its formation of reservoir, the lateral direction of the formation has multiple pressure systems forming the characteristics of high temperature and high pressure, which poses high requirements to the completion technique. Recent years several deep wells completed in Xujiaha Group had some problems in well completion techniques which directly influenced the evaluation and exploitation of the gas reservoir in West Sichuan deep formations. Thus, based on the well completion technique condition for HTHP gas wells, combining the geological condition of gas reservoir engineering in Xujiahe Group, the difficulties of choice of completion method was analyzed. Finally, according to the gas reservoir specie, reservoir characteristics, the formation conditions above the pay zone and the engineering requirements, utilizing the economic evaluation and dynamic analysis method, the well completion method of West Sichuan deep formation gas reservoir was optimized. The main achievements and conclusions are:1) By the laboratory rock mechanics experiment, the compression strength. Young's modulus, Poisson ration of Xu 2 gas reservoir was obtained; tensile strength of six cores was obtained, which gives data support to rock mechanics parameters of other wells in Xu 2 gas reservoir and crustal stress logging explanation..2) The change of rock mechanics parameters and crustal stress with well depth was comprehensively explained for well CG561, Well CG561B, Well CG561ZH, Well CL562C, Well CL562E, Well CX560B, Well CF563D. The comprehensive relation of rock mechanics parameters, crustal stress, fracture pressure to well depth was obtained. The maximum main stress, minimum main stress and fracture pressure obtained from statistic analysis accorded well with depth. The rock mechanics parameters, crustal stress, fracture pressure obtained provide basic data for sand production and sidewall stability prediction in the process of well completion method optimization.3) Based on the binomial expression production equation of gas well, the production prediction model for open hole completion and perforation completion was established.4) Considering the well bore stability, sand production, distribution of gas and water. based on production prediction, economical evaluation, the gas well optimization program was compiled. Well completion method of West Sichuan Xujiahe group deep formation was optimized using the program compiled. Well completion method recommended was perforated pipe completion. When actually processing, completion with packer or without packer could be chosen according to the drilling condition.The well completion optimization method formed in this paper could be of guidance and reference for well completion method optimization of similar gas reservoirs.