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The Main Control Factors For Shale Gas Accumulation And Favorable Targets Screening In Shunan And Around

Posted on:2014-01-18Degree:DoctorType:Dissertation
Country:ChinaCandidate:Q ZhaoFull Text:PDF
GTID:1220330398980885Subject:Mineral prospecting and exploration
Abstract/Summary:PDF Full Text Request
This study focused on shale gas province in Shunan and around. Through thedata analysis of exploration wells and shale samples, the gas shale features, the causesof overpressure, dominative factor for shale gas accumulation, gas content and resourceabundance were studied intensively. Shale gas accumulation zone were predicted andsome development targets were screened.Firstly, based on a large number of shale gas drilling and experimental data, it’sconcluded that the organic-rich shale of Longmaxi formation and Qiongzhusiformation spread stably, with big thickness, high organic content, and high maturity. Sothe shale is the main intervals of interest for shale gas.Secondly, according to the result of exploration wells for shale gas in the studyarea, it’s thought that the overpressure of shale reservoir shows the effectivepreservation of shale gas in the complex tectonic background. By establishingmathematical model, the simulation results show that the gas production in shale andtectonic uplift are the tow main reasons for shale gas reservoir overpressure.Thirdly, through analysis of typical shale gas accumulation charactorics and theprocess, Himalayan tectonic movement is thought to be the key geological events forshale gas accumulation in China. Combined with China’s shale gas formationgeological characteristics, it’s proposed that the TOC, brittleness mineral content arethe main factors to control the vertical shale gas reservoirs. Tectonic stability is thecontrolling factor of shale gas distribution in the area. The buried depth is the maininfluencing factor of the economic recoverable shale gas resources.Fourthly, through the data analysis of massive shale gas content, it’s found that themethods for estimating the lost gas and the free gas are with a big deviation. Throughestablishment of new methods and correcting reservoir original pressure, the shale gascontent calculation deviation was fixed. Based on the fixed gas content, the shale gasresources abundance consists with the single-well recoverable reserves by dynamicmethod.Finally, according to the key factors of shale gas accumulation in the study area,17zones were classified with three kinds of shale gas accumulation zone, with totalamount of10.7x1012m3resources. By adopting the method of BP neural networkoptimization, five shale gas development favorable targets were screened, withresources3.96x1012m3. In the current0.4yuan/m3financial subsidies conditions,the shale gas can be developed economically.
Keywords/Search Tags:shale gas, shale reservoir, overpressure, accumulation zone, resources
PDF Full Text Request
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