Research On Reservoir-Forming Rule Of Jurassic Gas In Chengdu Depression

Taking the research on Reservoir-Forming Rule in Chengdu depression as thetarget in this thesis, the latest theory and method of sequence stratigraphy,sedmentology and seismic straligraphy are adopted in this paper. By using the data ofseism data, log data, core information, the framework of sequence strata andsedimentary facies in Chengdu depression are analyzed and studied deeply, also theadvantageous targets are researched and forecasted primarily.The fruit enrich thetheories of sequence stratigraphy and sedimentology. All researching will play animportant role in exploration and development of this area. By the study of gas-basedlocalization characteristics of Chengdu depression, analyzing the relationship of thecarbon isotope and vitrinite reflectance, we know the Jurassic gas of Chengdudepression, coming from the underlying shall and Lower Jurassic Baitianbasystemgroup.Using organic geochemical studies, researching Jurassic source rocksabundance of organic matter, type of organic matter and organic matter maturity inChengdu depression. Studies suggest that abundance of organic matter, the LowerJurassic source rocks in Chengdu depression, with a certain thickness, the distributionarea relative to be more effective Xujiahe source rocks, organic matter type IIIorganic matter in the mature stage of evolution, the source rocks of Baitianba strongenough to meet the need the formation of large gas fields.On the basis of the analysis of reservoir test in Chengdu depression, study theshallow layers Department of reservoir rock characteristics, physical properties andreservoir sand body distribution characteristics. In Chengdu depression, Penglaizhensandstone composed by lithic sandstone, lithic sandstone and lithic quartz sandstone,the Suining Formation sandstone mainly composed by lithic sandstone and lithicsandstone, Shaximiao sandstone mainly composed by cuttingssandstone, lithicsandstone, lithic sandstone, compared with Penglaizhen Suining Formation,significantly less average content of quartz, feldspar content of more. Chengdudepression shallow gas reservoirs generally low-especially low porosity, low-especially low permeability.By the accumulation conditions as source rocks，reservoir and cover, I willresearch the main control factor of Jurassic gas accumulation in Chengdu depression,and establish of Chengdu Jurassic gas accumulation model.