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The Gas Reservoir-forming Conditions And Accumulation Models Of Subtle Traps In Upper Triassic In Central Sichuan Basin

Posted on:2007-05-18Degree:MasterType:Thesis
Country:ChinaCandidate:J W JiangFull Text:PDF
GTID:2120360182482512Subject:Structural geology
Abstract/Summary:PDF Full Text Request
The natural gas has been produced commercially from the central Sichuan basinsince the 1950s. Because of the importance for future domestic energy supply, it isessential to better understand the fundamental conditions and the main factorscontroling the gas reservoirs. In this study, a method, utilizing petroleumgeology,sequence stratigrapy, organic geochemistry and geophysics, based on drilledcore analysis data, well data and seismic sections, has been applied to establishmodels in this area.This paper mainly discusses the petroleum geological conditionsincluding the source rocks,the reservoir and the sealing condition.Based on thecharacteristics of the gas pools and the accumulation models ,we analyzed the mainfactors controling the gas reservoirs. The following results and recognition have beenobtained:1.The hydrocarbon source rock potentials for the the Upper Triassic XiangxiGroup are great.Oil-source correlation indicates that the natural gas is the self-sourcedcoal-gas.2.The sandstones mainly distributed in the Xiang'er Formation and XiangsiFormation are extensive.The Sandstone typically has very low porosity andpermeability.3.The sealing condition and trap condition are good.The source rocks ,reservoirand the caprock are fairly matched each other .The gas pools are mainly stratigraphicor structure-stratigraphic traps .4. The main geologic factors controling large-medium gas fields are the inheritedpalaeohigh,rich hydrocarbon sources,effective fracture and favorable reservoirprovided by channel sandstones .The last one is the fluid prsssure predominance thatallows the hydrocarbons migrating in the direction of the lower fluid pressure.5.There are two kinds of gas accumulation models in the Upper Triassic.6.The favorable places for exploration in the near future should be distributed inSouth-west of the Central Sichuan Basin.
Keywords/Search Tags:Central Sichuan basin, Upper Triassic, gas accumulation, main factor, accumulation model
PDF Full Text Request
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