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The Research Of Controlling Factors Of Gas Containing Property Of Shale Under The Complex Geological Background

Posted on:2017-03-23Degree:MasterType:Thesis
Country:ChinaCandidate:Q B HuangFull Text:PDF
GTID:2180330482484031Subject:Marine Geology
Abstract/Summary:PDF Full Text Request
In this paper, the author take the Hetang Formation, Lower Cambrian gas-shale of the Lower Yangtze region as the main study object, discussed the main factor of the shale of Lower Cambrian under the complex geological background. In this study, compare and analysis related parameters between the shale of Ningguo-hule Formation of Lower-Middle Ordovician in Lower Yangtze region and the shale of Longmaxi Formation of Lower Silurian in upper Yangtze region, comparing the similarity of organic geochemical characteristics and reservoir characteristics among them. Wishing the success of Fuling shale gas fields, could bring inspiration and guidance for the exploration and development of gas-shale in the study area.The main achievements are as follows:(1) Upper and lower Cambrian strata in the study area mainly developed in the condition of basin facies, deep-water continental shelf facies and partial plateau facies. The Hetang Formation mainly develop silica rock, silica mudstone carbargilite, carbon shale, carbon mudstone and so on, which is belong to deposit of basin facies. Lower Yangtze Region in Indo-Chinese epoch was in the structural environment of extruding, occurring tectonic inversion since Yanshan period in the structural environment of extend. Several times of structural evolution and the great buried depth of shale in the study area made the geological background of Lower Yangtze region very complicated. (2) The type of organic material of mud shale of the Hetang Formation, Lower Cambrian is mainly type I. The type for Longmaxi Formation in Chongqing-fuling area is also type Ⅰ. The type for Ningguo Formation is type I and the type for Hule Formation is type Ⅱ1 . The TOC of the black shale of Hetang Formation, Lower Cambrian in the study area is relatively high. The average value of TOC is 6.98%. The TOC of the black shale of Longmaxi Formation in Chongqing-fuling area is also relatively high. The average value of TOC is 2.54%. The TOC content of the Ningguo-hule Formation of Lower-Middle Ordovician is relatively low. (3) The average value of Ro of the Hetang Formation in the study area is 3.49%. The average value of Ro of the Longmaxi Formation of JY1 well in Fuling area is 2.58%. The organic geochemical characteristics of the shale of the Hetang Formation, Lower Cambrian in Lower Yangtze region have great similarity with that of the Longmaxi Formation of Lower Silurian, which shows that the shale of the Hetang Formation, Lower Cambrian may be a favorable area for the exploration and development of gas-shale. (4) The average content value of clay mineral of the shale of the Hetang Formation, Lower Cambrian is 35.3%,and its average content value of fragile mineral is 81.9%, with lower porosity and permeability overall; The content of goeschwitzite of Hule Formation and Ningguo Formation is relatively high, and the average content value of fragile mineral of Hule Formation and Ningguo Formation are 68.15%,41.6%; The average content value of clay mineral of Longmaxi Formation is 40.0%, and its average content value of fragile mineral is about 56.0%,with high degree of development of cracks and porosity. (5) Intensive tectonic movements occurring in Indo Chinese epoch of early Mesozoic, especially the denuded of the platform periphery, made Lower Yangtze region lose the conditions for the formation of shale gas. Upper Yangtze region and Lower Yangtze region had different post-tectonic movement. Upper Yangtze Region was in the structural environment of weak extruding since the late Mesozoic tectonic, which was benefit for the saving of gas-shale. Lower Yangtze Region was in the structural environment of extruding, occurring tectonic inversion since Yanshan period in the structural environment of extend, which was not benefit for the saving of gas-shale.
Keywords/Search Tags:Lower Yangtze region, organic geochemical characteristic, reservoir characteristic, gas containing property, main controlling factors
PDF Full Text Request
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