| The western Sichuan depression is a foreland basin located in the central and western parts of the Sichuan Basin.It is formed by the thrusting of the Longmen Mountain since the Indosinian period.It can be divided into Zitong depression,Xiaoquan-Fenggu tectonic belt,Chengdu depression,Duck River-Dayi Fracture Zone and Knowing the New Field-Longbaoliang Structure with 5 Tectonic Units.The eastern slope of the western Sichuan is related to the eastern tectonic zone of the northeastern east to the Xiaocheng-Xinchang-Fenggu tectonic belt,the north-south Zhixin field-Longbaoliang tectonic belt and the middle-slope belt zone,and the Middle Jurassic Shaximiao Formation As one of the main oil and gas layers.The eastern slope area of western Sichuan depression is rich in natural gas resources and is a hot spot in oil and gas exploration.On the basis of fully absorbing the research results of predecessors,this paper,based on the mechanism of natural gas accumulation and the principle of reservoir formation dynamics,clarifies the eastern slope of the western Sichuan depression by means of test gas,oil and gas display,logging and logging interpretation The characteristics of gas and water distribution in the Ximiao group gas reservoir are analyzed.Based on the characteristics of the transport system and the simulation results of the migration system,the dynamic analysis of the reservoirs and the typical gas reservoirs are used to reveal the eastern slope of the western Sichuan depression The different factors of hydrocarbon accumulation and accumulation and the evolution of reservoir formation under different tectonic location and different fault-sand configuration conditions,and the main controlling factors and enrichment laws of gas reservoir formation are pointed out.It is pointed out that the favorable target area of Shaximiao Formation on the east slope of western Sichuan depression,For the Shaximiao group oil and gas exploration and deployment to provide theoretical basis and technical support.According to the evolution history of hydrocarbon generation rocks and the results of fluid inclusions analysis,there are three reservoirs in Shaximiao Formation,which are roughly 141 ~ 68 Ma: the first stage is in the range of 141 ~ 128Ma(J3 ~K1),occurred in the 105~88Ma(K1 ~K2),and the third phase of the main reservoir in the 83~68Ma(K2).Anatomize the typical gas reservoirs in the study area,the Gamiaozi area and the Zhongjiang-Huilong area are mainly composed of gas and gas-bearing layers,and contain a certain amount of water and water.The analysis of the distribution characteristics of the formation water shows that the process of natural gas and formation water in the Shaximiao Formation gradually migrate from the vicinity of the hydrocarbon source fault to the distal end of the structure,and there is a process from the deep Xujiahe Formation formation along the fault channel to penetrate upward,Water accumulation process.Based on the analysis of erosion recovery and tectonic evolution,this paper analyzes the dynamic accumulation process of natural gas from the critical time to the Himalayan period,and establishes three dynamic evolution modes of Shaximiao Formation in the east slope of western Sichuan depression As follows:(1)Gaomiaozi area accumulation model: The gas migrates upward along the fault at abnormal high pressure,and the high quality reservoirs with good sandwiches are transported laterally to the structural high point.The mountain movement adjusts the direction of the gas again.(2)The accumulation evolution mode chart of J2 x in Zhongjiang area: There are gentle microstructures in the middle tectonics of the Yangtze River.Under the action of abnormal high pressure,the gas is filled with the sand body along the source fault and the reservoir is good.The mountain movement causes the fault to converge with the reservoir,the reservoir internal heterogeneity serious,leading to sand body closed,the formation of sausage structure.(3)The accumulation evolution mode chart of J2 s in Zhongjiang area: the gas migrates upward along the fault under the action of abnormal high pressure,and the high-quality reservoirs with good matching sand are transported laterally to the structural high point.However,due to the large scale of the fault,the adjacent sand bodies form the water-The mountain movement moves the gas again to adjust the direction of movement.Shaxiemiao group of natural gas accumulation of four major control factors were "broken sand control,reservoir control,structural control,evolution control tone." Based on the evaluation system,the natural gas enrichment area of?,?and ? were collected in the study area.The distribution of the sandy area is similar to that of the second member of the second member of the Shahejie Formation,which is close to the main development of the hydrocarbon source fault area.The main development of the third member of the third member of the third and third class..Favorable goal of a total of three rivers were: high temple JS24-2 northern river;in the JS31(3)river;in the JS33-3(4)river. |
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