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Triassic Fault Feature And Its Controlling Effect On Hydrocarbon Accumulation In Lunnan Fault Belt Of Tarim Basin

Posted on:2019-05-18Degree:MasterType:Thesis
Country:ChinaCandidate:C D GengFull Text:PDF
GTID:2370330620964585Subject:Geological Resources and Geological Engineering
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Many types of structural traps have been found in Lunnan fault belt,in which the primary type is fault block reservoir due to the well-developed faults.The faults have a significant effect on the accumulation and preservation of hydrocarbon.In order to reveal the hydrocarbon forming conditions and discuss the controlling effect of faults on hydrocarbon distribution in Lunnan fault belt,it is crucial to take further research on the formation and evolution of faults.Based on the 3-D seismic survey data,the geometrical and kinematic characteristics of the faults are systematically studied.The faults were divided into 4 fault systems according to fault strike and fault size.The fault activity of boundary faults and fault systems were evaluated by using strata subsidence and fault activity rate.Furthermore,the relationship between fault activity and hydrocarbon accumulation was clarified.In the current fault sealing assessment,the lateral fault sealing were studied by using lithologic juxtaposition and SGR,and the vertical fault sealing were studied by using fault plane normal pressure and fault tightness index.Based on the lateral and vertical fault sealing evaluation,the fault sealing characteristics were synthetically assessed.Results show that fault sealing are significantly controlled by fault strike,showing decreasing fault sealing in the following sequence of NEE,NE,NNE and SN.The fault sealing in footwall is better than that in the hanging wall.Based on the summary of hydrocarbon accumulation conditions and fluid inclusion measurement,hydrocarbon history from generation to expulsion and burial-thermal evolution history of strata were analyzed,and the hydrocarbon mainly accumulated in early Himalayan period.The relationships between faults and those factors including source rock,reservoir,hydrocarbon migration and accumulation were discussed,and the effect of faults on basin formation and hydrocarbon migration and sealing were illuminated.Finally,the effects of faults on hydrocarbon accumulation were summarized.The constant activity of boundary primary and secondary faults led to the formation of depression and large-scale trap belts.The I degree faults link the source rock and traps,and part II degree faults and III degree faults seal the oil and gas,resulting in the formation of the complicated fault block reservoirs.
Keywords/Search Tags:Lunnan fault belt, fault characteristics, fault activity, fault sealing, hydrocarbon accumulation
PDF Full Text Request
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