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Fault Characteristics And Its Controlling Effects On The Hydrocarbon Accumulation In The Cover Rocks Of Hong-che Fault Zone

Posted on:2019-04-25Degree:MasterType:Thesis
Country:ChinaCandidate:J X GuoFull Text:PDF
GTID:2370330620964520Subject:Geology
Abstract/Summary:PDF Full Text Request
The Hong-Che Fault Zone is located in the northwestern margin of Junggar basin and affected by strong tectonic movements,making the area has complex structural features.The basement of the Hong-Che Fault Zone is composed of Carboniferous and strata below,and the cover rocks consist of Permian and the strata above.The main fault of the Hong-Che Fault Zone is the Hong-Che fault,which cuts through the Carboniferous to the Jurassic.This fault can extend over a long distance and generate different structural characteristics in different position,causing the difference on the controlling effects on the oil and gas accumulation.This article mainly analyzes the structural characteristics and hydrocarbon accumulation mechanism in the cover rocks of the fault zone.Based on the data of well log,drill core and high-precision 3D seismic,the Hong-Che Fault Zone can be divided into two segments,including the north and south segments in the plain view.The north segment mainly develops reverse faults,whereas the strike-slip faults are highly developed in the south segment.In profile,the Hong-Che Fault Zone also has different characteristics and can be divided into upper and lower fault systems.The upper fault system is dominated by normal fault,and the lower segment is mainly composed of the compressional fault.Through structural restoration,it is believed that the fault zone experienced the compression in the late Hercynian,compression and strike-slip in the Indosinian to the middle Yanshanian and extension of the late Yanshanian to Himalayan period.The Ghe-guai area can be divided into four evolutionary stages:The stable uplift stage from the Late Carboniferous to the Late Permian,extensive uplift stage from the Triassic to the late Jurassic,the rapid subsidence stage from the Cretaceous to the Paleogene,and the strongly tilt stage to the South in Neogene.The fault activity become weaker and weaker from the Late Carboniferous to the Jurassic.The controlling effect on the hydrocarbon accumulation is highly depended on its fault sealing capacity.The cover rocks of the Hong-Che Fault Zone are the interbedded layers of sand and shale.The internal structure of fault zone is not obvious.The results of SGR,Rm,IFTT and F suggest that the sealing capacity of shallow part of the Hong-Che Fault Zone various in different periods.In the early stage of Cretaceous,the sealing capacity of south segment is better than the north segment.In the middle stage of late Paleogene and the early stage of Neogene,the sealing capacity of north segment is better than the south segment.One of the important factors of oil and gas adjustment is the changeof fault sealing property in this fault zone.The oil and gas reservoirs in the cap rock of the Hong-Che fault belt are mainly controlled by the fautls,unconformity and stratum,the deep reservoir is mainly controlled by fault,and shallow reservoir is controlled by stratum.On the basis of detailed studies of reservior,fluid characteristics,sealing and tectonic evolution history,the oil and gas accumulation process in the cap layer of the Hong-Che Fault Zone is well analyzed in this paper,and the accumulation pattern and reservoir forming model are summarized.The north segment has a“ladder-like”hydrocarbon accumulation model,the south segment has a“flower”hydrocarbon accumulation model.
Keywords/Search Tags:fault structure, fault system, fault sealing, difference of reservoir control, Hong-che Fault Zone
PDF Full Text Request
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