Study On Controlling Effects Of Faults On Ordovician Carbonate Hydrocarbon Accumulation In The YM2 Area

In this paper,the study area is located in the southwest of Tabei Uplift of Tarim Basin,NW China.The target layer series is the marine carbonate sedimentary facies,with multistage superimposition of regional tectonic movement,severe fault activities,and the controlling to hydrocarbon migration and enrichment of carbonate is obvious.Further study on the rule of faults controlling hydrocarbon accumulation has a significant effect on the exploration and development of oil and gas in this area.The geologic characterization of faults development characteristics,period and combination pattern in the study area is carried out by using seismic datas and related derivative datas,and consider it mainly developed North-South strike-slip fault in middle Caledonian,North-West strike-slip faults in early Hercynian,North-East thrust strike-slip faults in late Hercynian and so on,whose array patterns have obvious segmentation,and the evolution of the main vertical fault direction profile is also studied.In addition,the development of fracture,the activity and effectiveness of the fault zones are studied by core observation,stress distribution statistics,imaging logging and fracture inclusion experiment.According to the parameters of drilling and production,the characteristics of oil and gas geochemical parameters,the basic geochemical characteristics,the horizontal and vertical distribution characteristics of oil and gas are clarified.By using isotope,light hydrocarbon,saturated hydrocarbon,aromatic hydrocarbon and other parameters,the maturity is analyzed.On the basis of above,according to inclusions,basic geochemistry,biomarker,neutral nitrogen compounds and other representative parameters to study the hydrocarbon filling characteristics and its migration direction.Combined with the characteristics of faults,geochemical characteristics,distribution law and the direction of the dominant migration of oil and gas,to analyse the coupling of fracture development and the validity of the fault zone with the oil and gas filling period and local differential enrichment,thus determine the controlling of faults on hydrocarbon accumulation and local enrichment,Furthermore,the oil and gas accumulation law in the smaller scale of the study area is predicted.