Main controlling factors of hydrocarbon accumulation in Mahai-Dahonggou uplift

Located in the middle of North Qaidam basin,MahaiDahonggou uplift is surrounded by multiple hydrocarbongeneration sags,the hydrocarbon distribution is controlled by maturity evolution,discharge,and accumulation of Jurassic hydrocarbon source rock.The basic structure form,'two-sag-one-uplift'in the research area is formed by faulting,and the trap development and hydrocarbon migration are controlled by faulting as well.In the research area,three different sets of reservoir-caprock association play a big role in hydrocarbon preservation,and the tectonic movement has an effect on hydrocarbon adjustment and reform.The hydrocarbon accumulation of Mahai-Dahonggou region has been preliminarily believed to be mainly controlled by four factors,hydrocarbon source rocks(the generation ability and position included),the fracture distribution and transportation systems,the trap formation time and validity,and the reservoir preservation condition.