Response of Structural Elements to Hydrocarbon Accumulation in Foreland Basin

A foreland basin system may be divided into four structural elements such as piedmont fold-thrust belt, foredeep depression belt, slope belt and frontal uplift belt. This paper discusses hydrocarbon distribution regularity and hydrocarbon accumulation pattern of each structural element in foreland basin system by analysis of key factors of source rock, reservoir rock, source-reservoir-caprock assemblage and petroleum migration in order to post the differences of hydrocarbon accumulation among different structural elements and basinal petroleum distribution regularities. The study shows that the petroleum distribution in foreland basin is controlled by the basinal structure, and a hydrocarbon accumulation is responsible to the basinal structural element. Based on this proper classification, to comprehensively understand the hydrocarbon accumulation characteristics of sedimentary systems of pre-basin-forming and basin-forming period for different structural elements is the crucial way for foreland basin hydrocarbon accumulation study. Moreover, the post-reformations must be paid more attention to for petroleum exploration of foreland basins in central-western China.