Oil and Gas Distribution and Main Controlling Factors in Foreland Basins,South America

摘要

The South American foreland basin is rich in oil and gas resources,but the distribution is uneven.This paper analyzes the hydrocarbon accumulation and distribution characteristics of this area,and clarifies the main control factors to provide reference for oil and gas exploration in this area.Firstly,the reservoir formation,resource types and plane distribution of each basin are analyzed,and the distribution characteristics of oil and gas are summarized.Then study the ages and sedimentary evolution of source rocks in each basin,and clarify the characteristics of resources,potential and migration and accumulation.Finally,the relationship between source rock and oil and gas distribution is analyzed and compared,and its internal law is summarized.Oil and gas are mainly accumulated in the foreland slope areas around kitchens with belt distribution.The oil and gas distribution is significantly different from north to south.The oil production in the north basins is mainly concentrated in the Cretaceous and Tertiary systems;the gas production in the central basins is mainly in the Devonian and Carboniferous;the oil and gas in the south basins are mainly distributed in the Jurassic and Lower Cretaceous.Three sets of main source rock are developed:the Upper Cretaceous mudstone in the north basins is dominated by oil generation,and the hydrocarbon generation ability is the strongest;the central is the Devonian mudstone,which is dominated by the gas generation;the south is the Lower Cretaceous mudstone,and the oil and gas generation are both important.Source rock is the main controlling factor of oil and gas distribution in this area.The source rock quality determines the resource volume.The age of the source rock determines the hydrocarbon type,migration distance and oil and gas distribution.For the first time,the oil and gas distribution and source rocks in the foreland of South America are divided into three categories:south,central and north,and the source rocks are the main controlling factors.The results can provide reference for oil and gas exploration and new project evaluation in the foreland basin of South America.