柴达木盆地北缘侏罗系对比及含油气系统

Correlation of Jurassic in Northern Margin of Qaidam Basin and Its Petroleum System

柴达木盆地北缘是一个老油区,中、下侏罗统是主要烃源岩。通过区域研究,将侏罗系划为3统4组,即下侏罗统小煤沟组,中下侏罗统大煤沟组,上侏罗统红水沟组和采石岭组,其中大煤沟组可细划分7段。对钻遇侏罗系的38口井逐次进行了划分和对比,总结了下侏罗统、中侏罗统的沉积特征。在此基础上划分出下侏罗统含油气系统和中侏罗统含油气系统,提出冷湖—南八仙弧形构造带、鄂博梁构造带为勘探有利区。

The north margin of Qaidam basin is an old oil region. The Middle and Lower Jurassic strata are its main source rocks. Through regional studies, the Jurassic is divided into 3 series and four formations, i.e. Xiaomeigou formation of Lower Jurassic, Dameigou formation of Middle-Lower Jurassic and Hongshuigou formation and Caishiling formation of Upper Jurassic, of which Dameigou formation can be subdivided into 7 members. This paper presents the classifications and correlations of 38 wells encountered into the Jurassic one by one, and reviews the sedimentary characteristics of Lower Jurassic and Middle Jurassic, based on which the petroleum systems of the Lower Jurassic and the Middle Jurassic. It is concluded that the Lenghu-Nanbaxian arc structural belt and the Eboliang structural belt are favorable areas for petroleum exploration.