辽河坳陷辽中凹陷成岩作用与中深层孔隙演化

Diagenesis of Liaozhong sag in Liaohe depression and pore evolutionin its middle-deep strata

蒋恕 蔡东升 朱筱敏 朱光辉 胡孝林

Jiang Shu Cai Dongsheng Zhu Xiaomin Zhu Guanghui Hu Xiaolin

根据大量的岩石薄片、X衍射、地球化学等测试资料,对辽河坳陷辽中凹陷成岩作用及孔隙演化进行了详细研究,并在此基础上划分了5个成岩阶段:早成岩A期、早成岩B期、晚成岩A期、晚成岩B期和晚成岩C期。次生孔隙演化特点、形成机理及其与成岩演化的关系研究表明,中深层两个主要次生孔隙发育带分别对应于早成岩B期和晚成岩A期,次生孔隙的形成主要源于粘土矿物迅速演化、油气生成及超压发育。因此,辽中凹陷中深层超压区次生孔隙发育带油气藏勘探是当前乃至今后勘探的重点。

A detailed analysis based on test data of thin rock section,X-ray diffraction,geochemistry,etc.,is carried out on the diagenesis of Liaozhong sag in Liaohe depression and pore evolution in its middle-and deep-strata.Five diagenetic stages are classified according to the analysis.They are A and B stages of early diagenesis,and A,B,and C stages of late diagenesis.A study on the evolution characteristics and forming mechanism of the secondary pores and their relationships with diagenesis reveals that two main secondary pore zones in middle-and deep-strata are formed mainly by the rapid evolution of clay minerals,hydrocarbon generation,and overpressure,and correspond respectively to the B stage of the early diagenesis and the A stage of late diagenesis.It is concluded that the secondary pore zones in middle-and deep-strata of overpressured areas in Liaozhong sag are the potential exploration targets for the future.

10.11743/ogg20070309