湘东南拗陷上古生界碳酸盐岩储层成岩作用

THE DIAGENESIS OF THE UPPER PALEOZOIC CARBONATE ROCKS IN THE SOUTHEAST XIANG DEPRESSION

湘东南拗陷是中国南方古生代～新生代叠舍盆地之一，古生代～中生代地层普遍裸露，该拗陷油气勘探程度较低在野外剖面观测、室内薄片坚定等工作的基础上，分析了湘东南拗陷上古生界碳酸盐岩储层戍岩作用类型，包括：泥晶化作用、胶结作用、压溶作用、白云石化作用、重结晶作用、裂缝化作用、溶蚀作用等，以及经历的海底-大陆（淡水和混合水）-浅埋藏-深埋藏-表生等成岩环境。对储层孔隙发育起建设性的成岩作用主要有裂缝化作用、压溶作用、溶蚀作用和白云石化作用。裂缝化作用及压溶作用在一定程度上可改善储层的储集性能白云石化作用形成的白云石晶间孔为重要的孔隙类型，并成为工区最为有利的勘探目的层，

The Southeast Xiang depression, in which the Paleo～Mesozoic strata are generally exposed, is one of the Paleo～Cenozoic superimposed basins in South China. The attention is rarely paid to this area ever before. In this paper, based on the field outcrop survey and the thin section analysis, the major diagenetic types including micritization, cementation, pressure solution, dolomitization, recrystallization, cataclasis and dissolution are analyzed, all the diagenesis took place on seafloor, non-marine(fresh water and mixed water), shallow burial, deep burial to epigenetic environments. Of all the types of dianenesis, cataclasis, pressure solution, denudation and dolomaitization play a positive role in the porous development of reservoirs. Especially, cataclasis and pressure solution which are very typical in the area, improve the ability of the reservoir rocks, and the dolomite intercrystal pores caused by dolomitization is a very important pore space, in which the favorable petroleum exploration targets are expectable.