THE STUDY OF PETROLEUM-BEARING PROSPECT OF MARINE PALEOZOIC OF THE XIANG-ZAO DEPRESSION IN THE NANXIANG BASIN

The Xiang-Zao Depression of the Nanxiang Basin is a half graben-like sag in Mesozoic-Cenozoic with faulted in the south part and overlapped in the north,which is mainly controlled by the Xiangfan-Guangji fault,and has not been a breakthrough through many years of exploration in the Mesozoic-Cenozoic.Through the "petroleum sources of strategic electoral districts on the northern edge of the Qinling-Dabie Orogenic Belt" subject research,found that nonmetamorphose rock of Paleozoic marine strata was distributed in the periphery of Xiang-Zao Depression and its deep part.Among which,mudstone-shale containing phosphor is a potential high-quality source rocks at the bottom part of the Lower Cambrian;Dolomite and internal erosion surface formation are better reservoir strata in the Lower Paleozoic;Lower Paleozoic Dolomite containing paste is potential covered layer,which forms the basic geological conditions of oil-gas.But the source rocks are having high degree of thermal evolution.Paleozoic oil-gas of deep marine strata in the Xiang-Zao Depression is the new layer system and a new field,which is worth in-depth exploration.