塔里木盆地塔中低凸起油气聚集与分布

HYDROCARBON ACCUMULATION AND DISTRIBUTION IN TAZHONG LOW UPLIFT OF TARIM BASIN

塔里木盆地塔中低凸起是形成于晚加里东—早海西期的下古生界残余古隆起，具有丰富的油气资源。塔中低凸起具有多套油源层、多含油气层系、多种圈闭类型、多成藏期，具有多元复合含油气系统的特点，并具有四种油气聚集模式：下奥陶统碳酸盐岩潜山及背斜型、石炭系东河砂岩地层超覆型、石炭系断裂背斜及背斜型、志留系砂岩背斜及岩性（物性）型。奥陶系油气聚集一般与风化壳有关；志留系油气聚集受构造和岩性的双重控制；石炭系油气聚集一般与断裂及不整合面有关。只有沙漠地震过关，才能使塔中低凸起油气勘探成功率大为提高。在塔中低凸起西北倾没部位有可能找到大油气田。

Tazhong low uplift with abundant resources in Tarim Basin is a remnant Paleozoic uplift formed during late Caledonian and early Hercynian orogenies.The uplift possesses several multi sets of source beds and oil bearing horizons,several types of traps,multi stage of hydrocarbon formation,and are characterized by complex petroleum system.There are 4 kinds of oil and gas accumulation models:buried hill and anticlinal types of Lower Ordovician carbonate rock,overlapped stratigraphic type of the Carboniferous Donghe sandstone,faulted anticlinal and anticlinal types of the Carboniferous,anticlinal and lithological types of Silurian sandstone.Ordovician oil and gas bearing horizons are generally related to weathering crust,Silurian oil and gas accumulations are controlled by both structure and lithology,Carboniferous oil and gas accumulations are normally related to faults and unconformity.It is only by improving the technique of desert seismic exploration,the success ratio of oil and gas exploration could be increased,and giant oil and gas fields might be found in the pitching position of the uplift.