Accumulation Potential and Exploration Direction of Marine Petroleum in Jianghan Plain

Sedimentary evolution of basin and characteristics of petroleum geological response are studied in order to further ascertain the exploration potential of marine petroleum in plain.The authors state that marine stratum of Jianghan Plain have undergone multi-stage basin evolutions with the superimposed reformation of tectonic movements,including Craton basin stage during Caledonian-early Indo-Chinese Epoch,foreland basin stage during late Indo-Chinese Epoch-early Yanshannian,basin extension and transformation stage during late Yanshannian-Himalayan period and basin edge extrusion and deformation stage in late Himalayan period,so it is of preferable petroleum accumulation conditions.In Jianghan Plain,there are four marine hydrocarbon source rocks as Upper Sinian Series,Lower Cambrian Series,Lower Silurian Series and Permian System;three main reservoirs are developed,including Dengying Formation of Upper Sinian Series,Shilongdong Formation of Lower Cambrian Series and Huanglong Formation of Upper Carboniferous;Lower Cambrian Series,Silurian System,Middle-Upper Triassic Series-Jurassic and Cretaceous-Lower Tertiary System,as four regional caps,are existed in Jianghan Plain.Several exploration fields are discovered,such as paleo uplift developed area,stereo exploration area of"late hydrocarbon accumulation",relatively stable tectonic activity area and developed area of overthrust nappe.For now,only two exploration fields,relatively stable tectonic activity area and stereo exploration area of"late hydrocarbon accumulation",are paid more attentions.