江汉平原海相油气成藏潜力与勘探方向

Accumulation Potential and Exploration Direction of Marine Petroleum in Jianghan Plain

为进一步明确平原海相油气勘探潜力,通过对盆地沉积演化及石油地质响应特征研究认为,江汉平原海相地层经历了加里东—早印支期克拉通盆地期、晚印支—早燕山期前陆盆地期、晚燕山—喜山盆地伸展改造期、晚喜山期盆缘挤压变形期等多期盆地演化与构造运动的叠加改造,具备较好的油气成藏条件。主要发育了上震旦统、下寒武统、下志留统、二叠系等四套海相烃源层;发育了上震旦统灯影组、下寒武统石龙洞组、上石炭统黄龙组等三套主要储集层系;存在下寒武统、志留系、中上三叠统—侏罗系和白垩—下第三系四套区域盖层。形成了包括古隆起发育区、"晚期成藏"立体勘探区、构造活动相对稳定区、逆冲推覆体发育区等多个勘探领域。其中,构造活动相对稳定区、"晚期成藏"立体勘探区是目前主攻的油气勘探领域。

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 Epochearly 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 tour 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.