中国古生界海相碳酸盐岩油气藏的形成与分布

中国古生界多套海相烃源岩的叠合分布和中—新生界陆相地层的进一步覆盖,导致古生界油气藏的形成具有多源、多期性,烃源岩主要分布在克拉通盆地和克拉通内裂谷盆地。碳酸盐岩是主要的储集层,泥质岩是主要的区域和局部盖层。构造—热事件作用使得除塔里木盆地以外的盆地烃类相态以干气为主,包括干酪根裂解气和原油裂解气。根据储集层特征,将碳酸盐岩油气藏划分为4类:碳酸盐岩滩油气藏、不整合岩溶油气藏、生物礁油气藏和成岩油气藏。其中碳酸盐岩岩溶油气藏和高能环境下发育的滩相油气藏是最为重要的油气藏类型。断裂、不整合和古隆起控制着油气的空间分布,油气具有跨时代分布的特点。 

FORMATION AND DISTRIBUTION OF THE PALEOZOIC MARINE CARBONATE-ROCK POOLS IN CHINA

The superimposing distribution of many sets of the Paleozoic marine source rocks and the further overlying of the Meso-Cenozoic continental strata resulted in the multi-source and multi-stage formation of the Paleozoic oil and gas pools in China. Hydrocarbon source rocks are distributed in craton basins and in-tracratonic rift basins. Carbonate rocks are major reservoirs, and argillaceous rocks are major local and regional caprocks. The hydrocarbon phases of the basins except for the Tarim Basin are dominated by dry gases including pyrolysis gases from kerogen and crude oil because of tectonic-thermal events. According to the characteristics of reservoirs, carbonate rock pools were divided into four types, that is, carbonate rocky-beach pools, uncomformity-karst pools, biohermal pools and diagenetic pools. Among them, carbonate rocky-karst pools and the beach-phase pools developed in high-energy environments are the most important types of oil and gas pools. Faults, unconformities and paleouplifts control the spatial distribution of oil and gas, and the distribution of oil and gas is diachronous.