塔里木盆地凝析气藏形成的地质-地球化学条件

塔里木盆地凝析气藏数量多、分布广、储量大,是我国凝析气藏最富集的盆地。在凝析气形成机理及相态成因研究基础上,综合分析了塔里木盆地的成藏特征,并与四川、鄂尔多斯和吐哈等盆地进行对比分析,认为塔里木盆地凝析气藏具有两种形成机理三类相态成因的特征。盆地内富集凝析气藏的内在地化因素是不同类型烃源岩处于有利的热演化阶段,而晚期大幅度沉降和晚期气相运移聚集为凝析气藏的形成提供了重要的温压及保存条件。此外,油气的生成和聚集异步演化有利于过成熟干气富化为凝析气藏。

The Geologic and Geochemical Conditions of Condensate-Gas Reservoir A ccumulation in Tarim Basin

The condensate gas reservoirs in Tarim basin are characterized by great numbers, w ide distribution and lots of reserves, being the most enriched area in condensate gas reservoirs of China mainland. In this paper, based on the mechanism of condensate -gas reservoirs' formation and genesis of phase state, the authors analyzed the properties of reservoirs' formation in Tarim basin, and made a comparison with Sichuan, Erdos and Turpan-Hami basins, then pointed out that the condensate -gas reservoirs have two mechanism of formation and three types of phase state geneses. The key factor of condensate- gas reservoirs accumulation is that diversified hydrocarbon source rocks are in advantage stage of thermal evolution, and the late-stage heavily subsidence as well as late-stage gas migration accumulation provides important conditions of temperature, pressure, preservation for the condensate-gas reservoirs formation. Furthermore, the asynchronous evolution of hydrocarbon generation and accumulation makes for over. mature dry gas wet into condensate gas reservoirs.