莺歌海盆地中部坳陷天然气成藏条件及勘探方向

文章系统地分析了莺歌海盆地中部坳陷天然气的成藏条件，阐述了该区中新统和渐新统崖城组烃源岩具有良好的生气潜力，蕴藏着丰富的天然气资源；指出了底辟断裂为天然气运移提供了重要通道，而深部异常高压是天然气运移的关键驱动力。在此基础上，文章围绕中部富生烃坳陷，并结合天然气的成藏条件综合分析，认为底辟浅层是深部油气运移的有利指向和聚集场所，成藏条件优越，应作为近期天然气勘探主战场；底辟中深层尽管存在异常高压，但位处油气运移的必由之路且该带圈闭规模大，可作为近期探索领域；临高构造带圈闭类型好，具有较好的烃源条件，但勘探和研究程度低，需深入评价，故列为后备区。

GAS RESERVOIR FORMATION CONDITIONS AND FAVORABLE EXPLORATION AREAS IN THE CENTRAL DEPRESSION OF YINGEHAI BASIN

In the paper, through systematically analyzing the gas reservoir formation conditions in the central depression of Yingehai Basin, it is pointed out that the hydrocarbon source rocks of Miocene and Yacheng Formation of Oligocene have good gas generating potential and plentiful gas resources; and the diapiric faults have provided the main pathways for gas migration and the deep abnormal high formation pressure is regarded as the key drive force of gas migration. Therefore it is considered that the shallow strata in the diapiric structure are of excellent gas reservoir formation conditions, being the directional zones of hydrocarbon migration and the places of hydrocarbon accumulation, so that they should be taken as the main exploration targets in the near future; although there exists abnormal high formation pressure in the medium-deep strata in the diapiric structure, they are just on the pathway of hydrocarbon migration and some large-sized traps have been found here, so that they may be taken as the short-term investigation domain; and although the Lingao structural belt is possessed of good trap and hydrocarbon source conditions, it still needs to be evaluated further because of its low exploration and study levels, so that it can be only taken as the exploration reserve area.