【摘要】 南海北部深水西区是一个前瞻性的油气勘探新领域,包括神狐隆起西南端、永乐隆起及琼东南盆地中央坳陷带大部分区域,属于南海北部被动大陆边缘的一部分,构造演化上经历了裂陷和裂后两大阶段。本次研究通过对南海北部深水西区及邻区大量地震和钻井资料研究认为,该区不仅具有优越的基本石油地质条件,而且具有有利的成藏条件,其特点为:①三套烃源岩、五大富生烃凹陷,资源潜力巨大;②陵三段扇三角洲或滨海砂岩与陵二段海侵泥岩储盖组、三亚、梅山滨浅海相砂岩或低位扇砂体与浅海-半深海相泥岩储盖组合、黄流组低位扇砂体与半深海相泥岩付盖组合、梅山组台地边缘礁灰岩与莺黄组深海相泥岩的储盖组合等4套储盖组合;③构造、低位体和礁圈闭成群成带发育;④各种垂向和侧向运移通延发育齐全,存在超压-常压突变模式、超压-常压过渡模式和强超压区的构造与岩性圈闭成藏模式。南海北部深水西区具有与国外获得巨大成功的深水勘探地区类似的石油地质条件,因此,勘探前景良好,资源潜力巨大。但是深水勘探是一个高风险、高技术、高投入的领域,应当”由浅及深,循序渐进”地推动该区深水勘探。更多还原

【Abstract】 The deepwater area of northwestern South China Sea is a petroleum exploration frontier, which consists of southwestern Shenhu massif, Yongle massif, and most parts of the central depression zone in Qiongdongnan Basin. This area is a part of passive margin of northern South China Sea, which experienced two evolutionary phases of rifting and post-rifting. Based on lots of seismic and drilling data available for the deepwater area and its adjacent areas, this paper points out that there exist not only excellent petroleum geological characteristics but also migration-accumulation conditions in the area: ① There are 3 types of source rocks, 5 rich hydrocarbon depressions and great potential resources; ② There are 4 reservoir-seal pairs, namely, the pair of Ling-III fan deltaic or littoral sandstones combined with the Ling-II transgressive mudstone, the pair of sandstones in the Sanya-Meishan Formations littoral facies and LST fans combined with the bathyal or abyssal facies mudstone of Meishan-Yinghuang Formations, the pair of LST fans of Huangliu Formation combined with the bathyal facies mudstone of Yinghuang Formation, and the pair of Miocene limestone combined with the Yinghuang Formation mudstone. ③ Multiple traps of structures, lowstand deposit bodies and reef limestones are developed in groups and belts; ④ There are all kinds of vertical and lateral pathways and 3 types of migration-accumulation models, i.e., the overpressure-normal pressure drastically-changing model, the overpressure-normal pressure transitional model, and the overpressure source model. The deepwater area has similar petroleum geological conditions to areas abroad where deepwater exploration has been very successful. The deepwater area is therefore a prospective frontier and has quantities of potential resources. However, the exploration in the deepwater area is a frontier characterized by high risks, high techniques, and high expenditures, and hence the exploration in the deepwater area should be conducted in accord with the strategy of “step by step operation from shallower to deeper area”.更多还原