摘要
酒西盆地的白垩系与第三系构成一个完整的油气系统 ,白垩系发育油源层和储集层、盖层 ,第三系主要发育储集层和盖层。由柳沟庄、鸭儿峡、老君庙到石油沟 ,烷烃含量逐步增加 ,原油中的芳烃、非烃与沥青质含量逐渐降低 ,异胆甾烷、Ts、C2 9Ts含量略有增高 ,原油密度、含蜡量、凝固点降低。这些原油物性特征反映了油气运移的地质色层效应和运移方向 ,表明油气总体由西向东运移。青西坳陷的构造埋藏史控制了主要烃源岩(下白垩统赤金堡组和下沟组下部 )在晚第三纪晚期—第四纪才达到生油高峰期 ,目前仍处于成熟—高成熟阶段 ,因此以生油为主 ,主要形成油藏。该含油气系统的关键时刻是晚第三纪末至第四纪 ,圈闭形成期与油气生成运移期相匹配。喜马拉雅运动期的断裂活动提供了油气运移的通道 ,促进了油气的运移 ,油气可以在多种类型圈闭聚集成藏。油气资源潜力再评价的结果表明 ,青西坳陷总油气聚集量可达 2 .5× 1 0 8～ 4.0× 1 0 8t,仍然有 2× 1 0 8～ 3× 1 0 8t剩余油气资源 ,具有很大的勘探潜力。青西低凸起位于很有生油潜力的青南凹陷和红南凹陷之间 ,构造位置非常有利 ,是油气运移的主要指向目标区 ,油源供给很充足 ,且储集层、盖层发育 ,可能有多种类型的圈闭 。
An integrated petroleum system is formed by the Cretaceous and the Tertiary in the Jiuxi basin, in which the Cretaceous developed as source, reservoir and cap rocks and the Tertiary mainly developed as reservoir and cap rocks. The contents of alkanesin oils from Liugouzhuang, Yaerxia, Laojunmiao and Shiyougou oil fields increase gradually; on the contrary, the contents of aromatic hydrocarbon, non hydrocarbon, resin and asphalt in the oils decrease gradually. The contents of isocholestanes, Ts and C 29 Ts increase slightly, and the density, wax content and solidification point of the oils decrease. All of those features of the oils reflect the geological chromatogram efficient and direction of migration of the oils, suggesting that the oils migrated from west to east in an overall direction. The major source rocks (Chijinpu Formation and lower part of Xiagou Formation, Lower Cretaceous) reached a peak of petroleum generation during the late Neogene Quaternary, that were controlled by tectonic and buried history in the Qingxi depression, and that are still in a maturity high maturity stage now, during which oil is mainly generated and oil pools are mainly formed. The key stage for this oil system is Neogene to Quaternary, and the trap forming episode corresponds to the oil generation time. Fractures developed by the Himalayan tectogenetic movement form and improve the migrating channels and oil can be accumulated within various traps. The review about potential resources shows that the totally accumulated amount of petroleum is up to 2.5×10 8 -4.0×10 8 t, and still 2×10 8 -3×10 8 t remained resources can be found in this area, so the exploration potential is real high. The Qingxi low lift is just located between the Qingnan and Hongnan sags with high potential of oil gas generation, that should be a target of oil and gas migration, where existed a plentiful oil gas supply, reservoir and cap rocks well developed and various kinds of trap would be developed. Therefore, that area should be multiple oil and gas accumulation zones with bright future for exploration and would be the major directions and targets for oil and gas exploration in the Jiuxi basin.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2001年第3期12-16,共5页
Petroleum Exploration and Development
关键词
酒西盆地
油气形成
油气勘探
油气运移
成藏规律
Jiuxi basin, Oil and gas migration, Reservoir formation, Petroleum system, Oil and gas exploration, Direction
