四川盆地泥盆系-中三叠统层序格架内生储盖分布

摘要

Guided by the sequence framework, the characteristics of source rocks, reservoir rocks and source-reservoir-cap rock assemblages were discussed in detail for the Devonian to the Middle Triassic in the Sichuan Basin.Combined with the existing results of hydrocarbon exploration, a diagram of the source-reservoir-cap rock assemblages within the supersequence framework was established.Two sets of regional source rocks and three sets of regional reservoir rocks are developed under the supersequence framework.The dark carbonatite and mudstone that contain much organic matter are developed in the transgressive systems tracts of SS5 and SS6, and the hydrocarbon generating centers are developed in the cratonic depression and deep shelf.The SS4 transgressive systems tract reservoir is karat reservoir related to ancient uplifts.The SS5 highstand systems tract reservoir rock is mainly developed in the platform margin reef/beach.The SS6 transgressive systems tract-highstand systems tract reservoir rock is mainly developed in the platform margin reef/beach.In all, three source-reservoir-cap assemblages occur in the Sichuan Basin from the Devonian to the Middle Triassic, including composite, highstand and transgressive.Regional source rocks are developed in the transgressive system of the supersequence.Regional reservoir rocks are developed in the highstand system of the supersequence.The distribution characteristics of the regional cap rocks are similar to that of the regional source rocks.%在层序格架内讨论四川盆地泥盆系-中三叠统烃源岩、储集层发育特征及生储盖组合配置关系,结合盆地现有的油气勘探成果,建立四川盆地泥盆系-中三叠统层序地层格架与油气生储盖组合图解.研究表明,二级层序格架内盆地发育2套区域性烃源岩和3套区域性储集层;SS5和SS6海侵期,以发育富有机质暗色碳酸盐岩和泥岩为特征,克拉通台内坳陷和深水陆棚的烃源岩在后期热演化过程中形成生烃中心;SS4海侵体系域储集层主要是一套与古隆起相关的岩溶储集层,SS5高位体系域储集层主要发育干台地边缘礁滩相带,SS6海便体系域一高位体系域储集层主要发育于台地边缘礁滩相带.四川盆地泥盆系-中三叠统发育综合型、高位型、海侵型3种生储盖组合;区域性烃源岩发育于二级层序海侵期;区域性储集层发育于二级层序高位期;区域性盖层分布与烃源岩晨布特征具有一致性.图3参32