East Siberian Basin is an ancient platform-type petroleum-bearing basin and undergoes four phases in sedimentary structural evolution; basement-form ing stage and early-stage syn-nft are happened in the gestation periods of the basin; late-stage syn-rift and early-stage passive continental margin are the depositing periods of the source rocks; the passive continental margin stage becomes the developing period of the reservoirs and cap rocks; the collisional-compressional stage belongs to the key periods of the change of the inner structure frames and the formation of the oil sand deposit. The comprehensive action of diverse factors such as abundant oil resources, much better accornulating conditions, adequate driving force for long-distance hydrocarbon migration, smooth conducting system, hydrocarbon degradation-densification and so on are beneficial to the generation of large-size oil sand reserves in the basin. According to the forming principles of oil sand deposit, there are two kinds of deposit forming models; slope degradation and ancient oil reservoir damage, the oil sand resources are preliminarily predicted to be 23 380 × 108bbl.%东西伯利亚盆地是一个古老的地台型含油气盆地,经历了4个沉积构造演化阶段,其中基底形成阶段和同生裂谷早期阶段为盆地的孕育期,同生裂谷晚期阶段和被动边缘早期阶段为盆地烃源岩的沉积期,被动边缘阶段为盆地内储层和盖层的发育期,碰撞挤压阶段为盆地内部构造格局变化以及油砂成矿的关键期.丰富的油源、良好的储集条件、充足的油气远距离运移动力、畅通的疏导体系及烃类降解稠化等多种因素综合作用,促使东西伯利亚盆地形成规模化油砂资源.根据油砂的成矿机理,该盆地分为斜坡降解型和古油藏破坏型2种成矿模式,初步预测油砂资源为23 380亿桶.
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