砂岩透镜体成藏机理

砂岩透镜体油藏是隐蔽油气藏中增储上产的重要类型，但目前对其成藏机理的认识还存在很大分歧．从油气初次运移机理入手，结合砂泥岩压实成岩过程的分析，对砂岩透镜体的成藏动力和成藏阻力及成藏过程进行了分析．研究认为：烃类生成引起的膨胀力、烃浓度差引起的扩散力和砂泥岩间的毛管压力差是成藏主动力，岩石吸附和粘滞力是成藏主要阻力；油气水以混涌流方式为主，孔隙、微裂隙和微层理面是油气运移的通道；早成岩阶段不成藏，晚成岩早期成藏，晚成岩晚期进入保存阶段．

Accumulation and Filling Mechanism of Lenticular Sandbody Reservoirs

Lenticular sandbody reservoir is an important subtle reservoir type for increase of reserve, but its accumulation and filling mechanism is not well understood. Driven force and resistance during lenticular sandbody reservoir-filling have been analyzed based on integrated research on the process of compaction and diagenesis in interbedded sand/mud strata. The results indicate that the driven forces resulting in the filling of reservoir include pressure due to the generation of hydrocarbon, diffusion by hydrocarbon concentration difference, capillary pressure between sand and mud. Rock absorption and adhibition are taken as resistance of reservoir-filling. Hydrocarbon and water spill into the reservoirs in the mixing pattern through pore, fracture and joint fissure. Hydrocarbon is filled in early phase of late-diagenetic stage and preserved in late phase of late-diagenetic stage.