松辽盆地南部大情字井油田青二段油气成藏规律

 松辽盆地南部大情字井油田青二段具有良好的油气资源潜力。以大情字井油田为研究区，探求其油气成藏条件与分布规律。综合分析了岩心、录井、地震、测井等资料，运用“相-势-导三元控藏”理论，在对大情字井油田青二段沉积演化背景、沉积微相、储集层特征、压力势、流体势与输导体系特征进行研究的基础上，剖析各控藏要素及其配置关系对油气藏形成与分布的影响；指出“相-势-导”有利配置区，并提出以三角洲前缘砂体为主要储集岩的富烃凹陷成藏模式。研究认为：水下分流河道与河口坝砂体规模大，储集物性好，是有利沉积相带，凹陷的斜坡带是紧邻烃源灶的流体低势区，是油气运移的主要指向区，区内断层与层状砂岩的组合形成有利的“T”形输导体系；油气在流体势的驱动下，经“T”形输导体系运移至凹陷的斜坡带有利相带内汇聚成藏；区内油藏类型具分带特征：向斜西翼主要发育断层-岩性油气藏、断块油气藏；向斜东翼主要发育岩性上倾尖灭油气藏。

Formation Mechanism of Hydrocarbon Reservoir in Qn2 of Daqingzijing Oil Field in the South of Songliao Basin

Qn2 of Daqingzijing oil field sees a great potential in oil and gas resources. In this paper, with Daqingzijing oil field as the study area, the formation mechanism of hydrocarbon reservoir is comprehensively analyzed, including studies of core, geology log, seismic and well log. With the "facies-potential-transport ternary reservoir controlling" theory, sedimentary facies, sedimentary evolution, storing characteristics, pressure potential, fluid potential, carrier system, and the correlation of these factors and hydrocarbon are discussed. A pool-forming pattern of hydrocarbon-rich depressions is proposed, with the reservoir rock of the depression as the delta front sandstone. It is suggested that the underwater distributary channel and the mouth bar sand of a large scale, with good reservoir properties, are favorable sedimentary facies. Slopes of depression belong the low-potential zone. Fault and bedded sandstone are combined, to form a T-passage system. Fluid potential drives hydrocarbons to flow through the T-passage system, to be accumulated in the high-quality facies. Reservoir formation is controlled by facies and potential and carrier system. Reservoir types in research area see a distribution of a zoning feature. The west slope of synclines sees more growth of fault-lithological and fault block oil pools. The east slope of synclines sees more growth of up-dip pinchout of sandstone-reservoir.