论优质源储耦合关系的控藏作用:对比松南致密油与松北致密气成藏条件

为了更清晰地理解优质烃源岩和优质储层的耦合关系在致密油气成藏过程中的控制作用，本文应用地化测试、恒速压汞、常规压汞、含烃流体包裹体等多种资料，对比了松辽盆地南部致密油和松辽盆地北部致密气的成藏条件。研究表明：1）优质源岩生、排烃中心基本吻合超压高值区，超压到达的边界就是致密油气富集边界。2）孔喉结构约束下的松南泉四段优质储层渗透率下限为0.10×10^-3 μm²，松北沙河子组优质储层的渗透率下限为0.05×10^-3 μm²。3）时间上，形成致密油气藏的前提条件是源储之间应具备"先致密后成藏"的匹配关系，这是决定其成藏机理的根本；空间上，2个研究区的"甜点区"均发育在近源、强压、高渗的优质源储叠合部位，其展布特征受控于优质源储的空间耦合关系。

Controlling Action of Space-Time Coupling Relationship Between High-Quality Source Rocks and High-Quality Reservoirs: Contrasting Accumulation Conditions of Tight Oil in the Southern Songliao Basin with Tight Gas in the Northern Songliao Basin

In the forming process of tight sandstone oil and gas reservoirs,the spatial-temporal coupling relationship between high-quality source rocks and high-quality reservoirs is a crucial factor controlling the reservoir types and abundance.In order to better understand its controlling function,we applied the geochemical data,constant-rate mercury injection experiment,conventional mercury injection experiment,and fluid inclusions and other analytical data in the study area,and compared the tight oil reservoir in the southern Songliao basin with the tight gas reservoir in the northern Songliao basin.The distribution of a hydrocarbon generation and expulsion center of high quality source rocks is basically consistent with the overpressure zone,and its boundary limits the scope of tight oil-gas accumulation area.Besides,under the constraint of pore-throat structure,the lowest permeability of high-quality reservoirs is defined as 0.1 × 10-3 μm2 in the fourth member of the Lower Cretaceous Quantou Formation(K1q4)in the southern Songliao basin,while 0.05 × 10-3 μm2 in the Lower Cretaceous Shahezi Formation(K1Sh)in the northern Songliao basin.Furthermore,one of the preconditions for forming tight oil-gas reservoirs is that the tighten period of reservoir should be earlier than that of the main hydrocarbon expulsion of source rock,which is the basis of the reservoir-forming mechanism.Spatially,the ‘reservoir sweet spots’ are developed always in the intersection of high-quality source rocks and high-quality reservoirs,where powerful pressure and high permeability and other geologic features are available.