柴达木盆地南翼山混积岩储层岩石类型 及其与油气分布的关系

根据储层岩石的层理构造产状将柴达木盆地南翼山混积岩储层分为变形层理混积岩岩层、水平层理混积岩岩层和块状层理混积岩岩层3种类型.对各类岩层的成因、组成、岩石类型、孔隙结构特征及物性分布的研究结果表明,这3种类型的混积岩层对应3种沉积环境.岩层的岩石类型组合决定了储层岩石的微结构构造,而微结构构造决定了岩石的孔隙结构特征及微裂缝发育程度,进而决定了储层的物性.变形层理混积岩岩层的储层物性最好;水平层理混积岩岩层次之;块状层理混积岩岩层储层物性最差,这种储层必须配合以发育的构造裂缝才有实际意义.本区储层的含油气性与储层的岩性和构造裂缝的发育程度有关.

Rock types of mixosedimentite reservoirs and oil-gas distribution in Nanyishan ofQaidam Basin

The mixosedimentite reservoirs in Nanyishan of Qaidam Basin were divided into three types of deforming bedding mixosedimentite layer,horizontal bedding mixosedimentite layer and massive bedding mixosedimentite layer according to bedding structures of rock layers in the reservoirs. The analyses on the origin, composition, rock type, pore structure and physical properties of the rock layers show that the three kinds of mixosedimentite layers correspond to three types of sedimentary environments. The rock composition of mixosedimentite layers controlled the micro texture of rocks,and the micro-texture of rocks decided the pore structure of rocks and the development degree of the micro-fracture. The pore structure and fractures of rocks finally decided the porosity and permeability of mixosedimentite layers. The reservoir characteristic of the deforming bedding mixosedimentite layer is the best,while that of the massive bedding mixosedimentite layer is the worst if it has not developed a lot of structural fractures. The physical properties of Nanyishan reservoirs are seriously related with the rock features and the distribution of structural fractures.