低渗透储层不同成岩相可动流体赋存特征及其影响因素分析——以鄂尔多斯盆地 姬塬地区长6段储层为例

利用高压压汞、恒速压汞、核磁共振、扫描电镜、X射线衍射等资料，对姬塬地区长6段不同成岩相储层开展可动流体赋存特征及其影响因素分析。结果表明：(1)研究区三类有效成岩相储层，绿泥石膜胶结—残余粒间孔相、长石溶蚀相及高岭石胶结相，微观孔喉差异明显，主要体现在喉道上；(2)从T2谱分析可知，绿泥石膜胶结—残余粒间孔相孔喉半径均匀，连通性好，可动流体饱和度最高，长石溶蚀相次之，可动流体饱和度中等，高岭石胶结相孔隙类型单一且小，可动流体饱和度最低；(3)孔喉半径、主流喉道半径、孔喉半径比及有效孔喉体积是引起不同成岩相储层可动流体赋存特征差异的主控因素，渗透率的大小是影响其饱和度大小的重要因素之一，高岭石和伊利石含量的增多对其可动流体赋存具有破坏作用。

Characteristics of Movable Fluids in Different Diagenetic Facies and the Influencing Factors of Low-permeability Reservoir:Taking Chang 6 Jiyuan Oilfield as An Example

The distribution characteristics and factors of reservoir movable fluid saturation in different diagenetic facies of Chang 6 in Jiyuan oilfield are analyzed by using high pressure mercury injection, constant mercury injection and nuclear magnetic resonance. Results show that: (1) there are three significant types of diagenetic facies in research area, including the chlorite cementation residual intergranular pore facies, feldspar corrosion facies and kaolinite cementation facies, whose microscopic pore throat structure have remarkable difference, especially in throat. (2) Analyzed from T2 spectrum that the pore throat of cementation residual intergranular pore facies reservoir is well distributed, good connectivity, and percent of movable fluid saturation is high. The pore throat of feldspar corrosion facies reservoir is poorer than cementation residual intergranular pore facies reservoir, and the percent of movable fluid saturation is middle. The pore throat of kaolinite cementation facies reservoir is simplification and small, and the percent of movable fluid saturation is the lowest of all. (3) The main controlling factors of movable fluid saturation in different diagenetic are pore throat radius, mainstream throat radius, pore throat radius ratio, significant pore throat volume, and permeability is one of important factors influencing movable fluid saturation. Another adverse factor is the increase content of kaolinite and illite