马岭油田致密砂岩储层可动流体赋存特征及控制因素

Characteristics and controlling factors of movable fluid in low-permeability and tight sandstone reservoirs in Maling Oilfield

以马岭北油田三区延10储层为对象,运用恒速压汞、铸体薄片、核磁共振、X衍射等实验手段,探讨影响可动流体赋存差异的主控因素。结果表明:研究区可动流体饱和度较高,T2谱形态表现为4种类型,微观孔隙结构是可动流体赋存的主要控制因素,孔喉半径比和饱和度中值毛细管力与可动流体相关系数分别为0.911 8,0.870 7;黏土矿物类型、体积分数以及赋存状态也是影响可动流体饱和度的重要因素,而分选系数、变异系数、中值半径等则对可动流体饱和度的影响较弱。

Taking the Yan-10 low-permeability and tight sandstone oil reservoir of NoAh-Ⅲ Block in Maling Oilfield as an example, a series of experiments were conducted, including constant-speed mercury injection, casting thin slice, nuclear magnetic resonance, X- ray and so on. With all these techniques, the controlling factors which affect the distribution of movable fluid was discussed. The research shows that： the research area has high saturation of movable fluid and four modes of T2 pattern, and the micro-pore structure determines the existing state of movable fluid in low-permeability and tight sandstone reservoirs; the correlation coefficient between the pore-throat ratio and movable fluid is 0.918 8, and the coefficient between capillary pressure at medium saturation and movable fluid is 0.870 7; the content, the occurrence states, and the filling degree of clay mineral are also important factors affecting the saturation of movable fluid. While the sorting factor, the coefficient of variation and median radius have less effect.