致密砂岩储层可动流体赋存特征及影响因素

应用核磁共振、恒速压汞、铸体薄片等实验手段,分析辽河西部凹陷南段沙三段致密砂岩储层可动流体赋存特征及影响因素。结果表明:可动流体T2谱截止值低,孔隙内可动流体饱和度与可动流体孔隙度低且数值波动大;T2谱形态主要呈单峰型、左峰高右峰低型和左峰低右峰高型;T2弛豫时间受孔喉结构控制,喉道特征决定流体的可动程度,孔喉半径比、分选系数和微观均质系数反映孔隙结构非均质程度与流体参数线性相关性较强,T2谱分布特征与孔隙组合类型和孔喉结构特征有关;胶结物类型、产状与含量对可动流体影响较大。微观孔隙结构特征是可动流体赋存特征的主要影响因素,胶结物次之,物性对可动流体的影响是两者的综合反映。

Characteristics and Influencing Factors of Movable Fluidin Tight Sandstone Reservoir

The characteristics and influence factors of reservoir movable fluid of the tight sandstone reservoir of the third member of shanhejie formation in the southern west depression in liaohe basin are analyzed by using nuclear magnetic resonance, constant-speed mercury injection and the casting thin sections. Results show that the amplitude of T2 spectrum is relatively low, movable fluid saturation and fluid porosity in pore is low and varies a lot. T2 spectrum mainly display unimodal mode, right low left high mode and right high left low mode. The relaxation time of T2 spectrum is controlled by pore structures. The throat characteristics determine movable fluid level. The fluid is mainly contained in pore, pore throat radius ratio, coefficient of sorting and the mean micro prime numbers reflects that the heterogeneity degree of pore structure and the fluid parameters have strong linear relation. The distribution characteristics of T2 spectrum and pore combination type are related to pore structures characteristics. The type, occurrence and content of cements have great influence on movable fluid. Micro-pore structure is the main influence factor of the movable fluid, second is cements, and physical properties are comprehensive reflection of movable fluid for both factors.