摘要
W区位于鄂尔多斯盆地最为宽广的伊陕斜坡中段,整体表现为西倾单斜,坡度仅1°左右。延长组长9油层组为典型低孔、低渗储层。利用恒速压汞测试获得不同渗透率岩样的孔道半径、喉道半径分布曲线,其孔道半径分布差异不大,而喉道半径差异较大。运用核磁共振技术结合离心法确定W区横向弛豫时间τ2的截止值(τ2,cutoff);渗透率低于0.1mD的岩心核磁图谱主要为单峰结构,平均可动流体饱和度为23.68%,流体主要受到纳米级和亚微米级喉道所控制;渗透率高于0.1mD的岩心核磁图谱主要为双峰结构,平均可动流体饱和度为55.56%,可动流体主要赋存在亚微米和微米孔隙中。
W Area was located in the middle of the most broad Yishan Slope of Ordos Basin.It was wholly a western-leaning monoclinic slope with only about 1°of slope.It was a typical low porosity alow permeability reservoir.The method of constant speed mercury injection was used for obtaining the curves of pore radius and throat radius of rock samples with different permeability parameters,for the rock samples with different permeability parameters,there existed less variation in pore radius distribution and there existed much difference in throat radius.Combined with centrifugation,nuclear magnetic resonance(NMR)technology is used to determine cutoff value as 11.92 ms of timeτ2in W Area,while core nuclear magnetic map with permeability lower than 0.1mD is mainly unimodal structure,movable fluid saturation is 23.68% on the average.The fluid is mainly influenced by the nanoscale and sub-micron throats,core nuclear magnetic map with permeability higher than 0.1mD is mainly bimodal structure,movable fluid saturation is 55.56% on the average,movable fluid mainly occurs in the submicron and micro pores.
出处
《长江大学学报（自科版）（中旬）》
2016年第2期31-35,4-5,共5页
Journal of Yangtze University(Nature Science Edition)
关键词
孔隙结构
可动流体
恒速压汞
核磁共振
pore structure
movable fluid
constant speed mercury injection
NMR
