联合压汞法表征致密油储层孔隙结构

发布时间：2018-10-29 14:39

【摘要】：致密油是非常规油气资源的重要组成部分,致密油储层的孔隙结构决定并影响着渗流规律。当下主要有2种压汞方法进行储层定量表征,分别为高压压汞法和恒速压汞法。通过对8块致密岩心样品先后进行高压压汞和恒速压汞实验,逐一分析阐明了2种方法在致密油储层孔隙结构表征方面的特性,联合2种压汞实验方法,在同一图版上绘出2种方法的压汞曲线,计算得到8块样品完整的孔径分布曲线,并根据Loucks的分类方法计算得到8块样品的孔径分布直方图。研究结果表明:(1)在低汞饱和度下,恒速压汞总体曲线和高压压汞的进汞曲线重叠完好,说明了该区域是反映同一种孔隙结构。(2)通过综合后孔径分布曲线可以明显看出,致密油储层孔隙半径分布在9.2 nm~500μm之间,致密油储层孔径分布曲线呈多峰形态。右侧孔隙半径80~500μm之间有一个峰,峰值在半径150μm左右,孔隙半径小于1μm的纳米级孔隙大量发育,并出现多个峰值。(3)根据Loucks的分类方法,纳米孔(1μm)是主要的孔隙孔径类型,大于62.5μm的介孔数量次之,中间孔径即微米级孔隙分布最少。
[Abstract]:Tight oil is an important part of unconventional oil and gas resources. The pore structure of tight oil reservoir determines and affects the percolation law. At present, there are mainly two methods for reservoir quantitative characterization: high pressure mercury injection method and constant speed mercury injection method. The characteristics of the two methods in the characterization of pore structure of tight oil reservoir are analyzed one by one through the experiments of high pressure mercury injection and constant velocity mercury injection on 8 dense core samples, and combined with two experimental methods of mercury injection. The mercury injection curves of the two methods were drawn on the same plate, and the complete pore size distribution curves of 8 samples were calculated, and the pore size distribution histograms of 8 samples were calculated according to the classification method of Loucks. The results show that: (1) under low mercury saturation, the global curve of constant mercury pressure and the curve of mercury injection under high pressure are overlapped perfectly. It shows that the area reflects the same pore structure. (2) the pore radius of the tight oil reservoir is between 9.2 nm~500 渭 m, and the pore size distribution curve of the tight oil reservoir is multi-peak form. (2) through the comprehensive post-pore distribution curve, it can be seen that the pore radius of the tight oil reservoir is between 9.2 nm~500 渭 m. There is a peak between 80 渭 m and 500 渭 m of pore radius on the right side, the peak value is about 150 渭 m, the pore radius is less than 1 渭 m, and there are a lot of peaks. (3) according to the classification method of Loucks, Nanometer pore (1 渭 m) is the main pore type, the number of mesoporous larger than 62.5 渭 m is the second, and the middle pore size, that is, micron pore distribution, is the least.
【作者单位】：中国石油大学(北京)油气资源与探测国家重点实验室;
【基金】：国家自然科学基金项目“基于数字岩心的致密油纳米—亚微米尺度储层特征及微观渗流规律研究”(51474222)资助
【分类号】：P618.13;TE311

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