砂岩储层微观结构分形特征研究——以胜坨油田古近系沙河街组储层为例

Fractal Feature about the Micro-structure in Sandstone Reservoir: Taking the Paleogene Shahejie Formation in Shengtuo Oilfield as an Example

岩石微观结构研究是当今储层研究的难点问题,储层微观结构影响和控制了储层微观性质和宏观特征。运用胜坨地区3口井的40个不同沉积类型储层的岩心薄片分析资料及压汞资料求取了其分形维数,利用分形几何的基本理论研究了储层微观结构参数特征,结果表明储层微观孔隙结构在一定的尺度范围内具有分形特征,进一步研究了储层物性、储层微观结构参数与分形维数的定量关系。研究发现,无论从单井数据还是多井数据的分析结果均表明,分形维数与储层物性参数、孔隙结构参数具有较好的相关性,且与三角洲平原储层相比,三角洲前缘储层的分形维数与物性参数、储层微观结构参数的相关性更好。可见,分形维数可以综合反映孔隙空间复杂程度,可以用于储层微观结构分析。

The study of rock micro-structure is very difficult at present. The micro-structure of the reservoir controls not only the micro-character of the reservoir but also the macro-character. Using the fractal theory and the data of mercury injection and thin-section from 3 wells about 40 samples in Shengtuo, the micro- pore structure characteristics of the reservoir was studied. Results indicate that the micro-structure shows fractal features to some extent. We measured the fractal dimension and built up the quantitative relation- ship of physical property and the micro-structure parameters with fractal dimension. We found they have good correlation and correlation of delta-front is better than delta-plain. Thus it can be seen that the fraetal dimension can reflect the complexity of the pore-space synthetically and it can be used to do comparative e- valuation for different reservoirs.