鄂尔多斯盆地延安组储层分形特征研究——以红河油田为例

Study on Reservoir Fractal Characteristics of Yan’an Formation in Ordos Basin——Taking Honghe Oilfield as an Example

压汞是研究致密储层孔喉结构的技术之一,它可以测定总孔体积、孔径分布以认识致密储层的孔喉结构。通过对红河油田延安组红河207、红河198等井的19组岩心开展压汞实验并结合分形理论的几何模型,lgs和lgr的线性相关系数在0.977~0.998之间变化,标准偏差0.06,说明延安组储层岩石孔隙具有良好的分形结构;计算的孔隙结构的分形维数在2.49~2.68之间变化,平均值2.60,标准偏差0.06。经研究发现孔喉分形维数与孔隙度、渗透率、相对分选系数、结构系数、平均孔喉半径有一定的相关性,说明在延安组层位中分形维数也可以作为表征储层孔隙结构特征的参数,对准确认识储层有积极意义。

Mercury injection is one of the techniques to study pore throat structure of tight reservoir. It can measure total pore volume and pore diameter distribution to understand pore throat structure of tight reservoir. The linear correlation coefficients of lgs and lgr is between 0.977 and 0.998, and the standard deviation is 0.06.Aaccording to HH 207, HH 198 wells’ 19 cores mercury injection experiments of Yan’an formation in Honghe oilfield, the pore of Yan’an formation has a good fractal structure, and the fractal dimension of the pore structure varies from 2.49 to 2.68, with an average value of 2.60 and a standard deviation of 0.06. It is found that fractal dimension of pore throat is related to porosity, permeability, relative sorting coefficient, structural coefficient and average pore throat radius, it shows that the fractal dimension can also be used as a parameter to characterize the pore structure of the reservoir in Yan’an formation, which is of positive significance to accurately know the reservoir.