陇东地区长7致密油储层微观孔喉结构分形特征

Fractal Nature of Microscopic Pore-throat Structure in Chang 7 Tight Oil Reservoir of Longdong Area

微观孔隙结构研究对低渗、超低渗或致密砂岩油藏的渗流机理认识及开发有着极其重要的意义。利用鄂尔多斯盆地陇东地区36口井40块岩样的压汞资料,研究了长7储层微观孔隙结构的分形特征。研究发现,储层孔隙结构存在单一分形和多段分形特征。不同孔径范围具有不同的分形维数。不同的分形特征反映微观孔隙结构组合特征也是不同的,揭示了研究区储层孔隙结构的复杂性。表征微观孔隙结构的参数与分形维数存在良好的线性关系,表明可以用分形维数表征储层微观孔隙结构的非均质性。

[ Abstract] It is extremely important to study micro-pore structure for the understanding of the mechanism of seepage and oil exploitation in low permeability and uhra-low permeability reservoir. And the fractal characteristics of the pore structure are studied according to the capillary pressure analysis data from 40 core samples in 36 wells of Longdong area of ordos basin. The study found that there are both single and multistage fractal characteristics in mi- cro-pore structure. There are different fractal dimension in diameter range. The fractal characteristics of the charac-teristics of the micro-pore structure combination is also different,which reveals the complexity of the reservoir pore structure. Reservoir characterization of micro-pore structure parameters have a good linear relationship with the fractal dimension, thus,it can be seen that the fractal dimension can be used to characterize microscopic heterogeneity of pore structure in the reservoir.