利用NMR T2谱分布研究储层岩石孔隙分形结构

Using NMR T_2 spectrum distribution to study fractal nature of pore structure

利用NMR T_2谱分布进行储层岩石分形结构研究,进而分析岩石物性,是一种分析、评价储层孔隙结构与物性的新方法。在前人研究的基础上,首先,对中—高孔渗储层的分形性质作了进一步的分析;其次,着重讨论了在低孔低渗情况下,利用NMR T_2谱分布研究岩石分形结构这一方法的适用性与准确性;最后,对此方法在中—高孔渗储层与低孔低渗储层中的应用进行了对比分析。对中—高孔渗储层与低孔低渗储层研究均表明:利用NMRT2谱法可以较准确地判断岩石孔隙结构的分形性质与进行分形维数计算;同时应用该方法求取的分形维数可以较好地表征岩石物性,从而为储层特征研究、储层分类等提供参考依据。

It is a new method to analyze the fractal nature of pore structure and petrophysical property by using NMR T2 spectrum distribution. Based on the former study, the fractal nature of the medium-high porosity and permeability reservoir is analyzed, and then the applicability and reliability of this method are discussed in low porosity and low permeability reservoir, finally, the application effect of this method in medium-high porosity and permeability reservoir is compared with the effect in low porosity and low permeability reservoir. The result shows that it could determine the fractal nature of pore structure exactly and calculate the fractal dimension by using NMR T2 spectrum distribution. The fractal dimension calculated by this method could characterize the petrophysical property closely and provide reference for reservoir characteristics research and reservoir classification.