Focusing on the application of monofractal and multifractal theory in unconventional reservoir research, the research results on the application of fractal theory in quantitative characterization techniques, digital image techniques and techniques for joint multi-method characterization of full-scale pore structure are reviewed. There are four weaknesses in the existing research results: 1) lack of methodological research on joint multi-method for full-scale fractal geometric characteristics; 2) lack of research on the applicability of different fractal dimension calculation models; 3) lack of research on the control factors of segmental fractal pore size; 4) lack of research on the heterogeneity differences of reservoirs containing multiple types of resources by applying fractal theory. The development direction of the application of fractal theory in unconventional oil and gas reservoirs is proposed. On the one hand, the methodological and applicability research of fractal dimension calculation models should be strengthened, and the controlling factors of segmental fractal pore size should be clarified; on the other hand, more in-depth research should be conducted on the dynamic coupling relationship between hydrocarbon generation and fractal dimension change, and the further application of multiple fractal theory in the study of unconventional reservoirs should be strengthened.

围绕单重分形和多重分形在非常规油气储层研究中的应用问题, 总结分形理论在定量表征、数字图像和联合多种方法表征全尺度孔隙特征等方面的应用研究成果, 指出现有研究中存在4个方面的不足: 1) 缺乏联合多种实验方法表征全尺度分形几何特征的方法学研究; 2) 缺乏不同分形维数计算模型的适用性研究; 3) 缺乏针对分段的分形孔径控制因素研究; 4) 缺乏应用分形理论对蕴含多类型资源储层的非均质差异性研究。提出分形理论在非常规油气储层研究中应用的发展方向: 一方面, 应加强分形维数计算模型的方法学和适用性研究, 厘清分段分形孔径变化的控制因素; 另一方面, 应围绕油气生成与分形维数变化的动态耦合关系开展深入的探讨, 加强多重分形理论在非常规油气储层中的应用研究。