摘要
煤岩孔隙结构对煤层气解吸、扩散、渗流具有重要影响。分形理论为孔隙结构研究提供了有效的方法,但目前对煤岩孔隙分形特征的表征方法尚未形成统一认识,需要进一步研究。从分形定义出发,建立了新的煤岩孔隙结构分形特征表征方法,然后通过煤岩压汞实验对分形定义法和文章新建方法进行对比评价,最后对煤岩分形区间和分形维数进行了探讨。结果表明,通过文章提出的毛管压力法确定的分形区间和分形维数与通过分形定义法得到的结果非常接近,是表征煤岩孔隙结构分形特征的有效方法;煤岩在整个孔隙空间上具有分形特征,且其分形维数能够有效表征煤储层非均质性,分形维数越大,煤储层物性越差,非均质性越强。
Pore structure of coal rock has significant effect on the adsorption, diffusion and even seepage behavior of CBM. The fractal theory provides an effective method for the study of the pore structure, while there has not yet been a unified understanding of how to characterize the fractal features of pore structure of coal rock. Based on the fractal definition, we propose a new characterizing method for the fractal characteristics of coal pore structure. Then, mercury injection experiments are carried out to compare the new method proposed by this paper with the fractal definition method. At last, the fractal zone and fractal dimension values have been discussed. The results show that the fractal zone and fractal dimension values calculated by the capillary pressure method proposed by this paper are nearly equal to the values calculated by fractal definition method. So, the capillary pressure method is an effective method to identify the fractal features of pore structure of coal. The fractal dimension values can reflect the heterogeneous features of coal reservoir. When the fractal dimension values grow larger, the physical properties of reservoirs become poorer and the heterogeneous features of coal reservoir become stronger.
作者
徐欣
徐书奇
邢悦明
贾慧敏
XU Xin1, XU Shuqi3, XING Yueming3, JIA Huimin4(1.Key Laboratory of Oil and Gas Resources and Survey Technology of the Ministry of Education, Yangtze University, Wuhan 430100, China;2.College of Earth Sciences, Yangtze University, Wuhan 430100, China;3.School of Petroleum and Natural Gas Engineering, Chongqing University of Science and Technology, Chongqing 401331, China;4.Shanxi CBM Branch Company, Petro China Huabei Oifield Company, Jincheng 046000, Chin)
出处
《煤矿安全》
CAS
北大核心
2018年第3期148-150,共3页
Safety in Coal Mines
关键词
中高阶煤岩
孔隙结构
分形理论
表征方法
煤层气
medium to high rank coal rock
pore structure
fractai theory
characterization method
CBM
