黔西地区煤样孔隙综合分形特征及对孔渗性的影响

发布时间：2018-04-11 21:07

本文选题：黔西地区 + 煤储层　；参考：《煤炭学报》2017年05期

【摘要】：为了定量描述煤储层孔隙结构的复杂程度,基于压汞试验测试结果,运用分形理论,对黔西地区不同煤阶的32个煤样进行了分形特征研究,并探讨了分形几何参数与煤储层孔渗性的关系。结果表明:煤储层孔隙分形维数可分为渗流分形维数和扩散分形维数,利用不同分形段的孔隙体积比作为权值,通过加权求和方法可得到综合分形维数;渗流分形维数随变质程度增加而减小,扩散分形维数和综合分形维数均随变质程度增加而增大;分形界限、扩散孔隙体积分数及总孔体积都与综合分形维数、扩散分形维数具有较好的相关性,而且3个指标参数与综合分形维数的相关系数均高于与扩散分形维数的相关系数;综合分形维数、分形界限及扩散孔隙体积分数与煤储层孔隙度之间为负幂指数相关关系,总孔体积与煤储层孔隙度为线性正相关关系,与渗流分形维数和扩散分形维数相比,综合分形维数更有利于表征煤储层渗透性。
[Abstract]:In order to quantitatively describe the complexity of pore structure of coal reservoir, based on the test results of mercury injection test, the fractal characteristics of 32 coal samples with different coal ranks in western Guizhou were studied by using fractal theory.The relationship between fractal geometric parameters and porosity and permeability of coal reservoir is discussed.The results show that the pore fractal dimension of coal reservoir can be divided into seepage fractal dimension and diffusion fractal dimension.The fractal dimension of seepage decreases with the increase of the degree of metamorphism, the fractal dimension of diffusion and the fractal dimension of synthesis increase with the increase of metamorphism, the fractal limit, the volume fraction of diffusion pore and the total pore volume are all related to the comprehensive fractal dimension.Diffusion fractal dimension has good correlation, and the correlation coefficient between three index parameters and synthetic fractal dimension is higher than that with diffusion fractal dimension.The relationship between fractal boundary and diffusive pore volume fraction and coal reservoir porosity is negative power exponent correlation, and total pore volume is linear positive correlation with coal reservoir porosity, compared with seepage fractal dimension and diffusion fractal dimension.The comprehensive fractal dimension is more favorable for characterizing the permeability of coal reservoir.
【作者单位】：贵州省煤层气页岩气工程技术研究中心;贵州省煤田地质局159队;中国矿业大学资源与地球科学学院;
【基金】：国家科技重大专项资助项目(2016ZX05044001-005) 贵州省科技重大专项资助项目(黔科合重大专项字[2014]6002号) 中国地质调查局资助项目(12120114020201-05)
【分类号】：TD84

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