分形维数定量表征煤岩储层非均质性  

Quantitatively characterizing the heterogeneity of coal deposits based on fractal dimension

作　　者：袁哲[1,2] 刘鹏程[1,2] 冯高城[3] 

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]中国地质大学(北京)非常规天然气地质评价与开发重点实验室,北京100083 [3]中海油能源发展股份有限公司工程技术分公司非常规技术研究院,天津300457

出　　处：《中国科技论文》2015年第9期1010-1013,共4页China Sciencepaper

基　　金：中央高校基本科研业务费专项资金资助项目(2652013094);国家科技重大专项资助项目(2011ZX05015-002)

摘　　要：针对传统方法难以定量描述煤岩储层非均质性的问题,提出了一种新的适用于煤岩的毛管压力模型,来评价煤岩储层的非均质性。该模型基于分形理论,引入孔隙分布指数,并考虑迂曲度参数的影响,通过恒速压汞法测量某煤矿的煤岩岩心的孔隙度、渗透率,得到毛管压力曲线,对毛管压力曲线进行拟合得到分形维数;利用孔隙大小分布曲线,分析并验证计算得到的分形维数,与其他几种常用的计算分形维数的方法相比,该方法更精确可靠。最后定量分析分形维数与非均质性的关系及分形维数与煤岩的孔隙喉道,以及孔隙度和渗透率的关系,结果表明,该方法可以定量评价煤岩储层的非均质性。Traditional methods have difficulties in quantifying the heterogeneity of coal deposits.Therefore,a new capillary pres-sure model is proposed to evaluate the heterogeneity of coal reservoir.Based on fractal geometry,the model introduces pore size distribution index and considers the impact of tortuosity parameter.Capillary pressure curve is determined by porosity and perme-ability of drill cores from certain coal mine,which were measured by constant-rate mercury penetration technique.Fractal dimen-sion was obtained by fitting capillary pressure curve.In comparison with results of conventional methods,results of fractal di-mension can be testified by analyzing the pore volumetric percent curves,and thus are more accurate.Finally,relationships be-tween fractal dimension and heterogeneity,and relationships between fractal dimension and pore diameter,as well as relationships between porosity and permeability,were analyzed quantitatively.The new method is applicable in quantifying the heterogeneity of coal deposits.

关 键 词：煤岩 非均质性 毛管压力模型 分形维数 孔隙喉道 

分 类 号：P618.13[天文地球—矿床学]