摘要
基于对多孔介质流-固耦合力学特征的分析,引出了广义有效应力原理,提出了广义有效应力系数α概念。认为广义有效应力是对煤储层多相耦合渗流力学作用的综合表征。储层多相耦合的宏观动力强度特征可以通过α来集中反映。讨论了煤岩渗透率动态预测的2种方法:数学模型法和直接拟合法。研究认为直接拟合法不必考虑储层内部的各种耦合机制,操作简单易行。总结出可通过拟合的渗透率一般方程求取α的3种方法:方程变形法、Cross--plotting法和微分法。经实例运用Cross--plotting法和微分法对α进行求取,并讨论煤岩的广义有效应力特征,证实了对α及广义有效应力原理理解的正确性,广义有效应力原理在评价煤储层固-流复杂耦合过程中准确预测渗透率变化。
Based on analysis of the fluid-solid coupling mechanics features of the porous media,a general effective stress principle was derived and a conception of the general effective stress coefficient α was provided. The paper held that the general effective stress was a comprehensive characterization of the multiphase coupling seepage mechanics role in the coal reservoir. The multiphase coupling macro dynamic strength features of the coal reservoir could be centrally reflected with the α. Two methods of the coal-rock permeability dynamic prediction were discussed and they were the mathematic model method and the direct fitting method. The study showed that the direct fitting method could not consider different coupling mechanism within the reservoir and could be easily operated. The paper summarized that with the fitting permeability,the general equation could obtain three methods of the α and they were the Equation Deformation Method,Cross-plotting Method and Differential Method. With the case application,the Cross-plotting Method and Differential Method could be applied to obtain the α. The paper discussed the generalized effective stress features of the coal-rock. The paper verified the understand correction of the α and the generalized effective stress principle and the generalized effective stress principle was correct to predict the permeability variation of the coal reservoir in the fluid-solid complicated coupling process of the comprehensive evaluation.
出处
《煤炭科学技术》
CAS
北大核心
2015年第7期30-34,共5页
Coal Science and Technology
基金
国家科技重大专项资助项目(2011ZX05040-005)
河南省高校科技创新团队支持计划资助项目(14IRTSTHN002)
河南省瓦斯地质与瓦斯治理重点实验室--省部共建国家重点实验室培育基地资助项目(WS2013A11)
河南省教育厅重点研究资助项目(14A440008)
关键词
广义有效应力
多相耦合
渗透率
拟合方程
generalized effective stress
multiphase coupling
permeability
fitting equation
