收稿日期: 2013-01-16
修回日期: 2013-02-21
网络出版日期: 2013-10-10
基金资助
国家科技重大专项课题“煤层气开发动态评价模型与软件系统”(编号:2011ZX05034-005；2011ZX05042-003)；河南省安全生产发展计划项目(编号:H12-092)联合资助.
The Change Law about the Coal Matrix Shrinkage during Water-Gas Flow Stages
Received date: 2013-01-16
Revised date: 2013-02-21
Online published: 2013-10-10
查明煤层气井产气后煤基质收缩变化规律是进行此阶段渗透率变化研究的基础。基于排采过程中表面自由能、有效应力系数、弹性模量的改变对煤基质变形的重要影响，根据表面物理化学、损伤断裂理论分别对表面自由能增量数理模型、有效应力系数数理模型与弹性模量数理模型进行了构建；并基于弹塑性力学对三者的影响进行了叠加，结合樊庄区块地质与压裂排采资料，对气、水两相流阶段煤基质收缩变化规律进行了研究。结果表明:气、水两相流过程中综合表面自由能、有效应力系数与弹性模量影响下的煤基质收缩变形呈近对数形式持续逐步增加。其中表面自由能、有效应力系数对基质收缩变形的影响较大，弹性模量影响较小。排采时在气、水两相流阶段应注意后续气、水补给的连续性。
倪小明，张崇崇,王延斌，王向浩 . 气、水两相流阶段煤基质收缩变化规律研究[J]. 天然气地球科学, 2013 , 24(5) : 1069 -1073 . DOI: 10.11764/j.issn.1672-1926.2013.05.1069
It is a fundamental study of permeability′s variation by identifying the change law of the coal matrix shrinkage during water-gas flow stages.Due to the significant influence of surface energy,the effective stress coefficient,modulus of elasticity on the coal matrix shrinkage,according to surface physics-chemistry,fracture and damage mechanics,three mathematical models have been established.Then according to the elastic-plastic mechanics,overlying the three influences,combining the Fanzhuang fracturing and drainage data,the change law of the coal matrix shrinkage during water-gas flow stages was studied and the results show that the coal matrix shrinkage deformation is continual and it gradually increases in nearly logarithmic form.It can be seen that the surface energy and the effective stress coefficient have greater impact on the matrix shrinkage deformation than the modulus of elasticity′s.We should pay attention to the continuous supply when drainage during the water-gas flow stage.
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