Differential swelling and permeability change of coal in response to CO2 injection for ECBM
Differential swelling and permeability change of coal in response to CO2 injection for ECBM
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DOI：
10.1016/j.coal.2007.11.001
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发表时间：
2008-04
影响因子：
5.6
通讯作者：
S. Mazumder;K. Wolf
中科院分区：
文献类型：
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作者：
S. Mazumder;K. Wolf
当CO2 / CH4吸附在煤的结构上时，煤的基体体积膨胀。在煤层气储层中，基质膨胀会导致裂缝宽度减小，导致渗透率显著降低。单位浓度下，CO2对煤基质溶胀的影响程度大于CH4。这种差异很大程度上是由于煤对二氧化碳和甲烷的吸附能力不同。这种情况在煤储层中会导致差异膨胀。差异膨胀将导致孔隙度/渗透率损失，对碳封存项目的性能和实施产生严重影响。煤可以理解为一种大分子交联聚合物结构。已经进行了一项实验，以测量CO2 / CH4对这种大分子结构的差异膨胀效应，并从理论上将这种效应转化为孔隙度和渗透率。本工作的一个独特之处在于，通过实时渗透率测量来观察饱和CH4煤岩心驱油实验中差应变的真实效果。
The matrix volume of coal swells when CO2 / CH4 adsorb on the coal structure. In coalbed gas reservoirs, matrix swelling could cause the fracture aperture width to decrease, causing a considerable reduction in permeability. On a unit concentration basis, CO2 causes greater degree of coal matrix swelling compared to CH4. Much of this difference is attributable to the differing sorption capacity that coal has towards carbon dioxide and methane. This condition in a coal reservoir would lead to differential swelling. Differential swelling will have consequences in terms of porosity / permeability loss, with serious implication for the performance and implementation of carbon sequestration projects.Coal can be understood as a macromolecular cross-linked polymeric structure. An experimental effort has been made to measure the differential swelling effect of CO2 / CH4 on this macromolecular structure and to theoretically translate that effect in terms of porosity and permeability. A unique feature of this work is that, real time permeability measurements were done to see the true effect of differential strain from CH4 saturated coal core flooding experiments.