Modelling laboratory horizontal stress and coal permeability data using S&D permeability model

作者：Shi Ji Quan^*; Durucan Sevket

来源：International Journal of Coal Geology, 2014, 131: 172-176.

DOI：10.1016/j.coal.2014.06.014

• Laboratory permeability experiment
• Uniaxial strain condition
• Horizontal stress
• Model match
• S& D permeability model

A modelling study was carried out on a set of recently published horizontal (radial) stress and permeability data, obtained under uniaxial strain conditions, using Shi and Durucan permeability model. During the permeability experiment, the no-displacement lateral boundary condition was maintained through adjusting the applied confining pressure as the pore pressure was reduced to simulate coalbed methane production. The reported variations in the effective horizontal stress for a San Juan Basin core sample were first matched by tuning the elastic properties (Young's Modulus and Poisson's ratio) for the coal sample, which were unknown. The Young's Modulus was found to fall in a rather narrow range of 2.35 to 255 GPa, with the corresponding Poisson's ratio in the range between 0.25 and 0.35. The availability of both permeability and horizontal stress data allows for the determination of the cleat volume compressibility. It was found that the semi-log plot of permeability increase vs. reduction in the effective horizontal stress displayed a bi-linear trend. The results of this study have demonstrated that the published laboratory horizontal stress and permeability data can be adequately described by S&D permeability model.

• 出版日期2014-9-1