Direct and inverse problems of gas emission and the sorptive deformation of coal beds
NAZAROVA ; VANDAMME ; PEREIRA
Type de document
ARTICLE A COMITE DE LECTURE REPERTORIE DANS BDI (ACL)
Langue
anglais
Auteur
NAZAROVA ; VANDAMME ; PEREIRA
Résumé / Abstract
Using the equations of state for fractured-porous media that describe the sorptioninduced deformation of coal, we develop a geomechanical model for radial gas influx to a borehole drilled in a coal bed with the concurrent evolution of stress field in the borehole environment. A numerical-and-analytical method is proposed for solving the corresponding system of equations for poroelastic media. A relation is found between the volume of slack withdrawn in the borehole (when opening up the gas-bearing seams), the sorption-and-storage capacities of coal, the permeability k, and the horizontal component h of the natural stress field. We demonstrate the solvability of the inverse boundary-coefficient problem of determining k and h on the basis of pressure in the closed borehole. We substantiate an express-method for estimating the permeability by the measurements of pressure in the borehole operating in the pressure drop mode.
Source
Journal of Applied and Industrial Mathematics, num. 2, pp.236-243 p.
Editeur
MAIK Nauka/Interperiodica
