The production performances of horizontal drainage wells for the degasification of coal seams have been investigated with the aid of a multi-dimensional, two-phase coal seam degasification model. The model is written in rectangular coordinates and can handle a number of horizontal wells and operates in a one-, two-, or three-dimensional mode. The model accommodates multiple horizontal boreholes originating from a common vertical shaft or horizontal boreholes being drilled from the peripheries of the reservoir. In consideration of relatively thin but large lateral extent of coal seams, flow dynamics around a horizontal borehole is described in elliptical flow geometry. The non-linear system of equations generated by the finite-difference approximation are solved fully implicitly using Newton's iteration.
|State||Published - 1986 Dec 1|