ANALYTICAL SOLUTIONS FOR GAS-FLOW DUE TO GAS INJECTION AND EXTRACTIONFROM HORIZONTAL WELLS

Analytical solutions are developed for modeling the transient and stea dy-state gas pressure and the steady-state streamfunction fields resul ting from gas injection and extraction from a pair of parallel horizon tal wells. These solutions apply to cases in which the ground surface is open to the atmosphere, and in which the porous media is anisotropi c but homogeneous. By neglecting end effects due to the finite length of the wells, the three-dimensional gas flow field is approximated as a two-dimensional cross section perpendicular to the wells. These solu tions may be used to develop estimates of the horizontal well system b ehavior and to analyze horizontal well gas pump tests, and are useful for numerical model verification.