PERFORMANCE COMPARISON OF VERTICAL AND HORIZONTAL HYDRAULIC FRACTURES AND HORIZONTAL BOREHOLES IN LOW PERMEABILITY RESERVOIRS. A NUMERICAL STUDY.

A single/two-phase, multi-dimensional, finite-difference numerical reservoir simulator, which had been validated through history matches against field data, was used to investigate and compare the production performance of horizontal wells and hydraulically stimulated vertical wells. In the case of vertical wells performance characteristics of vertically and horizontally fractured systems were studied. In the mathematical formulation of the transport problem a multi-mechanistic flow mechanism which is obtained by superposition of the Darcian and Fickian flow components is implemented to describe the flow of gas in tight porous media. The non-linear system of equations resulting from the finite-difference approximation are solved by using fully implicit generalized Newton-Raphson procedure. Low permeability, single-phase and two-phase (gas-water) natural gas reservoirs have been selected as the target of this study.