Numerical simulation of heterogeneous fractured gas reservoir systems with turbulence and closure stress effects.

Abstract

Although techniques for designing a fracture treatment are available, the intended results of these techniques are often not attained. The evaluation of fracturing treatments on low permeability gas wells is required to both optimize the fracturing design and form prediction calculations of a treatments effect.

This study primarily investigates the effect of fracture height on the performance of vertically fractured wells. The effects of layered media, turbulance, and closure pressure are included in this work.

Consider that a well, intercepted by a vertical fracture, is in the center of a squared drainage system with closed outer boundary. Any increase in well productivity will be determined by fracture parameters, which are: fracture length, height, fracture conductivity, and location of the fracture in the formation.

Presented here are the numerical results of the three-dimensional model for a well intercepting a vertical fracture with finite conductivity. The results are presented in the general form of dimensionless variables. Type curves considering the effect of fracture height on well performance are included. In addition, type curves for turbulent flow in the fracture are also obtained. Finally, other important contributions of this work are the data showing the effect of layered formation on fractured well performance.

On the basis of the analysis of fluid flow in porous media, the problem solving technique used in this study is the numerical method. A three-dimensional finite difference fully implicit model was written for this. In addition, the Sparse Matrix technique was used as a solver. Furthermore, Slices Source Over Relaxation was used as an iterative method for solving routines.