Practical Well Test Analysis of a Hydraulically Fractured Low Permeability Gas Reservoir: A Case History

Abstract

The primary objective of hydraulic fracturing is to create a propped fracture with sufficient conductivity and length to amplify or at least optimize well performance of low permeability tight gas reservoir. The oil industry has suggested that hydraulically fractured tight gas wells performance is hindered significantly by non-Darcy flow effect.This work will present an investigation of non-Darcy flow effect to hydraulically fractured gas wells performance and provide the development, validation, and application of actual well test analysis for wells with a finite conductivity vertical fracture.Also, this work presents the results obtained in the study of actual post frac modified isochronal test data of gas wells intersected by a finite conductivity vertical fracture in a tight low permeability gas reservoir. In addition, the estimation of reservoir properties and fracture properties were carried out to construct a simple analytical model, which used for rate prediction.The effect of non-Darcy flow in fractures is clearly seen in the tests data and will lead to limiting production especially on higher chokes (after one inch). Therefore, non-Darcy effects should be considered in design of hydraulic fracture treatments, otherwise the design might be far from optimal