Optimization of Fractured Well Performance of Horizontal Gas Wells

Optimization of Fractured Well Performance of Horizontal Gas Wells. (August 2007) Fellipe Vieira Magalhães, B.S., Texas A&M University Chair of Advisory Committee: Dr. Ding Zhu In low-permeability gas reservoirs, horizontal wells have been used to increase the reservoir contact area, and hydraulic fracturing has been further extending the contact between wellbores and reservoirs. This thesis pre ents an approach to evaluate horizontal well performance for fractured or unfractured ga s wells and a sensitivity study of gas well performance in a low permeability formation . A newly developed Distributed Volumetric Sources (DVS) method was used to calculate d imensionless productivity index for a defined source in a box-shaped domain. The unique features of the DVS method are that it can be applied to transient flow an d pseudo-steady state flow with a smooth transition between the boundary conditions. In this study, I conducted well performance studies by appl ying the DVS method to typical tight sandstone gas wells in the US basins. The objective is to determine the best practice to produce horizontal gas wells. For fract u ed wells, well performance of a single fracture and multiple fractures are compared, and the effect of the number of fractures on productivity of the well is presented based on the well productivity. The results from this study show that every basin h as a unique ideal set of fracture number and fracture length. Permeability plays an important role on dictating the location and the dimension of the fractures. This study indicated that in order to achieve optimum production, the lower the permeability of t he formation, the higher the number of fractures.