Optimization of the Performance of High-Permeability Fractured Wells

Abstract

Abstract High-permeability fracturing (frac&pack) has become a major new stimulation treatment, intended to improve well performance and not just to control sand production. Viewed as such, an optimization is warranted balancing the size of the fracture with incremental well performance. Analogous schemes have been introduced in unrestricted fracturing for low-permeability formations, using the fracture half-length vs. the net present value (NPV) as the optimization criterion. While a physical optimization for all fractures, suggested by many, implies a dimensionless conductivity around unity, such a value may neither be possible nor economically attractive in high-permeability reservoirs. We are presenting here a scheme, combining high-permeability fracture modeling with expected well performance which, along with the NPV calculation, leads to a three-dimensional Optimization. This optimization, allowing fracture half-length and width variation, provides the optimum width for each fracture length and the global optimum for all lengths at which the NPV is maximum. Treatments should be designed for the optimum width and length combination. Parametric studies are done with post-treatment skins (other than the theoretical negative values) denoting the major impact of fracture face damage and fracture-well connectivity. P. 481