Abstract
Post-frac production analyses frequently suggest that effective fracture area is significantly less than that designed, implying either the existence of excessive proppant-pack damage or, that the proppant was not placed in designated areal location. The conductive fracture area is defined by the propped fracture height and the effective fracture length. Optimization of effective fracture area is among the principal tenets of fracturing design engineering. It is well understood that effective fracture area is a first order driver for well productivity, and optimization of such is often critical to economic exploitation of reservoir assets.
The results of extensive testing in a large-scale slot apparatus to delineate the relative effects of various component and treatment parameters on proppant transport capability were reported previously. In an extension of that effort, an empirical proppant transport model has been developed using the information gleaned from previous testing and then refined using newly generated data to expand the range of the various component parameters. The model has input parameters including fluid viscosity, proppant size, both fluid and proppant specific gravity, injection rate, and fracture geometry. The model output is the estimated propped fracture length of a given treatment design incorporating a fracturing fluid slurry having the input parameters.
Utilizing the new model, the most favorable combination of fracturing slurry component properties and pumping parameters can identified and incorporated in fracturing treatment design and applications to optimize effective propped fracture length, and thereby well performance.
