The productivity index of a hydraulically fractured natural gas well depends on the effective permeability of the propped fracture, mass of proppant placed into the formation and fracture geometry. Non-Darcy flow reduces the effective permeability of the propped pack. Therefore, for a predetermined mass of proppant, this effect should be considered to get the optimal fracture geometry that maximizes well performance. Β Factor is the most important variable to evaluate non- Darcy flow effects on the propped pack permeability. Therefore, a good estimation of this variable is required. An extended search through four databases allowed establishing that 24 b factor correlations have been developed so far. Proppant and core lab tests, as well as analytical studies have been the source of these correlations. In the past, these correlations have been used without considering the impact of correlation selected in the results of the fracture treatment design. An Excel/VBA application, which includes all b factor correlations, was developed for designing optimal fracture treatments in natural gas well considering non-Darcy flow effects through the propped fracture. Β factor correlations were evaluated in 108 hypothetical cases. Results suggest that only four correlations not obtained from proppant tests, besides correlations developed from this source, can be used in this case. Fracture designs performed in four natural gas wells, using Excel/VBA application, suggest that wider and shorter fractures are required to compensate non-Darcy flow effects, while maximizing well performance and economics.
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