Effects of perforation schemes and non-Darcy flow on hydraulically-fractured gas well performances.

Abstract

Limiting a perforation interval has been proposed as a means to improve hydraulic fracture configurations. This technique, however, may cause productivity impairment, as widely recognized for non-fractured wells. To examine how severe the impairment is for fractured wells, simulation case studies are performed.Unless non-Darcy flow prevails, limited completion does not impair the fractured-well productivity severely; thus, the limiting perforation technique can be applied to oil wells without excessive concern. Even in non-Darcy flow situations, the productivity impairment due to limited completion is not significant for wells with long-and wide-enough fractures. If the fracture configuration is not improved, on the contrary, the productivity impairment can be significant under non-Darcy flow conditions. In such a case, re-perforating the remaining interval is a viable option to reduce the degree of productivity impairment. It is important to assign flow rates evenly over the production interval for mitigating the effects of non-Darcy flow.