Oilfield operators and service companies continually face challenges to provide completions that not only produce at optimum levels but also accelerate return on investment (ROI). These operational demands are further complicated by the fact that the range of reservoir scenarios continues to expand. In attempting to satisfy these needs, one component of the completion process is often over looked or taken for granted - the perforation process.
In the energy industry, many companies base their selection of shaped-charge perforators solely on API Section I criteria such as depth of penetration or casing-exit hole size. Other factors, such as the actual performance of given shaped charges at in situ conditions, also should be evaluated when making perforating decisions for the completion process. Focusing perforator system performance on reservoir productivity rather than on the shaped-charge performance optimized for concrete testing (which is the case with API Section I) can ultimately lead to significant improvement in well inflow performance.
Although API RP43 Section IV perforating procedures (to evaluate well perforators under in-situ conditions) have existed since 1985, there has been limited field validation of experimental results and model predictions based on these procedures.1-3 This paper discusses insights gained from a series of Section IV tests conducted with Berea and Castlegate sandstone cores under varying in situ conditions. The Section IV lab experiments represent physical models of the near-wellbore region during perforation and completion processes under in-situ stress. The results of these experiments indicate that understanding the inherent system inadequacies and experimental conditions is critical to proper integration of the results with theoretical models and field data.