Several recently introduced oilfield perforators incorporate reactive materials that are derivatives of military-based weapons technology. Perforator suppliers claim that using reactive charges facilitates tunnel cleanup creating optimized perforations, thus improving downhole performance leading to increased well productivity. To better understand and quantify differences in penetration and flow performance between reactive shaped charges and conventional shaped charges, a comprehensive test matrix was designed. The performance assessments of reactive versus nonreactive perforators were carried out under controlled conditions in an API Perforation Flow Laboratory (PFL) (API, 2006).
The Phase I tests for this study, which involved shooting into stressed rock under simulated downhole conditions, were conducted in Berea Sandstone targets with mineral-oil flow, to simulate a typical oil-bearing formation. Phase II testing will be conducted in Carbon Tan Sandstone with nitrogen flow, to simulate a typical gas-bearing formation. The Berea Sandstone represented moderate-to-high porosity and permeability rocks with high, unconfined compressive strength (UCS). The Carbon Tan Sandstone will represent low-permeability and medium-porosity rocks with moderate-UCS.
In order to further understand the contribution of the ‘reactive’ component, tests designed for this study are carried out in balanced, underbalanced and overbalanced conditions. Charge performance measurements are taken for both conventional and ‘reactive’ charges in each target reservoir rock. This paper describes the methodology used for the comparative tests between ‘reactive’ and ‘nonreactive’ perforators in the Berea Sandstone portion of the program and summarizes the observations of core penetration, tunnel cleanup and productivity.