Time Lapse Wear Study Yields New Design Features to Improve the Erosion Resistance of Stand-Alone Screen Completions

Abstract

As operators focus on harvesting stranded reserves from existing infrastructures, specific technical challenges and ROI calculations are affecting sand control completion selection and putting screen design requirements in a new light. In-fill drilling and completion of sidetracked wells in depleted reservoirs are not favorable to gravel packing because low hydraulic frac pressures and small wellbores make conventional gravel packing operations incredibly challenging, if not downright impossible. Furthermore, gravel packing is selected when operators are looking for a long-term sand control solution warranted by significant reserves, something that is not necessarily present in brown field redevelopments. As a result, there is a need to improve stand-alone completions, and particularly improve the erosion resistance of screens that have been known to fail by hot spotting, where localized high flow situations erode the screen and lead to completion failure. A series of time lapse erosion tests was conducted to identify critical damaging mechanisms and evaluate solutions, including mesh materials and design features to improve the erosion resistance of mesh screens. The test program included detailed examination of the test coupons in frequent intervals to identify wear features and trends over time. This approach to testing was instrumental in characterizing damaging backward eddies inside the screen and developing solutions to mitigate their impact. From this test campaign, two new features were found to substantially improve screen erosion resistance. A hardening process to treat meshes commonly used in screens increased the Mean Time to Failure (MMTF) by 50%. Furthermore, a novel shielding concept aimed at preventing direct line-of-sight flow to the basepipe perforations (while maintaining the filter surface area and good flow distribution over the screen length) reduced mesh weight loss by 75% and maintained the original maximum pore size beyond the 72hour success criteria, for an estimated MTTF improvement well over 300%.