Erosion Aspects for Completion and Hydraulic Fracture Design in Long Horizontal Wells for Conventional Reservoirs

Abstract The impact of erosion when designing hydraulic fracture treatments in conventional assets has received less focus when compared to perforation erosion for unconventional wells using the limited-entry technique. For conventional assets that are hydraulically fractured, larger proppant and higher proppant concentrations are used in comparison to unconventional wells, and the stimulation operation is typically pumped down the production tubing where the completion jewelry is exposed to erosion risk. This study examines the erosion relationship of the hydraulic fracture design to the completion equipment. Larger proppant and higher proppant concentrations can increase the erosion risk considerably. The recent development of unlimited frac sleeve technology allows for more stages to be pumped in a well without typical ball seat restrictions and additional friction. However, more stimulation stages could increase the erosion risk of components due to more proppant volume. This study examines the downhole erosion post-stimulation by 1) multi-finger caliper (MFC), 2) ultrasonic image logging tool, 3) examination of retrieved isolation sleeves, and 4) visual inspection of the latch on a dummy valve retrieved post-frac, the frac trees and frac irons. In addition, surface erosion fixture testing was performed to quantify the erosion risk. Both MFC and ultrasonic image logs provided post-frac erosion measurements which allowed us to identify the root cause of frac sleeve opening failures. Isolation sleeves set across the upper completion components were retrieved which provided data on erosion of the downhole mechanical components. Surface erosion fixture testing was performed before any equipment was trialed downhole to avoid excessive erosion which would prevent stimulating the entire lateral. The erosion damage was found to be significant, requiring fracture fluid and completion hardware modifications. Erosion risk must be evaluated carefully when hydraulic fracture stimulation is performed in long horizontal wells. Predicting erosion is not straightforward even with advanced computational fluid dynamics modeling. This paper presents best practices to minimize substantial erosion damage downhole.