Data-Driven Optimization of Overflush Design to Prevent Wireline Conveyance Failures in Multistage Plug-And-Perf Fracturing

Abstract

Abstract

Abstract In multistage hydraulic fracturing of horizontal wells using the plug-and-perforate (P&P) technique, residual proppant and debris from inadequate flushing can lead to serious wireline (WL) conveyance issues. These include tool hang-ups, plug missetting, and incomplete perforating runs, often resulting in costly cleanout operations, increased non-productive time (NPT), and reduced job efficiency. This study analyzes historical fracturing and WL data to identify the key factors contributing to insufficient proppant cleaning and provide practical insights to optimize the overflush process for improved operational reliability. A comprehensive review of more than 4,000 hydraulic fracturing stages from horizontal wells across the United States and South America was conducted. Stages exhibiting WL conveyance problems were identified through detailed treatment chart analysis, focusing on insufficient end-of-stage pump rate, slurry concentration, and overflush volume behavior. Key parameters, including pumping rate, effective overflush volume, proppant concentration and size, and fluid viscosity, were evaluated and correlated with solids transport modeling results to assess their influence on proppant movement in horizontal wellbores. Comparative analysis between problem and problem-free stages was used to isolate operational parameters most critical to effective wellbore cleaning. The analysis revealed a strong correlation between WL conveyance issues and reduced pump rates during the flush stage, coinciding with the highest slurry concentrations. Insufficient effective flushing fluid volume was identified as another dominant factor. In problem stages, flow rates within the lateral sections appear to be near or below the critical velocity required for proppant suspension and transport at high friction reducer (FR) concentrations. Based on these findings, a set of design guidelines for flush and overflush optimization is proposed to minimize post-frac operational risks and reduce NPT. This work presents comprehensive case studies on proppant cleaning performance in P&P operations. The analysis results and recommendations provide a data-driven framework for diagnosing and mitigating WL conveyance problems. By enhancing understanding of proppant transport dynamics during the flush and overflush stage, the study offers actionable insights for improving completion efficiency and reliability in multistage horizontal fracturing—particularly relevant to emerging unconventional developments in the Latin American and Caribbean region.