Chemical Mitigation of Proppant Flowback

Abstract Proppant production from hydraulically fractured shale wells has emerged as a significant source of revenue loss for operators utilizing artificial lift systems. The recent cost-driven adoption of lower-quality local sands has intensified this challenge, as these grains exhibit higher susceptibility to crushing, fines generation, and drag forces downhole environments. While resin-coated proppants manufactured offsite offer a proven solution, supply limitations and high upfront costs hinder their ability to meet market demand. In this work, we present the development of a low-viscosity, non-epoxy-based proppant coating formulation designed for on-site application during primary stimulation operations. Conventional epoxy-based systems are constrained by excessive viscosity and extended cure times, making them impractical for long lateral completions. The proposed resin formulation enables rapid coating of proppant or sand across a range of mesh sizes and incorporates a novel internal activator that achieves cure times compatible with plug-and-perf completion strategies. Candidate formulations underwent rheological evaluation to confirm stability and prevent premature viscosity increase or early cure. Curing kinetics and the influence of individual chemical components on resin reactivity were characterized using Differential Scanning Calorimetry (DSC). Sand coating efficiency and consolidation performance were assessed through Loss on Ignition (LOI) and Unconfined Compressive Strength (UCS) measurements on coated and cured sand packs across multiple mesh size distributions. To statistically validate the robustness of the testing protocol, a comprehensive sensitivity analysis was conducted to optimize experimental power and resolution. This included implementing multiple controls over carrier fluid selection, coating procedures, sand mesh sizes, column packing techniques, and the number of condition-specific test iterations. Rheometer testing confirmed that the formulation behaves as a water-thin Newtonian fluid, even after extended exposure at 140 °F. Viscometer data indicate that cure-time profiles can be tuned between 6 and 24 hours, with an onset temperature of approximately 175 °F. Differential Scanning Calorimetry (DSC) further demonstrated that the choice of internal activator significantly lowers the glass transition temperature of the cured resin, yielding more than a 150% increase in UCS strength at reduced curing temperatures. Notably, this formulation achieves comparable UCS strength at lower polymer loading compared to conventional epoxy-based systems. Loss on Ignition (LOI) measurements revealed a linear relationship between sand coating concentration and cured resin residue on the grain surface, with optimal coating efficiency occurring at roughly 25% of the initial treatment concentration. Statistical evaluation of the testing protocol confirmed a method delivering 70% confidence with an associated ±30 psi error in UCS measurements for resin-consolidated sand packs. A comprehensive development strategy was employed to create a non-epoxy-based sand consolidation system designed for coating lower-quality, unsieved sand during primary hydraulic fracturing operations, while mitigating solids production after stimulation. The optimized resin formulation incorporates more environmentally responsible chemistry, delivering enhanced surface handling characteristics and strong compatibility with formation fluids.