Multi-scale characterizations of thermosensitive adhesive resin embedded with bridging materials: Toward forming stable plugging in fractured formations

Lost circulation in fractured formations remains a persistent challenge in drilling operations, causing substantial economic losses and increased operational risk. Conventional granular bridging packs are mechanically fragile and can be destabilized by pressure fluctuations, limiting one-trip plugging efficiency. This study incorporates a thermosensitive adhesive resin into bridging assemblies to enhance plug integrity by promoting interparticle adhesion and particle-wall coupling after thermal activation. Oscillatory temperature-sweep rheometry is used to quantify the temperature-dependent viscoelastic response of resin-particle composites. A wedge-shaped fracture analogue with photoelastic visualization is used to monitor force chain development and uniformity during progressive loading. Discrete element method simulations in Particle Flow Code, using a linear parallel-bond contact model, resolve mesoscale load-transfer pathways and isolate the contribution of adhesive interactions. Results indicate that thermosensitive adhesive resin increases assembly coherence, promotes a stable load-bearing skeleton, and suppresses stress localization that typically precedes plugging failure. The strengthening trend is governed by particle rigidity and surface characteristics, yielding consistent load-transfer patterns across experiments and simulations. These findings demonstrate that thermally activated adhesion can transform unconsolidated granular packs into mechanically stable plugging zones, providing a mechanistic basis for designing high-stability lost circulation control systems in fractured formations.