Enhancing Plugging Performance in Deep Fractured Formation Using a Hybrid Strategy with Temperature-Activated Bonding Materials

Lost circulation is a persistent global challenge that has long restricted the safe and efficient progress of oil and gas drilling operations. Its mitigation is primarily dependent on the structural stability and cost control of the sealing layer. For lost circulation control in fractured formations, the bridge plugging method is often adopted to seal fractures and prevent drilling fluid loss. However, the sealing barrier constructed by bridging materials constitutes a densely packed aggregate structure, whose integrity is predominantly sustained through physical interactions, including elastic forces, frictional resistance, and particle interlocking mechanisms. This physical interaction-dependent stabilization mechanism constrains further improvement of the pressure-bearing capacity of the sealing zone. Temperature-activated bonding plugging materials (TPBMs) have emerged as a promising solution for efficient loss circulation control. This study focuses on the enhancement mechanism of TPBMs in lost circulation in deep fractures, systematically revealing their role and enhancement mechanism in sealing formulations through a comparison of the bonding kinetics of three types of TPBMs and four groups of sealing experiments. Experimental results demonstrate that TPBMs, as the main bridging agent, are critical to the enhancement of the lost circulation control performance. The optimal sealing strategy combines TPBMs in the bridging layer with conventional sealing materials in the filling layer. This hybrid approach leverages a dynamic self-repairing framework and low-cost physical flow blockage, achieving both a cost reduction and enhanced pressure resistance. The findings provide a cost-efficient, high-performance solution for severe loss scenarios, providing crucial guidelines for the design of next-generation sealing formulations.