Plugging performance and mechanism of temperature-responsive adhesive lost circulation material

Abstract

Lost circulation is a great challenge during drilling and results in high financial costs. Despite the extensive advances in recent decades, lost circulation materials (LCMs) still have low success rates that fail to address lost circulation in fractured formations. This study proposes a novel temperature-responsive adhesive lost circulation material (TALCM) to control such losses. TALCMs consist of bridging and adhesive LCMs, which can be activated by formation heat. Once activated, the surfaces of the adhesive LCMs bond to the bridging LCMs through interdiffusion and entanglement of polymer chains. First, the thermodynamic properties of three kinds of thermoplastic resins were studied, namely low-density polyethylene, acrylonitrile butadiene styrene, and polyamide 6. Then, one of these resins was chosen as the adhesive LCM for its better adhesive and viscoelastic properties. Finally, a series of experiments was conducted on the plugging efficiencies of TALCMs. The results show that TALCMs achieve adhesive plugging when activated by formation heat during lost circulation control. The maximum pressure-bearing capacity of a TALCM was observed to be 14 MPa, with the compressive strength being higher than those of conventional bridging LCMs (7.5 MPa) when plugging a 1-mm-wide slot. More importantly, TALCMs can control severe lost circulation that the conventional LCMs or crosslinking polymers cannot address.