Preparation and Application of an Epoxy Soybean Oil-Based Plugging Agent

Resin plugging agents play a pivotal role in addressing casing damage in oil and gas fields. However, the widespread use of epoxy resin is constrained by its high cost and non-renewable origin, while plant-based resins often suffer from inadequate mechanical properties, which limit their effectiveness in such applications. This study introduces BEOPA, an innovative, renewable, high-strength resin plugging agent derived from epoxidized soybean oil (ESO) and enhanced with bisphenol A-type benzoxazine (BZ). In this study, the synthesis process, reaction mechanism, and application performance of this novel material are systematically presented, explored and optimized. It is shown that the optimal formulation of BEOPA includes 41.4 wt% ESO, 24.8 wt% BZ, 24.8 wt% methylhexahydrophthalic anhydride (MHHPA), 8.2 wt% styrene (ST), and 0.8 wt% N,N-dimethylbenzylamine (BDMA), yielding an impressive compressive strength of 93.7 MPa. The integration of ESO and BZ creates an intricate and robust double crosslinking network, significantly enhancing material strength and durability. BEOPA exhibits a tunable curing time, ranging from 0.5 to 15 h, with viscosities below 300 mPa center dot s at 25 circle C and 75 mPa center dot s at 50 circle C. Furthermore, it demonstrates exceptional thermal stability within the 100 circle C-150 circle C range, even in environments with mineral salt concentrations as high as 43,330 mg/L. Remarkably, BEOPA achieves superior plugging performance, sustaining breakthrough pressures exceeding 29.7 MPa in 1 mm crack cores.