Preparation and Performance Evaluation of a Self‐Generated Particle Plugging Agent Based on Thermosetting Resin

ABSTRACT A thermosetting in situ curing resin microsphere system has been developed. It has controllable phase transition time and particle size. This system addresses the current challenges of low strength, shear susceptibility, and short phase transition time in polymer microsphere blockers and thermoplastic particle blockers. This system is in liquid form under low temperature conditions on the ground and has a relatively good flowability, with an average viscosity of 6.7 mPa·s between 50°C and 90°C. The liquid‐phase microspheres in the system solution can transform into solid particles after a certain period at high reservoir temperatures, thereby sealing the pore spaces. The impact of resin, crosslinking agents, emulsifiers, dispersants, and auxiliary dispersants on the system performance was studied. The optimal formula for the system was determined to be 12% cashew phenol modified epoxy resin + 4.5% oil‐based imidazole + 0.45% DMP‐30 + 4% closed‐type hydrophilic aliphatic polyisocyanate + 4% OP‐10 + 0.6% silica sol. Experimental results showed that the phase transition time of the system at 90°C is 8 h, with the median particle size of the produced resin microspheres being 41 μm and a microsphere yield of 98.1%. Mechanical property tests and indoor sand‐packed core displacement tests revealed that the microsphere particles produced by this system have a crushing rate of 5.57% under a pressure of 50 MPa and exhibit good sealing ability for high‐permeability channels, with a sealing rate exceeding 90%. The system shows promising potential for wide application.