Self-Degradable Rubber Plug for Temporary Plugging and Its Degradation Mechanism.

Area of Science:

• Materials Science
• Polymer Chemistry
• Petroleum Engineering

Background:

• Existing temporary plugging technologies often suffer from poor self-degradation.
• Crosslinked polymer plugs present challenges in complete removal after service.

Purpose of the Study:

• To develop and optimize a self-degradable rubber plug (SDRP) with improved degradation properties.
• To evaluate the performance of the optimized SDRP in temporary plugging applications.

Main Methods:

• Response surface analysis was employed to optimize the SDRP synthesis formula.
• The SDRP's gelation time, degradation rate, viscosity, and breakthrough pressure were experimentally determined.
• The degradation mechanism involving hydrolysis of unstable crosslinkers was investigated.

Main Results:

• Optimized SDRP composition: 13 wt% monomer, 0.02 wt% initiator, 0.7 wt% crosslinker, 1.8 wt% degradation catalyst.
• Gelation occurred within 30-110 min at 70-120 °C; degradation completed in 3-10 days.
• Achieved a breakthrough pressure of 8.34 MPa at 1 PV injection volume.
• Degraded solution viscosity was < 20 mPa·s, indicating effective breakdown.

Conclusions:

• The developed SDRP offers a viable solution for temporary plugging with excellent self-degradation.
• Hydrolysis of unstable crosslinkers, accelerated by temperature and catalyst, drives the plug's network deterioration.
• This advancement contributes a novel system to the field of temporary plugging gels.