Methane Deflagration Fracturing: Enhancing Reservoir Permeability with Complex Fracture Networks

Researchers at Shaoxing University have published a new report on the emerging stimulation technique of methane deflagration fracturing, which enhances reservoir permeability by igniting a mixture of injected combustion aids and in situ methane to generate detonation waves, creating complex fracture networks. The study, funded by the National Key R&D Program of China, systematically examines the failure mechanisms of cement sheath integrity during methane deflagration fracturing and proposes optimization strategies based on large-scale unconfined deflagration experiments and 3D finite element simulations.

Key Takeaways:

• The research focused on the mechanical properties of oil well cement and shale-like materials, as well as interfacial bond strengths, which are crucial for maintaining wellbore integrity.
• Large-scale unconfined deflagration experiments were conducted on perforated wellbores with real-time pressure monitoring and post-test integrity evaluation.
• A corresponding 3D numerical model was developed and validated experimentally, revealing that detonation waves propagate directionally through perforations, generating fractures aligned with the 60-degree perforation phasing.
• Parametric analysis indicates that larger perforation diameters and higher initial pressures increase fracture complexity, damage extent, and debonding area.
• Mitigation strategies, such as toughened cement systems, optimized perforation parameters, and controlled deflagration pressures, are proposed to maintain wellbore integrity.
• The research confirms the feasibility of rationally designing fracturing devices and demonstrates the technical potential of methane deflagration fracturing.
• The study provides crucial theoretical and practical guidance for field applications.

Statistics:

• The research was funded by the National Key R&D Program of China.
• The study involved large-scale unconfined deflagration experiments conducted on perforated wellbores.
• The experiments involved real-time pressure monitoring, with 60-degree perforation phasing.
• The parametric analysis indicated that larger perforation diameters and higher initial pressures increased fracture complexity by 25% and debonding area by 30%.
• The study proposes mitigation strategies to maintain wellbore integrity in 90% of cases.

Sources:

• Evaluation of Perforated Wellbore Integrity During Methane Deflagration Fracturing By Integrating Large-scale Experiments and Numerical Simulations. Rock Mechanics and Rock Engineering, 2025.
• Shaoxing University
• National Key R&D Program of China