Dynamic Overpressure Characteristics of Methane Detonation Induced by Sodium Perchlorate in a Large Pipeline

Methane serves as a primary fuel for explosive fracturing technology. This study enhanced the combustion efficiency by employing combustion improvers to induce methane detonation and improve explosion characteristics. A formulation was designed utilizing sodium perchlorate as the primary oxidant and propylene oxide as an ignition agent. The dynamic overpressure characteristics and shock wave propagation mechanisms of CH4–NaClO4 mixtures were experimentally investigated within a 502.4 L pipeline. The results demonstrate that owing to particle agglomeration and reaction integrity limitations, NaClO4 with a specific particle diameter and concentration can promote complete methane combustion at a defined equivalence ratio. Through flame acceleration and shock wave superposition, the flame front and reflected waves converge, generating extremely high explosion overpressures. Under standard temperature and pressure conditions, the optimal sodium perchlorate particle diameter and concentration were determined to be 26.6 μm and 0.15 g/L, respectively. The corresponding optimal methane equivalence ratio and peak explosion overpressure were 1.25 and 41.58 ± 2.53 MPa. These findings establish a potential pathway and a significant foundation for the innovative development of reservoir reconstruction and permeability enhancement technologies.