# A Review of Failures and Malfunctions in Hydraulic Sandblasting Perforation Guns
## 3 High-Pressure Leakage in Perforation Guns
### Measures to Prevent High-Pressure Leakage  
High-pressure leakage in hydraulic sandblasting perforation systems directly compromises safety and operational efficiency. Effective leakage mitigation centers on optimizing seal structures, improving seal material durability, and integrating leakage detection with automated response mechanisms. Current research focuses on high-pressure seal designs, the longevity of dynamic sealing materials, and the application of early-warning and automatic response technologies. In terms of seal materials, ultra-high-performance elastomers (e.g., hydrogenated nitrile butadiene rubber, HNBR) and perfluoroelastomers (e.g., FFKM) have shown significantly enhanced thermal and chemical resistance under extreme pressures, tolerating temperatures up to 300 \({}^{\circ}\)C without substantial loss of elasticity. For harsh downhole fluids containing sulfur compounds or high chloride concentrations, metal-based or composite seal systems may be more appropriate to resist both corrosive and erosive forces. Incorporating temperature sensors and fluid composition analyzers can enable real-time adaptation of sealing parameters, minimizing leakage risks across a wide range of operational conditions. Metal-based seals such as Inconel X750 or bimetallic composites also exhibit superior creep resistance and dimensional stability in cyclic loading conditions, thus reducing the risk of seal deformation or fracture under fluctuating pressures. Additionally, specialized polymeric seals reinforced with glass or carbon fibers can achieve higher hoop strength while maintaining sufficient flexibility to accommodate microscale surface irregularities. These advanced sealing materials often incorporate anti-extrusion back-up rings or lip-shaped geometries to prevent material extrusion in high-pressure gaps. The sealing structure lies at the core of preventing high-pressure leakage. Traditional methods include static and dynamic seals, with the latter widely applied in high-pressure scenarios. Research shows that optimizing seal groove geometry and seal dimensions can greatly reduce leakage risks. In recent years, metal-to-metal hard sealing arrangements have gained traction, utilizing precisely machined metal contact surfaces. This not only improves sealing effectiveness but also circumvents the aging issues of rubber-based seals in high-temperature, high-pressure conditions [56; 57]. Further research indicates that low-impact and low-debris perforation gun systems can significantly decrease equipment damage under high pressure, thereby reinforcing sealing effectiveness [58]. Recent design improvements feature double or triple sealing rings to create multiple seal barriers, thereby limiting the possibility of catastrophic failure if one sealing element is compromised. Such multi-stage sealing systems often incorporate a primary high-pressure seal, a secondary seal for temperature buffering, and an outer seal that protects against debris intrusion. The selection of seal materials directly affects durability and sealing performance. Common sealing materials for perforation guns include rubber-based composites, PTFE, and high-performance thermoplastics (e.g., PEEK). Among these, PTFE is favored for its exceptional corrosion resistance and high-temperature stability, making it a prime candidate for high-pressure seals. Studies have demonstrated that incorporating nano-fillers (e.g., carbon nanotubes, graphene) into seal materials markedly enhances wear resistance and anti-aging properties, extending the perforation gun's service life [59; 60]. Metal elastic seals also exhibit excellent longevity under high-pressure conditions, maintaining functionality over prolonged periods in complex environments [61]. Beyond seal structure optimization, real-time monitoring technologies play an increasingly critical role in leakage prevention. Advanced sensor data analytics--encompassing pressure, temperature, acoustic emission, and vibration signals--enables proactive detection of micro-leakage or seal weakening.