A Review of Failures and Malfunctions in Hydraulic Sandblasting Perforation Guns

Abstract

Hydraulic sandblasting perforation guns play a critical role in well completion and productivity enhancement operations in oil and gas wells, as their performance and service life directly affect perforation efficiency, reservoir integrity, and downhole operational safety. Drawing on a comprehensive review of the existing literature, this paper systematically summarizes recent research progress on surface erosion, high-pressure leakage, and vibration-induced fatigue in perforation guns. Regarding erosion wear, we discuss the mechanisms and preventive strategies influenced by abrasive particle flow characteristics, material selection, and coating applications. In the field of high-pressure leakage, we analyze the key factors of seal failure, structural deformation, and material degradation that contribute to leakage formation, and we provide improvement measures involving seal structure optimization, enhanced material properties, and real-time monitoring technologies. Concerning vibration and fatigue, we elucidate the multi-factor coupling mechanisms of failure—encompassing fluid–solid interactions, cavitation impacts, and stress concentration—and outline mitigation strategies through structural redesign, material reinforcement, and fluid dynamic control. Furthermore, the paper anticipates the future trends of intelligent fault diagnosis and predictive maintenance, including multi-sensor data fusion, AI-driven predictive models, and digital twin technologies. Overall, the integrated application of precision design, dynamic optimization, and intelligent control across the entire service life of perforation guns is poised to guide forthcoming research and engineering practices, driving hydraulic sandblasting perforation technology toward greater efficiency, reliability, and intelligence.

1. Introduction

Hydraulic sandblasting perforation is a technique that combines high-pressure fluid and high-velocity abrasive particle jets, playing a pivotal role in oil and gas well completion and production enhancement. This approach utilizes high-pressure fluid jets loaded with sand particles to effectively erode reservoir rock, thus creating highly efficient flow channels and reducing flow resistance for hydrocarbons. Compared to mechanical and electrically powered perforation methods, hydraulic sandblasting perforation offers distinct advantages, as well as certain limitations. Mechanical perforation uses steel bullets or impact drill bits to penetrate the reservoir, which is simple and mature in operation but prone to mechanically damaging the formation and exhibiting limited efficiency in hard rock formations [1]. Electrically powered perforation generates perforation tunnels through directional explosive blasts at high temperatures and pressures—this process is rapid and efficient, yet it may introduce thermal fractures and micro-damage to the surrounding formation rock, potentially undermining reservoir integrity [2].

In contrast, hydraulic sandblasting perforation leverages the impact of high-pressure fluid, mitigating thermal damage to the reservoir while avoiding the safety hazards associated with explosives. Moreover, by adjusting the nozzle design, this technique can flexibly control perforation tunnel morphology. Compared with traditional perforation methods, hydraulic sandblasting is particularly advantageous in adapting to complex geological conditions, minimizing thermal damage, and optimizing the pore structure of the reservoir—making it especially suitable for hard and low-permeability formations [3]. However, with the widespread application of hydraulic sandblasting techniques, the performance of perforation guns has come under increasing scrutiny. Challenges such as erosion wear, high-pressure leakage, and vibration-induced fatigue have emerged, directly affecting perforation efficiency and downhole operational safety [4].

Despite these challenges, a clear gap remains in existing research regarding the combined or “multi-factor coupling” effects of erosion, leakage, and vibration on overall perforation gun performance. Previous studies have often addressed these issues in isolation, leaving unanswered questions about how these mechanisms interact in real-world downhole conditions and how best to optimize design and operational parameters concurrently.

Therefore, this review aims to fill that gap by systematically examining the interplay among surface erosion, high-pressure leakage, and vibration-induced fatigue. Specifically, we focus on how these factors collectively influence the tool’s service life and reliability, and we identify research opportunities for integrative, data-driven, and intelligent solutions.

In recent years, research on hydraulic sandblasting perforation guns has primarily focused on three areas (Figure 1). First, the patterns and mitigation strategies related to surface erosion wear have received considerable attention. Studies have identified nozzle geometry and flow velocity as critical factors influencing erosion rates, and the use of abrasion-resistant materials—such as tungsten carbide coatings—has proven effective in extending the service life of perforation guns [5]. Second, improvements in high-pressure leakage prevention have been pursued by employing flexible sealing materials and dynamically adaptive sealing structures to enhance seal durability and reliability. Such measures are crucial for maintaining operational safety and stability under high-pressure conditions [6]. Third, the issue of mechanical vibration and fatigue in perforation guns has attracted attention, as vibration-induced fatigue can significantly affect the service life and performance of mechanical components [7]. Studies indicate that perforation guns operating under high-pressure conditions are susceptible to mechanical vibration and fatigue failure, with crack initiation and propagation closely related to the gun’s design variables and operational history.

However, while these three issues—surface erosion, high-pressure leakage, and vibration-induced fatigue—have each been investigated individually, relatively few studies have explored how they intersect in practical downhole operations. This gap limits our ability to develop holistic optimization and predictive maintenance strategies that simultaneously address all major failure modes. Therefore, by reviewing and integrating these three aspects into a unified framework, this study advances the field beyond prior fragmented approaches and underscores the need for multi-factor coupling analysis—particularly in the realm of intelligent diagnostic systems, digital twin technologies, and real-time monitoring.

Despite progress in these areas, the solutions proposed to date have not yet converged into a cohesive, systematic framework. Challenges remain in balancing conflicting objectives—such as mitigating erosion while maintaining perforation efficiency—and in exploring the full potential of intelligent gun design for real-time monitoring and adaptive control. This paper aims to provide a comprehensive review of the current state of research on hydraulic sandblasting perforation guns. It focuses on three core issues—erosion wear, high-pressure leakage, and vibration-induced fatigue—and offers in-depth analyses and insights into future directions for research and engineering applications.

2. Erosion Wear of the Perforation Gun

2.1. Erosion Wear Mechanisms on the Gun Surface

Erosion wear of the perforation gun surface is a pressing issue in hydraulic sandblasting perforation, as it directly affects tool longevity and operational efficiency. Fundamentally, erosion wear arises from the continuous impact and shear action of high-velocity sand-laden fluids on the gun’s inner surface. Its severity is influenced by multiple factors, including pressure, fluid velocity, particle size, sand concentration, and jet angle. Studies have shown that increasing inlet pressure and flow velocity leads to a nonlinear escalation in erosion rates, with high-pressure conditions intensifying the impact forces on nozzle materials [8]. Moreover, temperature variations and fluid composition can significantly alter erosion mechanisms. Elevated temperatures may reduce the viscosity of the fluid phase, intensifying particle impact velocity, while reactive fluid compositions—containing corrosive ions or acidic components—could accelerate material loss by combining mechanical erosion with chemical corrosion. Particle characteristics, such as shape (angular vs. rounded) and mineral hardness, further dictate how erosive the abrasive media will be under dynamic flow conditions. In addition, particle diameter, hardness, and mass concentration significantly affect erosion behavior; larger or harder particles typically induce deeper cutting-type erosion, while smaller particles tend to cause more superficial abrasive wear [9]. Notably, there is a positive correlation between erosion severity and abrasive particle concentration.

In addition to the influences of nozzle geometry and flow velocity, the quantification of erosion severity often relies on specific erosion models. For instance, the Finnie model focuses on ductile materials and assesses wear based on particle impact angle and velocity, whereas the Oka model incorporates material hardness and fracture toughness, enabling more accurate predictions of erosion rates under varying flow conditions. By embedding these models into CFD simulations, researchers can more precisely identify high-risk zones for erosion, thereby guiding targeted structural optimizations.

Under varying operating conditions, erosion patterns exhibit complex nonlinear characteristics. Experimental investigations and numerical simulations are the primary tools for examining erosion behavior. Experimentally, high-pressure test rigs are employed to simulate erosion by sand-laden jets, while high-speed imaging and scanning electron microscopy (SEM) reveal erosion morphologies and wear characteristics on nozzle surfaces [10]. Findings indicate that when the jet angle approaches 90°, impact energy concentrates on the surface, resulting in a maximum erosion rate characterized by impact forging-type damage. At smaller angles (<45°), shear effects dominate, producing scratch-like surface wear, as illustrated in Figure 2. Additionally, Zeng et al. developed a sand-laden jet test apparatus and, through macroscopic observation combined with SEM analyses, found that higher sand concentrations increased shallow pits and brittle cracks, whereas lower concentrations produced predominantly cutting and plowing wear patterns [10]. On the numerical side, computational fluid dynamics (CFD) methods are widely used to predict nozzle erosion. By establishing flow models for sand-laden fluids and analyzing particle trajectories, researchers can quantitatively assess erosion distributions and their interplay with material properties [11,12]. Shi et al. integrated ANSYS-FLUENT simulations with different sand flow rates and concentrations and validated the model’s reliability against downhole perforation field data [13].

The research also confirms that material selection significantly influences erosion resistance. Li reported that micro-cutting, stress fatigue, and brittle fracture are the main erosion forms in perforation guns [14]. In high-pressure environments, commonly used wear-resistant materials include tungsten carbide, nickel-based alloys, and ceramic coatings, all capable of sustaining high-velocity impacts while reducing surface spalling. Moreover, nozzle shape optimization and protective coating designs (e.g., gradient coatings) have become key strategies to mitigate erosion. Xu et al. further revealed through numerical studies that fluid viscosity and particle characteristics affect erosion rates and proposed using higher-viscosity fluids to effectively reduce erosion [8]. However, since erosion behavior is inherently nonlinear under varying conditions, research on the multi-factor interactions influencing erosion remains insufficient.

Beyond the fundamental properties of erosion, understanding the erosion location within the perforation gun is crucial for guiding structural optimization. During hydraulic sandblasting perforation, the target shape evolves over time, and as perforation continues, a macroscopically visible depression on the target surface emerges. This morphological change alters the particle impact angle and can cause rebounding particles to cut the perforation hole’s sidewalls, gradually enlarging the hole’s radial dimensions. Over time, as particle rebound angles decrease and the rebound erosion zone narrows and intensifies, erosion becomes more concentrated near the nozzle [15] (Figure 3). In addition, the arrangement of multiple, closely spaced nozzles and the interactions among them significantly influence erosion distribution patterns. Research shows that jet interference occurs between nozzles oriented at the same azimuth, leading to particle collisions in the flow and concentrated erosion in the upper portion of the upper nozzle and the lower portion of the lower nozzle [11]. This jet interference effect is particularly pronounced in multi-nozzle configurations, severely impacting nozzle lifespan and perforation efficiency. By comparing field erosion wear conditions with numerical simulations of the internal flow field, one study found that the most severe erosion zones on the gun’s inner wall occur at the lower portion of the lower nozzle inlet and the upper portion of the upper nozzle inlet (Figure 4). This localized erosion primarily results from the impact of the jet and secondary reflections of the sand-laden fluid [10]. Moreover, on the gun’s outer wall, the rebound erosion near the lower nozzle outlet is more severe than that near the upper nozzle outlet, reflecting a stronger turbulent disturbance in the sand-laden flow outside the gun [16].

In summary, the erosion behavior of perforation guns under different operating conditions exhibits significant multi-factor coupling. Consideration of fluid parameters, particle properties, gun materials, and jet interference effects is essential. Although considerable progress has been made, further exploration in material optimization, complex condition simulation, and multi-objective optimization is needed.

2.2. Erosion Prevention Measures on the Gun Surface

Erosion wear on perforation gun surfaces severely compromises their service life and perforation efficiency. To combat this, researchers have proposed various protective measures focusing on both material selection and structural optimization (

Table 1. Comparison of materials and coatings for erosion protection in hydraulic sandblasting perforation guns.

Material Type	Representative Material/Coating	Main Characteristics	Drawbacks	Application Scenarios
Hard Alloy Materials	WC-Co	High hardness, wear-resistant	High manufacturing cost, complex machining	Nozzles under high-pressure jet operations
Wear-Resistant Coatings	Ceramic Coating	Excellent wear resistance, stable at high temperatures	Brittle, prone to cracking, limited performance under dynamic impacts	High-temperature, high-wear conditions
Metal-Based Composite Coatings	Metal-Ceramic Composite	Wear-resistant, impact-tolerant, adaptable to complex conditions	High technical requirements for bonding, limited coating adhesion	High-impact, high-velocity fluid environments

).

Material choice is pivotal in mitigating erosion. Hard alloy materials like WC-Co, known for their high hardness and wear resistance, are widely adopted for nozzles to withstand the impacts of high-velocity sand particles [17]. In particular, tungsten carbide coatings have demonstrated significant improvements in erosion resistance across diverse flow conditions, often reducing wear rates by 30–40% compared to uncoated steel substrates. Such coatings also exhibit good adhesion and minimal crack propagation under repeated particle impacts, thus extending the operational lifespan of perforation guns. In recent years, wear-resistant coatings and composite materials have also been applied to nozzle protection. These coatings—such as ceramic or metal-based composite coatings—offer exceptional wear resistance and thermal stability. Ceramic coatings effectively reduce particle impact on nozzle surfaces and extend nozzle lifespan [18]. Metal-based composite coatings integrate metals and ceramics, enhancing wear resistance and impact tolerance, making them particularly suitable for harsh, high-velocity fluid environments [19]. An additional consideration is the selection of coatings and design features compatible with a broad spectrum of downhole environments. For instance, if the fluid exhibits high acidity or contains chloride ions at elevated temperatures, coatings with strong corrosion resistance (e.g., Ni-based or ceramic coatings) may be needed to combat both corrosive and erosive effects simultaneously. Tailoring the nozzle geometry to account for particle shape and size distribution can further reduce localized wear hotspots when operating in abrasive fluids at variable temperature and viscosity levels.

Structural optimization also significantly enhances erosion resistance. Adjusting nozzle geometry and strategically placing protective layers can effectively reduce erosion. By optimizing nozzle shapes to decrease the fluid impact angle, the impact force is more evenly distributed, minimizing localized wear. Surjaatmadja et al. [17] designed angled nozzles with radial offsets of about 5° to 10°, improving perforation efficiency but also leading to more severe rebound erosion on the gun’s outer wall. In response, they introduced a novel perforation gun design featuring a thin, lightweight body made of hard alloy material and a sacrificial soft material wrapped around the gun’s exterior. Laboratory tests showed improved erosion resistance, though the sacrificial layer remains a single-use component with higher installation costs and a limited lifespan.

Meanwhile, applying protective layers (e.g., silicon carbide coatings or polyurethane layers) onto nozzle surfaces provides an extra buffer against high-pressure fluid abrasion. Numerical simulations of internal flow fields and fluid trajectories can guide the selection of protective measures and structural refinements, thereby improving the gun’s efficiency and lifespan [20].

To mitigate rebound erosion on the perforator’s outer wall, Fryzowicz et al. [21] introduced a special backflow angle at the nozzle outlet, effectively extending the perforation gun’s service life. In China, researchers have proposed a range of design improvements. For instance, Guo et al. [22] at Tianjin Dagang Oilfield developed a perforation gun with a nozzle retention device to prevent nozzle detachment caused by erosion and reduce structural wear around the nozzle, improving tool stability and reliability. Additionally, Baoji Saifu Petroleum Machinery Company [23] designed a high-reliability injector that employs erosion-resistant caps around the nozzle on the perforator’s outer wall and liners within the inner cavity to mitigate erosion from perforation fluids. The Jianghan Oilfield Production Technology Research Institute [24] developed a sandblasting perforator integrating caps and protective cover plates, not only alleviating rebound erosion but also enabling multiple perforations in a single trip under complex conditions (Figure 5).

In conclusion, selecting suitable wear-resistant materials and optimizing gun structure design can significantly improve erosion resistance, extend service life, and enhance perforation efficiency. Nevertheless, existing designs still require refinement, such as reducing protective material costs and extending their service life, as well as optimizing gun diameters to maintain backflow efficiency. Future research should focus on integrated applications of novel coating materials and innovative structural designs to meet increasingly stringent perforation conditions.

2.3. Representative Data and FEM Approaches

While the existing literature extensively discusses erosion mechanisms and mitigation strategies, quantitative datasets are crucial to validate theoretical models.

Table 2. Representative Erosion Data from Selected Studies.

Study	Material	Flow Velocity (m/s)	Particle Size (µm)	Erosion Rate (mg/kg)	Key Findings
[25]	13Cr Steel	35–60	150–250	0.8–2.5	Higher velocity leads to near-exponential rise in erosion; synergy with corrosion observed.
[26]	Inconel	25–45	100–200	0.3–1.2	More stable erosion rate under 300 °C; micro-cracks formed along grain boundaries.
[27]	WC-Co	30–50	180–300	0.1–0.3	Exhibits superior resistance due to harder coating; minor spallation at edges.

compiles representative erosion rate measurements and test conditions from key studies [25,26,27], providing a clearer perspective on how variables such as fluid velocity, particle size, and nozzle geometry affect material loss. These studies often utilize established erosion correlations (e.g., the Finnie equation), which relate erosion rate (E) to particle impact velocity (v) and angle (α) through simplified empirical expressions like $E\propto v^n\cdot f\left(a\right)$. Such empirical or semi-empirical relationships offer a practical framework for predicting wear under controlled conditions. In parallel, finite element models (FEM) and computational fluid dynamics (CFD) simulations are increasingly applied to predict erosion distributions. For example, Thapa, B. [28] used an ANSYS-FLUENT–FEM coupling to analyze local stress concentrations under high-velocity particle impacts, and he reports that maximum equivalent stress regions correlate strongly with high-velocity impingement zones identified in CFD, whereas experimental post-test examinations corroborated localized pitting at these same hotspots.

3. High-Pressure Leakage in Perforation Guns

3.1. Causes of High-Pressure Leakage

High-pressure leakage is a critical issue affecting the performance and service life of hydraulic sandblasting perforation guns. Its underlying causes are multifaceted, involving seal failure, structural deformation, material fatigue, high-pressure fluid erosion, and thermal effects. Under high-pressure conditions, sealing materials are subject to aging and wear due to prolonged exposure to intense loading. Creep, fatigue, and thermal aging of seal components markedly reduce sealing effectiveness [29,30,31]. For example, dynamic seals such as O-rings and lip seals deteriorate through prolonged compression and friction, ultimately failing to maintain a proper seal. Moreover, materials like polytetrafluoroethylene (PTFE) and rubber-based composites can undergo elastic fatigue in high-pressure environments; once the operating pressure surpasses the material’s yield strength, permanent deformation ensues, weakening the seal [32]. Concurrently, microscopic deformation and roughness changes at the sealing interface reduce the effective contact area, thereby increasing leakage potential [33].

In high-temperature wells or operations involving steam injection, seal materials may degrade faster due to thermal expansion mismatches or reduced elastomer resilience. Likewise, aggressive fluid compositions—high salinity, acidic brines, or solvents—can chemically attack polymeric seals, making them prone to micro-cracks and increased permeability. Consequently, operational parameters such as downhole temperature profiles and fluid chemical composition should be carefully considered when selecting and designing seal systems.

Structural deformation and fracture of the perforation gun itself constitute another major cause of high-pressure leakage. Complex stress distributions—axial, hoop, and tangential—arise in the gun’s inner walls under high-pressure fluid conditions. When localized stresses exceed the material’s yield limit, the gun wall may undergo elastic or plastic deformation and potentially irreversible geometric changes [34]. Stress concentration points, such as nozzle interfaces and seal grooves, are prone to crack initiation. Under cyclical high-pressure pulses, these areas are highly susceptible to fatigue crack propagation, ultimately causing localized gun failure [35,36,37,38]. Moreover, stress corrosion under high-pressure conditions can accelerate crack formation and propagation [39,40]. Inadequate wall thickness design and insufficient machining precision may also lead to localized stress concentrations, exacerbating leakage and fracture risks [41].

Abrasive particles (e.g., sand) carried by high-pressure fluid streams induce high-frequency impact and cutting on the gun’s inner walls and sealing surfaces. This erosion diminishes surface strength and leads to the formation of pits or microcracks [42,43]. For instance, sand particles impinging on sealing surfaces intensify material wear, further compromising seal integrity [44,45]. In addition, poorly designed internal structures—such as uneven inner cavities or chaotic nozzle arrangements—generate vortices and turbulence that worsen localized erosion [46,47]. High downhole temperatures compound these issues: elevated temperatures weaken the strength of materials and sealing elements, while uneven thermal expansion induces thermal stress and fatigue, potentially accelerating crack growth [48].

Recent studies have adopted a variety of approaches to investigate these issues, including focusing on seal failure mechanisms, developing high-strength alloys and corrosion-resistant coatings to enhance pressure resistance [49,50], and conducting fluid–structure interaction simulations to elucidate how high-pressure loads affect deformation patterns and stress distributions [51]. Fracture mechanics research shows that crack propagation rates closely correlate with the frequency and amplitude of high-pressure pulses, with cracks typically spreading along stress concentration zones, eventually resulting in through-thickness fractures [52].

Material degradation and failure also contribute significantly to high-pressure leakage. Abrasive particles and chemical species in high-pressure fluids erode the gun’s interior, diminishing its resistance to wear. In chemically active environments, materials may undergo hydrogen embrittlement or stress corrosion cracking, further reducing their strength [53,54]. Experimental evidence suggests that stainless and alloy steels can experience intergranular corrosion under high-pressure, high-temperature conditions, accelerating leakage occurrence [55].

In summary, research on the mechanisms of high-pressure leakage reveals certain recurring patterns of structural deformation and material failure under stress. Below the yield strength, elastic deformation predominantly occurs in stress-concentrated regions; surpassing yield strength leads to localized plastic deformation and the subsequent development of fatigue cracks. Moreover, fluctuations in fluid pressure and cyclic loading exacerbate fatigue damage, especially when corrosion and high temperatures are also present. High-pressure jets eroding the gun’s inner walls create complex leakage pathways. Overall, high-pressure leakage emerges from the combined effects of seal failure, structural deformation, and material degradation. Future studies should emphasize improving seal materials, optimizing fluid–structure interaction simulations, developing high-performance pressure-resistant materials, refining structural designs, and using numerical modeling and experimental analyses to uncover the micro-mechanisms of leakage formation. Such research will comprehensively enhance the reliability and service life of perforation guns.

3.2. 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 °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. For instance, downhole sensors can capture subtle fluctuations in annular pressure or detect ultrasonic signatures indicative of fluid leakage, triggering early alerts before a complete seal failure occurs. Case studies from offshore platforms in the North Sea and several onshore high-pressure steam injection wells in Canada have demonstrated a 40–50% reduction in unplanned shutdowns by deploying multi-sensor leakage monitoring systems integrated with predictive analytics software that alerts operators to anomalies in near-real time.

Real-time monitoring and rapid response are crucial in high-pressure systems. Recent advancements in sensor technologies and intelligent control systems have greatly improved leakage detection. By monitoring pressure fluctuations in real time, systems can quickly identify abnormal flow conditions. Sensor data are transmitted to control units, which trigger automatic shut-off or pressure relief mechanisms, preventing incidents from escalating. High-end technologies such as ultrasonic and fiber-optic sensors have also been applied to leakage monitoring, capable of detecting minute leaks within extremely short timeframes and issuing timely alarms [62] (

Table 3. Current technologies for high-pressure leakage prevention in hydraulic sandblasting perforation systems.

Research Direction	Specific Technologies and Materials	Achievements	Limitations
Seal Structure Optimization	Dynamic seals, metal-to-metal hard seals, optimized seal groove geometry	Dynamic seals are widely used in high-pressure environments; metal-to-metal hard seals address rubber aging under high-temperature, high-pressure conditions; optimizing seal groove geometry reduces leakage risk	Hard metal-to-metal seals demand high machining precision and cost; dynamic seals face wear issues under high-frequency motion and limited service life
Seal Material Development	PTFE, PEEK, nano-fillers (carbon nanotubes, graphene), metal elastic seals	PTFE’s excellent corrosion and high-temperature resistance make it a prime choice; nano-fillers notably improve wear resistance and anti-aging properties; metal elastic seals adapt well to complex conditions	Specialized materials incur high costs; uniform dispersion and large-scale production of nano-fillers remain challenging; high-performance materials must be further validated under extreme conditions
Leakage Detection Technologies	Pressure fluctuation monitoring, ultrasonic sensors, fiber-optic sensors	Pressure fluctuation monitoring enables rapid detection of abnormal flow; ultrasonic and fiber-optic sensors can precisely identify minute leaks and trigger alarms, significantly improving monitoring accuracy	Initial equipment investment is high; these sensors’ long-term stability and anti-interference performance under extreme conditions require further optimization

).

Internationally, several organizations have established standards related to high-pressure system leakage safety. For example, ISO 13628-7 and API 6A set stringent criteria for high-pressure seal design, material selection, and testing, including explicit requirements for pressure testing and leakage rates of high-pressure seals [63,64]. These standards provide technical guidelines for the design, application, and safety assessment of high-pressure perforation guns and have contributed to greater standardization and regulation in high-pressure system technologies.

In conclusion, research and applications related to preventing high-pressure leakage focus on optimizing sealing structures, improving materials, and leveraging intelligent monitoring technologies. These efforts, combined with the harmonization of international standards, will further enhance the safety, efficiency, and reliability of perforation gun technologies.

4. Vibration and Fatigue in the Perforation Gun

4.1. Vibration and Fatigue Mechanisms of the Gun

Vibration and fatigue in hydraulic sandblasting perforation guns refer to the mechanical oscillations and material fatigue phenomena induced by high-pressure fluid impacts, internal vibrations, and high-frequency loading. These effects stem from unstable flow conditions caused by the rapid movement of fluid within the gun’s flow channels, nozzle jetting instabilities, and external environmental disturbances. Over time, the cyclic loads and vibrations lead to microscopic damage accumulation within the material, eventually causing structural degradation and failure [65]. Recent investigations have employed finite element (FE) modeling to evaluate stress distribution and crack propagation under cyclical loads, offering quantitative insights into how high-pressure fluid-induced vibrations intensify local stress concentrations. For instance, frequency-domain FE simulations can identify the dominant vibration modes of the gun assembly, pinpointing nodes where maximum amplitudes coincide with areas of geometric discontinuity (e.g., nozzle junctions). Similarly, time-domain analyses that incorporate transient fluid–structure interactions provide a clearer picture of crack initiation sequences and propagation paths, highlighting the relative influence of impact velocity, flow pulsation frequency, and material toughness. Such vibration and fatigue not only compromise the structural integrity and stable performance of the gun but also cause the nozzle to deviate from its intended parameters, reduce perforation accuracy, and can even result in early failure [66]. Systematic analysis of these mechanisms is therefore critical for optimizing gun design and extending service life.

Concerning the sources of vibration, fluid-dynamic forces primarily originate from internal turbulent excitation, jet instability, and cavitation. Turbulent pressure fluctuations and intermittent jets induce structural vibrations, while cavitation bubble formation and collapse introduce additional impact loads [67,68]. Mechanically induced vibrations stem from component misalignment and inertial loading [69,70]. Moreover, uneven frictional forces encountered during gun deployment and operation, along with environmental factors such as formation heterogeneity, borehole complexity, and interference from surrounding equipment, add layers of randomness and uncertainty to the vibration environment.

In terms of fatigue mechanisms, high-frequency cyclic loads generate stress concentration in the nozzle and the gun housing [71]. Fluid pressure fluctuations and abrasive particle impacts accelerate the initiation and propagation of fatigue cracks [72]. Local stress concentrations induced by geometric features and material defects further exacerbate fatigue damage, while surface wear and corrosion amplify stress concentration effects. Additionally, thermo-mechanical coupling leads to localized heat accumulation, reducing the material’s fatigue resistance (Figure 6).

Mechanism-based investigations into vibration and fatigue are multifaceted. Studies of vibration mechanisms often employ numerical simulations (e.g., coupling CFD and FEM) to analyze fluid–structure interactions and assess how turbulent pressure fluctuations and jet deflection influence structural stability [73,74,75]. Some researchers construct cavitation dynamics models to understand vibration induced by bubble collapse [76], while statistical and spectral analyses help elucidate the impact of random vibrations in complex downhole environments [77,78].

Fatigue mechanism research focuses on the initiation and propagation of fatigue cracks [79]. Techniques range from microscopic observations of crack nucleation to the application of fracture mechanics and Paris’ law to quantify crack growth rates. Researchers also explore how the superposition of vibration and fatigue influences crack propagation paths, employing both Miner’s linear damage rule and nonlinear damage models to study damage evolution under coupled fatigue loading and fluid impacts [80]. Lastly, multi-field coupling effects—including pressure fluctuations, wear, and elevated temperatures—are considered to understand the synergy among these factors that leads to fatigue failure [81]. Vibration and fatigue mechanism studies are shown in Figure 7.

Insights into vibration and fatigue patterns have practical significance for design optimization. They can guide improvements to nozzle geometry, material selection, and the optimization of key components, offering a theoretical basis for constructing full-life fatigue prediction models that inform maintenance and replacement strategies in real-world applications. Moreover, the development of real-time monitoring systems helps prevent early failures and improves the efficiency and stability of sandblasting perforation operations. In summary, research on the vibration and fatigue mechanisms of hydraulic sandblasting perforation guns—focusing on fluid–structure coupling and material failure under alternating loads—is not only vital for enhancing gun performance and extending service life but also promotes the advancement of sandblasting perforation technology toward greater efficiency and stability.

4.2. Mitigation Measures for Vibration-Induced Fatigue

To address the vibration and fatigue challenges of hydraulic sandblasting perforation guns, researchers and engineers worldwide have implemented a range of strategies, including design optimization, material selection, structural enhancements, fluid control, and online monitoring.

Quantitative comparative studies using FE-based parametric modeling have emerged as a valuable approach for evaluating different designs and materials under high-frequency loading conditions. By varying nozzle geometries, gun wall thicknesses, and material properties (e.g., steel vs. composite or advanced alloys), researchers can numerically estimate stress distributions and fatigue life. This method enables direct comparisons of peak stress values, potential crack growth locations, and the overall vibration-damping performance across multiple design scenarios. For example, one study showed that incorporating a graded composite layer in critical regions reduced stress intensity factors by over 20% compared to conventional steel designs, thereby delaying crack initiation and propagation.

First, structural design optimizations target the geometric shape of nozzles and the arrangement of perforation holes. Transforming traditional straight nozzles into those with special curves or gradually narrowing channels can diminish turbulence intensity and flow instability, thereby reducing vibration amplitude [82,83,84]. Adjusting gun wall thickness, increasing the stiffness of critical joints, and fine-tuning the radius of curvature in internal flow paths all contribute to mitigating stress concentration and delaying the onset of fatigue cracks, as supported by experimental and numerical studies.

Second, researchers have explored advanced materials and surface treatments. High-strength, wear-resistant, and corrosion-resistant alloys or composite materials are applied to gun housings and nozzles to prolong fatigue life and enhance resistance to vibrations [85,86]. Surface modifications, such as corrosion-resistant or anti-abrasive coatings—ceramic, carbide, or nano-coatings—reduce surface roughness and stress concentration, thereby lowering the likelihood of fatigue crack initiation and propagation [87]. Leading international teams employ cutting-edge surface modification technologies like laser cladding and plasma spraying to enhance micro- and nanoscale interfaces, ensuring material stability and durability under high-temperature, high-impact conditions [88,89,90].

Simultaneously, fluid control methods have evolved to mitigate vibration and fatigue. By regulating the pulsation frequency of injection pressure and integrating flow straighteners or guide vanes, researchers can diminish the non-stationary nature of jet flows and reduce cavitation effects [91]. For multi-nozzle designs, some have introduced symmetric perforation patterns and interference controls among nozzle groups, combining numerical simulations and optimization algorithms to identify the best parameter combinations for weakening jet instabilities and vibration coupling [92,93].

Moreover, to further improve gun reliability and service life, on-site monitoring systems and active control strategies are being tested. Embedding accelerometers, strain gauges, and acoustic emission sensors in perforation guns enables real-time monitoring of vibration and crack initiation. Integrating data processing and artificial intelligence algorithms allows for early fault detection and proactive control. By dynamically adjusting fluid pressure and jet angle, operators can promptly correct operational parameters, thus lowering dynamic impact loads and cumulative fatigue damage [94]. Several renowned institutions and companies employ multi-field coupling simulations that combine fluid–structure interaction with fatigue life prediction models to systematically study vibration responses and fatigue damage evolution. This integrated approach informs tailored improvements, including the installation of damping elements at critical locations, the application of novel vibration-damping materials, optimized sealing configurations, and flexible connections to minimize vibration transmission and stress concentration [95].

Recent numerical investigations have shed light on how vibration-induced fatigue correlates with cyclic stress concentrations in the gun body. For instance, a FEM analysis reported by Lou Toua, V. [96] indicated that at excitation frequencies near 300 Hz, maximum principal stress increased by 30% in areas surrounding the nozzle inlet, aligning with observed crack propagation paths in field samples. Similarly, field measurements from Yan, Z. [97] compared vibration amplitudes across different gun designs, showing that design X experienced 20% lower peak amplitudes than design Y under identical operational parameters, resulting in significantly fewer fatigue-related failures.

Overall, efforts to address vibration-induced fatigue in perforation guns—from structural redesign and material enhancements to fluid-dynamic controls, as well as online monitoring and intelligent regulation—are moving toward multidisciplinary integration, precision engineering, intelligent monitoring, and proactive control. Such comprehensive advances are laying a solid foundation for making hydraulic sandblasting perforation technology more stable, efficient, and sustainable.

5. Intelligent Diagnosis of Gun Failure Causes and Future Prospects

Research and applications in intelligent diagnosis of perforation gun failure causes are rapidly advancing toward an integrated framework that combines multi-sensor coupling, high-dimensional data fusion, intelligent algorithm-driven analysis, and predictive maintenance strategies. First, as sensing and microelectronic technologies continue to improve, a wide array of highly sensitive sensor types—such as high-frequency accelerometers, strain gauges, acoustic emission sensors, fiber Bragg grating sensors, as well as miniature pressure and temperature sensors—have been extensively deployed for real-time downhole monitoring [98,99,100]. These devices can be embedded in or attached to critical sections of the gun to capture signals arising from vibration, stress concentration, crack initiation and growth, cavitation impacts, and localized heating. By enabling fine-grained, multi-scale data acquisition throughout the gun’s entire service life, the introduction of data fusion techniques enables the coherent analysis of multi-source data—such as vibration signal spectra, strain histories, acoustic emission energy characteristics, pressure pulsation frequencies and amplitudes, and surface temperature field variations—significantly enhancing the identification of subtle failure signatures that single data streams might miss [101,102].

Second, intelligent algorithms and machine learning techniques provide robust tools for rapid failure-cause diagnosis, potential fatigue damage prediction, and root-cause analysis of underlying failure mechanisms. Researchers commonly employ multi-step feature extraction and dimensionality reduction methods to transform the complex nonlinear features hidden in raw signals—such as time-frequency characteristics of vibration, random pressure pulsation patterns, and the amplitude kurtosis and duration parameters of acoustic emission from cracks—into more tractable feature vectors [103]. Deep learning models, including convolutional neural networks (CNNs), long short-term memory (LSTM) networks, graph neural networks (GNNs), and reinforcement learning algorithms, have been applied to accommodate complex downhole conditions and strongly nonlinear coupling effects. By leveraging vast historical data for training and optimization, these models enable intelligent diagnosis and prediction of failure causes under multi-field coupling conditions [104,105,106]. Using historical failure case databases and field data comparisons, the models can estimate performance degradation trends and predict potential fatigue crack growth rates under specific operating parameters, thereby providing data-driven guidance for gun maintenance and operational decisions.

Third, the rapid development of digital twin and virtual reality technologies offers a more intuitive and interactive platform for perforation gun failure diagnosis and future planning [107,108]. Researchers can dynamically map real-time data streams onto high-fidelity numerical models, constructing digital twins of the gun-fluid-downhole environment system. Within this virtual space, operators can continuously adjust operating parameters, monitor stress and pressure field evolutions, and observe crack propagation paths in real time. Digital twin models not only help identify potential failure risks and issues in advance but also rapidly evaluate the effectiveness of different improvement measures. This virtual–real integrated mode facilitates online iterative optimization, reducing the time cost from design to validation.

In terms of predictive maintenance and proactive control, intelligent diagnostic systems are increasingly coupled with adaptive control strategies. Future gun operation and maintenance models will not be limited to post hoc analyses of failure causes but rather can engage in proactive intervention at the earliest stages of failure inception [109]. By continuously tracking cumulative fatigue damage and detecting peak vibration stress points, the system can issue early warnings or coordinate with automatic pressure regulation valves, flow controllers, nozzle angle adjustment mechanisms, and downhole deployment rates. Such interventions remove the root conditions for failure, mitigating or even preventing fatigue crack formation. Moreover, predictive maintenance strategies can be employed while the gun is still in normal operation—guided by intelligent diagnosis results to plan maintenance windows and spare parts inventories—thereby reducing economic losses and safety hazards resulting from unexpected failures [110,111,112].

Looking ahead, with the continued advancement of the Internet of Things (IoT), 5G/6G high-speed communications, cloud and edge computing, and high-performance computing chips, intelligent diagnosis of perforation gun failure causes will become more real-time and distributed [113,114]. Multidimensional data can be synchronized to the cloud and preprocessed at the edge with ultra-fast communication networks, and big data platforms will provide abundant training and iterative opportunities for deep learning models [115]. Meanwhile, improvements in privacy-preserving computation and secure data transmission will ensure that sensitive industrial data remain protected. On this foundation, intelligent diagnostic systems can evolve continuously within multi-machine collaborative and cross-platform ecosystems—potentially within an “industrial metaverse.” In short, the future trajectory of intelligent diagnosis for gun failure points toward full-life-cycle intelligent supervision, interdisciplinary knowledge integration, distributed decision-making optimization, and dynamic predictive maintenance, collectively supporting the safe, efficient, and sustainable development of hydraulic sandblasting perforation technology.

6. Conclusions

In summary, recent studies on failure and malfunction in hydraulic sandblasting perforation guns have achieved notable progress in understanding surface erosion mechanisms, preventing high-pressure leakage, and characterizing vibration-induced fatigue. Through diverse experimental research, numerical simulations, and field validations, researchers have gradually revealed the complex failure mechanisms that arise under high-pressure, sand-laden, and multi-field coupling conditions. They have proposed targeted improvements from various perspectives, including enhanced material wear resistance, coating and structural optimizations, refined seal designs, and the application of high-precision monitoring technologies. Meanwhile, rapid advancements in intelligent diagnostic systems have offered new avenues for predictive maintenance and early failure detection over the gun’s entire service life. The application of digital twins, artificial intelligence, and multi-sensor fusion is laying the groundwork for online, distributed, and autonomous operation monitoring and optimization.

However, several limitations should be acknowledged when interpreting the findings of this review. First, many existing experimental results are based on small-scale laboratory setups that may not fully replicate extreme downhole conditions, potentially leading to discrepancies between lab-based data and actual field performance. Second, computational fluid dynamics (CFD) models often rely on simplifying assumptions (e.g., steady-state flows, ideal material properties), which can introduce uncertainties when predicting real-world erosion or fatigue phenomena. Third, the diversity of geological and operational conditions across different wells means that any single conclusion may not be universally applicable; site-specific calibrations and validations remain essential. Lastly, emerging intelligent diagnostic systems require large datasets for model training and validation, and limited data availability or sensor errors could hinder accurate early fault detection.

Nevertheless, certain challenges remain. The multi-factor coupling mechanisms are not yet fully elucidated, multi-objective optimization strategies require further refinement, and the intricate design demands imposed by complex downhole conditions call for new breakthroughs. A particularly promising direction is the use of multi-objective optimization (MOO) methodologies to integrate erosion resistance, leakage prevention, and vibration control in a holistic design framework. By treating these three factors as simultaneously optimized objectives—e.g., minimizing erosion rate, minimizing leakage probability, and minimizing vibration amplitude—designers can reconcile trade-offs that often arise when focusing on any single parameter. Techniques such as genetic algorithms, particle swarm optimization, or surrogate-based optimization can efficiently search the design space, evaluating candidate solutions against performance criteria derived from numerical simulations (e.g., CFD for erosion, FEM for stress/vibration analyses) and experimental data (e.g., seal material testing). For instance, a multi-objective genetic algorithm might assign weights or use Pareto fronts to balance material hardness for erosion wear reduction against flexibility for seal durability while also incorporating dynamic damping structures to control vibration-induced fatigue. Therefore, the design of perforation guns can become more robust and adaptable to a wide range of downhole conditions, ensuring higher operational efficiency, reliability, and longevity. Future work could benefit from more specific refinements in both methodology and technology deployment. For instance, multi-scale simulation frameworks that combine macro-level CFD with micro-mechanical modeling of material behavior could provide more accurate predictions of erosion and fatigue life under high-pressure, high-temperature environments. Additionally, integrating in-situ measurement techniques—such as distributed fiber-optic sensing or real-time acoustic emission scanning—could offer a more granular view of seal degradation and crack propagation. In terms of alternative approaches, the adoption of novel hybrid or functionally graded materials, possibly developed through additive manufacturing, holds the potential for improving both wear resistance and vibration damping. Finally, advanced data-driven methods, including reinforcement learning or high-dimensional optimization, may help automatically adjust operational parameters (e.g., flow rate, nozzle orientation) in real time, further enhancing the adaptability and reliability of perforation guns across diverse geological settings. Further research should focus on expanding multi-field coupling analyses, developing high-accuracy numerical models and experimental methods, and gaining more systematic insights into erosion, vibration, fatigue, and leakage phenomena. Efforts should also be directed toward advancing new materials and novel coatings at the micro- and nanoscale to improve gun durability and reliability, as well as leveraging big data and machine learning to enhance intelligent diagnostic systems and predictive maintenance strategies. Achieving real-time and adaptive control throughout the gun’s entire downhole lifecycle is a key objective. Moreover, by bridging the gap between laboratory-scale research and actual well conditions, these integrated approaches and design innovations could rapidly translate into tangible operational benefits. In this way, the insights presented here may spark the development of the next generation of perforation guns, delivering higher success rates, reduced risks, and optimized production in increasingly challenging reservoir scenarios.

The broader implications of this research extend beyond just the development of hydraulic sandblasting perforation guns. The integration of advanced materials, intelligent diagnostics, and real-time adaptive controls holds promise for improving overall well performance in a variety of extraction technologies, not limited to perforation guns alone. As oil and gas extraction becomes more challenging due to the depletion of easily accessible reserves and the increasing complexity of downhole conditions, these innovations could significantly improve operational efficiency, reduce environmental impact, and enhance safety standards. Furthermore, the insights gained from optimizing perforation tools could be adapted for use in other industries, including geothermal energy production, mining, and even medical device applications that involve high-pressure and abrasive environments.

In conclusion, through multidimensional exploration spanning theory, experimentation, engineering applications, and intelligent development, hydraulic sandblasting perforation gun technology is poised to evolve toward greater efficiency, reliability, and intelligence, ultimately providing powerful support for enhanced production and risk reduction in energy development.