页岩气压裂管汇冲蚀损伤行为研究

Erosion Damage Behavior of High-pressure Manifold in Shale Gas Fracturing

材料冲蚀是油气行业常见的失效模式。在页岩气水力压裂过程中,地面高压管汇持续受管内压裂液支撑剂固体颗粒高速冲击。在苛刻工况下,高压管汇敏感部位易由冲蚀损伤而导致穿孔甚至爆裂。然而,对页岩气压裂管汇冲蚀损伤机理尚不完全清晰,导致对冲蚀行为难以预测。对高压管汇材料开展了固液两相流冲蚀磨损试验,分析了携砂液冲击角度、流速对靶材冲蚀磨损的影响机制,然后基于试验参数开展了颗粒冲蚀过程中的冲击动力学仿真,对不同工况下材料冲蚀过程进行分析。结果表明:冲击角度和流速会严重影响冲蚀磨损程度,冲蚀率随冲击角度增大呈现出先增大后减小的趋势;随着冲击角增大,靶材处接触应力的各个分量变化较大,导致不同角度的冲击颗粒对靶材产生的切削、唇片、凹坑等微观损伤形貌的差异。随着流速增大,由于靶材接触应力影响区的范围和应力值大幅增加,冲蚀率呈幂函数增加。

Erosion wear of structural materials is a prevalent failure mode in the oil and gas industry.During hydraulic fracturing of shale gas,the high-pressure manifold is continuously subjected to high-speed impact from solid proppant particles in the fracturing fluid flowing through the pipe.Under harsh operating conditions,the vulnerable components of the high-pressure manifold can be easily damaged by erosion wear,leading to pipe perforation or even rupture.However,there remains a lack of complete understanding regarding the erosion mechanism of high-pressure manifold,which hinders accurate evaluation and prediction of erosion behavior.In this study,we conducted a solid-liquid two-phase flow erosion wear test on materials used in high-pressure manifolds for hydraulic fracturing.We analyzed how parameters such as impact angle and flow velocity influence the erosion wear of target materials when exposed to sand-carrying fluids.Subsequently,based on the test condition parameters,we performed simulations to investigate the dynamics of solid-particle erosion processes and analyzed material micromechanics under different conditions.The results show that the impact angle and flow velocity will seriously affect the erosion wear degree,and the erosion rate will increase first and then decrease with the increase of impact angle.With the increase of the impact angle,the contact stress components at the target material change greatly,resulting in the difference in the microscopic damage morphology of the target such as cutting,lip and pit caused by the impact particles at different angles.With the increase of flow velocity,the erosion rate increases as a power function due to the significant increase in the range and stress value of the target material contact stress zone.