高压压裂液对JY-50压裂弯管冲蚀行为影响的数值模拟

目的研究在水力压裂作业中,高压压裂液对JY-50压裂弯管冲蚀磨损的影响规律及其主要影响因素。方法基于液-固两相流理论、FLUENT冲蚀模型,为消除误差,应用FLUENT3次重复性分析并取平均值,得到支撑剂密度、粒径、质量浓度、压裂液流速的变化对弯管冲蚀行为的影响。结果压裂弯管的易冲蚀区域为弯管段靠近出口的内壁面外侧区域和接近弯管出口的直管区域。随着支撑剂密度和粒径的增大,最大冲蚀速率均增大,支撑剂密度从2500 kg/m3增大到3500 kg/m3时,最大冲蚀速率增长了0.69倍,粒径从0.074 mm增大到0.54 mm时,最大冲蚀速率增长了1.45倍,但二者对平均冲蚀速率数值影响变化不大。支撑剂质量浓度的增大,导致冲蚀速率呈近似线性增大,从40 kg/m3增大到210 kg/m3时,最大冲蚀速率增长了2.3倍,平均冲蚀速率增长了1.526倍。流速从5 m/s增大到25 m/s时,最大冲蚀速率平均增长了34.30倍,平均冲蚀速率也增长了34.85倍。结论对JY-50压裂弯管冲蚀行为及影响进行了数值模拟,获得了压裂液的参数变化对压裂弯管的冲蚀影响规律,综合最大冲蚀速率和平均冲蚀速率数值及其增长倍数分析,压裂液流速是冲蚀速率增长的主要因素,对弯管冲蚀磨损影响显著。

Numerical Simulation for Erosion Behavior of High-pressure Fracturing Fluids on JY-50 Fracturing Bend Pipe

The work aims to study the influence laws and main influence factors of high pressure fracturing fluid to JY-50 fracturing bend pipe in the process of hydraulic fracturing operation. Based on the liquid-solid two-phase flow theory and FLUENT erosion model, the FLUENT software was used for 3 times to repeat analysis and take the average to eliminate the error and obtain the effects of proppant density, particle size, mass concentration and change of fluid velocity on bend pipe erosion behavior. The easy erosion area of fracturing bend pipe was the curved section near the exit of the inner wall of the lateral area and close to the straight tube of bend pipe export area. As proppant density and particle size increased, the maximum erosion rate increased. When the density of proppant increased from 2500 kg/m3 to 3500 kg/m3, the maximum erosion rate increased by 0.69 times. When diameter changed from 0.074 to 0.54 mm, the maximum erosion rate increased by 1.45 times, but the impact on the average erosion rate value was not obvious. The increasing proppant concentration led to the approximately linear increase of erosion rate. When the proppant concentration changed from 40 kg/m3 to 210 kg/m3, the maximum erosion rate increased by 2.3 times and the average erosion rate increased by 1.526 times. When velocity ranged from 5 m/s to 25 m/s, the maximum erosion rate and the average erosion rate increased by 34.30 and 34.85 times, respectively. Through the numerical simulation for erosion behavior and effects on JY-50 pressure fracturing pipe, the erosion laws of pressure fracturing fluid parameters on pressure frac-turing bend are obtained. Combined with the maximum erosion rate, average erosion numerical value and growth times analysis, fracturing fluid flow rate is the main factor for erosion rate growth and significantly affects the erosion wear of bend.