全通径滑套分段压裂工具耐冲蚀性能试验研究

Experimental Study for Erosion Resistance of Full-bore Sliding Sleeve Staged Fracturing Tools

结合全通径分段压裂滑套工具现场使用工况,设计了一套适用于大排量、高砂比、长时间冲蚀模拟试验装置以及性能验证装置,试验时平均排量4.5~6.0 m3/min,含砂体积分数20%~30%,有效冲蚀时间达到24 h,充分模拟了全通径分段压裂滑套和开关工具的耐冲蚀性能,并深入分析了工具各项性能指标。试验结果表明,滑套孔眼中轴向冲蚀较周向冲蚀更为严重;开关工具经冲蚀后液缸边角位置发生一定的冲蚀磨损,经联机及密封测试后,滑套密封压力仍稳定在70 MPa,开关工具锁块仍能顺利伸缩,并成功多次打开、关闭滑套。全通径滑套分段压裂工具经长时间、大排量、高砂比冲蚀后,工具性能均能满足使用要求。

Considering field application of full-bore staged fracturing sliding sleeve tools,one package of simulation testing facilities and performance testing devices applicable for large discharging capacities,high sand ratios and prolonged erosion has been developed. Average discharging capacity of 4. 5 ~ 6. 0 m3/ min,sand volume fraction of 20% ~ 30% and effective erosion time up to 24 h used in these tests can fully simulate erosion resistance of full-bore staged fracturing sliding sleeve and switches. In addition,various performances of such tools can be analyzed in detail. Test results show that sliding sleeves have pore axial erosion much severe than circumferential erosion; switches after erosion experienced certain erosive wear around edges of the liquid cylinder. On-line and sealing tests show that sliding sleeves can maintain pressure at 70 MPa,whereas lock blocks of switches can operate smoothly with sliding sleeves opened and closed successfully in several times. After prolonged erosion with large discharging capacity and high sand ratios,the full-bore sliding sleeve staged fracturing tools maintained desirable performances in every aspect.