含缺陷连续管冲蚀规律研究

针对内壁含缺陷的连续管冲蚀磨损严重、易失效的问题，基于冲蚀理论和液-固两相流，建立了含缺陷连续管内壁冲蚀模型。利用Grant和Tabakoff模型求解砂砾冲蚀速率，借助实验数据验证了CFD数值模型。利用该模型研究了连续管内壁周向均布缺陷数量及缺陷形状参数（深度、长度和宽度）对连续管内壁含缺陷时的冲蚀影响。研究表明:完整连续管与含1个缺陷时对比，最大冲蚀率增加了4.5倍。对于深度或宽度较小的缺陷，冲蚀更为严重，缺陷会在冲蚀作用下迅速加深或变宽，增速下降较快。含大长度缺陷连续管在压裂中会被加速损坏。

Study on erosion laws of coiled tubing containing defect

The erosion of coiled tubing(CT) containing defects in internal wall is serious, and the CT is easy to fail. Based on the erosion theory and fluid & solid two-phase flow dynamics, an erosion model of internal wall for CT containing defects was established. The Grant and Tabakoff models were applied to calculate the erosion rate of gravel, and the CFD numerical model was verified with the experimental data. The erosion influence of the number of defects with circumferential uniform distribution in internal wall of CT and the shape parameters of defects such as depth, length and width on CT containing defects in internal wall was studied by the model. The results showed that the maximum erosion rate of CT containing one defect increases 4.5 times compared with the complete CT. The erosion is more serious for the defects with smaller depth or width, and the defects deepen or widen rapidly under the effect of erosion, with a faster drop of growth rate. The damage of CT containing defects with large length will be accelerated in the fracturing.