可钻式贴堵管材及连接方式的优选研究

Research on Optimization of Paste Pipe and Connection Mode

摘要: 老油田开发后期，套管损坏较为严重，低成本贴堵技术是行之有效的治理措施之一，而可钻式贴堵管材是该工艺长期有效的基础。选取壁厚3~7 mm不同材质的贴堵管，采用数值模拟计算、实验室测试仪器对比所选材质的抗压、抗拉强度，耐腐蚀性等特征，根据试验结果，选出最优化的管材进行通径设计。同时通过数值模拟，得出只有FOX型螺纹连接方式的接触应力峰值较小，且各牙应力分布较为均匀；普通偏梯形螺纹连接和NK3SB螺纹连接均在最后一扣处应力较大，其余各牙应力分布较均匀；圆螺纹的受力情况、连接效果最差，开始端和结束端的牙承受了大部分的力，而中间那些扣牙所承受的载荷非常有限，导致两端接触应力大而中间小，各牙受力不均。故贴堵管材优选采用FOX扣型进行连接。

Abstract: At the late stage of old oilfield development, casings damage is serious, low cost plugging technology is one of the effective treatment measures, and drillable plugging pipe is the basis of this technology for a long time. In this paper, 3 - 7 mm plugging pipes with different wall thickness are selected, and the yield, compressive, tensile strength and corrosion resistance of the selected materials are compared by numerical simulation and laboratory testing instruments. Based on the experimental results, the optimal pipe material and path design are selected. Through numerical simulation, the contact stress peak of FOX thread connecting mode is small, and the stress distribution of each tooth is more uniform. Ordinary trapezoidal thread connections and NK3SB thread connections have greater stress at the last buckle, and the rest of the teeth have a more uniform stress distribution. The force situation and connection effect of the round thread are the worst. The teeth at the beginning and the end bear the most of force, and the load of the middle buckling teeth is very limited, resulting in large connect stress on both ends and small in the middle. The force is uneven of each tooth. Therefore, it is preferable to use FOX buckle type pipe connection.