材料期刊网

石油钻具在钻井作业中，要承受拉、扭、压弯等多种应力作用，同时受到泥浆的冲刷和腐蚀，服役条件十分苛刻。为了提高生产安全效率，对钻具的损伤情况和预期寿命有必要做认真检测。基于金属磁记忆检测技术，提出一种适合钻井现场使用的钻具适用性评价方法，用以评价在役钻具的使用状况，检测出不能继续使用的钻具，从而有效避免井下钻具事故的发生。通过理论推导与现场试验建立了钻具磁记忆检测信号与应力水平的试验关系,用断裂力学原理建立钻具的应力强度因子模型，利用FAD图对钻具的无损评价进行初步尝试，现场试验表明该方法对钻具的评价具有指导意义。

During drilling operations, drilling rigs must bear tensile, distortion, bending and other stress. At the same time, drilling rigs subject to corrosion and erosion of the mud, and have very harsh conditions of service. In order to improve the efficiency of production and safety, the situation of drilling damaged and expected life must be seriously tested. For avoiding the accident of drilling tools in the well effectively, based on the metal magnetic memory technique, an evaluating approach, which was suitable for the actual use of drilling tools, was brought out to evaluate the usage condition of the serviced drill and examine out the drill that can continue to use or not. The relationship between drillings magnetic signal and stress level was built up through theoretic deduction and local experiments. The stress factor model was developed base on the fracture mechanic principle. The attempt was carried out through using the FAD chart, and the results show that the testing method offers a guidance of drilling rigs evaluation.