基于光纤光栅传感的螺纹钻杆复合载荷多节点检测技术

引入光纤光栅应变传感器和温度传感器，结合螺纹钻杆复合载荷（轴向压力、弯矩和扭矩）分离理论，实现对钻进过程中螺纹钻杆多节点处复合载荷自动分离与在线检测，同时对钻进过程中出现的温升进行了补偿。将检测结果与电机施加的载荷（压力和扭矩）进行对比分析，认为螺纹钻杆前端（靠近钻头一侧）受到被钻物侧向挤压和摩擦阻力较大，使得电机施加的压力和扭矩传递损耗较多，导致易磨损、变形；而螺纹钻杆中段和末端只是短暂甚至未进入被钻物，传递损耗相对较少，受弯矩的影响较大。该检测技术为钻杆材料的选择、结构优化和钻进参数的选定提供技术支撑。

MULTI-NODE DETECTION TECHNIQUE OF THREADED DRILL PIPE COMPOUND LOADS BASED ON FIBER BRAGG GRATING SENSING

Based on the separation theory of compound loads (axial force, bending moment and torque), the multi-node compound loads of a threaded drill pipe are separated and detected online in a drilling process by using fiber Bragg grating (FBG) strain sensors and temperature sensors. Temperature compensation is realized synchronously. Compared the measured value with the applied axial force and torque, the transfer losses in the front end of the threaded drill pipe (close to drill bit) is considered being greatly influenced by the lateral squeezing force and frictional resistance. The bigger value makes this part of the drill pipe easy wear and deformation. The middle and terminal end of the drill pipe are greatly influenced by bending moment. The former enters the object with short time. And the latter does not enter. It leads to low transfer losses. The detection technique provides a technical support for material selection, structural optimization, and drilling parameter selection of a drill pipe.