NTQ248-25Y型无牙痕套管动力钳研制

高含硫油气井的完井管串一般采用耐蚀合金(CRA)套管，这种套管的材质较软，常规套管动力钳工作时极易破坏套管表面的防腐镀层，加速硫化氢对套管的腐蚀，影响完井管串质量。依据套管动力钳内曲线爬坡滚子机构的特点，采用材料优选、结构优化设计与室内试验相结合的方式，研制出NTQ248-25Y型无牙痕套管动力钳。室内试验和现场应用表明，该无牙痕套管动力钳作业后套管表面完全没有牙痕，最大输出转矩为25 kN·m,能完成外径为114.3～177.8 mm套管的上卸扣作业。

Development of NTQ248-25Y Toothless Casing Power Tong

he completion string of high sulfur oil and gas wells generally adopts corrosion-resistant alloy(CRA)casing. The material of this kind of casing is relatively soft. When the conventional casing power tong works, it is very easy to damage the anti-corrosion coating on the casing surface, accelerate the corrosion of hydrogen sulfide to the casing and affect the quality of the completion string. According to the characteristics of the curve climbing roller mechanism in casing power tongs, the NTQ 248-25Y toothless casing power tong was developed by combining material optimization, structural optimization design, and indoor tests. The indoor tests and field application show that there is no tooth mark on the casing surface after the operation of the toothless casing power tong, and the maximum output torque is 25 kN·m. It can complete the up-and-down operation of the casing with an outer diameter of 114.3 mm to 177.8 mm.