Abstract: Petroleum drilling has seen more and more deep wells, super-deep wells and horizontal wells with large displacement in recent years. The wear and inefficiency rates of drilling tools are increased owing to significant improvement of drilling rate and drilling pressure. The API-certified drilling rod of S135 steel grade has high risks for such well cases and application. The reliability of highly-reliable drilling rod of S grade is improved at the three positions of the drilling rod that are the easiest to become inefficient. The thermal treatment process parameters are optimized to solve the contradictions in improvement of strength and tenacity so far as some of drilling rod materials is concerned. Impact energy of the developed tube body at -20℃ is raised by more than 109 percent under the high strength of 930. 825MPa, while horizontal impact energy of joint at - 10℃ is raised by more than 48 percent. The unique tube - end homogeneously heating technology, matched with mechanical tube-end thickening process, is used to the tube end making the length of inner transitional zone exceed 130mm. R≥300mm at the vanishing point of inner transitional zone, effectively reducing stress concentration to avoid drill rod thorn leakage. A new type of joint thread (BHDX) is adopted for the joint, thus improving torsional strength more than 35 percent as compared to API joint of the same specification. The designed service life of the drilling rod is significantly increased as compared to the ordinary API -certified drilling rod of S steel grade, obviously improving application reliability of the drilling rod.

摘要： 近年来石油钻探中深井、超深井、大位移水平井越来越多, 钻井速度和钻压也大幅提高, 增大了钻具的 磨损和失效几率, API 标准S135 钢级钻杆对该类井况及使用均存在较大风险。S 钢级高可靠钻杆在钻杆最易失效的3 个部位进行了可靠性提升, 钻杆材料部分通过优化热处理工艺参数解决了强度与韧性提高的矛盾, 研制出在 930. 825MPa 高强度下, 管体-20℃冲击功提高109%以上, 接头-10℃横向冲击功提高48%以上; 管端加厚部分通过采 用独有的管端均热技术配合机械式管端加厚工艺, 将内过渡带长度达到130mm 以上, 内过渡带消失处圆弧R≥300mm, 有效降低应力集中避免钻杆刺漏; 接头部分采用一种新型接头螺纹牙型(BHDX), 比同规格API 接头抗扭强度提高 35%以上。钻杆整体设计寿命比普通API 标准S 钢级钻杆大幅提高, 钻杆的使用可靠性显著提升。

关键词: 钻杆, S135 钢级, 高韧性, 冲击功, 钻杆螺纹