摘要
由于我国的优质天然气资源主要集中在深层及超深层,超深井的钻探对钻柱提出了更高的性能要求。钛合金钻杆由于具有高强、低密、耐蚀、抗疲劳、耐热和无磁性等优点,是超深层天然气钻柱的研究热点。本文使用三维有限元分析方法,对比研究不同外载条件下钛合金材料和钢钻杆材料对高承载钻杆接头承载性能和密封性能的影响,并分析高承载钻杆接头在工况下的失效方式和力学特性。结论表明:钛合金材料可以使钻杆接头的整体应力水平降低20%,抗扭能力提高约60%,但在同样扭矩上扣后螺纹接头的主台肩密封压力比钢制钻杆接头低15%~20%;当加载内压+拉伸+弯矩的复合载荷后,螺纹的最大危险点由外螺纹主台肩圆弧凹槽处转移到了在外螺纹主台肩侧第一圈齿根处,螺纹整体的应力水平增高,密封性能下降。因此为了满足超深井天然气井钻采需求,使用钛合金/钢钻杆复合钻柱时,可适当提高钛合金钻杆的上扣扭矩,提高螺纹接头的密封性能。
Due to the concentration of high-quality natural gas resources in deep and ultra-deep formations in China,drilling of ultra-deep wells presents higher performance requirements for drill strings.Titanium alloy drill pipes have become a research focus for ultra-deep natural gas drill strings due to their advantages such as high strength,low density,corrosion resistance,fatigue resistance,heat resistance,and non-magnetic properties.In this study,a three-dimensional finite element analysis method is used to compare and investigate the effects of titanium alloy and steel drill pipe materials on the load-bearing and sealing performance of high load-bearing drill pipe joints under different external loading conditions.The failure modes and mechanical characteristics of the high load-bearing drill pipe joints under working conditions are also analyzed.The results show that the use of titanium alloy materials can reduce the overall stress level of the drill pipe joints by 20%and improve the torsional resistance by approximately 60%.However,under the same make-up torque,the sealing pressure of the main shoulder of titanium alloy joint is 15%~20%lower than that of the steel drill pipe joint.When subjected to composite loads of internal pressure,tension and bending moment,the maximum critical point of the thread transitions from the fillet groove of the external thread shoulder to the first tooth root of the external thread shoulder.The overall stress level of the thread increases,while the sealing performance decreases.Therefore,to meet the requirements of ultra-deep natural gas drilling,when using a composite drill string of titanium alloy and steel drill pipes,it is recommended to appropriately increase the make-up torque of the titanium alloy drill pipe to improve the sealing performance of the thread joint.
作者
张益铭
张建军
李晓
杨柳
李桂变
刘强
吴永清
马欣华
祝国川
尹成先
ZHANG Yiming;ZHANG Jianjun;LI Xiao;YANG Liu;LI Guibian;LIU Qiang;WU Yongqing;MA Xinhua;ZHU Guochuan;YIN Chengxian(State Key Laboratory of Oil and GasEquipment,CNPC Tubular Goods Research Institute,Xi′an,Shaanxi 710077,China;School of Materials Science and Engineering,Xi′an University of Technology,Xi′an,Shaanxi 710048,China;Downhole Service Company,CNPC Chuanqing Drilling Engineering Company Ltd.(CCDC),Chengdu,Sichuan 610213,China;PetroChina Southwest Oil and Gas Field Materials Branch,Chengdu,Sichuan 610017,China;Sichuan Changning Natural Gas Development Co.Ltd.,Chengdu,Sichuan 610051,China;Shanxi North Fenglei Industrial Group Co.Ltd.,Houma,Shanxi 043009,China)
出处
《石油管材与仪器》
2024年第3期51-59,I0004,共10页
Petroleum Tubular Goods & Instruments
基金
国家重点研发计划“高承载钛合金特殊螺纹接头制造及连接关键技术研究与应用”(编号:2021YFB3700804)
中国石油科学研究与技术开发项目“耐蚀、抗菌、高强度低密度油井管新材料开发”(编号:2021DJ2703)
陕西省自然科学基金“Nb对极端油气工况下钛合金微观结构与耐蚀性交互影响机制研究”(编号:2021JM-607)。
关键词
超深井天然气开发
钛合金钻杆
高承载接头
三维力学
有限元分析
复合载荷
ultra-deep gas exploration
titanium alloy drilling pipe
high load-bearing joint
three-dimensional mechanical
finite element analysis
composite loads
