在下套管以及压裂作业过程中,套管螺纹在多轴交变载荷作用下极易发生疲劳失效,影响施工进度。针对该问题,通过有限元方法,利用Abaqus软件建立套管长圆螺纹有限元模型,对上扣后套管螺纹在拉伸、压缩、内压力等多轴交变载荷作用下的应力、应变进行了分析,并基于Mises屈服准则的寿命评估法对套管螺纹在多轴交变载荷下的寿命进行计算。研究表明;在拉伸、压缩、内压力等多轴交变载荷作用下,套管螺纹上最大应力都出现在公扣大端5扣齿底处;在轴向拉伸、压缩交变载荷作用下螺纹疲劳寿命仅为1 298次,内压力为46、66、100 MPa时,螺纹疲劳寿命随内压力增加呈现递减趋势,分别为1 094、1 050、901次。该研究结果对致密油等非常规油田在压裂过程中套管螺纹失效分析具有参考意义。
During casing running and fracturing, it is easy to cause fatigue failure to casing threads under multi-axial alternate loads, affecting the construction progress. To address this problem, a finite element model of long round thread of the casing was established by Abaqus software with finite element method, and an analysis was conducted on the stresses and strains of casing thread under multi-axial alternate loads such as tension, compression, and internal pressure after buckling, and the life of casing threads under multi-axial alternate load was calculated by the life assessment method based on the Mises yield criterion. It was found in the study that under the action of multi-axial alternate loads such as tension, compression, and internal pressure, the maximum stress on the casing thread acted at the bottom of the 5 teeth at the big end of the male buckle; under the action of alternate loads such as axial tension and compression, the fatigue life of the lower thread is only 1 298 times. When the internal pressure was 46, 66, and 100 MPa, the fatigue life of the thread was decreased with the increase of the internal pressure, 1 094, 1 050, and 901 times, respectively. The study results provide a reference for the analysis of casing thread failure during fracturing in tight oil and unconventional oilfields.
[1] MANSON S S,FRECHE J C,Ensign C R.Application of a double linear damage rule to cumulative fatigue in fatigue crack propagation[C].ASTM STP 415,1967:384-412.
[2] LORD D C,COFFIN L F.Low cycle fatigue hold time behavior of cast rené 80[J].Metallurgical Transactions,1973,4(7):1647-1654.
[3] 陈勇,练章华,唐玉宏,等.NC50型钻铤公螺纹疲劳寿命计算分析[J].石油矿场机械,2006,35(4):58-60.
CHEN Yong,LIAN Zhanghua,TANG Yuhong,et al.The fatigue life calculation of pin thread on NC50 drill collar[J].Oil Field Equipment,2006,35(4):58-60.
[4] 练章华,梁红军,施太和,等.超深井小钻工具接头螺纹结构研制与应用[J].石油钻采工艺,2016,28(2):160-165.
LIAN Zhanghua,LIANG Hongjun,SHI Taihe,et al.Development and application of screw structure of miniature drilling tool for super-deep wells[J].Oil Drilling & Production Technology,2016,28(2):160-165.
[5] 李群生,王希勇,林铁军,等.气体钻井API钻铤螺纹多轴疲劳寿命研究[J].石油钻采工艺,2014,36(3):56-58.
LI Qunsheng,WANG Xiyong,LIN Tiejun,et al.Research on multiaxial fatigue life of API drill collar thread in gas drilling[J].Oil Drilling & Production Technology,2014,36(3):56-58.
[6] 吴应喜.偏梯形套管螺纹接头多轴疲劳寿命研究[D].西安:西北工业大学,2007.
WU Yingxi.Study on multiaxial fatigue life of buttress casing thread connector[D].Xi'an:Northwestern Polytechnical University,2007.
[7] 彭嵩,张全立,王宏伟,等.基于LMBP神经网络的连续油管疲劳寿命预测方法[J].石油管材与仪器,2018,4(6):36-40.
PENG Song,ZHANG Quanli,WANG Hongwei,et al.Coiled tubing fatigue life prediction method based on LMBP algorithm of neural network[J].Petroleum Tubular Goods & Instruments,2018,4(6):36-40.
[8] 齐维闯,张中东,梁景恒,等.深孔焊补接头内螺纹疲劳试验方法研究[J].兵器材料科学与工程,2016,39(3):128-131.
QI Weichuang,ZHANG Zhongdong,LIANG Jingheng,et al.Fatigue test method of internal thread on repair welding joints of deep holes[J].Ordnance Material Science and Engineering,2016,39(3):128-131.
[9] 吴志荣,胡绪腾,宋迎东.多轴随机载荷下的疲劳寿命估算方法[J].航空动力学报,2014,29(6):1403-1409.
WU Zhirong,HU Xuteng,SONG Yingdong.Estimation method for fatigue life under multi-axial random loading[J].Journal of Aerospace Power,2014,29(6):1403-1409.
[10] GOVINDARAJAN N.钻井工具多轴高周疲劳寿命预测模型优选[J].石油勘探与开发,2015,42(6):808-811.
GOVINDARAJAN N.Multi axial high cycle fatigue life model optimization for drilling tools[J].Petroleum Exploration and Development,2015,42(6):808-811.
[11] 宋生印,高德利.石油套管钻井中套管柱疲劳寿命试验研究[J].科技导报,2007,25(21):27-30.
SONG Shengyin,GAO Deli.Experimental study on fatigue life of casing string after casing drilling[J].Science & Technology Review,2007,25(21):27-30.
[12] 张智,祝效华.钻杆接头多轴疲劳寿命[J].石油学报,2019,40(7):839-845.
ZHANG Zhi,ZHU Xiaohua.Multiaxial fatigue life of drill pipe joint[J].Acta Petrolei Sinica,2019,40(7):839-845.
[13] 聂宏,乔新.一种新的应变疲劳材质参数估算方法[J].南京航空学院学报,1992,24(2):226-231.
NIE Hong,QIAO Xin.A new prediction method of material behavior parameters for strain fatigue[J].Journal of Nanjing University of Aeronautics & Astronautics,1992,24(2):226-231.
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