摘要
针对单筒双井技术中大尺寸表层套管的作业时效低、井口稳定性差的问题,设计了一种新型双线螺纹结构。该大尺寸套管规格为762 mm×25.4 mm,双线螺纹,螺纹参数为3牙/25.4 mm(3牙/in)、齿高3.6 mm,齿间间隙0.3 mm,锥度1∶6,齿形导向角45°,承载角7°,采用橡胶密封圈密封。通过静力学数值模拟分析表明,新型双线套管螺纹在压缩、拉伸载荷下,最大接触应力小于材料的屈服强度;在海况重现期为100 a时,强度和稳定性安全系数大于1.25,符合百年一遇波流作用的安全作业要求。在水压、拉伸、压缩、上卸扣、极限弯曲试验中,套管实物均未发生失效。应力应变试验结果和有限元数值模拟结果相似。现场应用2井次,新设计的双线螺纹套管均到达预定地层位置,二开技术套管完井顺利,作业时效比普通螺纹套管提高近1.8倍,满足了单筒双井井身结构设计要求,具有推广价值。
A new type of two-wire thread structure was designed for the problem of low aging and poor wellhead stability of large-size surface casing in twin hole-in-monobore technology.The large-sized threaded casing was designed with following parameters:762 mm×25.4 mm,3 teeth/in,tooth height 3.6 mm,inter-tooth clearance 0.3 mm,taper 1∶6,tooth guide angle 45 degree,bearing angle 7degree and double-thread with the rubber sealing ring.The static numerical simulation analysis of double thread structure shows that the maximum contact stress of the new double thread casing thread is less than the yield strength of the material under compression and tension loads.The safety factor of strength and stability is more than 1.25 when the sea condition recurrence period is 100 years and the double thread casing fully meets the requirements of safe operation under the action of wave and current once in 100 years.The physical test did not fail in hydraulic pressure,tension,compression,buckling and ultimate bending tests.The results of the stress-strain test are similar to those of the finite element numerical simulation.Two wells have been used successfully and the newly designed double-threaded casing has reached the predetermined formation position.The completion of the second-threaded casing was smooth.The operation time was 1.8 times faster than that of the common threaded casing,meets the wellbore structure design requirements of twinhole-in-monobore.
作者
李振坤
殷启帅
左凯
徐鲲
李铁
施山山
赵金城
柴龙顺
LI Zhenkun;YIN Qishuai;ZUO Kai;XU Kun;LI Tie;SHI Shanshan;ZHAO Jincheng;CHAI Longshun(CNOOC Ener Tech-Drilling&Production Co.,Tianjin 300452,China;China University of Petroleum-Beijing,Beijing 102249,China;Tianjin Branch,CNOOC China Limited,Tianjin 300459,China;Pengbo Operating Company,CNOOC China Limited,Tianjin 300459,China)
出处
《石油矿场机械》
2019年第5期16-22,共7页
Oil Field Equipment
基金
“十三五”国家科技重大专项“海外重点油气田开发钻采关键技术”(2017ZX05032-004)
国家自然科学基金项目“海洋深水浅层钻井关键技术基础理论研究”(51434009)
