西南石油大学学报(自然科学版) ›› 2021, Vol. 43 ›› Issue (4): 71-80.DOI: 10.11885/j.issn.16745086.2021.06.03.03

• 深层和非常规油气钻完井专刊 • 上一篇    下一篇

考虑扭矩影响的弯曲井眼内钻柱屈曲特性分析

庞东晓1, 卢齐1, 邓虎1, 彭炽2, 付建红2   

  1. 1. 中国石油川庆钻探工程有限公司钻采工程技术研究院, 四川 广汉 618300;
    2. 油气藏地质及开发工程国家重点实验室·西南石油大学, 四川 成都 610500
  • 收稿日期:2021-06-03 发布日期:2021-08-06
  • 通讯作者: 彭炽,E-mail:pengchiswpu@swpu.edu.cn
  • 作者简介:庞东晓,1973年生,男,汉族,河北沧县人,高级工程师,博士(后),主要从事完井技术方面的研究。E-mail:dongxx_zyy@cnpc.com.cn
    卢齐,1986年生,男,汉族,四川内江人,工程师,硕士,主要从事钻完井井下工具、工艺技术的研究。E-mail:luq_ccde@cnpc.com.cn
    邓虎,1974年生,男,汉族,四川阆中人,高级工程师,博士,主要从事气体钻井及欠平衡钻井研究。E-mail:dengh@cnpc.com.cn
    彭炽,1991年生,男,汉族,四川广汉人,博士(后),主要从事油气井流体力学和管柱力学方向的研究。E-mail:pengchiswpu@swpu.edu.cn
    付建红,1964年生,男,汉族,湖北红安人,教授,博士生导师,主要从事深井超深井钻井、特殊工艺井钻井等方面的研究工作。E-mail:fujianhong@126.com
  • 基金资助:
    中国石油-西南石油大学创新联合体科技项目(2020CX040100);川庆钻探公司-西南石油大学工程技术联合研究院基金(CQXN-2019-03)

An Analysis of Drilling Pipe Buckling Characteristics in Curved Hole Under the Effect of Torque

PANG Dongxiao1, LU Qi1, DENG Hu1, PENG Chi2, FU Jianhong2   

  1. 1. CCDC Drilling and Production Technology Research Institute, Guanghan, Sichuan 618300, China;
    2. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China
  • Received:2021-06-03 Published:2021-08-06

摘要: 分析了弯曲井眼内钻柱屈曲特性,推导了考虑扭矩影响下的弯曲井眼内钻柱屈曲微分方程和屈曲临界载荷计算模型。针对ϕ215.9 mm井眼内的ϕ127.0 mm钻杆,建立了增斜和降斜井段钻柱的有限元模型,对比分析了考虑和不考虑扭矩影响时的钻柱屈曲特性。结果表明,钻柱正弦屈曲构型与扭矩无关,而只与钻柱所受轴向载荷有关,扭矩对螺旋屈曲构型影响较大。数值模拟得到的弯曲井段不同造斜率下的钻柱屈曲临界载荷与解析解的相对误差在15%以内,证明了数值模拟的可靠性。弯曲井眼内施加扭矩后,螺旋角位移增大,正弦和螺旋屈曲临界载荷降低。钻柱正弦屈曲形态变化较小,扭矩对螺旋屈曲变形的影响更大。增斜井段钻柱从顶部开始发生正弦和螺旋屈曲,钻柱底部保持平衡状态;在降斜井段,不考虑扭矩时,初始正弦和螺旋屈曲均首先出现在钻柱下部,考虑扭矩影响时,降斜段初始正弦屈曲出现在钻柱上部,初始螺旋屈曲同时出现在钻柱上部和下部。相对于增斜段,降斜段钻柱屈曲临界轴向载荷非常小,说明增斜井段发生屈曲的可能性相对较小,降斜井段则很容易发生屈曲。结果有望为水平井、大位移井弯曲井眼内钻柱设计、屈曲控制与强度校核提供参考。

关键词: 弯曲井眼, 屈曲, 扭矩, 数值模拟, 解析解

Abstract: This paper analyzes the buckling characteristics of drilling string in curved wells under the influence of torque. The buckling differential equation and the buckling critical load calculation model of drilling string in a curved wellbore are derived. The finite element models of drilling string in buildup and drop-off sections are established for ϕ127.0 mm drilling pipes in a ϕ215.9 mm wellbore, and the buckling characteristics of drilling strings with and without torque are compared and analyzed. The results show that the sinusoidal buckling configuration of drilling string is not related to torque. It is only decided by the axial load on drilling string. Torque has great influence on spiral buckling configuration. The relative error between the critical buckling loads of drilling strings obtained by numerical simulation under different build-up rates and analytical solution is within 15%, which proves the reliability of numerical simulation. When torque is applied in curved wellbore, the helical angular displacement increases, and the corresponding critical sinusoidal and helical buckling loads decrease. Sinusoidal buckling of drilling string does not change much, and torque has more influence on spiral buckling deformation. In the buildup section, sinusoidal and spiral buckling start at the top of the drilling string, while the bottom of the drilling string maintains a balanced state. In the drop-off section, when the torque is not considered, the initial sinusoidal buckling and spiral buckling first appear at the lower part of the drilling string. When the torque is considered, the initial sinusoidal buckling appears at the upper part of the drilling string, while the initial spiral buckling appears at both the upper and lower parts of the drilling string. Compared with the buildup section, the critical axial loads of drilling string buckling in the drop-off section are very small, which indicates that the possibility of buckling in the buildup section is relatively small, while that in the drop-off section is much easer to occur. The results are expected to provide a reference for the design, buckling control, and strength check of drilling strings in horizontal and extended reach wells.

Key words: curved hole, buckling, torque, numerical simulation, analytical solution

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