摘要
Φ450稳定器在某超深井钻进过程中内螺纹丝扣部位发生了刺漏开裂失效。通过螺纹及刺漏裂纹宏观形貌分析、金相组织试验、硬度试验和材料力学性能试验,分析了失效稳定器刺漏开裂的原因。结果表明,刺漏稳定器的拉伸强度、冲击韧性和金相组织结果均符合SY/T 5051—2016标准的要求,但该稳定器刺漏部位附近内壁处硬度测试结果小于该标准的要求,且内螺纹丝扣部位存在大量沉积物。内螺纹应力集中部位的齿根底部产生了裂纹,裂纹在扭矩和轴向应力交变载荷作用下持续扩展,同时高压泥浆经齿牙损坏部位流入至裂纹中,裂纹在应力集中和泥浆冲蚀综合作用下快速扩展形成大尺寸裂纹,直至该稳定器内螺纹部位刺漏穿孔失效。
During the drilling of an ultra deep well,the stab leakage cracking occurred at the bottom of the female buckle of∅450 centralizer.The causes of stab leakage cracking of centralizer were experimentally analyzed by macroscopic morphology observation,thread and stab leakage crack characteristics analysis,metallographic structure test,hardness test and material mechanical property test.The results show that the tensile strength,impact toughness and metallographic structure of the centralizer all meet the standard requirements.However,the hardness test result of the inner wall near the puncture part of the centralizer is less than the standard requirement.There are a lot of deposits in the female buckle teeth of the centralizer.The stress concentration part of the female buckle is overloaded,resulting in the nucleation of cracks at the bottom of multiple tooth roots.The cracks continue to expand under the alternating load of torque and axial stress.At the same time,high-pressure fluid enters the cracks through the tooth defect part,and the cracks rapidly expand under the combined action of stress concentration and fluid erosion to form large-size cracks.Finally,stab leakage occurs on female buckle of the centralizer.
作者
谭雷川
李洪兴
高德利
胡殊睿
周效民
TAN Leichuan;LI Hongxing;GAO Deli;HU Shurui;ZHOU Xiaomin(Chuanxi Drilling Company,CNPC Chuanqing Drilling Engineering Company Limited,Chengdu,Sichuan 610051,China;MOE Key Laboratory of Petroleum Engineering,China University of Petroleum(Beijing),Beijing 102249,China)
出处
《石油管材与仪器》
2022年第5期43-47,共5页
Petroleum Tubular Goods & Instruments
基金
国家自然科学基金项目“页岩和致密油气田高效开发建井基础研究”(编号:U1762214)
中国石油集团川庆钻探工程有限公司科技项目“故障复杂预防与治理技术研究与试验”(编号:CQ2021B-41-Z3-3)。
关键词
稳定器
刺漏
裂纹
失效分析
超深井
centralizer
stab leakage
crack
failure analysis
ultra deep well
