闸板防喷器壳体疲劳寿命及裂纹扩展分析  

Fatigue life and crack propagation analysis of ram blowout preventer casing

作　　者：王仕强 于佩航 何莎 俞嘉敏 徐强 WANG Shiqiang;YU Peihang;HE Sha;YU Jiamin;XU Qiang(Safety Environment Quality Surveillance and Inspection Research Institute of CNPC Chuanqing Drilling&Exploration,Guanghan,Sichuan 618300,China)

机构地区：[1]中国石油集团川庆钻探工程有限公司安全环保质量监督检测研究院,四川广汉618300

出　　处：《中国科技论文》2024年第10期1089-1096,共8页China Sciencepaper

基　　金：国家重点研发计划项目(2023YFC3009200);中国石油集团重大攻关项目(2021ZG08);中国石油集团科技重大专项(2021ZZ03-1)。

摘　　要：为研究闸板防喷器壳体在实际使用过程中凹坑与裂纹对其安全使用的影响,采用ABAQUS仿真模拟与实验分析了防喷器壳体在工作压力(70MPa)与静水压测试压力(105MPa)下的应力变化,研究了凹坑缺陷对闸板防喷器使用寿命的影响,分析了防喷器壳体疲劳裂纹扩展特性。结果表明:当壳体通径存在ϕ170mm的凹坑时,最大应力达到520MPa,其位于凹坑边缘表面,而其他区域应力远小于材料屈服强度;当壳体腔室与通径高应力处存在腐蚀凹坑(直径<40 mm)时,最高应力幅分别为520MPa和344MPa;闸板防喷器疲劳裂纹随着不断扩展,逐渐呈现对称的半椭圆裂纹。通过对防喷器壳体在腔室与通径高应力区腐蚀凹坑的深入分析,发现腐蚀凹坑对防喷器的安全使用影响较小。同时,分析了防喷器缺陷大小与使用频次之间的关系,论证了防喷器不以统一使用年限作为判废指标的合理性。In order to study the effects of pit and crack defects on the safety of the ram blowout preventer(BOP)shell in practical use,ABAQUS simulation and experiment were carried out to analyze the stress variation of BOP shell under working pressure(70 MPa)and hydrostatic testing pressure(105 MPa).The influence of pit defects on the service life of ram BOP was studied,and the fatigue crack propagation characteristics of BOP shell were analyzed.It is found that,when the diameter of the shell isϕ170 mm,the maxi⁃mum stress reaches 520 MPa.This maximum stress is located on the edge surface of the pit,while the stress in other areas is much less than the yield strength of the material.When there is a corrosion pit(diameter<40 mm)at the high stress position of the shell chamber and the diameter,the maximum stress amplitude is 520 MPa and 344 MPa,respectively.The fatigue cracks of ram BOP gradually appear symmetric semi-elliptic cracks with the continuous expansion.An in-depth analysis of the corrosion pits in the chamber and high-stress areas of the borehole of the BOP casing indicates that the impact of these corrosion pits on the safe operation of the BOP is relatively minor.Additionally,the study has elucidated the relationship between the size of BOP defects and the fre⁃quency of use,substantiating the rationality of not using a uniform service life as the criterion for BOP decommissioning.

关 键 词：闸板防喷器 壳体 腐蚀凹坑 寿命分析 裂纹扩展 仿真模拟 

分 类 号：TE931[石油与天然气工程—石油机械设备]