射孔套管应力强度及影响因素仿真分析  

Simulation Analysis of Thermal Stress and Strength of Perforated Casing and its Influencing Factors

作　　者：李明飞[1] 窦益华[1] 刘玉雪 LI Ming-fei;DOU Yi-hua;LIU Yu-xue(Mechanical Engineering College,Xi'an Shiyou University,Xi'an Shanxi 710065,China)

机构地区：[1]西安石油大学机械工程学院,陕西西安710065

出　　处：《计算机仿真》2020年第3期100-105,133,共7页Computer Simulation

基　　金：陕西省教育厅自然科学专项资助项目(16JK1606)。

摘　　要：压裂过程中,套管温降产生附加热应力,将改变套管受力状态,影响套管安全。应用Solid Works和Workbench软件,建立射孔段套管-水泥环-围岩三维导热有限元模型,井底温度从125℃降至60℃,考虑温度与热应力场耦合,分析射孔套管的热应力分布和强度安全性。研究表明,存在一个水泥环临界厚度,超过临界值,套管热应力增加明显,于套管强度安全不利;针对建立模型,水泥环弹性模量增加15.3%,其应力增加6.3%,套管应力减小2.9%,水泥环泊松比增加50%,其应力增加15.8%,套管应力增加5.9%;据上述算法,可确定任意套管-水泥环-围岩组合水泥环最优弹性模量范围。During the fracturing process,the temperature drop of the casing creates additional thermal stress,which will change the bearing state of the casing and affect the safety of the casing.In this paper,Solid Works and Workbench software were used to establish a three-dimensional heat conduction finite element model of perforation section casing-cement ring-surrounding rock.The temperature of bottom hole was reduced from 125℃ to 60℃.Considering the coupling of temperature and thermal stress field,the perforation casing was analyzed with its thermal stress distribution and strength safety.The research shows that there is a critical thickness of cement ring,exceeding the critical value,the thermal stress of the casing increases obviously,and the strength of the casing is safe and unfavorable.For the model established in this paper,the elastic modulus of the cement ring increases by 15.3%,and the stress increases by 6.3%.The stress is reduced by 2.9%,the cement ring Poisson’s ratio is increased by 50%,the stress is increased by 15.8%,and the casing stress is increased by 5.9%.According to this algorithm,the optimal range of elastic modulus of any casing-cement ring-surrounding rock combination cement ring can be determined.

关 键 词：射孔套管 强度 热应力 仿真 

分 类 号：TE375[石油与天然气工程—油气田开发工程]