发布时间 : 星期四 文章井下套管损坏机理及围压分析-设计论文更新完毕开始阅读
西安石油大学本科毕业设计（论文）
井下套管损坏机理及围压和应力分析
摘 要:首先本文作者通过对油田套管大量损坏这一问题的调查，发现了套管损坏是当今石油开采过程中存在的普遍问题，给石油生产带来了巨大的损失。提出对井下套管损坏机理和围压应力分析的必要性。
之后通过阅读相关文献，综合分析了各种引起套管损坏的原因。推导套管挤毁压力公式，计算井下套管围压。得出相应的结论。其中套管损坏的主要原因有：是套管柱设计不合理，尤其当套管处于盐岩、泥(页)岩地层，设计载荷偏小;不合理的注水，加速套管的损坏;套管柱本身设计强度较低，射孔在一定程度上对套管的强度产生影响，加速了套管损坏;腐蚀使套管避变薄，甚至穿孔，降低套管强度，损坏套管;油层出砂、固升质量差、套管缺陷等造成的套管损坏。造成套管损坏的因素很多，其中套管围压的增大是套管损坏的主要因素之一，因此我们很有必要对套管的围压进行分析。
最终本文在分析与研究了造成套管损坏因素的基础上，提出相应的套管损坏防治措施对套管损坏形式进行了分析研究；分析了在考虑与不考虑固井水泥石的情况下套管围压的计算方法；设计了完井井下管柱载荷试验台。
关键词：套管损坏；套管围压；应力分析
西安石油大学本科毕业设计（论文）
Casing pipe damage mechanism and analysis of confining pressure
exert on underground casing
firstly, the writer based on the fact that large number of casing pipe are damaged during working time. Obviously, it is a common problem which causes large amount of finance lost during the production procedure.It is necessary and urgent to analysis the mechanism of casing damage and confining pressure.
Then the writer read some documents on this subject.Analysised the factors that could cause casing damage.Evaluated confining pressure and got the solution to the problem. Here are some factors that might be response to casing damage.1.unreasonable design of casing string (especially in salt bet and mudslide (shale) formation); 2.unreasonable water injection; 3.casing perforation; 4.corrosion; 5.sand problems, cementing quality and casing defect. According to a lot of theoretical research and practice has proved that due to increasing pressure casing tube casing damage is one of the main reasons. So the mechanism of damage to underground casing and confining pressure and stress analysis is essential.
Finally,based on the factors that may cause casing damage,the writer gave some solutions to reduce casing damage. Then the writer designed a facility for casing damage and stress analysis
Subject heading: Casing Failure；Confining Pressure；Stress Analysis
西安石油大学本科毕业设计（论文）
目录
目录 ........................................................................................................................................................... 1 第1章 绪论 ........................................................................................................................................... 1
1.1 课题目的与意义 ....................................................................................................................... 1 1.2 国内外研究现状 ....................................................................................................................... 1 1.3 毕业设计的主要内容 ............................................................................................................... 3 1.4 毕业设计的主要方法 ............................................................................................................... 4 第2章 套管损坏因素及预防措施 ........................................................................................................ 5
2.1 地质因素 .................................................................................................................................... 5
2.1.1 围岩压力........................................................................................................................ 5 2.1.2 泥岩膨胀和蠕变 ............................................................................................................ 5 2.1.3 现代地壳运动、地震和滑坡 ........................................................................................ 6 2.1.4 油井出砂........................................................................................................................ 6 2.2 工程技术因素........................................................................................................................... 7
2.2.1 固井质量不好 ................................................................................................................ 7 2.2.2 水泥返高不够 ................................................................................................................ 7 2.2.3 套管质量不合格 ............................................................................................................ 8 2.2.4 丝扣不密封 .................................................................................................................... 8 2.2.5 施工不合理 .................................................................................................................... 9 2.2.6 磨损 ............................................................................................................................... 9 2.2.7 注水压力变化 ................................................................................................................ 9 2.3 其它因素 ................................................................................................................................ 10
2.3.1 射孔 ............................................................................................................................. 10 2.3.2 永冻层解冻和再冻结 .................................................................................................. 10 2.3.3 腐性 ............................................................................................................................. 11 2.4 套管损坏的预防措施 ............................................................................................................. 11
2.4.1 提高套管抗挤压强度加强套管下井前的检测和保护 .............................................. 11 2.4.2 防止注入水窜入软弱底层 .......................................................................................... 13 2.4.3 防止油层出砂 .............................................................................................................. 14 2.4.4 防止套管腐蚀 .............................................................................................................. 15 2.5 本章小结 ................................................................................................................................ 16 第3章 套管挤毁理论基础和公式推导 .............................................................................................. 17
3.1 挤毁压力计算公式 ................................................................................................................. 17
（1） 屈服强度挤毁压力： .................................................................................................. 17 （2） 塑性挤毁压力： .......................................................................................................... 17 3.1.1 挤毁压力公式使用范围的确定 .................................................................................. 19 3.2 套管挤毁压力公式的推导 ..................................................................................................... 20
3.2.1 屈服强度挤毁压力公式 .............................................................................................. 20 3.2.2 塑性挤毁压力公式 ...................................................................................................... 21 3.2.3 弹塑性挤毁压力公式 .................................................................................................. 22
西安石油大学本科毕业设计（论文）
3.2.4 弹性挤压公式的推导 .................................................................................................. 24 3.3 套管抗内压强度公式及其推导 .......................................................................................... 28 3.4本章小结 ................................................................................................................................... 29 第4章 套管围压计算.......................................................................................................................... 30
4.1 不考虑固井水泥石影响，弹性围岩中套管的围压 ............................................................. 30 4.2 考虑固井水泥石影响，弹性围岩中套管的围压 ................................................................. 31 4.3 本章小结 ................................................................................................................................ 33 第5章 井下管柱载荷测试器说明书 .................................................................................................. 34
5.1设计说明书内容........................................................................................................................ 34 5.2井下管柱载荷测试器工作原理 ................................................................................................ 34 5.3 概述 .......................................................................................................................................... 34
5.3.1 原始设计参数 ................................................................................................................ 34 5.3.2 总体方案设计 .............................................................................................................. 35 5.3.3 机械设计...................................................................................................................... 36 5.3.4 相关计算...................................................................................................................... 37
第6章 结论 ......................................................................................................................................... 38 致谢 ......................................................................................................................................................... 39 参考文献 ................................................................................................................................................. 40
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