油管内衬层性能试验及其内瘪分析.pdf

品油材与仪需
PETROLEUM TUBULAR GOODS INSTRUMENTS
2016年2月
失效分析与预防
油管内衬层性能试验及其内瘪分析
曹峰,刘琰,姚欢,苏杭,蒋承君
(中国石油集团石油管工程技术研究院陕西西安710077)
摘要:某煤层气公司所用的内村油管频繁地出现内村层内瘪问题。对超高分子聚乙烯材料使用前后性能进行了检测,结果表
明其无明显变化且符合标准要求;通过对内村油管的失效过程调查、对失效内衬管宏观、微观分析,以及内衬材料特性综合分析,表
明内村材料与油管线膨胩系数差异、井内外温度差异、内衬层的偏磨、地层水窜入夹层形成的负压差共同导致内衬层内瘪,对内衬
油管生产与使用提出了建议。
关键词:煤层气;内衬油管;偏磨;负压差;内衬内瘪
中图法分类号:TE931
文献标识码:A
文章编号:2096-0077(2016)01-0050-03
Tubing Inner Liner Performance Test and Collapse Analysis
CAO Feng, LIU Yan, YAO Huan, SU Hang, JIANG Chengjun
(CNPC Tubular Goods Research Institute, Xi'an, Shaanxi 710077, China)
Abstract: The lining layer collapse problems occurred frequently in one coal bed methane company. The properties of ultra high molecular
weight polyethylene were tested, and the results showed that the properties can meet the requirements of the standard without significant
changes before and after use. The failure process was investigated, the macro and micro properties and the comprehensive material charac
teristics of the tubing inner liner were analysed, it showed that the lining collapse of tubing inner liner resulted in negative pressure differ
ence in lining layer of flat, which formed by combined actions of the difference of expansion coefficient between lining material and pipe
line, and the temperature difference between the outside and the inside of the well and also the lining layer of eccentric wear and the forma-
tion of water channeling into the interlayer. The suggestions on the production and use of the inner liner pipe were given.
Key words: coal bed methane; liner tubing; eccentric wear; negative pressure difference; lining collapse
1基本情况
出现塌陷并产生裂纹,裂纹长度约1.5m,内衬翻边区
域、内衬管外壁残留煤粉,如图1所示。
1.1失效过程
某煤层气公司采用有杆泵排水的方式进行采气作
业。某定向井泵挂深度761.9m,冲次每分钟3.14次,
排量5.9m/d,井底压力1.66MPa,井内温度30℃
40℃。在排采过程中因泵出现故障进行修井作业,在修
(a)沿纵向塌陷整体形貌
(b)沿纵向塌陷截面
井作业中抽油杆、油管起出过程未见异常。排除了泵的
故障后将油管、抽油杆下入井中,在下入抽油杆的过程
图1送检样失效形貌
中遇阻,再次将抽油杆、油管起出,观察发现其中1支油
参考标准QB/T268-2004高分子量聚乙烯衬
管靠近外螺纹端内衬层塌陷,经查证得知该支油管距井管,对图1中所示的失效样管进行形貌观察。剖开内
口约400m,服役时间为113d。
衬管后发现塌陷处存在沿轴向磨痕及壁厚减薄现象(图
1.2失效内衬管形貌
2),这可能是由于抽油杆对内衬层内壁摩擦作用造
将失效的内衬层从油管中取出,发现内衬管沿纵向成的。
第一作者简介:曹峰,男,1984年生,工程师,200年毕业于西安石油大学油气井工程专业,主要从事石油专用管材产品科研、质量监督
工作及工程技术服务工作。E-mail:caofeng003@cmpe.com.cn