模糊识别及预测在役套管的变形损坏  

FUZZY DIAGNOSIS AND PREDICTION OF ON STREAM CASING DAMAGE

作　　者：张效羽[1] 徐秉业[1] 赵国珍[2] 

机构地区：[1]清华大学工程力学系 [2]中国石油天然气集团公司

出　　处：《天然气工业》1999年第2期72-74,共3页Natural Gas Industry

摘　　要：近年来，我国许多油气田的套管损坏均呈快速增长势头，套管损坏的频繁出现带来了巨大的经济损失，也严重防碍了正常生产。然而，按照以往的方法对井下套管变形情况进行识别，进而预测其损坏程度是非常困难的。这种困难来自于许多方面，诸如井眼周围地下情况的不明确、套管受力难以确定、复杂的失效机理、因素的模糊性、套管损坏原因与结果之间的模糊关系等等。为此文中首先系统地分析了这些困难，对套管损坏的原因进行归纳及分类，然后在此基础上利用模糊数学建立了对套管损坏的数学描述，提出了用模糊综合评判方法识别套管的变形情况，进而用序列评判结果来预测套管损坏程度和使用寿命。该方法考虑并利用了影响套管损坏的许多模糊因素，在一定程度上解决了以往方法中遇到的困难，为套管寿命预测研究提供了一种新的途径，并得到了生产单位的肯定。In recent years, the casing damage is rapidly rising in many oil and gas fields in China, by which anormous economic loss has been made and the routine production has been severely hindered. It is very difficult, however, to diagrose the downhole casing deformation, then to predict the degree of its damage by use of the conventional methods. There are a lot of reasons to result in these difficulties there, such as unclear ground circumstances around the hole undetermined casing loads, complicated failure mechanisms, fuzziness of various causes, and some fuzzy relations between the causes and results of the casing damage, etc. Thus, in the paper, firstly these difficulties are systematically analyzed and the generalization and classification of the reasons causing the casing to be damaged are made, then, on the basis of that, a mathematical description for the casing damage is set up by use of fuzzy mathematics and a method of 'Sequential Fuzzy Synthesis Evaluation' is proposed for diagnosing deformation, which results can be used for predicting the degree of the casing damage and the service life of the casing. In this method, many fuzzy factors causing the casing to be damaged were considered and applied and the difficulties encountered when the conventional methods were used were partially solved. This method provides a new way for predicting and studying the service life of the downhole casing and has been approved by the production units.

关 键 词：模糊数学 套管损坏 套管变形 油气田 井下套管 

分 类 号：TE931.207[石油与天然气工程—石油机械设备]