某大斜度井三开井段卡钻事故分析  

Sticking Accident Analysis of the Third Opening Section of a High-angle Well

作　　者：董树伟[1] 熊明[2] 

机构地区：[1]中国地质大学工程学院,武汉430074 [2]胜利油田现河采油厂,山东东营257000

出　　处：《安全与环境工程》2012年第6期148-151,共4页Safety and Environmental Engineering

摘　　要：在大斜度定向井和水平井的钻进过程中,岩屑颗粒极易下沉形成岩屑床,对后续钻进造成很大的困难。冀东油田某大斜度井在三开钻井中即因岩屑床过厚而发生卡钻事故,分析此次卡钻事故原因对类似钻井中避免卡钻事故具有重要的意义。本文基于岩屑床厚度评价模型在解决卡钻事故中有着广泛的应用,运用钻井液流体动力学建立了同心环空和偏心环空的岩屑床厚度理论模型,在此基础上对各参数进行了修正从而得到岩屑床厚度经验模型,并运用此模型对该井岩屑床厚度进行了计算,得出钻井液排量不够大和钻井液携岩性能不理想是导致此次卡钻事故的主要原因。针对事故原因,提出了优选钻井液排量、提高环空返速和合理选用钻井液流型及流变参数等解决方案,并介绍了该井的解卡过程。During the drilling of high-angle wells and horizontal wells, cuttings particles tend to form cuttings bed by accumulating in the low-side wall,which will influence the subsequent operations. A sticking accident occurred in a well in Jidong Oilfield because of thick cuttings bed in the third opening section,so the analysis of this sticking accident has significance for avoiding the sticking in drilling process under simi- lar conditions in the future. On the basis of drilling fluid dynamics,the theoretical model of the cuttings bed thickness of concentric annulus and eccentric annulus is established, and the empirical model is obtained by the correction of some parameters. Through cuttings bed thickness evaluation model this paper calculates the thickness of cuttings bed in the third opening section of the well and obtains the conclusion that the drilling fluid displacement which is not big enough and poor performance of carrying cuttings are the main reasons of the sticking. For these two reasons, the paper proposes to optimize the displacement of drilling fluid,improve the annulus return speed and reasonably select drilling fluid flow pattern and rheological parameters to settle the sticking. At the end the paper describes the unsticking process of the well.

关 键 词：大斜度井 卡钻事故 岩屑床厚度模型 原因分析 

分 类 号：X93[环境科学与工程—安全科学] TE28[石油与天然气工程—油气井工程]