金属磁记忆检测在钻具评价中的应用

Applications of metal magnetic memory in drillstring evaluation technique

在钻井过程中,钻具在井下承受着复杂的交变应力的作用,经过一段时间的使用后则会产生破坏,这给钻井生产带来巨大的经济损失。因此开展钻具适用性评价方法研究不仅具有理论意义,而且有重大的实际意义。本文主要讨论的是利用无损检测技术,提出一种适合于钻井现场使用的钻具适用性评价方法,用以评价在役钻具的使用状况,检测出不能继续使用的钻具,从而有效避免井下钻具事故的发生。为此本文将磁记忆检测用于钻具的失效分析,通过理论推导与现场实验建立了钻具磁记忆检测信号与应力集中系数的实验关系。利用R.E.Peterson提出的疲劳缺口系数公式对钻具的无损评价进行了初步尝试,现场实验表明该方法对钻具的评价具有指导意义。

Drill endures complicated alternative stress in the well during drilling process, it will produce breakage after using a period of time, this will bring artesian well a huge economic loss. Therefore researching the applicability evaluation method of drilling tools not only has theoretical meaning, but also has important practical meaning. This paper mainly discusses how to make use of NDT technique, bring out a drilling tool applicability evaluation method suitable for practical use, evaluate the using condition of the serviced drill and detect the drill that can＇t continue to be used, so that we can avoid the accident of drilling tools in the well effectively. This paper uses magnetic memory test method to analyze the drilling tool invalidation and build up an experimental relationship between drilling tool magnetic memory test signal and the stress concentration coefficient through theoretical deduction and on site experiments. A fatigue indentation coefficient formula proposed by R.E. Peterson is used as a first try to the non-destruc- tive evaluation of the drilling tool; on site test proves that this method has great significance to the evaluation of the drilling tools.