油气钻井井场防雷击理论及实践

Theories and practices of lightening proof at oil and gas drilling sites

钻井井场防雷击是一个系统工程,涉及多种复杂设备,需要满足防火防爆防雷等耐环境特殊要求,不是普通防雷厂家在井场简单地安装防雷器所能解决的。针对川渝高雷暴地区雷击风险高的特点,中国石油天然气集团公司川庆钻探工程公司对钻井井场专用防雷击系统进行了科技攻关,开展了钻井井场防雷接地、井场总等位联结和井场接零保护等理论研究,将电气保护、防静电和防雷击3者有机结合起来,形成油气钻井井场防雷击实用理论,并将该理论应用于钻机总体设计、改造及安装。两年多来,在川渝地区68台钻机上进行了应用,结果证明,该理论在降低井场直击雷损失和预防感应雷方面起到了重要作用。同时,在使用中发现了该系统存在的问题,制订了相应的整改措施,并指出采取屏蔽和均压方法可将直击雷损失降到最低,以及功能地与现场故障地错误联结的危险性。

Lightening proof at the drilling sites is a system engineering involving numerous kinds of complex equipments,which needs a strong environmental resistance against fire,explosion and thunderbolts.This can not be easily achieved by the lightening protection device produced by common plants which is simply installed at the drilling sites.In view of the characteristics of frequent lightening strokes in Sichuan and Chongqing areas,we have tackled this hard-nut problem to develop a typical lightening proof system used at drilling sites.First,we conducted theoretical studies on the solutions to grounding for lightening,main equipotential bonding,and neutral connection at the drilling sites.Then,we developed a practical theory on lightening proof system for oil and gas drilling sites in combination with electric protection,static-free,and lightening proof.Finally,this theory was applied in an overall design,rebuilding and installation of drilling rigs at the drilling sites.After two years' field practice in 68 drill rigs in Sichuan and Chongqing gas fields,this theory has been proved to play an important role in the prevention of indirect lightening strokes and the reduction of loss due to direct lightening strokes.Moreover,we also found out some problems in the actual application of this theory so as to work out corresponding countermeasures,among which shielding and voltage balancing could minimize the loss due to direct lightening strokes,while there could be a high risk in the wrong connection between the function zone and the on-site fault zone.