大修精确倒扣技术研究

Heavy Repair Accuracy Backoff Technology Research

大修井活动解卡无效时,需要倒扣取出卡点以上的管柱。为提高倒扣准确率,缩短施工周期,对精确倒扣技术进行研究。首先通过理论推导获得了考虑管柱自身重力的拉伸法卡点深度计算公式,再根据"中和点"法中浮力补偿项的描述,从现场量取管柱的有效密封面积,获得了精确计算倒扣拉力的方法。现场应用表明精确倒扣技术能明显提高倒扣的准确率,现场推广具有较高的应用价值。

When activity unfreezing is invalid in heavy repair procedure, the column above stuck point need to be taken out by backoff operation. In order to improve the backoff operation accuracy and shorten the construction cycle, it is necessary to research accuracy backoff technology. The stuck point depth calculation formula by consid- ering the column its own gravity stretching method is derived theoretically, then according to buoyancy compensa- tion item depicted in ＂neutral point＂ method and field column effective sealing area, finally accurate calculation method of backoff tensile force is obtained. Field application shows that exact backoff technology can significantly improve the backoff operation accuracy