管内投砾新工艺在水文水井围填滤料中的应用

Application of a new technology to gravelling in the casing during the filling of filter materials in a hydrological well

水文水井滤料围填的质量对供水水质及使用寿命具有重要影响,常规填料工艺经常出现"架桥"现象和投砾不到位的问题。为此,提出了一种管内投砾新工艺,可以克服上述缺陷。首先阐述了其核心设备—专用转换接头的基本原理,介绍了其施工工艺流程;最后基于两个工程实例,分析了设计与施工方面的难点并给出了相应的解决方案。结果表明:(1)与常规工艺相比较,管内投砾法既能够实现止水、注浆和固井的一体化操作,又能够减少成井环节,缩短成井周期,经济效益显著,可靠度100%;(2)采用专用转换接头围填滤料,能够保证水文水井滤料的充填质量,工艺简单易行、安全高效;(3)在深井投砾时,应安装井口自动投砾器;在井管内宜设置投砾导向管,并采用动水投砾。

The quality of fiher materials in a hydrological well is important to the quality of water supply and the service life of a water-supply well. Conventional feeding technologies often meet the ＂ bridging＂ phenomenon and cause the filter materials not to reach the designated position. A new technology of gravelling in the casing is proposed, which can avoid the above disadvantages. The basic principle and the construction methods of the special adapter substitute is presented. Based on two field site projects, the difficulties in the design and construction process are analyzed and corresponding resolving solutions are also presented. The results show that this technology of gravelling in the casing can realize the integrated operation of.sealing, grouting and cementing together, decrease the well completion process and shorten the well completion time. Therefore it is of obvious economic efficiency. Using the special adapter substitute to fill the filter materials can ensure the filling quality. This technology is simple, convenient and efficient, and has the reliability of 100%. Automatic filling machines are preferred on the surface in the filling of deep wells. Moreover, a draft tube for filling should be installed in the casing and filling in flowing water is also suggested.