钢板式浮塞下管工艺在煤矿大口径工程井中的应用

Casing running process with the steel buoyancy plug for large diameter wells at coal mines

摘要:

针对煤矿大口径工程井采用常规水泥浮塞下管技术存在的施工工序多、钻井液易污染、水泥块沉渣多和易残留等工艺缺陷，以霍州某煤矿大口径瓦斯抽采钻孔工程实践为例，开展钢板式浮塞下管技术研究。介绍了该技术的工艺原理，对瓦斯孔工作套管发生弹性失稳变形和材料屈服破坏的临界强度进行校核计算，开展了钢板浮塞的结构和装配方案设计，并对其强度进行验算。采用本工艺完成直径836 mm，重150 t瓦斯抽采管路的下放作业。经实践验证，该技术可减少下管固井期间起下钻工作量，缩短作业时间，成井后套管内无水泥块残留，且工艺制作过程简单、操作方便，可为今后类似工程施工提供经验和借鉴。

Abstract:

In view of the defects with the conventional casing running process with the cement buoyancy plug for coal mine large diameter wells， such as multiple steps， drilling fluid pollution， high amount of concrete settlement and residuals， research was carried out on the casing running process with the steel buoyancy plug in the case of a large diameter gas extraction well at a coal mine in Huozhou . This paper introduces the process principle， calculation of critical casing strength at elastic buckling deformation and material yield failure， the structure and assembly design and strength calibration for the steel buoyancy plug. This process was used to run gas extraction casing of 150t at ?836 mm diameter， and the field use has proven that this technique can reduce tripping of the drilling string during casing running operation， shorten the operation time， and eliminate concrete residue in casing； in addition， the process is feature of simple manufacture and convenient operation. It can provide experience and reference for future similar projects.