单孔多层抽水试验综合止水技术实践

为查明对煤层开采有充水意义的含水层(体)的分布特征及富水性,对各充水含水层进行了分层抽水试验。以抽水试验水文钻孔为例,采用改进后的多层综合止水技术,获取含水层的水文地质参数和水质情况,并进行了横向对比。实践结果表明,综合止水技术在大孔径抽水环境下,可以减少因孔径问题不能正常下放水泵的问题;水文孔洗井过程中在钻具组合方面设计钻杆加入逆止阀进行负压洗井作业,可使套管内保持沙清水静;在抽水试验中可加入瓦斯数据的提取工作,可以节省重复勘探造成的资源浪费。单孔多层抽水试验综合止水技术为彬长矿区后期超前疏放、注浆改造含水层以及治理煤层顶板水害等问题提供了数据,既达到了勘探目的,又提高了工程效率。

Practice of comprehensive water stop technology in single-hole multi-layer pumping test

In order to find out the distribution characteristics and water abundance of aquifer(body)with water filling significance for coal seam mining,stratified pumping test was carried out for each aquifer.Taking the hydrological drilling of pumping test as an example,by using the improved multi-layer comprehensive water stop technology,the hydrogeological parameters and water quality of the aquifer are obtained and the horizontal comparison is made.The practice results show that the comprehensive water stop technology can solve the problem that the water pump cannot be run normally under the condition of large diameter water pumping;the negative pressure well washing operation can be carried out by adding the check valve in the hydrological hole to the drill pipe to keep the sand and water still in the casing;the gas data extraction can be added in the pumping test to save the resource waste caused by repeated exploration.The comprehensive water stop technology of single hole multi-layer pumping test provides the basis for advanced drainage,grouting transformation of aquifer,and control of water damage of coal seam roof in Binchang mining area,which not only achieves the exploration purpose,but also improves the engineering efficiency.