井筒冻结孔解冻涌水发生机制及其控制技术

发布时间：2018-05-07 01:31

本文选题：冻结孔 + 井筒　；参考：《煤田地质与勘探》2015年01期

【摘要】：针对冻结井筒解冻后频繁发生涌水灾害的情况,通过工程实例分析了冻结技术、井筒地层条件及解冻涌水特征。结果表明,涌水发生是由于解冻后冻结止水帷幕失效,冻结管周围地层介质渗透性增强,介质接触界面粘结强度降低而致界面缝隙扩大连通,使冻结钻孔连通含、隔水层而形成竖向导水通道,通道内高压水通过井筒薄弱部位发生涌水。采取在井筒外围适宜地层开挖环形巷道,在环形巷道内逐个切断冻结管并向冻结管内外注浆加固,最后将环形巷道用混凝土回填,形成人工隔水塞层。利用RFPA2D Flow渗流耦合模型验证了该治理方案的可行性,且利用FLAC3D程序计算出环形巷道距离井壁7.50 m是最佳开凿位置。经该措施处理后的井筒涌水由原来的90 m3/h降低至2 m3/h,且井筒保持了稳定。
[Abstract]:In view of the frequent water inrush disaster after freezing wellbore thawing, the freezing technology, wellbore formation conditions and characteristics of thawing water inrush are analyzed through engineering examples. The results show that the water gushing occurs due to the failure of freezing curtain after thawing, the enhancement of the permeability of stratum media around the freezing pipe, the decrease of bond strength between the contact interfaces of the medium and the expansion and connectivity of the interface gap, which makes the frozen borehole communication contain. A vertical guide water channel is formed in the water isolation layer, and the water gushing occurs through the weak part of the wellbore under high pressure in the passage. The circular roadway should be excavated in the proper formation outside the shaft, the freezing pipe should be cut off one by one and the grouting should be strengthened inside and outside the freezing pipe. Finally, the annular roadway would be backfilled with concrete to form the artificial water-proof slug layer. The feasibility of the control scheme is verified by using RFPA2D / Flow seepage coupling model, and the optimum excavation position is calculated by using FLAC3D program, which is 7.50m from the shaft wall of the circular roadway. After treatment, the wellbore water inflow decreased from 90 m3 / h to 2 m3 / h, and the wellbore remained stable.
【作者单位】：中煤科工集团西安研究院有限公司;陕西彬长矿业集团;
【基金】：陕西省科学技术研究发展计划项目(2012K08-06)
【分类号】：TD745;TD262

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