基于孔中瞬变电磁法的井下覆岩导水裂隙带发育高度研究
Research on the development height of water-conducting fracture zone in overburden rock based on transient electromagnetic method in hole
梁庆华 1丁相军 2刘广亮 3刘志成 4王春源 1张桓1
作者信息
- 1. 自然资源部滨海城市地下空间地质安全重点实验室,山东 青岛 266101;青岛理工大学,山东 青岛 266520
- 2. 自然资源部滨海城市地下空间地质安全重点实验室,山东 青岛 266101;青岛地质工程勘察院(青岛地质勘查开发局),山东 青岛 266101
- 3. 中煤科工西安研究院(集团)有限公司,陕西 西安 710076
- 4. 山西省地质勘查局 二一二地质队有限公司,山西 长治 046000
- 折叠
摘要
瞬变电磁法在探测导水通道方面具有良好的效果,但是常规的方法探测导水裂隙带发育会受到环境的影响,不适宜完成探测工作.为此,采用孔中瞬变电磁法,对井下覆岩导水裂隙带发育高度进行研究,利用COMSOL软件对于孔中瞬变电磁法的传播特性和响应特征进行研究,并结合孔中瞬变电磁探测试验,研究孔中瞬变电磁探测导水裂隙带的可行性.研究结果表明:孔中瞬变电磁可以有效完成异常体的探测任务,通过调整收发装置的位置以达到提高信噪比的效果,孔中瞬变电磁径向扩散方式与矿井瞬变电磁理论基本相同;但是,模拟发现低阻区响应场受高阻区影响较大,导致 60 m交界面相邻低阻区衰减速度过快,响应曲线在低阻区出现"尖点",说明受高阻岩体影响 60 m附近的低阻区视电阻率大于低阻区理论值.经过井下试验得出:孔中瞬变电磁探测已开采煤层导水裂隙带发育异常明显,且成片连接;而未开采煤层瞬变电磁低阻异常不明显,且未形成大片连接,说明通过钻孔瞬变电磁系统观测导水裂隙带高度具有较高的可行性.
Abstract
Transient electromagnetic method has shown great effectiveness in detecting water channels.However,conventional methods for detecting the development of water-conducting fracture zones are not suitable due to environmental influences.In this study,the borehole transient electromagnetic method was used to investigate the development height of water-conducting fracture zones in the overlying strata underground.The propagation characteristics and response features of the borehole transient electromag-netic method were studied using COMSOL software.Combined with borehole transient electromagnetic testing,the feasibility of de-tecting water-conducting fracture zones using the borehole transient electromagnetic method was investigated.The research results showed that the borehole transient electromagnetic method can effectively complete the task of detecting anomalous bodies.The sig-nal-to-noise ratio can be improved by adjusting the position of the transmitter-receiver devices.The radial diffusion mode of the borehole transient electromagnetic method is basically the same as the theory of mine transient electromagnetic.However,simula-tions revealed that the response field of low-resistivity zones is greatly affected by high-resistivity zones,resulting in rapid attenu-ation of adjacent low-resistivity zones near the 60 m interface and the appearance of"peak points"in the response curve of the low-resistivity zones.This indicates that the apparent resistivity of the low-resistivity zones near the 60 m interface is greater than the the-oretical value of the low-resistivity zones due to the influence of high-resistivity rock masses.Through underground experiments,it was concluded that the borehole transient electromagnetic method can effectively detect the significant abnormal development of wa-ter-conducting fracture zones in mined coal seams,which are connected in large patches.In contrast,the low-resistivity anomalies in unmined coal seams using the transient electromagnetic method are not obvious,and large-scale connections have not been formed.This suggests that observing the development of water-conducting fracture zones through the borehole transient electromagnetic sys-tem is highly feasible.
关键词
导水裂隙带/孔中瞬变电磁法/探测方法/异常特征/数值模拟Key words
water conduction fracture zone/transient electromagnetic method in hole/detection method/abnormal characteristics/numerical simulation引用本文复制引用
出版年
2025
国家科技期刊平台
NSTL
万方数据