煤矿老窑采空区地—井TEM响应特征
TEM response characteristics of borehole in goaves of old coal mines
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摘要: 瞬变电磁法在我国广泛应用于煤田水文地质勘探和采空区调查,但由于方法本身的特点,地面装置纵向分辨率低,无法实现采空区精细探测。在山西某煤矿采空区探查项目中,通过岩心、测井曲线,结合以往电法勘探经验,建立了简单的煤系地层采空区模型,数值模拟了均匀半空间采空区含水、不含水时的地面瞬变电磁响应和三维水平薄板的地—井瞬变电磁响应,并结合实际案例探讨了采空区的地面、地—井瞬变电磁特征,证实了地—井瞬变电磁法具有较高的纵向分辨率,为采空区精细探查提供了思路。Abstract: The transient electromagnetic (TEM) method is widely used in coalfield hydrogeological exploration and goaf investigation in China. However, due to the characteristics of the method itself, the vertical resolution of the ground device is low, and thus it is impossible to realize the fine detection of goaves. In a goaf exploration project of a coal mine in Shanxi Province, a simple goaf model of coal measure strata was established according to the study on cores and logging curves, as well as previous experience of electrical exploration. Based on this, numerical simulation was conducted for the ground TEM response of goaves with and without water in a homogeneous half-space and the ground-well TEM response of three-dimensional horizontal thin plates. As confirmed by the characteristics of the ground and ground-well TEM response of goaves in some practical cases, the ground-well TEM has high vertical resolution, which provides an idea for fine exploration of goaves.
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