高密度电法与磁法探测煤田火区的数值模拟

Numerical simulation of electrical resistance tomography method and magnetic method in detecting coal fires

通过建立煤田火区地电、地磁模型并进行计算分析,分别研究高密度电法中温纳α装置与温施装置对火区燃烧中心温度、埋深的敏感性和磁法探测对燃烧中心温度、火区埋深、燃烧时间的敏感性。通过对比分析正反演结果,可知高密度电法温纳α装置适合探测埋深大于50 m的煤田火区,温施装置适合探测埋深小于50 m的煤田火区,且两种排列方式均对火源中心温度和埋藏深度有较准确反演;而磁法可对煤田火区边界进行准确有效的圈定,无法定量判断煤田火区燃烧中心温度与埋深。根据所建立模型与反演分析结果,可为现场高效准确探测煤田火区与后期数据分析提供参考借鉴。

In order to study the sensitivity of Wenner-α / Wenner-Schlumberger array detections and magnetic measurement to central burning temperature,buried depth and burning duration,the geo-electrical and geo-magnetic models of coal fires were established. The comparison and analysis results of forward and inverse simulation illustrate that Wenner-α array can be adopted for detecting the coal fires with buried depth larger than 50 m while Wenner-Schumberger array can be applied for the shallow survey within 50 m,and also,the inversion results of central temperature and buried depth of both arrays are reasonably accurate. Magnetic method could delineate the borders of coal fires accurately and effectively,but it is difficult to quantitatively determine the temperature and buried depth of burning center. The research results could provide a reference for the accurate and efficient detection of coal fires and data postprocessing according to the forward models and inversion results.