College of Geology and Environment, Xi’an University of Science and Technology
Shaanxi 194 Coal Geology Co., Ltd.

陕北侏罗系煤层埋藏较浅,历史上形成了大片隐伏古火烧区,古火烧区积水对矿井的安全生产构成了严重威胁。为了有效探测古火烧区的分布范围,分析其积水情况,以直流电法基本原理为基础,三维高密度电法勘探机理为前提,采用数值模拟和工程实践的方法,对浅埋煤层火烧区的三维高密度响应特征进行了研究。建立了多种烧变岩的三维地电模型,运用有限单元法进行了三维高密度正演模拟,对比均匀半空间中电位数值解与解析解的相对误差,验证了正演程序的准确性,分析了二极、三极及偶极装置在均匀半空间、二层、三层和四层地电模型中地质异常体的三维高密度电法响应特征。结果表明:三维高密度电法勘探时二极装置对地质异常体响应效果较好,对复杂地层响应效果一般;偶极装置对地质异常体和复杂地层的响应效果均较好,具有更高的横向分辨率;与二维高密度电法正演模拟相比,三维模拟通过多方向,多层面的数据采集提高了高密度电法探测精度,解决了三极装置解释异常偏移问题;在陕北红柳林煤矿北二盘区2−2煤火烧区进行了三维高密度偶极装置和二极装置勘探实践,其实际探测结果与该地区已有的地质资料吻合较好,证明了利用三维高密度电法探测煤矿火烧区分布范围及其积水情况具有一定的可行性。

The Jurassic coal seams in northern Shaanxi contain a large number of palaeo-fire zones, which pose a seriousthreat to the safe mining of the underlying coal when water accumulates in these palaeo-fire zones.To effectively detect thedistribution of ancient fire zones and analyze their water accumulation conditions, this study is based on the fundamentalprinciples of direct current resistivity and the exploration mechanism of three-dimensional (3D) high-density resistivity.Using numerical simulation and engineering practices, the 3D high-density resistivity response characteristics of shallowcoal seam fire zones were investigated.Multiple 3D geo-electrical models of burnt rocks were established, and forwardsimulations were conducted using the finite element method. The relative error between numerical and analytical solutionsin a homogeneous half-space was analyzed to verify the accuracy of the forward modeling program. The 3D high-densityresistivity response characteristics of geological anomalies were analyzed using pole-pole, pole-dipole, and dipole-dipolearrays in homogeneous half-space, two-layer, three-layer, and four-layer geo-electrical models.The results indicate that thepole-pole array demonstrates better sensitivity to geological anomalies but is less effective in complex stratigraphy. Thedipole-dipole array shows strong responses to both geological anomalies and complex stratigraphy, offering higher lateralresolution. Compared to 2D high-density resistivity forward simulations, 3D simulations improve detection accuracythrough multidirectional and multilayer data acquisition, resolving the anomaly shift issues associated with the pole-dipolearray.Field practices were conducted in the 2 coal fire zone of the northern second panel of the Hongliulin Coal Mine innorthern Shaanxi using both 3D high-density dipole-dipole and pole-pole arrays. The actual exploration results alignedwell with existing geological data of the area, demonstrating the feasibility of using 3D high-density resistivity to delin-eate the distribution and water accumulation of coal mine fire zones.

陕煤联合基金资助项目(2021JLM-11)

解海军,梁咏琪,李晚露,等.浅埋煤层火烧区三维高密度电法数值模拟及应用[J].绿色矿山,2024,2(4):397−407.

XIE Haijun,LIANG Yongqi,LI Wanlu,et al. Numerical simulation and application of three-dimensional high-density electrical method in shallow coal seam fire area[J]. Journal of Green Mine,2024,2(4):397−407.