激电测深中的地形改正
发布时间：2019-03-03 19:01
【摘要】：激电测深是在稳定的直流电场或者交流电场下,通过逐渐增加供电电极之间的距离来进行地下电性性质的观测工作。使用对称四级装置可以得到同一观测点下方不同深度范围内的视电阻率以及视极化率。根据地表各点不同供电极距时测量的视电阻率和视极化率的变化特点来对地下矿产资源进行勘察,确定其分布范围并解决相应的地质问题。地形对激电测深中的视电阻率影响较大,因此在实际应用中,起伏地形下所获得的视电阻率数据需要进行地形改正,压制地形所引起的视电阻率假异常。激电测深使用对称四级观测装置,为了校正该装置下的地形对视电阻率的影响,本文使用求解维度小,计算效率更高的边界单元法分别正演原始地形与起伏地形下均匀介质的视电阻率,使用比较法对各个测深点获得的实测数据进行数值校正,并且使用正交投影法来还原各供电极距下测深范围的真实位置,通过两种方法联合的方式压制起伏地形对视电阻率的影响。该地形改正方法具有计算速度快、适用性高、稳定的特点。为了检验该地形改正的效果,文中分别建立了若干二维非均匀介质不同地形下的模型体,对模型体使用边界单元法正演出对称四级观测装置下的视电阻率值,并使用联合地形改正分别对地表各点视电阻率值以及有效测深范围的位置进行改正,有效压制了地形所造成的假异常,突出了地下异常体所引起的异常。最后将该联合地形改正的方法应用于湘西的铜镍矿区,含铜镍矿的岩体会产生高重力、高磁化率、低视电阻率、高视极化率异常。对矿区采集的大功率激电数据中的视电阻率进行地形改正。非均匀极化介质在地表观测到的视极化率受地形的影响其幅值与形态会发生变化,但是变化幅度较小,一般不会出现假视极化率异常。在该铜镍矿区中,将地形改正后所获得的视电阻率与视极化率图件进行对比,在矿区的1号岩体区域出现吻合度较高的低视电阻率与高视极化率对应关系,且与高重力、高磁异常、地质资料对应较好,为矿区的井位设计提供有力支撑。
[Abstract]:IP sounding is to observe the underground electrical properties by gradually increasing the distance between the power supply electrodes in a stable DC or AC electric field. The apparent resistivity and apparent polarizability at different depths below the same observation point can be obtained by using a symmetrical four-stage device. According to the change characteristics of apparent resistivity and apparent polarizability measured at different power supply poles at different points on the surface, the underground mineral resources are investigated, the distribution range is determined and the corresponding geological problems are solved. Terrain has a great influence on apparent resistivity in IP sounding, so in practical application, the apparent resistivity data obtained under undulating terrain need to be corrected to suppress the false anomaly of apparent resistivity caused by terrain. In order to correct the effect of topography on apparent resistivity of IP sounding, a symmetrical four-order observation device is used in this paper, and the solution dimension is small. The more efficient boundary element method is used to calculate the apparent resistivity of the homogeneous medium in the original terrain and the undulating terrain respectively, and the measured data obtained from each bathymetric point are numerically corrected by the comparison method. The orthogonal projection method is used to restore the true position of the sounding range under each distance of the power supply pole, and the effect of the undulating topography on the apparent resistivity is suppressed by the combination of the two methods. The terrain correction method has the characteristics of fast computing speed, high applicability and stability. In order to test the effect of terrain correction, several models of two-dimensional non-uniform medium under different terrain are established, and the apparent resistivity values under symmetrical four-order observation device are obtained by using boundary element method for the model body. Combined terrain correction is used to correct the apparent resistivity and the position of the effective sounding range, which effectively suppress the false anomaly caused by the terrain and highlight the anomaly caused by the underground anomaly body. Finally, the combined terrain correction method is applied to the Cu-Ni ore area in the west of Hunan Province. The rock mass containing Cu-Ni ore will produce the anomalies of high gravity, high magnetic susceptibility, low apparent resistivity and high apparent polarizability. The terrain correction of apparent resistivity in high power IP data collected from mining area is carried out. The apparent polarizability observed by the non-uniform polarization medium on the surface of the earth is affected by the topography, its amplitude and shape will change, but the range of change is relatively small, generally there will be no false apparent polarizability anomaly. In this copper-nickel mine, the apparent resistivity obtained after terrain correction is compared with the apparent polarizability map. In the area of rock mass No. 1 in the mining area, there is a high correspondence between low apparent resistivity and high apparent polarizability, and it is also related to high gravity. The high magnetic anomaly and the geological data correspond well, which provide strong support for the well position design of the mining area.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P631.3
本文编号：2434008
[Abstract]:IP sounding is to observe the underground electrical properties by gradually increasing the distance between the power supply electrodes in a stable DC or AC electric field. The apparent resistivity and apparent polarizability at different depths below the same observation point can be obtained by using a symmetrical four-stage device. According to the change characteristics of apparent resistivity and apparent polarizability measured at different power supply poles at different points on the surface, the underground mineral resources are investigated, the distribution range is determined and the corresponding geological problems are solved. Terrain has a great influence on apparent resistivity in IP sounding, so in practical application, the apparent resistivity data obtained under undulating terrain need to be corrected to suppress the false anomaly of apparent resistivity caused by terrain. In order to correct the effect of topography on apparent resistivity of IP sounding, a symmetrical four-order observation device is used in this paper, and the solution dimension is small. The more efficient boundary element method is used to calculate the apparent resistivity of the homogeneous medium in the original terrain and the undulating terrain respectively, and the measured data obtained from each bathymetric point are numerically corrected by the comparison method. The orthogonal projection method is used to restore the true position of the sounding range under each distance of the power supply pole, and the effect of the undulating topography on the apparent resistivity is suppressed by the combination of the two methods. The terrain correction method has the characteristics of fast computing speed, high applicability and stability. In order to test the effect of terrain correction, several models of two-dimensional non-uniform medium under different terrain are established, and the apparent resistivity values under symmetrical four-order observation device are obtained by using boundary element method for the model body. Combined terrain correction is used to correct the apparent resistivity and the position of the effective sounding range, which effectively suppress the false anomaly caused by the terrain and highlight the anomaly caused by the underground anomaly body. Finally, the combined terrain correction method is applied to the Cu-Ni ore area in the west of Hunan Province. The rock mass containing Cu-Ni ore will produce the anomalies of high gravity, high magnetic susceptibility, low apparent resistivity and high apparent polarizability. The terrain correction of apparent resistivity in high power IP data collected from mining area is carried out. The apparent polarizability observed by the non-uniform polarization medium on the surface of the earth is affected by the topography, its amplitude and shape will change, but the range of change is relatively small, generally there will be no false apparent polarizability anomaly. In this copper-nickel mine, the apparent resistivity obtained after terrain correction is compared with the apparent polarizability map. In the area of rock mass No. 1 in the mining area, there is a high correspondence between low apparent resistivity and high apparent polarizability, and it is also related to high gravity. The high magnetic anomaly and the geological data correspond well, which provide strong support for the well position design of the mining area.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P631.3
【参考文献】
中国期刊全文数据库 前10条
1 熊勇;;高密度电法勘探中地形影响校正方法探讨[J];人民长江;2014年14期
2 麻昌英;柳建新;刘海飞;郭荣文;;复杂地形下高密度激电法2.5维有限单元法数值模拟[J];物探化探计算技术;2014年04期
3 刘海飞;阮百尧;柳建新;吕玉增;;起伏地形电导率连续变化的三维激电数据有限元数值模拟[J];物探化探计算技术;2008年04期
4 简兴祥;王绪本;杨利容;高永才;;高密度电阻率法地形影响校正[J];物探化探计算技术;2008年04期
5 孙建国;;复杂地表条件下地球物理场数值模拟方法评述[J];世界地质;2007年03期
6 吕玉增;阮百尧;;复杂地形条件下四面体剖分电阻率三维有限元数值模拟[J];地球物理学进展;2006年04期
7 吴小平;非平坦地形条件下电阻率三维反演[J];地球物理学报;2005年04期
8 杨华,李金铭;起伏地形对近矿围岩充电法影响规律的数值模拟研究[J];物探与化探;1999年03期
9 阮百尧,村上裕,徐世浙;电阻率/激发极化率数据的二维反演程序[J];物探化探计算技术;1999年02期
10 刘继东;用异常电位边界单元法做电测深资料地形改正[J];煤田地质与勘探;1998年03期
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