基于二维高密度电阻率勘探数据的三维反演及应用

3-D inversion of high density resistivity method based on 2-D exploration data and its application

针对目前高密度电阻率法所采用的数据处理方法主要是把地质结构体视为二度体进行二维处理,从而二维数据资料处理结果只是一种近似解释,其计算精度与反演效果达不到精确反演的要求,设计一种典型的地质体模型,利用有限单元法进行正演计算,对含有高斯随机误差的各测线二维正演数据分别进行高密度电阻率法二维、三维反演,对比二维和三维的反演结果。最后在广东某场地采用高密度电阻率法对岩层划分,利用二维勘探的数据进行二、三维反演。研究结果表明:三维反演受高斯随机误差的影响更小,反演结果与实际地质模型更接近;三维反演在岩层划分中更能凸显岩层分界面区域,岩层的空间分布及岩层、覆盖层的整体连续性能更真实地体现,与钻探结果吻合程度更好。

Based on the fact that the 2-D date processing adopted by the high density resistivity method regards the geological structures as two degrees, which makes the results of the two-dimensional data inversion only an approximate interpretation, the accuracy and effect can not meet the precise requirement of the inversion, a typical model of the geological body was designed, forward calculation was carried out using fmite element method, then 2-D and 3-Dinversion of the high-density resistivity method was performed using the 2-D forward calculation data containing Ganssian random error to the survey lines respectively, and the results of 2-D inversion and 3-D inversion were contrasted. Besides, combining with the engineering investigation example of the high-density resistivity method for rock stratum partition in Guangdong, 3-D inversion was performed using the 2-D exploration date. The results show that 3-D inversion can eliminate the Gaussian random error more effectively, and 3-D inversion results are more suitable with the geological model. The 3-D inversion divides the boundary area of rock stratum more prominently, the results of 3-D inversion reflect the spatial distribution of rock stratum and the overall continuity of covering layer and rock stratum, and the coherence with drilling results is better.