地球物理学报  2014, Vol. 57 Issue (3): 961-967 PDF

1. 桂林理工大学广西隐伏金属矿产勘查重点实验室, 桂林 541004;
2. 中国科学院地质与地球物理研究所, 北京 100029

Statistic modeling 2D VES inversion in complex geo-electric structures
CHENG Bo1, DI Qing-Yun2
1. Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration, Guilin University of Technology, Guilin 541004, China;
2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
Abstract: In order to enhance 2D VES (Vertical Electric Sounding) inversion based on statistic modeling, we improved the detail of the modeling part, built the connection between statistic parameters and the location of geology object. For the models with fault, for example, the improved modeling process includes the following steps: use statistic layer structure characters to build an initial model, use weighted horizontal gradient to locate the fault, use piecewise statistics to determine the local parameters, and add the a priori information into the initial model. The model test and the field data inversion proved that the statistic modeling method could get clear and definite results in complex models.
Key words: VES     2D inversion     Statistic modeling     Genetic algorithm

1 引言

(1)设计逐级统计判断模型结构的机制，并将水平梯度、电测深曲线类型等信息，也纳入到统计内容中.在初次判断地层结构类型之后，设计第二级的分段统计判断方法，使统计学特征值和异常体空间位置联系起来；

(2)增加了水平梯度信息统计的权重分配、对地层分区后局部范围内的统计学特征值、测深曲线类型再次统计，给出局部地层的详细层参数；

(3)增加加入先验信息模块，利用岩石的电性信息、钻孔资料等地质信息参与建立初始模型，使初始模型更加接近实际地层结构.

2 复杂地层结构条件下统计学建模的方法
2.1 复杂地层结构条件下统计学建模流程

 图1 统计学建模流程图 Fig.1 The process of statistic modeling
2.2 统计权重的分配

2.3 曲线类型统计

2.4 先验信息的加入

3 理论模型算例

 图2 有断裂存在的模型示意图 Fig.2 The sketch map of a model with fault

 图3 断裂模型模拟结果(单位：Ωm) Fig.3 The stimulation result of a model with fault

 图4 部分极距的视电阻率水平梯度 Fig.4 The gradient of apparent resistivity

 图5 初始模型示意图 Fig.5 The sketch map of initial model

 图6 反演结果 (a) 统计学建模反演; (b)线性反演(使用RES2DINV软件) Fig.6 The inversion result
4 应用实例

 图7 实测数据及线性反演结果 (a) 实测数据断面等值线图; (b) RES2DINV软件反演结果 Fig.7 The field data profile and linear inversion result

 图8 初始模型示意图 Fig.8 The sketch map of the initial model

 图9 实测数据反演结果 Fig.9 The inversion result of field data

 图10 反演结果正演视电阻率断面 Fig.10 The stimulation result of the final model
5 结论

 [1] Auken E, Christiansen A V. 2004. Layered and laterally constrained 2D inversion of resistivity data. Geophysics, 69(3): 752-761. [2] Cheng B. 2012. 2D inversion of resistivity sounding base on GA and statistic [Ph. D's thesis]. Beijing: Institute of Geology and Geophysics, Chinese Academy of Science. [3] Cheng B, Di Q Y. 2012a. 2D inversion of resistivity sounding base on GA and statistic. Progress in Geophysics (in Chinese), 27(2): 788-795. [4] Cheng B, Di Q Y. 2012b. 2D inversion of resistivity sounding base on partial derivative and statistic. Oil Geophysical Prospecting (in Chinese), 47(6): 1006-1013. [5] Di Q Y, Ni D L, Wang R, et al. 2003. High-density resistivity image. Progress in Geophysics (in Chinese), 18(2): 323-326. [6] Huang J G, Bao G S, Ruan B Y. 2005. A study on anomalous bodies of DC resistivity sounding in tunnel. Chinese J. Geophys. (in Chinese), 48(1): 222-228. [7] Loke M H, Barker R D. 1995. Least-squares deconvolution of apparent resistivity pseudosections. Geophysics, 60(6): 1682-1690. [8] Luo Y Z. 2006. 2.5-D inversion software for high density resistivity. Computing Techniques for Geophysical and Geochemical Exploration (in Chinese), 28(3): 188-193. [9] Ruan B Y, Murikami Y, Xu S Z. 1999. 2D inversion programs of induced polarization data. Computing Techniques for Geophysical[KG2*2]and Geochemical Exploration (in Chinese), 21(2): 116-125. [10] Su Z L, Hu W B, Yan L J. 2005. The forward modified inversion of resistivity and induced polarization sounding. Geophysical Prospecting for Petroleum (in Chinese), 44(2): 194-198. [11] Wang H J, Luo Y Z. 2000. Windows version software system designing of 2D man-machine interactive inversion for conventional DC electric method. Computing Techniques for Geophysical and Geochemical Exploration (in Chinese), 22(4): 356-360. [12] 程勃, 底青云. 2012a. 基于偏导数和统计学方法的电阻率测深二维反演. 石油地球物理勘探, 47(6): 1006-1013. [13] 程勃, 底青云. 2012b. 基于遗传算法和统计学的电阻率测深二维反演研究. 地球物理学进展, 27(2): 788-795. [14] 底青云, 倪大来, 王若等. 2003. 高密度电阻率成像. 地球物理学进展, 18(2): 323-326. [15] 黄俊革, 鲍光淑, 阮百尧. 2005. 坑道直流电阻率测深异常研究. 地球物理学报, 48(1): 222-228. [16] 罗延钟. 2006. 高密度电阻率法的2.5维反演软件. 物探化探计算技术, 28(3): 188-193. [17] 阮百尧, 村上裕, 徐世浙. 1999. 电阻率/激发极化率数据的二维反演程序. 物探化探计算技术, 21(2): 116-125. [18] 苏朱刘, 胡文宝, 严良俊. 2005. 电阻率和极化率测深法的正演修正法反演. 石油物探, 44(2): 194-198. [19] 王华军, 罗延钟. 2000. 常规直流电法二维人机联作反演软件系统WINDOWS版的设计与实现. 物探化探计算技术, 22(4): 356-360.