Effects of geologic noise on cross-borehole electrical surveys
Effects of geologic noise on cross-borehole electrical surveys
复制标题
地质噪声对跨井电测的影响
DOI：
10.1190/1.1442053
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
S. Ward
中科院分区：
文献类型：
--
作者：
J. Zhao;L. Rijo;S. Ward
使用有限元算法，允许直流电阻率中的地下电流和电位电极，我们分析了在存在几个地质噪声源的情况下对薄的二维导电不均匀性的检测。具有固定在一个钻孔中的电流电极和在相邻钻孔中可移动的电势电极的极极阵列是主要关注的阵列。噪声源包括地表地形、埋藏地形、随机地质噪声、准随机地质噪声（非目标不均匀性）、分层和垂直接触。对于井下源电极的几个位置，已计算出归一化的表观折射率。在剖面图中已绘制了这些曲率轮廓，以适合跨钻孔调查。对于这里研究的模型，表面地形、埋藏地形、随机和准随机地质噪声不会掩盖由于薄导电不均匀性而导致的异常。在垂直或水平分层的地球中，异常...
Using a finite‐element algorithm which allows for subsurface current and potential electrodes in dc resistivity, we have analyzed the detection of a thin, 2-D, conductive inhomogeneity in the presence of several sources of geologic noise. The pole‐pole array with the current electrode fixed in one borehole and the potential electrode movable in adjacent boreholes is the main array of concern. The sources of noise are surface topography, buried topography, random geologic noise, quasi‐random geologic noise (nontarget inhomogeneities), layering, and a vertical contact. For several positions of a downhole source electrode, normalized apparent resistivities have been computed. These resistivities have been contoured in section view as appropriate to cross‐borehole investigations. For the models studied here, surface topography, buried topography, random and quasi‐random geologic noise do not obscure the anomaly due to the thin conductive inhomogeneity. In a vertically or horizontally layered earth, the anomal...