Computation of optimized arrays for 3-D electrical imaging surveys
Computation of optimized arrays for 3-D electrical imaging surveys
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DOI：
10.1093/gji/ggu357
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发表时间：
2014-12
影响因子：
2.8
通讯作者：
M. Loke;P. Wilkinson;S. Uhlemann;J. Chambers;L. Oxby
中科院分区：
文献类型：
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作者：
M. Loke;P. Wilkinson;S. Uhlemann;J. Chambers;L. Oxby
需要三维电阻率勘测和反演模型来精确地解析具有非常复杂的地质的区域中的结构，其中二维模型可能遭受伪影。许多3-D勘测使用网格，其中沿沿着一个方向（x）的电极数量远大于沿垂直方向（y）的电极数量。通常，由于多电极系统中的独立电极的数量的限制，勘测使用具有少量沿x方向沿着对准的平行勘测线的沿沿着系统的滚动。以前用于2-D勘测的“比较R”阵列优化方法适用于这种3-D勘测。二维测量中使用的线内阵列的偏移版本包括在可能阵列的数量（综合数据集）中，以提高对线间结构的灵敏度。在构造综合数据集时，利用阵列几何因子及其相对误差滤除可能不稳定的阵列。传统的（包括偶极-偶极和温纳-斯伦贝谢阵列）和优化阵列的比较是使用合成模型和实验测量在一个坦克。实验表明，优化后的阵列能更好地分辨出位于线间的结构。与传统阵列相比，优化阵列还具有显著更好的深度分辨率。
3-D electrical resistivity surveys and inversion models are required to accurately resolve structures in areas with very complex geology where 2-D models might suffer from artefacts. Many 3-D surveys use a grid where the number of electrodes along one direction (x) is much greater than in the perpendicular direction (y). Frequently, due to limitations in the number of independent electrodes in the multi-electrode system, the surveys use a roll-along system with a small number of parallel survey lines aligned along the x-direction. The ‘Compare R’ array optimization method previously used for 2-D surveys is adapted for such 3-D surveys. Offset versions of the inline arrays used in 2-D surveys are included in the number of possible arrays (the comprehensive data set) to improve the sensitivity to structures in between the lines. The array geometric factor and its relative error are used to filter out potentially unstable arrays in the construction of the comprehensive data set. Comparisons of the conventional (consisting of dipole-dipole and Wenner–Schlumberger arrays) and optimized arrays are made using a synthetic model and experimental measurements in a tank. The tests show that structures located between the lines are better resolved with the optimized arrays. The optimized arrays also have significantly better depth resolution compared to the conventional arrays.