Interpretation of tensor gravity data using an adaptive tilt angle method
Interpretation of tensor gravity data using an adaptive tilt angle method
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DOI：
10.1111/1365-2478.12039
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发表时间：
2013-09
影响因子：
2.6
通讯作者：
A. Salem;S. Masterton;S. Campbell;J. Fairhead;J. Dickinson;C. Murphy
中科院分区：
文献类型：
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作者：
A. Salem;S. Masterton;S. Campbell;J. Fairhead;J. Dickinson;C. Murphy
完整张量重力梯度测量（FTG）数据通常用于勘探计划，以评估和勘探蕴藏碳氢化合物和矿产资源的地质复杂性。FTG数据通常用于映射宿主结构并使用无数成像技术定位感兴趣的目标响应。然后使用2D和3D正演和反演建模方法对识别出的感兴趣异常进行深度估计。然而，这样的方法往往是耗时的，并依赖于一个独立的约束澄清。本文提出了一种使用自适应倾角方法来解释FTG数据的半自动方法。本方法仅使用FTG数据的三个垂直张量分量（Tzx、Tzy和Tzz），其尺度值与源的性质（点异常或线性异常）相关。通过这种调整，可以估计简单埋藏重力源的位置和深度，例如点质量、线质量以及垂直和水平薄片，前提是这些源孤立存在，并且FTG数据已被充分过滤，以最大限度地减少噪声的影响。计算时间很快，产生与异常直接相关的单解深度估计的合理结果。对于厚片材，该方法可以解析这些层的厚度，假设从钻井或其他独立的地球物理数据已知到顶部的深度。我们证明了该方法的实用性，使用的例子FTG数据获得的文顿盐穹，路易斯安那州，美国和玄武岩流在法罗设得兰群岛盆地，英国。该方法的一个主要优点是能够快速构建深度图。这些结果被用来产生最佳估计的初始深度源地图，可以作为初始模型的任何详细的定量建模工作，使用二维/三维正向/反向建模技术。
Full Tensor Gravity Gradiometry (FTG) data are routinely used in exploration programmes to evaluate and explore geological complexities hosting hydrocarbon and mineral resources. FTG data are typically used to map a host structure and locate target responses of interest using a myriad of imaging techniques. Identified anomalies of interest are then examined using 2D and 3D forward and inverse modelling methods for depth estimation. However, such methods tend to be time consuming and reliant on an independent constraint for clarification. This paper presents a semi‐automatic method to interpret FTG data using an adaptive tilt angle approach. The present method uses only the three vertical tensor components of the FTG data (Tzx, Tzy and Tzz) with a scale value that is related to the nature of the source (point anomaly or linear anomaly). With this adaptation, it is possible to estimate the location and depth of simple buried gravity sources such as point masses, line masses and vertical and horizontal thin sheets, provided that these sources exist in isolation and that the FTG data have been sufficiently filtered to minimize the influence of noise. Computation times are fast, producing plausible results of single solution depth estimates that relate directly to anomalies. For thick sheets, the method can resolve the thickness of these layers assuming the depth to the top is known from drilling or other independent geophysical data. We demonstrate the practical utility of the method using examples of FTG data acquired over the Vinton Salt Dome, Louisiana, USA and basalt flows in the Faeroe‐Shetland Basin, UK. A major benefit of the method is the ability to quickly construct depth maps. Such results are used to produce best estimate initial depth to source maps that can act as initial models for any detailed quantitative modelling exercises using 2D/3D forward/inverse modelling techniques.