AGCOS presented “Evaluation of Conductive 3-D Ore Bodies Parameters Using Tipper Frequency Response Functions” at 76th EAGE Conference & Exhibition 2014 Amsterdam RAI, The Netherlands, 16-19 June 2014.
Evaluation of Conductive 3-D Ore Bodies Parameters Using Tipper Frequency Response Functions
Summary
The main parameters of isometric conductive 2-D bodies (shape of the body’s cross-section, total longitudinal conductivity of the body’s cross-section G, depth H, etc.) can be quickly and accurately determined using the frequency response and the vertical cross-section of the tipper. Research carried out by the authors for 3-D and quasi 2-D (ratio of body’s length to width L/a (relative length) is 3-80) has shown that the main parameters for these bodies can also be quickly identified. Unlike 2-D bodies, the body’s relative length L/a (the ratio of body’s length to width) plays a very important role in this case. The authors have proposed a methodology for determining this parameter using characteristic data points of the tipper frequency response. Since values of the parameters for these bodies are strongly dependent on the body’s relative length L/a, a technique for introducing corrections is proposed (correction factors) for determining the true values of anomalous body’s parameters. Where the body’s relative length is decreased, tipper anomalies (induction vectors) are weakened by several orders, thus highlighting the importance of accurate alignment of magnetic field component sensors to their respective axis’s during the course of a field survey.