Exploration with Deep Transient Electromagnetics

1. Introduction. The role of electromagnetic methods in exploration. Historical development of LOTEM. Electrical conductivity / resistivity in exploration. 2. Basic Theoretical Background. Physical principles. Theoretical background. Apparent resistivity. All time apparent resistivity. Image presentation of the data. 3. Distortions of the Signal and their Compensation. The field problem. Deconvolution of the system response. Recursive digital filters. Selective stacking methods. Calibration factor. Prestack and poststack processing. 4. Data Interpretation. One-dimensional inversion. Interpretation of distorted transients ( reversals ). Three-dimensional modeling. 5. The Field System and Field Procedures. System concepts. Field procedures. Survey techniques. 6. Survey Feasibility Studies. Survey design based on well logs. Resolving a deep carbonate unit. High resolution feasibility study. Feasibility study over a two-dimensional structure. 7. General Case Histories. Field survey north of the Ruhr district, FRG. Geological calibration of the technique in the Denver - Julesburg Basin, USA. First field tests in Australia ( Sydney Basin ). 3-D Interpretation case history Munsterland Basin, FRG. 8. Case Histories: Resolving Resistive Layers with LOTEM. Extension of the physical concept to resistive layers. European case history. Canning Basin, Australia, case history. Tai Xing area, PRC, case history. 9. Case Histories: Deep Crustal Applications. Historical case histories. The first demonstration for deep crustal applications in FRG. Black Forest survey. Urach geothermal area. Test survey over the Kaapvaal Craton, R.S.A. Test measurements in China for the application of LOTEM for earthquake prediction. Discussions. Appendix 1 - Derivations. Proof of the iterative deconvolution. Singular value decomposition. Solution of Maxwell's equations using scalar potentials. Appendix 2 - Data Format Standards. Introduction. File formats. File header. Trace header structure. Appendix 3 - Useful Information. Glossary. Operator's log - single site receiver system. Clock drift measurement log. LOTEM transmitter record sheet. Inversion statistics. Appendix 4 - Documentation of the Forward Modeling Program MODALL. Software installation. Description of the menus. Examples. Appendix 5 - List of Figures, Tables, Symbols and References. List of figures. List of tables. Conventions and list of symbols. References. Appendix 6 - Subject Index. Appendix 7 - Color Figures. INSERT: FLOPPY DISKETTE with SOFTWARE.