3D Geoscience Modeling

I. Computer Techniques for Geological Characterization.- 1 The Geological Characterization Process.- 1.1 Prediction of Geological Variables.- 1.2 Interpretation of Geological Characteristics.- 1.3 Uncertainty and Risk.- 1.4 Spatial Analysis.- 1.5 The Generic Characterization Process.- 1.6 Conventional Approaches to Characterization.- 1.7 Evolution of Computerized Approaches.- 1.8 Advantages and Limitations.- 1.9 Errors and Approximations.- 2 Complicating Factors for Computerization.- 2.1 Geological Complexity.- 2.2 Geometrical Complications.- 2.3 The Need for Interpretational Control.- 2.4 Spatial Variation Complexity.- 2.5 Information Source Variety.- 2.6 Geological Variety.- 2.7 Time Dimension.- 2.8 Measurement of Uncertainty.- 3 Features of an Integrated 3D Computer Approach.- 3.1 Overview.- 3.2 Spatial Data Management.- 3.3 Time Data Management.- 3.4 Visualization Tools.- 3.5 Statistical Analysis.- 3.6 Spatial Variability Analysis.- 3.7 Interactive Interpretation.- 3.8 Modeling Discrete Geological Volumes.- 3.9 Modeling from Geological Surfaces.- 3.10 Modeling Geological Variables.- 3.11 Geostatistical Prediction and Uncertainty.- 3.12 Spatial Analysis of Volumes.- 3.13 Advantages of Process Integration.- 3.14 Technology Interfacing.- 3.15 Process Summary.- 4 Spatial Data Types and Structures.- 4.1 Rationale for Spatial Data Management.- 4.2 Data Categories and Their Organization.- 4.3 Spatial Integration of Data Structures.- 4.4 Hole Data Structure.- 4.5 Map Data Structure.- 4.6 Volume Data Structure.- 4.7 3D Grid Data Structure.- 4.8 Data Definitions and Identities.- 4.9 Data Interfacing Considerations.- 5 Analysis of Spatial Variability.- 5.1 Objectives of Spatial Variability Analysis.- 5.2 Measurement of Spatial Variability.- 5.3 Understanding Geostatistical Semi-Variograms.- 5.4 Analysis of Geological Influences.- 5.5 Analysis of Directional Influences.- 5.6 Use of Data Transforms.- 5.7 The Effects of Spatial Trends.- 5.8 Geostatistical Prediction Models.- 5.9 Cross-Validation of Prediction Models.- 6 Geological Interpretation and Modeling.- 6.1 Interactive Geological Interpretation.- 6.2 Interpretation of Geological Volumes.- 6.3 2D and 3D Geological Sections.- 6.4 Analysis of Geological Volumes.- 6.5 Volumes of Intersection.- 6.6 Spatial Integrity in the Modeling Process.- 6.7 3D Modeling Considerations.- 7 Geological Modeling from Surfaces.- 7.1 Advantages and Disadvantages of Modeling from Surfaces.- 7.2 Representing Surfaces as Triangulated Networks.- 7.3 Structural, Stratigraphic and Topographical Surfaces.- 7.4 Manipulation of Surfaces.- 7.5 Derivation of Volumes from Surfaces.- 7.6 Modeling Stratigraphic and Structural Discontinuities.- 8 Geostatistical Prediction Techniques.- 8.1 Spatial Prediction Process.- 8.2 Implications of Spatial Discretization.- 8.3 Point Kriging to a 3D Grid.- 8.4 Sample Selection Controls.- 8.5 Management of Spatial Anisotropy.- 8.6 Volume Kriging to a 3D Grid.- 8.7 Kriging with Data Transforms.- 8.8 Kriging with Data Trends (Universal Kriging).- 8.9 Indicator Kriging and Probability Estimation.- 8.10 Alternative Prediction Techniques.- 8.11 Cross-Checking of Prediction Results.- 8.12 Common Problems in Spatial Prediction.- 8.13 Performance Review of Prediction Techniques.- 9 Spatial Analysis Techniques.- 9.1 Spatial Analysis Objectives.- 9.2 Simple Geological Volumes and Intersections.- 9.3 Volumes Defined by an Isosurface of a Variable.- 9.4 Manipulation of Spatial Variations.- 9.5 Visualization Techniques.- 9.6 Excavation Design Applications.- 10 Uncertainty, Sampling Control and Risk Assessment.- 10.1 The Implications of Geostatistical Uncertainty.- 10.2 Sampling Considerations and Optimum Sample Locations.- 10.3 Risk Assessment Based on Uncertainty.- 10.4 The Application of Probability Isosurfaces.- 10.5 Geostatistical Prediction of Geological Surfaces.- 10.6 Other Sources of Geological Uncertainty.- 10.7 Visualization of Uncertainty.- II. Applications in the Geosciences.- 11 Subsurface Soil Contamination Assessment.- 11.1 Project Overview.- 11.2 Site Investigation Records.- 11.3 Information Review and Analysis.- 11.4 Spatial Variability Analysis of Contaminant Samples.- 11.5 Representation of Soil Geology.- 11.6 Geostatistical Prediction of Contamination.- 11.7 Geostatistical Control of Sampling.- 11.8 Spatial Analysis of Contaminated Volumes.- 11.9 Remediation Risk Assessment.- 11.10 Project Summary.- 12 Hazardous Waste Site Characterization and Underground Repository Design.- 12.1 Project Overview.- 12.2 Site Geology and Source Information.- 12.3 Information Review and Evaluation.- 12.4 Representation of Geological Structure.- 12.5 Interpretation of Geology.- 12.6 Modeling Geological Uncertainty.- 12.7 Prediction of Geomechanical Properties.- 12.8 Engineering Design of the Repository.- 12.9 Project Summary.- 13 Ore Deposit Evaluation and Underground Mine Planning.- 13.1 Project Overview.- 13.2 Geology, Structure and Mineralogy of the Deposit.- 13.3 Project Information Base.- 13.4 Spatial Variability Analysis of Mineral Grade Samples.- 13.5 Geological Interpretation.- 13.6 Prediction of Mineral Grades.- 13.7 Spatial Analysis of Mineral Grades.- 13.8 Ore Excavation Design.- 13.9 Mine Development Design.- 13.10 Mining Reserve Volumetrics.- 13.11 Project Summary.- 14 Characterization and Development Planning for a Small Oil Reservoir.- 14.1 Project Overview.- 14.2 Reservoir Geology and Exploration Records.- 14.3 Preliminary Modeling of Member Sequence.- 14.4 Detailed Modeling of Reservoir Structure.- 14.5 Geostatistical Prediction of Reservoir Properties.- 14.6 Pay Zone Interpretation.- 14.7 Reservoir Evaluation.- 14.8 Risk Assessment.- 14.9 Development Planning.- 14.10 Project Summary.- 15 Geotechnical Characterization for an Underground Powerhouse Excavation.- 15.1 Project Overview and Information Sources.- 15.2 Structural Rock Joints and Faulting.- 15.3 Lithology and Rock Mass Characterization.- 15.4 Production of Analytical Sections.- 15.5 Rock Reinforcement Design.- 15.6 Project Summary.- 16 New Directions in Spatial Prediction, Modeling and Database Management.- 16.1 New Directions in Geoscience Modeling.- 16.2 Direct Geostatistical Prediction for Irregular Volumes.- 16.3 Splining Techniques for Volume Representation.- 16.4 Conditional Simulation and Stochastic Approaches to Spatial Prediction.- 16.5 Evolution of a 3D Geoscience Information System (GSIS).