ABSTRACT
This chapter focuses on the methodology of geologic modelling without dwelling on the algorithms. The modelling process can be broken down into three steps: compositing of geologic data to obtain surface intercept coordinates, exploration of structures using maps and sections, and interpretation/estimation of section and map data into continuous surface or volume models. Drillhole and well data are not logged in a fashion which can be readily used for geologic interpretation. The triangle set can subsequently be used for contouring of surfaces and volumetric calculation of thicknesses and intersection volumes between different geologic and engineering models. Techbase provides several methods of compositing: value, length, bench, code and interval. A large variety of geologic structures can be represented as surfaces: seam top and bottom structures, soil horizon thickness, faults, phreatic surfaces, or any other topological data which can be represented by a single z value at a xy coordinate on a plane.
