Building solid models from boreholes and user-defined cross-sections

Solid models of geologic structures are useful tools for geologists and engineers. Solid models completely and unambiguously define the stratigraphy for the site being modeled, including complex boundaries and embedded seams. Past research has focused on the "set operations" approach to create solid models. Whereas the set operations approach is flexible, it requires significant user intervention and is therefore difficult to use. A simple approach for generating solid models from borehole data, called the horizons method, is presented. The horizons method can be used to build solids directly from borehole data with minimal user intervention. The user first assigns horizon ids to each of the borehole contacts. The horizon ids represent the depositional sequence and increase from the bottom to the top of the boreholes. The solids are then built by interpolating each of the surfaces defined by the horizons and extruding the surface into a solid. In each case, the solid is built by extruding the solid from the current surface down to the uppermost surface defined by the top of all previous horizons. In cases where more control over the resulting solids is necessary, the horizons method can be easily modified to honor user-defined cross-sections in addition to the borehole data. (C) 2003 Elsevier Science Ltd. All rights reserved.