INTERFACING MESH GENERATION WITH 3D GEOLOGIC FRAMEWORK MODELS

Computational model set-up, including mesh generation, setting of material properties, boundary conditions and initial conditions, can be closely tied to a geologic framework model (GFM). Tools exist to automate workflow so that as the needs of the physics process model change (increased resolution through high gradients, decreased resolution to speed computations) the workflow can be streamlined and be independent of specific GFM format.

GFMs, in which 3D space is divided into volumes bounded by surface, edges and vertices, are conceptually similar to engineering CAD models (planes, trains and automobiles). However, most GFMs do not have key features of CAD models. They do not have a full model description that includes information about geometry, topology and material properties. Most GFMs do not have an application programming interface (API) to perform geometric and topological queries. GFMs are often good sources for presentation graphics and support limited export capabilities. As a result, it is difficult to build a general mesh generation application that interacts with GFMs developed by different geologic modeling packages.

Some of the differences between geologic and engineering set-up are highlighted based on examples from basin scale hydrology and fault system. Features that impact mesh design include: 1) discretization, 2) physics process model and 3) computational resources. These factors influence mesh design but workflow is still tightly tied to the underlying GFM.

Next generation GFM tools can be enhanced by development more functional APIs and adoption of selected standards from engineering CAD. However, fundamental differences exist between engineering CAD and geologic models. The wholesale adoption of engineering standards will not solve some of the outstanding bottlenecks in the workflow interfacing 3D GFMs with physics process models. In the meantime, set-up workflow must be adapted to the GFMs available.