FORTRAN Programs for Calculating Connectivity of 3-D Numerical Models and for Ranking Multiple Realizations

Given a 3-D numerical geological model it is often useful to determine the geological modeling cells that are connected in 3-D. These connected 3-D bodies are referred to as geo-objects; a program geo obj is presented to calculate the geo-objects from 3-D lithofacies, porosity, and permeability models. Relevant summary statistics such as the number of geo-objects, their sizes, and their tortuosities are reported. The connected volumes may be used for ranking geostatistical realizations, e.g., establishing realizations with low, median, and high connectivity. A program rank obj is presented for this purpose. It may also useful to rank realizations according to the connectivity to one particular location (e.g., a well location) or between two locations (e.g., injector-producer pair); programs rank loc and rank2loc are presented. The concept of 3-D connectivity and the topology of 3-D Cartesian grids are well understood; however, the programs presented here will be useful to anyone dealing with 3-D numerical geological models.