Lithology-based modeling and simulation of complex algal mound reservoirs, Paradox Basin, Colorado

The Paradox Basin is a silled Pennsylvanian depocenter and the main oil production comes from Ismay and Desert Creek phylloid-algal carbonate stratigraphic traps. Phylloid algae are typical reef builders in the Late Paleozoic and are known to form important hydrocarbon reservoirs (G.Michael Grammer and Audrey L. Ritter). Most of the Paradox Basin production comes from Ismay and Desert Creek phylloid-algal carbonate stratigraphic traps (Wilson H. Herrod, 1985).;The main purpose of this project is to build and evaluate a synthetic geological model based on lithology and formation evaluation of the phylloid algal mounds in the Lower Ismay formation of the Paradox Basin to gain a better understanding of the effect on fluid flow of algal mound geological structures. This research should improve future complex algal mound reservoir evaluations and development plans. The main research area for this study is the North Mail Trail field which has two producing wells with high initial production rates. Algal mound formations in the Paradox Basin are predominately limestone and dolomite lithology and typically have an average estimated 22% recovery rate.;Synthetic reservoir modeling and simulation for the North Mail Trail field was achieved using Landmark's Nexus-VIP software. After simulation and analysis, models were capable of reproducing observed complex connections between different algal mound sequences, which can lead to adjacent wells with no connectivity and distant wells which can be connected. The research result represents a good analog for real field algal mound simulation of North Mail Trail Field.