Modeling of Petroleum Generation, Williston Basin, North Dakota

Because most easily-found oil has already been exploited, new prospects typically lie in complex and challenging geologic formations. Therefore, sophisticated basin and petroleum system modeling continues to grow in popularity because it provides an integrative exploration tool, which can be used to quantify many of the key aspects of an evolving basin and active petroleum systems within it. The Williston Basin in North Dakota has become a prolific petroleum province. Currently, hydraulic fracturing of “tight” Bakken shale allows enhancement of production, but still much oil remains in the rock. Typically we have been successful in getting 30% of total recoverable hydrocarbons, therefore much need to be done to improve production efficiency. This research focuses on modeling (using Platte River Associates’ Basin MOD) of petroleum generation and fluid overpressure development in the Williston Basin, using data such as source rock thickness and TOC, kerogen type, petroleum attributes (API gravity, maturity and volume), and burial/thermal history (stratigraphic column, ages of units, any heat flow or heat production data). By comparing the modeled amount of oil generated in the rock with actual total amounts produced from wells, we estimate the percent of oil that remains in the rock after the well is no longer in production. We also evaluate the source of “excess” fluid pressure in the Bakken shale. These data can be useful in developing more-efficient oil production strategies