Characterization and Spatial Uncertainty Quantification for Unconventional Gas Resources in Piceance Basin, Colorado

This paper summarizes an ongoing interdisciplinary study for quantitatively modeling unconventional gas resources in Piceance Basin and in particular, the use of geostatistical approaches to address spatial uncertainties which are rarely tackled in basin and petroleum system modeling discipline. A 3D numerical basin model was first constructed from integrated seismic, well logs and organic geochemistry data to study the tight gas resources in Mesaverde Petroleum System in Piceance Basin. Having this model served as ‘base case scenario’, we introduced a stochastic workflow to construct multiple basin models and different scenarios in order to capture spatial uncertainties resulted from source rock properties and thermal event. This abstract demonstrates the workflow with an example of capturing spatial uncertainties from source rock thickness when only sparse data are available. Stochastic realizations of thickness maps are first generated using geostatistical tools, an ensemble of basin model are built from these realization maps and then simulated. The model predictions of gas resources show a large associated uncertain range and indicate the importance of utilizing multiple models to improve the resource assessment with better uncertainty quantification.