Using Geological Process Modeling to Enhance Lithofacies Distribution in a 3-D Model: An Example

Summary A major challenge in reservoir modeling is the accurate representation of lithofacies in a defined framework to honor geologic knowledge and available subsurface data. Considering the impact of lithofacies distribution on reservoir petrophysics, a two-stage methodology was applied to enhance lithofacies characterization in the Hugin formation, Volve field. The approach applies the Truncated Gaussian Simulation method that relies on sediment patterns and variograms, derived from geological process simulations. The methodology involves: (1) application of the geological process modeling (Petrel-GPMTM) software to reproduce stratigraphic models of the shallow-marine to marginal-marine Hugin formation (2) define lithofacies distribution in GPM outputs by using the property calculator tool in PetrelTM. Resultant lithofacies trends and variograms are applied to constrain facies modeling. Data includes: seismic data and 24 complete suites of well logs. The Hugin formation consists of a complex mix of wave and riverine sediment deposits within a period of transgression of the Viking Graben. Twenty depositional models were reproduced using different geological process scenarios. GPM-based facies models show an improvement in lithofacies representation, evident in the geologically realistic distribution of lithofacies in inter-well volumes, leading to the conclusion that a robust stratigraphic model provides an important stratigraphic framework for modeling facies heterogeneities.