The Mapping, 3-D Modelling And Upscaling Of A Mixed-Influence Delta System And The Effect On Reservoir Heterogeneity And Connectivity
Engineering Honours Degree, 2010
University of Adelaide
Upscaling of reservoir models is a process commonly used when converting static geological models into dynamic simulation models. Upscaling is needed in order to minimise processing time. However, it can cause important reservoir model attributes to be lost. This project investigates the effect of upscaling on reservoir heterogeneity and connectivity in a modern mixed influence delta system.
The Gilbert River Delta located in the southeastern Gulf of Carpentaria, Queensland, Australia, was chosen for this study due to the availability of vertical profile information in the form of core data and field observations. This data was valuable for the creation of a 3-D reservoir model. Sedimentary facies were mapped at a fine scale using satellite imagery and statistics from this map classed the study area as a tide dominated, wave influenced, fluvially affected (Twf) coastal environment
A 3-D reservoir model was created based on the map using a base case 5x5x1 m grid. This model was laterally upscaled into progressively coarser grids. The model was found to preserve reservoir heterogeneity and connectivity at a grid size of 10x10x1 m. Due to the narrowness of the channels in the area, accurate modeling of reservoir connectivity was lost at a cell size >10x10m.
Vertical upscaling was investigated from a base case 20x20x1 grid. Vertical upscaling was found to be dependent on the initial facies thickness. The 20x20x2 grid was found to be the optimal grid size for vertical upscaling, with a minimal change in reservoir volume or connectivity when compared to the base case.