A Systematic Approach to Effective Flow Property Determination for Deepwater Heavy Oil Evaluation

Abstract

Coarse scale modeling of deepwater turbidites requires that effective properties be developed to capture the fine scale flow behavior. In displacements with unfavourable mobility ratio, displacement instabilities at the shockfront may exist resulting in the occurrence of viscous fingers that reduce breakthrough recovery and increase gas and water production. Viscous fingering effects have been studied and demonstrated by laboratory experiments. The practical scale of fine scale models is usually too large to resolve viscous fingering effects. Hence evidence of viscous fingering has to be tested and appropriate upscaling applied at the fine scale modeling stage. A two stage upscaling technique has been developed for heavy oil effective flow properties determination, a viscous fingering correction and generation of dynamic pseudos. The viscous fingering correction was done using the method of Clemens and Wit. This assumes that viscous fingers can be described by using a segregated flow approach. Upscaled rock relative permeability for viscous fingering was then used as input into the fine scale modeling. To upscale to the coarse scale model a history matching approach was applied to generate dynamic pseudos. The application of appropriate effective flow properties to heavy oil characterization improves the quality of the production forecasts, and facilitates proper sizing of facilities.