Determination and Upscaling of Rock Properties in Heterogeneous Carbonates Using Digital Rock Physics and Dynamic Simulation: From Nano-Meter to Grid Block Scale
Vahrenkamp, Volker C.*1; Zhao, Weishu 2; Hurley, Neil 2; Grader, Avrami 3
(1) Exploration, Abu Dhabi Company for Onshore Oil Operations, Abu Dhabi, United Arab Emirates. (2) Schlumberger Research, Boston, MA. (3) Ingrain Rocks, Houston, TX.
In many carbonate reservoirs pore type and size heterogeneities on a micro to macro scale dominate static and dynamic flow properties. However, traditionally, rock properties are measured in the laboratory on plugs - with insufficient consideration of the impact of these heterogeneities on the validity of the measurements. Furthermore results from plug measurements are applied to simulation grid blocks which are orders of magnitude larger in volume without any further upscaling. Uncertainties and imprecision with this approach are potentially huge. A new approach combing dynamic properties derived from high resolution CT scanning, Bore Hole Image (BHI) logs and multipoint statistics has been developed to account for carbonate inherent heterogeneities via small scale simulation models. These small scale models approximate representative element volumes for grid blocks and produce pseudo functions ready for use in reservoir scale simulations. For given fluid properties input data for the simulations are derived from the high resolution segmentation of full core rock samples using CT technology and calculation of porosity, permeability, relative permeability curves and capillary pressure tables for the segmented principle rock types. The approach is demonstrated with data from a giant carbonate field in Abu Dhabi.
AAPG Search and Discovery Article #90141©2012, GEO-2012, 10th Middle East Geosciences Conference and Exhibition, 4-7 March 2012, Manama, Bahrain