Effective integration of reservoir rock-typing and simulation using near-wellbore upscaling. (November 2015)

• Record Type: Journal Article
• Authors: Chandra, Viswasanthi; Barnett, Andrew; Corbett, Patrick; Geiger, Sebastian; Wright, Paul; Steele, Richard; Milroy, Paul
• Is Part Of: Marine and petroleum geology. Volume 67(2015:Nov.)
• Page Start: 307
• Page End: 326
• Publication Date: 2015-11
• Subjects: Carbonate reservoirs -- Rock-typing -- Near-wellbore upscaling -- Initialisation -- Permeability -- Relative permeability -- Capillary pressure -- J function; Submarine geology -- Periodicals; Petroleum -- Geology -- Periodicals; Géologie sous-marine -- Périodiques; Pétrole -- Géologie -- Périodiques; Petroleum -- Geology; Submarine geology; Periodicals; Electronic journals; 551.468
• DOI: 10.1016/j.marpetgeo.2015.05.005
• Languages: English
• ISSNs: 0264-8172

Abstract

Abstract: Obtaining a fit-for-purpose rock-type classification that adequately incorporates the key depositional and diagenetic heterogeneities is a prime challenge for carbonate reservoirs. Another prevailing issue is to integrate the static and dynamic data consistently with the rock-typing scheme in order to correctly initialise the reservoir flow simulation model. This paper describes a novel near-wellbore rock-typing and upscaling approach adopted to address the crucial challenges of integrating reservoir rock-typing and simulation in carbonate reservoirs. We demonstrate this workflow through a case study for a highly heterogeneous Eocene-Oligocene limestone reservoir, Field X. Geological studies carried out in Field X suggested that the key permeability pathways are strongly related to the mechanism of reservoir porosity and permeability evolution during late-burial corrosion. The rock-typing and upscaling methodology described in this paper involves the geological-petrophysical classification of the key reservoir heterogeneities through systematic evaluation of the main paragenetic events. Associations between the depositional and late-burial corrosion features, and their impact on reservoir flow properties, were accounted for in our workflow. Employing near-wellbore rock-typing and upscaling workflow yielded consistent initialisation of the Field X reservoir simulation model and therefore improved the accuracy of fluids-in-place calculation. Subsequently, the cumulative production curves computed by the reservoir simulation model of Field X showed closer agreement to the historic production data. The revised Field X simulation model is now much better constrained to the reservoir geology and provides an improved geological-prior for history matching. Highlights: Novel rock-typing workflow integrated with near-wellbore upscaling. Workflow successfully applied to giant carbonate field with long production history. Improved accuracy of FIP calculations during reservoir simulation. Improved geological-prior obtained for history matching and forecasting studies.