Korolev Field, Kazakhstan - Reservoir Modeling and the Evaluation of Key Static and Dynamic Uncertainties
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Health safety and environment(12%), Geochemistry(15%), Numerical simulation(32%)
Korolev Field is one of the largest oil fields in the Republic of Kazakhstan and is among the largest in the Chevron portfolio. Korolev field is an isolated carbonate platform located near the giant Tengiz field with 1.5 billion STB OOIP. Korolev field oil production comes from a Carboniferous age limestone reservoir that is over 1 km thick. A project was undertaken to construct new earth and simulation models for updating the reserve estimates for Korolev field. This project was in part necessitated due to the availability of new well, geologic, and engineering data. The sequence stratigraphy and depositional history of Korolev is nearly the same as Tengiz but there are some significant differences. The Korolev platform area is proportionally much smaller than Tengiz field and is dominated by an extensive lost circulation zone (LCZ). Korolev porosity is lower than Tengiz while permeability is roughly double and the bitumen content is significantly higher at Korolev. To evaluate the volumetric uncertainty over 800 earth models were constructed. The workflow involved the use of Monte Carlo simulation and Experimental Design (ED) to evaluate the key static and dynamic reservoir uncertainties impact on original-oil-in-place (OOIP) and recovery. The static uncertainties include: porosity, Swir (Bvw), permeability, and gross rock volume above the oil-water contact. Other static uncertainties evaluated but were handled as part of the dynamic ED were matrix permeability, LCZ extent, oil-water contact, and permeability barriers and baffles.