Generation of PVT properties for modified black-oil simulation of volatile oil and gas condensate reservoirs

This paper presents a discussion of methods for generating PVT properties for modified black-oil simulation of volatile oil and gas condensate reservoir fluids. Methods for generating modified black-oil PVT properties have been presented previously in the petroleum literature. However, it is not apparent how the PVT properties generated by these methods differ, and how the differences affect modified black-oil simulation results.; Modified black-oil PVT property generation methods are evaluated by comparing the results of modified black-oil simulation to results of full equation-of-state (EOS) compositional simulation. The methods are evaluated using ternary fluid systems and four actual reservoir fluid systems spanning a wide range of volatile oil and gas condensate fluid characteristics. The results indicate that modified black-oil simulation of reservoir depletion using PVT properties generated with the Whitson and Torp{dollar}sp1{dollar} method provides better agreement with full EOS compositional simulation than modified black-oil simulation using PVT properties generated using the Coats{dollar}sp2{dollar} method.; This paper also presents a method for generating modified black-oil PVT properties from laboratory constant volume depletion (CVD) data without using a regressed EOS. A K-value model, based on the method of Hoffman, Crump and Hocott{dollar}sp3,{dollar} is developed to smooth and extrapolate (to the saturation pressure) K-values obtained from laboratory CVD data. The smoothed K-values are used to regenerate mathematically CVD data from which modified black-oil PVT properties are determined. Modified black-oil simulations of reservoir depletion using PVT properties generated from laboratory data and smoothed with the K-value model show reasonable agreement with full EOS compositional simulation.