Estimation of Mass Transfer Parameters of Gaseous Solvents in Heavy Oils Using the Pressure-Decay Technique

Abstract

Estimating the mass transfer parameters of gaseous solvents in heavy oils is relevant for many petroleum engineering applications. These parameters are inferred from data obtained through diverse experimental methods, with the pressure-decay technique (PDT) being the most convenient. Therefore, in this research, analytical-graphical, numerical, and experimental approaches were implemented to estimate mass transfer parameters from PDT data. In particular, two analytical-graphical methods based on the Integral Method were developed to estimate Henry’s constant, diffusion, and interface-mass transfer coefficients. Additionally, the capability of PDT data to estimate the dependency of diffusion coefficient on gas concentration in bitumen was evaluated. Finally, and in response to very limited data, PDT tests were conducted to determine solubility and diffusivity of CH4 and CO2 in hydrocarbons at low temperatures. This work builds upon the current research in gaseous solvent transport in heavy oil and also provides new insights for using PDT data.