Numerical simulation study on characterization of foamy oil behavior in heavy oil/propane system

Abstract

A new non-equilibrium kinetic model is developed with non-constant reaction rate to characterize foamy oil behavior for heavy oil/propane system in pressure depletion tests and obtained desired history matching results. The effect of k values, relative permeability curves and reaction frequency factors under different pressure depletion rates are analyzed based on the simulation results. The simulation results suggest that both k values and gas phase relative permeability reduce with the increase of pressure depletion rate. The oil phase relative permeability and reaction rate for both Reaction (1) and Reaction (2) increase with the increase of pressure depletion rate. When consider a constant value of reaction frequency factor for Reaction (1) and non-constant value of reaction frequency factor for Reaction (2), good history matching results could be obtained. Better history matching results could be obtained for the intermediate pressure depletion rate case when consider non-constant reaction frequency factor of both Reaction (1) and Reaction (2). The simulation study suggests different foamy oil characterization under different pressure depletion rates. Gas bubbles pass smoothly and have low dissolve rate at low pressure drop rate. Increasing pressure drop rate, gas bubbles expand a larger size and blocked by pore throat. Gas bubbles evolve and dissolve process both influence the foamy oil and gas-oil flow at this pressure drop rate. Exceed pressure drop rate could cause gas bubbles evolve rate faster than dissolve rate and shorter production time. This work provides an innovative methodology to characterize foamy oil flow in heavy oil/propane system.