Estudo de modelos das reações químicas no processo de combustão in situ

Abstract

In situ Combustion (CIS) is the oldest thermal method of oil recovery. This method consists of partial combustion of in situ oil, its goal is to generate a combustion front that helps to move the oil. This combustion front will heat the surrounding areas, achieving a reduction in oil viscosity and allowing its displacement into the production well. It may seem a simple process, however in situ combustion involves a series of complex mechanisms that difficult until today its representation through analytical models, physical models and numerical simulation. The aim of this investigation is to analyze and determine the parameters that influence the process, highlighting the kinetics of the process (activation energy, Arrhenius coefficient and percentage of cracking for the production of coke) three different models of chemical reactions and the air injection rate. To verify the applicability of the process in Brazil a simulation study was conducted in heavy oil reservoirs with characteristics of the Brazilian Northeast. The simulations were performed using the "STARS" module from the "Computer Modelling Group", which objective is to study methods of enhanced oil recovery. Among all the analyzed parameters, the activation energy-pre-exponential factor showed the greatest influence, that is, the lower the value of the activation energy-preexponential factor the higher the fraction of oil recovery. The cracking percentage also showed a strong influence in the process, the smaller the amount of coke formed the larger volume of oil recovery.