Análise paramétrica da injeção de vapor e solvente com poços horizontais em óleos de diferentes viscosidades

Abstract

The high existence of reservoirs containing heavy oil is a reality in Brazil and in the world. Heavy oil reservoirs have production difficulties, which are mainly associated with the high viscosity of the present oil, causing low production through conventional recovery methods. The application of thermal methods alone as well as in conjunction with miscible methods, such as solvent injection can contribute to the production, since the increase in temperature promotes the viscosity reduction and solvent helps in the miscibility by reducing the interfacial tension between oil and solvent. This study had as objective to apply the steam injection process, initially alternating with solvent, in a homogeneous reservoir model with main characteristics of the reservoirs of the Brazilian Northeast region, in three oils with different viscosities. Some operational parameters were analyzed, such as: steam injection flow, solvent injection flow, vertical distance between the horizontal wells and time of alternation between steam and solvent, after, it was analyzed the same case, fixing the highest injected steam flow and the highest solvent injection flow in the continuous mode, the possibility of injecting solvent only at the start of production was also analyzed. Numerical simulations were performed using the STARS thermal simulator from CMG (Computer Modelling Group). The results showed the importance of the vertical distance between the wells and the steam injection flow, it was also observed that the higher the viscosity of the oil, the lower the influence of the alternating solvent injection in time, showing that the solvent has a higher solubility with the lighter oil that was studied.