Estudo da configuração de poços no processo de drenagem gravitacional assistida por vapor (SAGD) em reservatórios do nordeste brasileiro

摘要

New technologies that use the enhanced oil recovery emerged the need to remove theoil that remains in the reservoir after primary recovery. The goal of these methods is toincrease the oil recovery factor. Thus, some projects start to become economically viablewhen using these methods. The thermal methods, including steam injection, promote therecovery of oil through the thermal energy within the insert reservoir. The increasedtemperature causes the oil to have its viscosity reduced, thereby increasing its speed towardsthe production wells. The steam assisted gravity drainage process (SAGD) is an advancedmethod of recovery. Its configuration has two parallel horizontal wells, one above the other.The steam is injected continuously during the injection well, and then forms a steam chamberwhich grows to find the limits of the reservoir. This oil is then reduced its viscosity and, bythe action of gravitational forces, it is drained toward the producing well. In this context, thisstudy aimed to carry out a study of different configurations of injection wells in SAGDprocess, considering the effects of load loss and heat in the injection well in the Braziliannortheast reservoirs. A factorial design was used to investigate the influence of the parametersstudied in the recovery factor. It also performed an economic analysis of the technical settingsof injection wells in order to analyze the profitability of the projects studied. To perform thenumerical simulations we used the thermal simulator CMG STARS (Computer ModellingGroup). The results showed that the inclined injection wells had a lower production comparedto the configuration with horizontal wells. A setting producer injectors offset from the well(W-SAGD) for injection flowrates from 100 ton/day, led to the formation of a vapor chamberlarger and more efficient. It was also observed that the use of vertical injection wells (VSAGD),for larger flowrates, showed a lower cumulative production of oil, however, similar to SAGD injector well horizontally. In the economic analysis, the SAGD model showed thehighest NPVs.