Foam assisted water alternating gas - fawag: um potencial método de recuperação avançada para aplicação no pré-sal brasileiro

Abstract

Besides its multifaceted applications in various kinds of industries, petroleum constitutes, today, the most used power supply in the world. The world's oil and gas reserves still have a large part of their resources untapped due to the lack of technology within enhanced oil recovery area. The importance of studying advanced oil recovery methods has a fundamental role in the industry, with great efforts applied in the development of new techniques for the production of more and more resources from the already discovered reservoirs. The pre-salt has placed Brazil on the list of the largest holders of oil reserves in the world, and with this, investments to advance its effective exploration have been the focus of current technologies in the Brazilian oil and gas industry. The pre-salt carbonate reservoirs suffer from great heterogeneity, despite the excellent quality of the oil. The advanced recovery methods used in the pre-salt are mostly based on the injection of gas and water, especially alternately. The methods based on gas injection share a problem when combined with reservoirs with great heterogeneity, which is a poor sweeping efficiency. In order to present a solution to this current problem, the present work brings a general review on the advanced oil recovery technique of gas and water injection assisted by foam injection: the FAWAG method - Foam Assisted Water Alternating Gas. The application of the method in the field of Snorre, North Sea, Norway, presented excellent results in applications regarding the improvement of sweeping efficiency, gas storage, production improvement and excellent cost benefit. The data from this application were used to base a possible application in the Brazilian Pre-salt, being a solution to the problem of poor sweeping efficiency present in the Brazilian Pre-salt reservoirs.