Evaluation of polymer flooding in model-based closed-loop reservoir management

• Grant number: 21/05816-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: August 01, 2021
• End date: July 31, 2023
• Field of knowledge: Engineering - Mechanical Engineering
• Agreement: Equinor (former Statoil)
• Principal Investigator: Denis José Schiozer
• Grantee: Bruno Marco de Oliveira Silveira
• Host Institution: Centro de Estudos de Energia e Petróleo (CEPETRO). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Company: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Mecânica (FEM)
• Associated research grant: 17/15736-3 - Engineering Research Centre in Reservoir and Production Management, AP.PCPE

Abstract

Heavy oil petroleum fields have normally low recovery factors and, consequently, lower net present values. Many techniques can be used to improve oil recovery in these reservoirs. Polymer flooding is one of the most successful chemical Enhanced Oil Recovery (EOR) methods and is implemented primarily to accelerate oil production by sweep improvement (Skauge et al.,2018). Polymer flooding seeks to improve oil displacement efficiency by increasing the viscosity of the injected water-flood. A more viscous flood gives a lower mobility ratio of injected brine to displaced oil and reduces viscous fingers, which is key for heavy and viscous oils (Skauge et al., 2018). In addition, polymer also adsorbs to the reservoir rock reducing the flow in high permeability streaks, reducing the impact of heterogeneity (Chapman et al., 2015). Thus, the tendency for water to under run oil is reduced, improving both a real and vertical sweep efficiency and increasing oil recovery (Chapman et al., 2015). Polymer flooding is currently being studied by EQUINOR to be applied to a Brazilian offshore heavy-oil field. However, the application of this EOR method is not straight forward, involving many uncertainties and challenges related to polymer properties and operations. On the one hand, several phenomena related to polymer flooding are absent in water flooding, such as adsorption and non-Newtonian behavior, making these processes more difficult to model and predict. On the other hand, uncertainty exists on polymer stability and efficiency in the reservoir, and also in injectivity loss; these aspects strongly affect the performance of polymer flooding. The most influencing properties on the field economic return are effective salinity, degradation, retention level and rheology (Lamas et al., 2016). This postdoctoral project was proposed in light of these combined challenges, which raise uncertainty in the viability and profitability of polymer projects, as well as in the best approach to optimize polymer-flooding operations. The project will probably have the cooperation of Arne Skauge from University of Bergen. (AU)