Polymer flooding, known for enhancing heavy oil displacement, may encounter efficiency-limiting physical phenomena. This work assesses the impact of key factors like viscosity, shear rate, and adsorption in field applications using a model-based approach on the EPIC001 case, a real offshore Brazilian heavy oil reservoir. In simulation results, increasing the displacing fluid viscosity using apparent or zero-shear functions, oil production and economic returns show improvements over waterflooding. The shear rate effect slightly increases oil production and enhances injectivity loss due to shear-thinning in polymer flow. However, modeling it increases computation costs, as it extends simulation run time from minutes to days, making it impractical for intensive processes like production optimization. An analysis of the method’s effectiveness shows that it varies based on the adsorption level considered. At its highest value, even with a higher oil recovery factor, the economic return was lower than using waterflooding. Combining shear rate and adsorption has a minimal impact on field indicators when compared to adsorption alone. This work enhances the comprehension of physical phenomena and non-Newtonian behavior in tertiary polymer flooding on heavy oil reservoirs and its impact on the production forecast. It also highlights important considerations for modeling-based procedures.
Tag: Enhanced oil recovery
Fundamental aspects, mechanisms and emerging possibilities of CO2 miscible flooding in enhanced oil recovery A review
Capturing carbon dioxide (CO2) at its combustion point and thereby storing it in geological sites or its usage for enhancing oil recovery (EOR) through miscible gas flooding technology aims to mitigate atmospheric/anthro- pogenic CO2 emissions. Injection of CO2 possesses an immense potential for production improvement in matured oil reservoirs. Oil recovery is increased by viscous fluid drive, oil phase swelling and oil viscosity reduction. Miscible CO2 floods diminish interfacial tension (IFT ~ 0) between gas and oil, and alters the wettability. This review discusses the various technical aspects of oil production enhancement via miscible CO2 application with identification of the significant research gaps. The mechanisms of first contact and multiple contact miscibility, techniques of minimum miscibility pressure (MMP) determination (experimental, theoretical and numerical), the influence of CO2 concentration on rock mineralogy and surface roughness with various associated reservoir parametric (pressure, temperature, salinity, etc.), and the mechanisms of oil displacement from laboratory ex- periments to field applications are discussed elaborately. The review also deals with the new approaches of CO2 flooding viz. carbonated water injection, near miscible CO2 flooding, water alternating gas (WAG) injection, CO2 huff ‘n’ puff, and CO2 thickening. Finally, CO2-EOR in carbon capture, utilization and storage (CCUS), the environmental aspects, challenges and future outlooks of CO2 miscible flooding are discussed. Therefore, a re- pository of CO2 miscible EOR is established in this review assisting an enrichment in our current understanding of this topic.