InterPore2024

Effect of interfacial tension reduction agents on fluid flow and oil production in reservoirs with low permeability layers

Not scheduled

1h 30m

Online Presentation (MS06-B) Interfacial phenomena across scales

Speaker

Ms JACQUELINE NANGENDO (China University of Petroleum (East China))

Description

The application of interfacial intension reducers (surfactants) in oil recovery has been widely applied because of the ability to reduce the interfacial tension in immiscible displacement. They also can change the wettability of the porous media to more water-wet and emulsify the oil to displace it in the subsurface porous media. Using surfactants to improve the performance of steam-assisted gravity drainage (SAGD) has been an intriguing idea for decades. This has been attributed to the ability of surfactants to form emulsions with oil and reduce interfacial tension (IFT) of the oil-water system which allows more oil to drain out of the reservoir. According to earlier research, surfactants increase oil's relative permeability by decreasing the IFT, de-wetting the surface, and emulsifying oil droplets, which increases oil mobility and displacement. In addition, this phenomenon can reduce the capillary pressure and enhance spontaneous imbibition. Therefore, some surfactants may increase production in reservoirs with barrier layers if carefully selected. Surfactants reduce interfacial tension (IFT) in the oil-water system, making the barrier layer extremely water-wet. In this study, numerical simulation using CMG-STARS backed up by experimental studies has been conducted. Several selected surfactants have been used to investigate their ability to overcome the challenges and impedance of the barrier layer on steam chamber expansion and the flow of oil across them to production. The simultaneous injection strategy was employed in both experimental and simulation studies. The surfactant played a great role in overcoming the barrier layers' effect on steam chamber expansion, oil production, and production rates increasing the flow of steam and oil across the barrier layer. From the experimental and simulation studies, the project with surfactant co-injection produced more oil and had greater oil production as compared to the pure-SAGD projects for various barrier layer thicknesses of a given permeability. The ability of the surfactant to enhance steam chamber growth, oil production, and production rate was seen to decrease with increasing and decreasing barrier layer thickness and permeability respectively. The residual oil results also showed significant differences in residual oil saturation (unproduced oil) for a given reservoir thickness and permeability under the same operation parameters. The steam flow and oil drainage across the low permeability layer were significantly greater and therefore reduced the amount of unproduced oil by over 50% compared to the pure SAGD process. The oil recovery rate also increased by almost two-fold while the oil production rates were one and a half times higher than pure SAGD at any given production time.
Keywords: Surfactant-aided SAGD, Steam chamber growth, Improved SAGD, Chemical-SAGD, Chemical-aided, thermal oil recovery, low permeability layers