Foam Propagation in Rock Samples: Impact of Oil and Flow Caracterization

Abstract

Foams are among the most promising and cost effective means to alleviate the drawbacks associated with gas-based EOR-processes. The objective of this work is to probe the impact of residual oil saturation on CO 2 -foam generation and on their flow behavior in porous media Designing a foam-EOR process requires its evaluation and optimisation at laboratory scale using coreflood tests. However, such coreflood tests are usually performed on relatively long core sample, this lead to long time-consuming experiments. In this study are presented results using both long and short coreflood systems. Short coreflood systems (allowing short-duration test) are coupled to a NMR apparatus and to an CT-scanner that allow live and non-invasive measurements of the fluids saturation.In a first part of this work, the efficiencies of two proprietary formulations to generate stable foam in porous media under reservoir conditions and in absence of oil have been compared. We used a coreflood set-up equipped with X-Ray detection to monitor gas propagation inside relatively long core samples. Then, their ability to resist the oil (Dodecane) have been evaluated and compared. The results evidenced two largely different behaviors. One of the two formulations resists the presence of oil up to an oil saturation of 35-40% while the second is destabilized as soon as the oil saturation exceeds 20%. Both formulations were insensitive to oil bellow an oil saturation of 15%. Depending on the application targeted, this laboratory evaluation should be coupled with a detailed economic evaluation to select the formulation to be used.In a second part, we performed co-injection tests using NMR small coreflood set-up and IRM-scanner in absence of oil. They brought more detailed information regarding fluid saturations that help interpreting foam characteristics and flow behavior in porous media.

Study on the regional characteristics during foam flooding by population balance model

“…The effects of residual oil on the rate of foam generation were studied through experiments and simulations. The results suggest that the presence of crude oil can result in hysteresis of the foam front (Batot et al, 2016). This is because the oil-water interfacial tension is far less than the gas-water interfacial tension, and the interface alteration leads to interfacial tension reduction when oil, gas, and water coexist in porous media.…”

Characterization of foam flowing in a granular medium in the presence of oil by small angle neutron scattering

“…One important issue for applications in oil industry is the effect of oil on the stability of the foam. In the presence of oil, the foam flow can be highly modified, and its relative viscosity decreased, leading to a decrease in efficiency 23,[27][28][29][30][31][32] .…”

Effect of Oil Presence on CO2 Foam Based Mobility Control in High Temperature High Salinity Carbonate Reservoirs

“…Despite its huge potential, this technique seems to give a much lower recovery than anticipated, for example, up to 20% of the original oil in place for CO 2 in miscible condition. 4,5 This poor performance of gas injection as an EOR method can be attributed to the numerous challenges it faces, the most prominent of which is contributed by the low density and viscosity of CO 2 gas (when compared to that of oil and water). 6 In addition, the high mobility of CO 2 gas worsens the effect of gravity thereby forming high mobility channels, which ultimately lead to an early breakthrough of gas.…”

“…6−8 In order to negate or rather alleviate these setbacks, foam can be used as one of the most promising and cost-effective means of EOR. 5 Foam can be defined as a dispersion of gas in liquid such that the liquid phase is interconnected and at least some of the gas flow paths are blocked by lamellae. 9 Foam reduces the mobility of gas by trapping the gas bubbles in porous media, and the presence of these bubbles provides stability to the displacement process by increasing the gas effective viscosity.…”