Enhancing Foam Stability Through a Combination of Surfactant and Nanoparticles

Abstract

Gas injection is amongst the oldest and most used enhanced oil recovery (EOR) methods in the petroleum industry. Nevertheless, gas EOR is subject to poor macroscopic sweep efficiency due to the higher mobility and lower density of gas compared to reservoir fluids. Foamed-gas injection can regulate the mobility of gas by trapping a large fraction of the gas inside the porous medium, thereby increasing its apparent viscosity and reducing its relative permeability. However, the poor stability of foam at harsh reservoir temperature and salinity conditions is a major limitation that hinders the effectiveness of the foam flood. A combination of surfactant and nanoparticles (NPs) provides a novel solution to foam stability challenges. This study evaluates the role of NPs on enhancing foam stability. Static and dynamic laboratory tests were conducted along with particle size and zeta potential measurements to capture the foam stability and strength in porous media for a cationic surfactant combined with surface modified silica NPs. The static bulk foam stability was determined by measuring the foam half-life over time. The dynamic foam stability was determined through the mobility reduction factor (MRF) using a micromodel apparatus. The tests were carried out on a variety of NPs concentrations and fixed surfactant concentration. The results from the experiments show that the use of surfactant combined with NPs enhances the stability and strength of the generated foam when compared to the use of surfactant alone. The foam static tests show that the mixture of NPs and surfactants produces foams with smaller bubbles and longer half-life when compared to those in the absence of NPs. The results also demonstrate that the concentration of surfactant and NPs is a crucial parameter for foam stability and that there is an optimal concentration of NPs for strong foam generation. In porous media, the addition of NPs to surfactant solutions results in larger pressure differences across the micromodel chip and, accordingly, greater reduction of gas mobility when compared to those using surfactant solution alone. The results also reveal that the generation of NPs flocs is the main mechanism of foam stabilization enhancement. This work shows that using NPs at carefully selected concentrations in combination with surfactant can improve the foam static and dynamic stability in porous media, effectively lowering the mobility of the injected fluids and, eventually, improving the sweep efficiency of gas compared to the typical application of using surfactant alone.

Experimental Investigation of Foam Flooding Using Anionic and Nonionic Surfactants: A Screening Scenario to Assess the Effects of Salinity and pH on Foam Stability and Foam Height

“…In other words, only at an intermediate surfactant concentration, maximum foam is generated, and at any surfactant concentration below and above this intermediate, concentration foam stability is deteriorated. 37 …”

“…Based on this theory, any enhancement of surfactant concentration enhances the foam stability but this enhancement is accomplished up to an extent that is often close to critical micelle concentration (cmc). In other words, only at an intermediate surfactant concentration, maximum foam is generated, and at any surfactant concentration below and above this intermediate, concentration foam stability is deteriorated …”

Modified silica nanoparticles stabilized foam for enhanced oil recovery

“…Foam will plug high-permeability layers, redirecting subsequent fluid flow toward low-permeability layers (Sun et al, 2014;Shi et al, 2023). Nonetheless, the thermodynamic instability of foam is a critical factor influencing its application (Sun et al, 2015;Almubarak et al, 2020). To address this issue, surfactants and polymers are commonly employed to stabilize foam (Mingming and Shuzhong, 2014;Wang and Li, 2016).…”

Foam Stabilization Mechanism of a Novel Non-cross-linked Foam Fracturing Fluid

“…The non-cross-linking fracturing fluids, such as viscoelastic surfactant (VES) fracturing fluids, have become an important development direction of fracturing fluid technology. − VES forms associated structures through rodlike micelles, which is essentially a kind of association. − In 1999, Zhang and Gupta first proposed the combination of VES and foam fracturing fluid. In 2006, VES–CO 2 foam fracturing fluid technology was first successfully applied in Park, Wyoming .…”