Foam Flooding with Ultra-Low Interfacial Tension to Enhance Heavy Oil Recovery

Abstract

Severe viscous fingering during water flooding of heavy oil leaves a large amount of oil untouched in the reservoir. Improving sweep efficiency is vital for increasing heavy oil recovery. Previous researches have proved that foam flooding can increase the sweep efficiency and oil recovery. The polymers could make the foam more stable and have better plugging capacity, but the interfacial tension (IFT) of oil and water increase which could decrease the displacement efficiency of the heavy oil. In view of the deficiency of conventional foam flooding, it is necessary to research the ultra-low interfacial tension foam which could improve macro-swept volume and micro-displacement efficiency in heavy oil reservoir. In this paper a novel foam agent is developed by the combination of surfactant and additives to lower the IFT of oil and water. The operating parameters including foam injections modes and gas liquid ratio were investigated by core flooding experiments. Field test performance shows that oil production per day increased from 85.6 to 125.7 t, water cut declined from 92.1 to 83.6% after 3 months injection. This study provides a novel method to improve heavy oil recovery with an ultra-low interfacial tension foam flooding system.

Polymer-Enhanced Foam Flooding for Improving Heavy Oil Recovery in Thin Reservoirs

“…This demonstrates that polymer can greatly improve the foam stability, which is mainly related to the stability of foam film. Such a film should have slow liquid drainage and good elasticity to stand some deformation without rupturing. , The polymer can enhance the viscosity of the foaming solution (that is, the liquid solution within the foam lamella), reduce the rate of liquid drainage in the foam film, and create a protective viscoelastic film around the gas bubble, and consequently improve the foam stability. However, the addition of polymer also adversely influences foaming ability as shown in Figure .…”

“…36 Kang et al and Zhang et al explored a novel method of ultralow interfacial tension PEF for a heavy oil (461 mPa•s at 60 °C) and discovered that this new method could greatly enhance oil production and control water cut and direct injection foam had a better performance compared to N 2 /water coinjection and water alternating gas. 37,38 Telmadarreie and Trivedi studied PEF flooding for improving postsurfactant flooding in oil-wet fractured carbonate reservoirs, and their micromodel tests showed that PEF could enhance sweep efficiency by diverting surfactant liquid from the fractures into the matrix. 39 They also compared the performance of foam and PEF using a heavy oil (670 mPa•s at 22 °C) in both homogeneous and fractured rock samples and found that PEF had better performance than foam, with more stable frontal displacement, better sweep efficiency, and higher trapped gas saturation in the cores, and that PEF significantly improved heavy oil recovery in the fractured cores by the liquid diversion into the matrix.…”

“…Pei et al and Wang et al examined the low gas–liquid ratio PEF flooding for the Zhuangxi heavy oil (325 mPa·s at 55 °C) and found that PEF could improve oil recovery by 39% after water-flooding, which was 11% higher than that of alkali/surfactant/polymer-flooding, and PEF was more stable in heavy oil than in light oil, as shown in their microscopic study. , Ma et al investigated nitrogen PEF flooding to solve the injection water breakthrough in an offshore heavy oil reservoir, and their field pilot test showed that PEF could plug high permeability zones and big channelings, improve water injection profile, decrease water cut and increase the oil recovery . Kang et al and Zhang et al explored a novel method of ultralow interfacial tension PEF for a heavy oil (461 mPa·s at 60 °C) and discovered that this new method could greatly enhance oil production and control water cut and direct injection foam had a better performance compared to N 2 /water coinjection and water alternating gas. , Telmadarreie and Trivedi studied PEF flooding for improving postsurfactant flooding in oil-wet fractured carbonate reservoirs, and their micromodel tests showed that PEF could enhance sweep efficiency by diverting surfactant liquid from the fractures into the matrix . They also compared the performance of foam and PEF using a heavy oil (670 mPa·s at 22 °C) in both homogeneous and fractured rock samples and found that PEF had better performance than foam, with more stable frontal displacement, better sweep efficiency, and higher trapped gas saturation in the cores, and that PEF significantly improved heavy oil recovery in the fractured cores by the liquid diversion into the matrix .…”

Numerical simulation of enhanced oil recovery studies for aqueous gemini surfactant‐polymer‐nanoparticle systems

“…Surfactant flooding is a promising EOR technique employed by the production sector since 1970s decade 5,6 . This type of recovery functions by allowing surfactants or “surface‐active agents” to adsorb onto the interface of oil/water, thereby decreasing interfacial free energy and increasing dimensionless capillary number 5‐7 . Polymer improves the viscosity of displacing (injected) fluid to reduce the mobility ratio between water and oil 8,9 .…”

Numerical Simulation of Enhanced Oil Recovery (EOR) studies for aqueous Gemini Surfactant-Polymer-Nanoparticle systems

“…Surfactant flooding is a promising EOR technique employed by the production sector since 1970s decade [5,6]. This type of oil recovery functions by allowing surfactants or "surface-active agents" to adsorb onto the interface of oil/water, thereby decreasing interfacial free energy and increasing dimensionless capillary number [5][6][7]. Polymer improves the viscosity of displacing (injected) fluid to reduce the mobility ratio between water and oil [8,9].…”