Why is surfactant flooded?
Surfactant flooding is an important technique used in enhanced oil recovery to reduce the amount of oil in pore space of matrix rock. Surfactants are injected to mobilize residual oil by lowering the interfacial tension between oil and water and/or by the wettability alteration from oil-wet to water-wet.
What is the role of surfactant in EOR?
Surfactant EOR improves the wetability of porous rocks allowing water to flow through them faster displacing more oil. When introduced to an oil field the alkaline agent reacts with the oil, forming surfactants which reduce interfacial tension. This allows oil to pass through porous rock more effectively.
How does surfactant flood work?
What is the main aim of foam flooding in an EOR process?
Foam flooding technology is used to inject foam formed by gas−liquid mixture into oil reservoirs to control fluidity (increase swept volume due to its high viscosity) in order to prevent gas channeling and enhanced oil recovery (EOR).
What is the role of surface active ages in EOR?
The main functions of surfactants are to reduce interfacial tension and wettability alteration [3]. Surfactant EOR mechanisms are discussed separately according to these two functions.
Which is the most widely used type of surfactants in EOR?
Branched alkyl benzene sulfonate. C15-18 BABS/C16-18 BABS are the most common surfactants from this family that has been used in EOR studies. This family is classified as anionic surfactants with a similar behaviour to linear alkyl benzene sulfonate as explained earlier.
What is the screening parameters of surfactant flooding?
Many parameters can affect the surfactant flooding process, but the most critical are reservoir temperature, oil composition, formation water salinity and divalent contents, and clay content. Oil viscosity and formation permeability may be less important.
What is foam in EOR?
Foam is a dispersion of a gas (nitrogen, carbon dioxide, or methane) as a non-wetting fluid in a continuous wetting phase. The wetting phase is water that contains surfactant at a particular concentration that is above the critical micelle concentration (CMC). Foam quality for EOR applications is typically 75–90%.
What is foam flooding?
1. n. [Enhanced Oil Recovery] An enhanced oil recovery process in which foam is injected into a reservoir to improve the sweep efficiency of a driving fluid. Foam can be generated either in the reservoir pore space or at the surface before injection.
What is alkaline flooding?
Alkaline flooding (caustic flooding) is an enhanced oil recovery technique in which an alkaline chemical, such as sodium hydroxide, sodium orthosilicate, or sodium carbonate, is injected during water flooding or during polymer flooding operations. Alkalis such as sodium hydroxide or potassium hydroxide are used.
How do surfactants affect the surface tension of water?
The reason for the reduction in the surface tension when surfactant molecules adsorb at the water surface is that the surfactant molecules replace some of the water molecules in the surface and the forces of attraction between surfactant and water molecules are less than those between two water molecules, hence the …
What is chemical flooding?
Chemical flooding is an important tertiary oil recovery technology that can improve oil recovery by adding various chemicals in the injected water. For chemical flooding, the chemical agents used in polymer flooding, surfactant flooding, alkaline flooding, and combination flooding are described.