The Smart Surfactant system (U.S. patent number 7373977) is a one-component system that provides low interfacial tension and proper viscosity. Mixtures of surfactants can be employed to selectively block reservoir channels containing water and allow the surfactant(s) to penetrate channels containing oil and mobilize the oil by lowering interfacial tension.

The advantages of using the Smart Surfactant System include:

• No residue

• Tolerant to salts and divalent cations

• No water treatment is required

• Minimal surface equipment required

• Minimal up-front investment

• No polymer dissolving or hydration units required

Water Flood

In general, water flood can remove an additional ~ 10 - 30% residual oil after primary recovery. Extensive water flooding causes water channels though the most permeable area and causes premature water break-through, leaving many oil containing areas untouched.

 

Surfactant Flood

 

After the water channels are formed, if only surfactant is used for the flood, without any profile control, most likely the surfactant flood will follow the existing water channels in the formation and still leave many oil containing areas un-touched. Because the sweep efficiency is not optimized the oil recovered using this tertiary recovery process is often disappointing.

 

Smart Surfactant

The Smart Surfactant system provides both low interfacial tension between the injection water and residual oil and the viscosity necessary for profile control. It selectively blocks the water channels, seeks out the remaining oil-bearing sections of the formation that were untouched by the water flood, lowers the interfacial tension and mobilizes the residual oil to further increase the oil production.