Paper: Fluorochemical Surfactants Their Current And Future Applications In Oil And Gas Well Stimulation

Surfactants have performed well in a variety of applications with regard to stimulation. The role of surfactants, or surface active agents, in both acidizing and fracturing has been somewhat taken for granted; but these agents nonetheless play an extremely important and ever-increasing part in almost all successful stimulation treatments. Surfactants have been discussed thoroughly in the literature with respect to use in oil well treating fluids. Until recently, most surfactants used in stimulation have come from one of two families. The most commonly used are hydrocarbon-based, and the others consist of silicone-based materials. Numerous blends of these types are used to deal with a number of situations. In varying concentrations, the above-mentioned "conventional" surfactants have been used in a variety of applications which are as follows. 1. To lower the surface tension or interfacial tension of a fluid. 2. To provide non-emulsion characteristics to a fluid. 3. To provide emulsion-breaking characteristics to a fluid. 4. To provide emulsion-forming characteristics to a fluid. 5. To provide foaming characteristics to a fluid. 6. To suspend fines or particles in fluids. 7. To retard or extend the reaction time of various acids. 8. To allow more effective penetration by aqueous or acid systems. 9. To facilitate a desired wetting function on a particular surface (i.e., metal, rock, etc.). 10. To assist or prevent various types of material in adsorbing to particular surfaces under certain conditions or to allow low adsorption. 11. To provide protection from various harmful reactions (i.e., corrosion, precipitation, etc.).4 12. To allow interaction with other physical problems in the oil or gas reservoir such as fluid imbibitions, capillarity, saturation or permeability.5"6 13. To allow water block removal or more effective treatment load recovery. 14. To improve wetting and thereby hydration of polymers used in stimulation. There are probably other uses which could be mentioned, but those above are generally considered most essential. Correct use requires careful selection of a particular surfactant type. The criteria for surfactant selection for use in a treatment is given below to emphasize the importance of appropriate materials.