Field application alkaline flooding

Mungan, N. "Enhanced Oil Recovery Using Water as a Driving Fluid, Part 5 - Alkaline Flooding Field Applications , World Oil, Vol. 193, No. 1, July 1981, pp 181-190. 

Recent research and field tests have focused on the use of relatively low concentrations or volumes of chemicals as additives to other oil recovery processes. Of particular interest is the use of surfactants as CO (184) and steam mobility control agents (foam). Also combinations of older EOR processes such as surfactant enhanced alkaline flooding and alkaline-surfactant-polymer flooding have been the subjects of recent interest. Older technologies polymer flooding (185,186) and micellar flooding (187-189) have been the subject of recent reviews. In 1988 84 commercial products polymers, surfactants, and other additives, were listed as being marketed by 19 companies for various enhanced oil recovery applications (190). 

Field Application. Field trials of classical alkaline flooding have been disappointing. Mayer et al. (60) indicated that only 2 of 12 projects had significant incremental oil recovery North Ward Estes and Whittier with 6-8 and 5-7% pore volume, respectively. Estimated recovery from the Wilmington field was 14% with a classical alkaline flooding method (61). However, post-project evaluation of that field indicated no improvement over water-flooding (62). 

Alkaline flooding is also called caustic flooding. Alkalis used for in situ formation of surfactants include sodium hydroxide, sodium carbonate, sodium orthosilicate, sodium tripolyphosphate, sodium metaborate, ammonium hydroxide, and ammonium carbonate. In the past, the first two were used most often. However, owing to the emulsion and scaling problems observed in Chinese field applications, the tendency now is not to use sodium hydroxide. The dissociation of an alkali results in high pH. For example, NaOH dissociates to yield OH" ... 

The theories of alkaline flooding and polymer flooding alone are discussed in their respective chapters. This chapter focuses on the interaction and synergy between alkali and polymer. It also presents a field application. 

Hawkins, B. F., K. C. Taylor and H. A. Nasr-El-Din, Mechanisms of Suer-factant and Polymer Enhanced Alkaline Flooding Application to David Lloydminster and Wainright Sparky Fields, JCPT 33, 52-63 (1994). 

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