Book excerpt: In this chapter, we briefly present the fundamentals of alkaline flooding which include comparison of alkalis, alkaline reactions with crude oil, water and reservoir rock, and alkaline flooding mechanisms. Typical field injection data like alkaline injection concentrations and volumes, and field application conditions are discussed. Finally, we present two mobility-control cases in Russia, one case using high alkaline concentration in Hungary, one caustic-flooding case in India, three cases in the United States, and one case in a Canadian heavy oil field.