Due to low oil prices, many of the conventional enhanced oil recovery (EOR) techniques have become unattractive. The biggest challenge for any novel recovery technique is to be able to produce under attractive economic conditions. Also, any novel EOR technique should be able to address marginal reservoirs, such as heavy oil reservoirs, reservoirs with bottom water, and others, because these reservoirs contain the most proven reserves. This article focuses on economically attractive EOR techniques. Many of these techniques are in the areas of heavy oil and tar sand reservoirs. Studies are presented for some of the most promising emerging technolo gies, such as electromagnetic oil recovery, cosurfactant enhanced chemical processes, microbial EOR, low pressure gas foam injection, and others. Also discussed is the use of horizontal wells in order to improve the effectiveness of various EOR schemes. Finally, some of the relevant scaling criteria and numerical simulation results are discussed in order to familiarize readers with the difficulties of scaling up laboratory results before planning a field application.