 The declining discovery of oil has led to increased interest in enhanced oil recovery, or, techniques. This paper reviews the current state of our technology and its potential for increasing production from various types of reservoirs. The paper focuses on sandstone and carbonate reservoirs, which account for most of the world's oil reserves, and also briefly addresses turbidite reservoirs. It examines the risks and rewards associated with different our methods, including CO2 injection, HPAI, and chemical flooding. Finally, the paper provides an economic analysis of CO2 or projects. This article was authored by Vladimir Alvarado and Eduardo Menrique.