Steam flooding is a thermal enhanced oil recovery (EOR) method introduced in the 1970s that involves injecting steam into oil reservoirs to increase oil recovery. There are two main types: steam drive involves injecting steam into injection wells while producing from other wells, allowing a hot water bank to form and push oil to producers; cyclic steam stimulation involves alternating steam injection and shut-in periods in single wells. Steam flooding reduces oil viscosity and expands oil, but heat is lost to the formation, making it most applicable for deep, massive reservoirs with viscous oil. Recovery rates are typically around 50% of original oil in place.