 Enhanced oil recovery operations in the form of steam production and injection have been used on the thick viscous crude oil of the Midway-Sunset field since the mid-to-late-1960s.The reservoirs of the Midway-Sunset field are composited layers of mostly unconsolidated sandstones of late Miocene age, shallowly buried.The shallow burial depth and ideal nature of the sandstones make them almost perfectly suited for steam injection.