US Patent 7543638 - Nanoparticle enhanced oil recovery

http://www.freepatentsonline.com/7543638.html

In the later stages of oil recovery operations it is necessary to perform chemical procedures to recover heavy oils or tar which can require a great deal of energy expenditure. This patent from Schlumberger Technology Corporation teaches a method of using nanoparticle catalysts to reduce these energy costs in recovering oil from late stage oil reserves. Claim 1 reads:

1. A method for enhancing oil recovery in a formation, comprising:

placing a metal or metal oxide catalyst in a wellbore, wherein the metal or metal oxide catalyst comprises nanoparticles having diameters less than about 1 micrometer; and

introducing an oxidizing agent into the wellbore to contact the metal or metal oxide catalyst such that a hydrocarbon in the formation is oxidized to produce heat and at least one gas.