Hydrocarbons trapped in solid media, such as bitumen in tar sands may be recovered from deep formations by relieving the stress of the overburden and causing the formation to flow from an injection well to a production well, for example, by fluid injection, recovering a tar sand/water mixture from...http://www.google.com.hk/patents/US5823631?utm_source=gb-gplus-share專利 US5823631 - Slurrified reservoir hydrocarbon recovery process
