1
Donald J Anderson, Charles F Kirkvold, Peter Pisio: Method of recovering viscous petroleum from tar sand. Chevron Research Company, R L Freeland Jr, Edward J Keeling, November 30, 1976: US03994340 (275 worldwide citation)

Recovery of viscous petroleum such as from tar sands is assisted using a substantially vertical passage from the earth's surface which penetrates the tar sand and has extending therefrom a lateral hole containing a flow path isolated from the tar sand for circulating a hot fluid to and from the vert ...


2
Donald J Anderson, Charles F Kirkvold, Peter Pisio, John R Lishman: Recovering viscous petroleum from thick tar sand. Chevron Research Company, R L Freeland Jr, Edward J Keeling, November 30, 1976: US03994341 (255 worldwide citation)

Recovery of viscous petroleum such as from thick tar sands is assisted using a closed-loop flow path from the earth's surface through a substantial portion of the formation for conducting hot fluid to reduce the viscosity of the petroleum in the formation to develop a potential passage in the format ...


3
Peter Pisio, Charles F Kirkvold: System for recovering viscous petroleum from thick tar sand. Chevron Research Company, E J Keeling, R L Freeland Jr, April 26, 1977: US04019575 (245 worldwide citation)

Recovery of viscous petroleum such as from thick tar sands is assisted using a closed-loop flow path formed in a well by concentric casing and tubular members extending from the earth's surface through a substantial portion of the formation for conducting hot fluid to reduce the viscosity of the pet ...


4
Peter Pisio, Charles F Kirkvold: Arrangement for recovering viscous petroleum from thick tar sand. Chevron Research Company, Edward J Keeling, R L Freeland Jr, May 3, 1977: US04020901 (73 worldwide citation)

An arrangement is provided for recovering viscous oil from a tar sand formation having a large vertical dimension including a substantially vertical lined shaft extending through the tar sand formation. A first opening is formed in the lower portion of the shaft lining and at least one lateral hole ...


5
Donald J Anderson, Peter Pisio, Charles F Kirkvold: Method of recovering viscous petroleum from thick tar sand. Chevron Research Company, R L Freeland Jr, E J Keeling, February 22, 1977: US04008765 (25 worldwide citation)

Recovery of viscous petroleum such as from thick tar sands is assisted using a closed-loop flow path formed in a well by concentric casing and tubular members extending from the earth's surface through a substantial portion of the formation for conducting hot fluid to reduce the viscosity of the pet ...