Abstract: 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 extends into the formation through the first lateral hole. A plurality of tubular members are positioned in the lateral hole to provide both a closed loop flow path for fluid flow from the shaft into and out of the hole out of contact with the formation and a separate flow path for production fluids from the hole into the shaft. A steam source is connected to the tubular members forming the closed loop flow path. A second opening is formed in the shaft lining and a steam injection conduit extends through the second opening into the formation. The steam injection conduit is connected to the steam source for injecting steam into the formation.

Abstract: 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 petroleum in the formation to develop a potential passage in the formation outside the flow path into which a drive fluid is injected to promote movement of the petroleum to the well for production up a production flow line extending up the interior of the tubular member.

Abstract: 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 petroleum in the formation to develop a potential passage in the formation outside the flow path into which a drive fluid is injected to promote movement of the petroleum to the well for production up a production flow line extending up the interior of the tubular member.

Abstract: 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 vertical passage to develop a potential flow path into which a drive fluid is injected to promote movement of the petroleum to a production position.

Abstract: 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 formation outside the flow path into which a drive fluid is injected to promote movement of the petroleum to a production position.