03994341 is referenced by 255 patents and cites 9 patents.

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.

Title
Recovering viscous petroleum from thick tar sand
Application Number
5/627306
Publication Number
3994341
Application Date
October 30, 1975
Publication Date
November 30, 1976
Inventor
John R Lishman
Calgary
CA
Peter Pisio
Calgary
CA
Charles F Kirkvold
Calgary
CA
Donald J Anderson
Newport Beach
CA, US
Agent
Edward J Keeling
R L Freeland Jr
Assignee
Chevron Research Company
CA, US
IPC
E21B 43/24
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