03994340 is referenced by 275 patents and cites 9 patents.

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.

Title
Method of recovering viscous petroleum from tar sand
Application Number
5/627305
Publication Number
3994340
Application Date
October 30, 1975
Publication Date
November 30, 1976
Inventor
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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