04399865 is referenced by 14 patents and cites 8 patents.

A downhole concentric tubing string is disclosed for use in distributing steam, or other hot fluids, to separated subsurface formations along a well bore. The apparatus includes elements for deflecting the steam from one string into the annulus of a cased well for injection through openings into the formation, elements for conducting the steam in another of the concentric string to a second set of openings for injection into another portion of the formation, and elements for isolating and separating the two separate injection intervals.

Title
Concentric steaming string downhole apparatus
Application Number
6/284748
Publication Number
4399865
Application Date
July 20, 1981
Publication Date
August 23, 1983
Inventor
Stanley O Hutchison
Bakersfield
CA, US
Glenn W Anderson
Oildale
CA, US
Agent
Edward J Keeling
G W Wasson
Assignee
Chevron Research Company
CA, US
IPC
E21B 43/24
E21B 36/00
E21B 33/126
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