04373582 is referenced by 49 patents and cites 11 patents.

This invention relates to a self-contained circulation sub which may be operated upon control from the surface. It may be in the shape of a short section of drill collar and utilizes a sleeve valve to cover the circulation ports. Upon reception of an acoustic signal from the surface, a control valve directs fluid from the pipe bore onto a pressure face on the sleeve valve. The sleeve valve then moves down and exposes the circulation ports thereby allowing drilling fluids to pass from its interior to its exterior.

Title
Acoustically controlled electro-mechanical circulation sub
Application Number
6/218602
Publication Number
4373582
Application Date
December 22, 1980
Publication Date
February 15, 1983
Inventor
Terry V Jones
Houston
TX, US
Daniel P Postler
Houston
TX, US
John M Bednar
Houston
TX, US
Agent
E T Wheelock
Assignee
Exxon Production Research Co
TX, US
IPC
E21B 34/16
E21B 34/08
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