3800277 is referenced by 52 patents and cites 8 patents.

Downhole operations within a well borehole are controlled by utilization of various communication channels within the borehole. The conditions within these communication channels are detected downhole and are applied to downhole comparators. Whenever the condition with a communication channel is changed by an operator on the earth's surface so that it exceeds a reference value, the comparator provides an output signal. A control gate selectively combines the output signals from the comparators to provide control signals for utilization in the control of the downhole operations.

Title
Method and apparatus for surface-to-downhole communication
Application Number
05/272,838
Publication Number
3800277
Application Date
July 18, 1972
Publication Date
March 26, 1974
Inventor
Harrell John W
Sexton James H
Patton Bobbie J
Agent
Hager Jr George W
Gaboriault A L
Assignee
Mobil Oil Corporation
IPC
E21b 41/00
G01v 01/40
G01V 03/18
G01V 03/34
E21B 44/00
E21B 47/12
E21B 47/18
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