Title:
Subsurface well control apparatus
United States Patent 3375874
Inventors:
Cherry, Vonner R.
Cox, Roland O.
Application Number:
US44780365A
Publication Date:
04/02/1968
Filing Date:
04/13/1965
Assignee:
OTIS ENG CO
Primary Class:
Other Classes:
166/148, 166/321
International Classes:
E21B33/12; E21B34/10; E21B34/12; E21B34/00
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