preventereinheit to manufacture a seal between a casing in a bohrgestaenge under pressure the application of methods from computer science

摘要

1398017 Blow-out preventer ATLAS COPCO AB 31 July 1973 [7 Aug 1972] 36354/73 Heading E1F [Also in Divisions F2 and G3] A blow-out preventer 15 for establishing a seal between a casing tube 12 and a drill stem I comprises an elastic packing sleeve 17 rotatably mounted on the casing tube, the outside of which sleeve communicates with a pressure fluid source for applying pressure to the drill string, and a pressure control valve S1, Fig. 2, connected to both the pressure fluid source and the casing tube to control the packing sleeve pressure in response to the casing tube pressure by controlling pressure fluid drainage. The source pressure and casing tube pressure act on opposite sides of a spring-loaded piston 32 which seats in an opening 34 through which the pressure fluid source may be connected to drainage outlet D2.