| 摘要 |
<p>766,231. Well casing apparatus. BAKER OIL TOOLS, INC. March 21, 1955 [April 2, 1954], No. 8165/55. Class 85. An apparatus for controlling the filling of a well casing during running in includes a tubular member, adapted to form part of a conduit string, having an elastic diaphragm member with an orifice therethrough to allow fluid to flow through said tubular member at a restricted rate. Between the tubular member 10 and upper end lower valve housings 31, 34 is an annulus 15 of cementitious material which supports the rubber diaphragm 21. As the conduit string is lowered in the well bore fluid flows up through the orifice 22 and by-passes a ball valve 32 pressed against lugs 33. When the running in stops the ball 32 is pushed down against a stop ring 38 which shears and fractures when sufficient pressure is applied to the fluid in the conduit string causing the ball 32 to be pushed through the orifice 22 until it engages lugs 35 when cement slurry can be pumped down the conduit string past the ball 32. After cementing return of fluid up the conduit is prevented by the ball 32 closing the orifice 22, the bore of a valve member 19 being such that with the thickness of the rubber 21 the ball 32 is unable to pass upwards through the orifice 22. The valve apparatus may be drilled out. In a modification the stop ring may be replaced by a disintegrateable cast iron plate 53, Fig. 7, having a passage 52 which limits the size to which the upward fluid stream can stretch the orifice 22, and if the pressure differential across the diaphragm 21 is too great it will push the rubber inside the passage 52 so decreasing it in size. The housings 31,34 and body 19 may be made of synthetic resin and the ball of cast iron. The housings 31,34 and the stop ring may be dispensed with and the ball 32 placed on top of the charge of cement slurry as it is being pumped down through the casing conduit.</p> |
