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US 3,981,360 AGranted
Well tubing drain
AssigneeCook Testing Co.
InventorAnil Marathe
Life of this patent
Estimating the term…
Abstract
A well tubing drain including a ported mandrel interposed in the tubing string of a pumping well, and a sleeve initially covering and sealing the mandrel ports, the sleeve being subject to a predetermined internal fluid pressure applied through the ports to shear a retainer pin and cause motion of the sleeve to open the ports.
Claims8
A drain for a well tubing string, comprising:
- a. a tubular mandrel member having at least one lateral port and adapted to be interposed between sections of a tubing string;
- b. an axially movable annular sleeve member surrounding the mandrel member;
- c. at least one shear pin connecting the sleeve and mandrel to restrain the sleeve against axial displacement;
- d. a pair of axially spaced annular seal means disposed between the sleeve member and mandrel member isolating and sealing the port each of the seal means presenting a pressure responsive area, and one being of larger diameter than the other whereby both pressure areas are operable to apply a shearing load in the same direction on the shear pin;
- e. and at least one of the seal means presenting an axially directed annular pressure responsive area, exposed to the interior of the mandrel member through the port and responsive to a predetermined fluid pressure in the mandrel member to exert a shearing load on the shear pin permitting downward axial displacement of the sleeve member to expose the port.
2 more elements
A drain for a well tubing string, comprising:
- a. a tubular mandrel member having means at its extremities for interposing the mandrel member between sections of the tubing string, said mandrel member having at least one radial drain port intermediate its ends;
- b. an axially movable annular sleeve member surrounding the mandrel member and adapted to occupy an upper position covering the drain port;
- c. at least one shear pin joining the sleeve member and mandrel member to secure the sleeve member in its upper position;
- d. seal means between the mandrel member and sleeve member above and below the drain port;
- e. and annular piston means associated with at least one of the seal means exposed to pressure in the mandrel member and tubing string and adapted to exert an axial force, when subjected to a predetermined pressure, to shear the shear pin and permit downward movement of the sleeve member to open said drain port.
2 more elements
Dependencies are inferred from the claim text.