CEMENTING FLOAT SHOE

• US 3,759,281 A
• Filed: 11/19/1971
• Issued: 09/18/1973
• Est. Priority Date: 11/19/1971
• Status: Expired due to Term

• Current Assignee: Persiu Falcuta
• Original Assignee: Persiu Falcuta
• Inventors: Falcuta, Persiu
• Primary Examiner(s): Schwadron, Martin P.
• Assistant Examiner(s): Gerard, Richard
• Application Number:
  US05/200,348
• Time in Patent Office: 669 Days
• Field of Search: 137/68-71,540.11,433,519.5 166/224,225 175/235,318
• US Class Current: 137/68.17
• CPC Class Codes: F16K 17/40 with a fracturing member, e.g. fracturing diaphragm, glass, fusible joint valves opening on surplus pressure F16K17/14
• CPC Class Codes: Y10T 137/1677 Pressure causes pin or bolt to destruct
• CPC Class Codes: Y10T 137/7436 Float rigid with valve
• CPC Class Codes: Y10T 137/7873 Ball valves

Abstract

A float valve for a well casing comprises a fixed ring or seat threaded onto the wall of a generally cylindrical shell and receiving a tubular boss to which the ball cage is threaded. The cylindrical boss and the cage are anchored on the shoe casing by a plurality of shear pins so that they may be dislodged by the application of downward over-pressure in the event the valve becomes plugged. A fluted ring is provided beyond the aforementioned fixed ring to intercept the boss and thereby retain the valve while permitting fluid circulation through the flutes.

Claims

1. A float shoe for a well string, comprising an elongated tubular casing adapted to be threaded at an upper end on to said string;

a fixed annular seat anchored in said casing at a location above the lower end thereof;

a float-valve assembly in force-meeting relationship with said fixed seat and including a detachable annular seat normally received in said fixed seat and having an upwardly facing shoulder bearing against a downwardly facing shoulder formed on said fixed seat, said detachable seat being axially ejectable from said fixed seat in a downward direction, a cage affixed to said detachable seat and extending downwardly therefrom, and a float valve received in said cage;

shear pins detachably anchoring said assembly to said casing with said detachable seat received in said fixed seat, said detachable seat being formed with outwardly projecting longitudinal ribs beyond said cage; and

a fluted ring anchored in said casing at a location below said assembly when said assembly is held in place by said shear pins, said ring clearing said cage upon dislodgement of said assembly and having inwardly extending ledges intercepting said ribs for supporting said assembly within said casing and permitting fluid flow past said assembly through the flutes of said ring.