Large bore auto-fill float equipment
An auto-fill type float collar assembly is provided. The float collar assembly of the present invention has at least one curved flapper-style valve, preferably constructed of composite, non-metallic material. Each flapper of the present invention has a substantially 90° range of motion, and is closed via a torsion spring. Each flapper is held in the open (or “auto-fill”), position via an external shifting mechanism passing around, rather than through, the central flow bore of the assembly. A floatable actuation ball can be run with the tool, or pumped downhole, in order to selectively actuate the assembly and close the flappers when desired.
1. A float assembly comprising:
a. an upper valve assembly having a body, a substantially cylindrical central flow bore extending therethrough and a flapper hingeably connected to said body;
b. a lower valve assembly having a body, a substantially cylindrical central flow bore extending therethrough aligned with the central flow bore of said upper valve assembly, and a flapper hingeably connected to said body;
c. a seat member disposed below said lower valve assembly, wherein said seat member travels in a direction parallel to the longitudinal axis of said aligned central flow bores;
d. a first retaining member having a first end and a second end, wherein said first end is connected to said seat member, and said second end is releasably joined with the flapper of said upper valve assembly when said flapper is in an open position; and
e. a second retaining member having a first end and a second end, wherein said first end is connected to said seat member, and said second end is releasably joined with the flapper of said lower valve assembly when said flapper is in an open position.
2. The float assembly of claim 1 , further comprising an actuation ball.
3. The float assembly of claim 2 , wherein said actuation ball is floatable.
4. The float assembly of claim 3 , wherein said actuation ball is constructed of a low-density phenolic material.
5. The float assembly of claim 3 , wherein said actuation ball is retained within said float assembly offset from the central axis of said aligned central flow bores.
6. The float assembly of claim 1 , wherein said valve assemblies are constructed of non-metallic material.
7. The float assembly of claim 1 , wherein said flappers are constructed of non-metallic material.
8. The float assembly of claim 1 , wherein said flappers each comprise a sealing surface and a non-sealing surface, and said non-sealing surface has a substantially convex shape.
9. The float assembly of claim 1 , wherein said flappers do not extend into said aligned central flow bores of said upper and lower valve assemblies when said flappers are in an open position.
10. The float assembly of claim 1 , wherein the hinge connection of said flapper of said upper valve assembly is out of phase with the hinge connection of said flapper of said lower valve assembly.
11. The float assembly of claim 10 , wherein said hinge connections are phased 180 degrees relative to one another.
12. The float assembly of claim 1 , wherein said seat member further comprises a substantially cylindrical body having a central flow bore extending therethrough, and a plurality of cooperating collets defining said seat.
13. The float assembly of claim 1 , further comprising a ball retaining member comprising:
a. a substantially cylindrical housing having a central flow bore extending therethrough;
b. a first transverse bore extending through said cylindrical housing;
c. a second transverse bore extending though said cylindrical housing, and in alignment with said first transverse bore; and
d. an elongate member extending through said first and second transverse bores across said central flow bore.
14. The float assembly of claim 13 , wherein said elongate member substantially bisects said central flow bore of said substantially cylindrical housing.