Reduced Stress Ball Seat

摘要

A releasable ball seat with a capturing sleeve having a restricted diameter portion and an enlarged lower end opening. The restricted diameter portion is separated from the enlarged lower end opening to ensure that hoop stresses are not imposed upon the lower end opening.

主权项

1. A releasable ball seat for use in a tool within a wellbore to capture and release a ball, the ball seat comprising:
a capturing sleeve formed of a material that is sufficiently rigid to allow a ball to be captured upon a seating surface therein but plastically deformable to release the ball in response to an overpressure, the capturing sleeve having:
an upper portion having a ball opening and which presents a seating surface upon which a ball will rest when captured and a lower end;a restricted diameter central portion at the lower end of the tapered upper portion; anda flared portion below the restricted diameter central portion, the flared portion extending between the restricted diameter portion and an enlarged diameter lower opening.