Method and apparatus for catching darts and other dropped objects
AssigneeBlackhawk Specialty Tools, LLC
InventorsJ. CHRISTOPHER JORDAN, BRAD GROESBECK
Life of this patent
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Abstract
A dart or other dropped object having a rigid nose is dropped or launched down hole, typically during cementing operations, until it lands on a resilient seat within a dart catcher receptacle. By increasing a pressure differential across the landed dart to a predetermined amount, the dart extrudes through the seat and passes into a ported catcher sub. The seat member can be constructed of engineered composite material that does not yield in response to passage of the dart and returns to its original size following such passage.
Claims13
A dart catcher apparatus comprising:
- a) a dart having a rigid nose defining an outer diameter;
- and
- b) a housing having a central through bore, wherein a portion of said through bore has a reduced internal diameter defining a seat having an inner diameter smaller than said outer diameter of said nose, and wherein said seat comprises resilient material adapted to expand to allow passage of said rigid dart nose in response to a predetermined axial force acting on said dart.
A method for catching dropped objects in a well comprising:
- a) introducing a dart having a rigid nose defining an outer diameter into said well;
- b) receiving said dart on a seat in a dart catcher assembly, wherein said dart catcher assembly comprises a housing having a central through bore defining said seat, and wherein said seat has an inner diameter smaller than said outer diameter of said dart nose and is at least partially constructed of resilient material adapted to deform to allow passage of said rigid dart nose in response to a predetermined axial force;
- c) applying axial force to said dart;
- and
- d) passing said dart through said seat.
Dependencies are inferred from the claim text.