Blowout preventers and methods of use

• US 20080286534A1
• Filed: 05/05/2008
• Published: 11/20/2008
• Est. Priority Date: 04/25/2006
• Status: Active Grant

• Current Assignee: National Oilwell Varco LP (NOV, Inc.)
• Original Assignee: National Oilwell Varco LP (NOV, Inc.)
• Inventors: Springett, Frank Benjamin, Brugman, James D.
• Granted Patent: US 7,814,979 B2
• Time in Patent Office: Days
• US Class Current: 428/192
• CPC Class Codes: E21B 33/063 for shearing drill pipes cutting of wireline E21B29/04
• CPC Class Codes: Y10T 428/24777 Edge feature
• CPC Class Codes: Y10T 83/0581 Cutting part way through from opposite sides of work
• CPC Class Codes: Y10T 83/0596 Cutting wall of hollow work
• CPC Class Codes: Y10T 83/75 With or to tool guide
• CPC Class Codes: Y10T 83/9447 Shear type

Abstract

Methods and apparatuses for severing a wellbore tubular, the apparatus, in certain aspects, including: a first member movable toward a tubular to be severed; a second member with a second blade disposed opposite to the first member and movable toward the tubular; a first blade on the first member having a projection projecting from a center of a blade body with point structure on the projection for puncturing the tubular and cutting surfaces on the projection for cutting the tubular; and cutting surfaces, as needed, on the blade body adjacent the projection for cutting the tubular.

Claims

1-20. -20. (canceled)

21. A blade useful in a method for severing a tubular, the blade comprising

a blade body,

a projection projecting from the blade body,

a point structure on the projection for contacting and puncturing a tubular,

projection cutting surfaces on the projection defining the point structure and for cutting the tubular,

the projection cutting surfaces at an acute angle to each other, and

the point structure having a point projecting sufficiently from the blade body so that the point can contact the tubular and enter into the tubular before any other part of the blade body contacts the tubular.

22. The blade of claim 21 wherein the projection is coated with a low friction coating.

23. The blade of claim 21 wherein the blade has a top and a bottom, the top and the bottom coated with a low friction coating.

24. The blade of claim 21 wherein the blade has a top and a bottom, and the projection cutting surfaces slope down from the top to the bottom.

25. The blade of claim 21 wherein the projection cutting surfaces are at an angle to each other ranging between 30 degrees and 90 degrees.

26. The blade of claim 21 wherein the tubular is useful in wellbore operations and is one of casing, drill pipe, drill collar, and tool joint.

27. A pair of blades for severing a tubular, the pair of blades comprising

the first blade comprising a first blade body, a first projection projecting from the first blade body, a first point structure on the first projection for contacting and puncturing a tubular, first projection cutting surfaces on the first projection defining the first point structure and for cutting the tubular,

the first projection cutting surfaces at an acute angle to each other,

the first point structure having a point comprising a first point, the first point structure projecting sufficiently from the first blade body so that the first point contacts the tubular and enters into the tubular before any other part of the first blade body contacts the tubular,

a second blade movable toward the first blade,

the second blade comprising a second blade body, a second projection projecting from the second blade body, a second point structure on the second projection for contacting and puncturing the tubular, second projection cutting surfaces on the second projection defining the second point structure and for cutting the tubular,

the second projection cutting surfaces at an acute angle to each other,

the second point structure having a point comprising a second point, the second point structure projecting sufficiently from the second blade body so that the second point contacts the tubular and enters into the tubular before any other part of the second blade body contacts the tubular, and

the first projection disposed above and opposite the second projection.

28. The pair of blades of claim 27 wherein the two point structures are located to contact the tubular substantially simultaneously and enter into the tubular substantially simultaneously.

29. The pair of blades of claim 27 further comprising

the first blade and the second blade positioned for maintaining a position of the tubular so that puncturing and severing of the tubular can proceed with the first blade and the second blade both puncturing and severing the tubular.