Blowout Preventer with Blade Including Multiple Profiles

Abstract

A blowout preventer may be used for shearing a tubular positioned in a bore extending through the blowout preventer. The blowout preventer includes a first shear ram movable towards the tubular, the first shear ram including a first blade, and the first blade including an outer cutting profile and an inner cutting profile. The blowout preventer further includes a second shear ram positioned opposite the first shear ram with respect to the tubular and movable towards the tubular, the second shear ram including a second blade, and the second blade including the outer cutting profile and the inner cutting profile. The outer cutting profile includes blade portions on opposite sides of the inner cutting profile, and positioned between an angle of about 120 degrees and an angle of about 140 degrees from each other.

1 . A blowout preventer for shearing a tubular positioned in a bore extending through the blowout preventer, the blowout preventer comprising:
 a first shear ram movable towards the tubular, the first shear ram comprising a first blade, the first blade comprising an outer cutting profile and an inner cutting profile;   a second shear ram positioned opposite the first shear ram with respect to the tubular and movable towards the tubular, the second shear ram comprising a second blade, the second blade comprising the outer cutting profile and the inner cutting profile; and   the outer cutting profile comprising blade portions on opposite sides of the inner cutting profile, and positioned between an angle of about 120 degrees and an angle of about 140 degrees from each other.   
     
     
         2 . The blowout preventer of  claim 1 , further comprising:
 a first insert removably connectable to the first shear ram;   wherein the first insert comprises at least a portion of the first blade.   
     
     
         3 . The blowout preventer of  claim 1 , wherein the first blade portion and the second blade portion of the outer cutting profile are positioned at an angle of about 120 degrees from each other. 
     
     
         4 . The blowout preventer of  claim 1 , wherein the outer cutting profile comprises a V-profile. 
     
     
         5 . The blowout preventer of  claim 1 , wherein the inner cutting profile comprises a diameter. 
     
     
         6 . The blowout preventer of  claim 5 , wherein the inner cutting profile comprises the diameter of about 8.5 in (21.6 cm). 
     
     
         7 . The blowout preventer of  claim 1 , wherein the inner cutting profile comprises at least one projection to define an initial contact point of the first and second blades with the tubular when the first and second shear rams move towards the tubular. 
     
     
         8 . The blowout preventer of  claim 7 , wherein the at least one projection comprises a first projection and a second projection such that at least one of the first projection and the second projection defines the initial contact point of the first and second blades with the tubular. 
     
     
         9 . The blowout preventer of  claim 7 , wherein the at least one projection comprises a third projection, and wherein tips of the first projection, the second projection, and the third projection are positioned on a diameter with respect to each other. 
     
     
         10 . The blowout preventer of  claim 9 , wherein the diameter comprises about 8.5 in (21.6 cm). 
     
     
         11 . The blowout preventer of  claim 7 , wherein the at least one projection comprises a radiused edge. 
     
     
         12 . The blowout preventer of  claim 1 , wherein the first and second blades are symmetrical such that a line of symmetry extends through the inner cutting profile of the first blade. 
     
     
         13 . The blowout preventer of  claim 1 , wherein the tubular comprises a plurality of tubulars comprising a drill pipe joint, a casing joint, and a tool joint such that the blowout preventer is configured to shear each of the drill pipe joint, the casing joint, and the tool joint. 
     
     
         14 . A method for operating a blowout preventer to shear a tubular within the blowout preventer, comprising:
 moving a first blade comprising a first outer cutting profile and a first inner cutting profile toward the tubular, the first outer cutting profile comprising a first blade portion and a second blade portion, each on opposite sides of the first inner cutting profile, and positioned between an angle of about 120 degrees and an angle of about 140 degrees from each other;   moving a second blade comprising a second outer cutting profile and a second inner cutting profile toward the tubular within the blowout preventer, the second outer cutting profile comprising a third blade portion and a fourth blade portion, each on opposite sides of the second inner cutting profile, and positioned between an angle of about 120 degrees and an angle of about 140 degrees from each other; and   shearing the tubular with the first blade and the second blade.   
     
     
         15 . The method of  claim 14 , wherein the tubular comprises a plurality of tubulars comprising a drill pipe joint, a casing joint, and a tool joint, wherein the shearing the tubular comprises at least one of:
 shearing the drill pipe joint by moving the first blade and the second blade towards the drill pipe joint;   shearing the casing joint by moving the first blade and the second blade towards the casing joint; and   shearing the tool joint by moving the first blade and the second blade towards the tool joint.