Quadruple RAM BOP

Abstract

A blowout preventer having a body, a main bore in the body, and rams that project into the main bore. The rams can be shear rams for shearing a tubular in the main bore, pipe rains for sealing around a tubular in the main bore, or sealing rams that seal across the main bore. The rams are in cavities formed in the body, the cavities are formed such that more than two rams can be disposed at the same elevation in the body thereby reducing the overall height of the blowout preventer stack.

What is claimed is: 
     
         1 . A blowout preventer for use with a wellhead assembly comprising:
 a body having axis;   a main bore in the body that is substantially parallel with the axis;   at least three cavities in the body at substantially the same axial location in the body and that intersect the main bore; and   a ram in each of the cavities.   
     
     
         2 . The blowout preventer of  claim 1 , wherein one of the rams comprises a pipe ram and one of the rams comprises a shear ram. 
     
     
         3 . The blowout preventer of  claim 1 , wherein each ram comprises a block having a forward side facing the main bore, a rearward side distal from the forward side, lateral sides extending between the forward and rearward sides and that are in a plane that is generally parallel with the axis. 
     
     
         4 . The blowout preventer of  claim 3 , wherein the ram block further comprises an upper side that extends between upper terminal ends of the forward and rearward sides. 
     
     
         5 . The blowout preventer of  claim 4 , wherein a seal is provided on the ram that extends along the upper side and the forward side. 
     
     
         6 . The blowout preventer of  claim 1 , wherein the axial location comprises a first axial location, wherein the cavities comprise a first set of cavities, and wherein a second set of cavities are formed in the body at a second axial location that is spaced axially away from the first axial location. 
     
     
         7 . The blowout preventer of  claim 6 , further comprising rams in the second set of cavities. 
     
     
         8 . The blowout preventer of  claim 1 , wherein four cavities are provided in the body at the same axial location, and wherein rams in two of the cavities comprise shear rams and rams in two of the cavities comprise pipe rams. 
     
     
         9 . The blowout preventer of  claim 1 , further comprising an upper connection that selectively couples to a riser and a lower connection that selectively couples to a wellhead housing. 
     
     
         10 . A blowout preventer for use with a wellhead assembly comprising:
 a body having an axis and a main bore aligned with the axis;   cavities in the body that extend radially outward from the main bore and along paths that range up to about 90° from one another; and   a ram assembly in each of the cavities.   
     
     
         11 . The blowout preventer of  claim 10 , wherein the cavities are at about the same axial location along the axis. 
     
     
         12 . The blowout preventer of  claim 10 , wherein each ram assembly comprises a block and a forward portion that selectively extends into the main bore. 
     
     
         13 . The blowout preventer of  claim 12 , wherein each ram assembly further comprises a forward side on which the forward portion is attached, a rearward side opposite the forward side, and lateral sides that extend between the forward and rearward sides, wherein the lateral sides are substantially flat. 
     
     
         14 . The blowout preventer of  claim 10 , further comprising an actuator for urging each ram assembly from the cavity towards the main bore. 
     
     
         15 . A blowout preventer stack selectively coupled with a wellhead assembly and comprising:
 an axis in the stack;   a plurality of blowout preventers stacked on one another and each having a body;   a main bore projecting axially through each of the bodies and that is substantially parallel with the axis;   cavities in each body at substantially the same axial location in the body and that intersect the main bore and that extend along paths that range up to about 90° from one another; and   rams in the cavities.   
     
     
         16 . The blowout preventer stack of  claim 15 , wherein each ram comprises a block having a forward side facing the main bore, a rearward side distal from the forward side, lateral sides extending between the forward and rearward sides and that are in a plane that is generally parallel with the axis. 
     
     
         17 . The blowout preventer stack of  claim 15 , wherein the cavities in each body are at about the same axial location along the axis. 
     
     
         18 . The blowout preventer stack of  claim 15 , wherein four cavities are provided in each body at the same axial location, and wherein rams in two of the cavities comprise shear rams and rams in two of the cavities comprise pipe rams. 
     
     
         19 . The blowout preventer stack of  claim 15 , further comprising an upper connection that selectively couples to a riser and a lower connection that selectively couples to a wellhead housing. 
     
     
         20 . The blowout preventer stack of  claim 15 , wherein each ram comprises a block and a forward portion that selectively extends into the main bore.