Multi-stage blowout preventer and method of using same

Abstract

A blowout preventer includes a housing, a ram block carrier which moves within the housing, and one or more ram blocks configured to be placed within the ram block carrier. The ram block carrier may include an opening, an upper shelf within the opening configured to hold an upper ram block, and a lower shelf within the opening configured to hold a lower ram block. The housing may include a central bore, cavities on both sides of the bore, and openings which allow ram blocks to access a pipe within the bore.

1 . A ram block carrier, comprising:
 an opening;   an upper shelf within the opening configured to hold an upper ram block; and   a lower shelf within the opening configured to hold a lower ram block.   
     
     
         2 . The ram block carrier of  claim 1 , further comprising an extension tab configured to be attached to a carrier hydraulic actuator for moving the ram block carrier. 
     
     
         3 . The ram block carrier of  claim 1 , further comprising a rack configured to contact a pinion for moving the ram block carrier. 
     
     
         4 . The ram block carrier of  claim 1 , further comprising a detent button configured to be pressed in response to the ram block carrier moving, inserted into an upper groove in response to the ram block carrier being in an upper position, and inserted into a lower groove in response to the ram block carrier being in a lower position. 
     
     
         5 . A housing of a blowout preventer, comprising:
 a bore;   a first cavity on a side of the bore;   a second cavity on another side of the bore; and   inside walls, adjacent to the first and second cavities, each comprising an opening which allows a ram block to access the bore,   wherein the first cavity and the second cavity are each configured to receive a ram block carrier that is movable within the housing.   
     
     
         6 . The housing of  claim 5 , further comprising outside walls, adjacent to the first and second cavities, each comprising:
 a pinion which is configured to contact the ram block carrier and to move the ram block carrier within each cavity; and   an indicator which is configured to indicate a position of the ram block carrier.   
     
     
         7 . The housing of  claim 5 , wherein a length of each of the cavities is at least two times greater than a length of each of the openings. 
     
     
         8 . The housing of  claim 5 , further comprising outside walls, adjacent to the first and second cavities, each comprising:
 an upper detent groove; and   a lower detent groove,   wherein the upper detent groove is configured to receive a detent button of the ram block carrier in response to the ram block carrier being in an upper position and the lower detent groove is configured to receive the detent button of the ram block carrier in response to the ram block carrier being in a lower position.   
     
     
         9 . The housing of  claim 5 , further comprising outside walls, adjacent to the first and second cavities, each comprising a hole configured to receive a ram block hydraulic actuator for moving one or more ram blocks towards the bore. 
     
     
         10 . A blowout preventer, comprising:
 a housing;   a ram block carrier configured to move within the housing; and   one or more ram blocks configured to be placed within the ram block carrier.   
     
     
         11 . The blowout preventer of  claim 10 , further comprising a carrier hydraulic actuator for moving the ram block carrier within the housing. 
     
     
         12 . The blowout preventer of  claim 10 , further comprising:
 a piston; and   an actuating stem attached to the piston,   wherein the ram block carrier comprises an extension tab which is attached to the actuating stem for moving the ram block carrier.   
     
     
         13 . The blowout preventer of  claim 10 , further comprising a carrier mechanical actuator for moving the ram block carrier within the housing. 
     
     
         14 . The blowout preventer of  claim 10 , further comprising:
 a pinion installed on the housing;   a rotating pin for rotating the pinion; and   a rack installed on the ram block carrier and contacting the pinion,   wherein the ram block carrier moves within the housing in response to the pinion rotating.   
     
     
         15 . The blowout preventer of  claim 10 , further comprising an indicator for monitoring a position of the ram block carrier. 
     
     
         16 . The blowout preventer of  claim 10 , wherein the one or more ram blocks comprises a plurality of ram blocks. 
     
     
         17 . The blowout preventer of  claim 10 , further comprising:
 a central bore extending through the housing;   another ram block carrier configured to move within the housing; and   one or more ram blocks configured to be placed within the other ram block carrier,   wherein the ram block carrier is on one side of the central bore and the other ram block carrier is on another side of the central bore.   
     
     
         18 . The blowout preventer of  claim 17 , wherein the one or more ram blocks of the ram block carrier comprises a plurality of ram blocks, and the one or more ram blocks of the other ram block carrier comprises another plurality of ram blocks. 
     
     
         19 . The blowout preventer of  claim 18 , wherein each of the plurality of ram blocks of the ram block carrier corresponds to one of the other plurality of ram blocks of the other ram block carrier. 
     
     
         20 . The blowout preventer of  claim 10 , further comprising a ram block hydraulic actuator configured to move the one or more ram blocks. 
     
     
         21 . The blowout preventer of  claim 10 , further comprising:
 a piston;   an exterior actuating rod attached to the piston;   an interior actuating rod attached to the piston; and   a connector on an end of the interior actuating rod for making contact with and moving the one or more ram blocks.   
     
     
         22 . The blowout preventer of  claim 10 , further comprising a ram block mechanical actuator configured to move the one or more ram blocks. 
     
     
         23 . The blowout preventer of  claim 21 , further comprising:
 a mechanical actuator stem; and   a push rod threadedly engaged to the mechanical actuator stem,   wherein in response to rotating the mechanical actuator stem, the push rod pushes the exterior actuating rod into the piston and the interior actuating rod, and the one or more ram blocks are moved.   
     
     
         24 . The blowout preventer of  claim 10 , further comprising one or more doors attached to the housing by fasteners. 
     
     
         25 . The blowout preventer of  claim 10 , wherein the one or more doors are circular doors configured to be opened by removing the fasteners. 
     
     
         26 . The blowout preventer of  claim 25 , wherein the one or more circular doors comprise a covering member, a top plate, and a bottom plate, and pressure within the blowout preventer is released in response to an opening of the covering member. 
     
     
         27 . A method of operating a blowout preventer, the method comprising:
 moving a ram block carrier within the blowout preventer; and   moving a ram block of the ram block carrier towards a bore of the blowout preventer.   
     
     
         28 . The method of  claim 27 , wherein the moving of the ram block carrier comprises injecting hydraulic fluid into a carrier hydraulic actuator, and the moving of the ram block comprises injecting hydraulic fluid into a ram block hydraulic actuator. 
     
     
         29 . The method of  claim 27 , wherein the moving of the ram block carrier comprises rotating a pin on an outside of the blowout preventer and attached to a pinion on an inside the blowout preventer, and moving the ram block comprises rotating an actuator stem on an outside of the blowout preventer. 
     
     
         30 . The method of  claim 27 , wherein the moving of the ram block carrier comprises moving the ram block carrier into an upper position in order to use a lower ram block installed on a lower shelf of the ram block carrier. 
     
     
         31 . The method of  claim 30 , wherein the moving of the ram block carrier further comprises moving the ram block carrier into a lower position in order to use an upper ram block installed on an upper shelf of the ram block carrier. 
     
     
         32 . The method of  claim 31 , wherein the moving of the ram block carrier into the upper position causes a connector of a ram block actuator to engage with the lower ram block, and the moving of the ram block carrier into the lower position causes a connector of a ram block actuator to engage with the upper ram block.