Assembly and Method for Monitoring Position of Blowout Preventer Rams

Abstract

The present disclosure generally relates to an assembly and method for monitoring the position of one or more opposing rams in a ram-type blowout preventer (“BOP”) during opening and closing operations. In particular, a BOP includes a vertical bore extending through the body, a ram cavity intersecting the bore, and a port located below the ram cavity. A sensor assembly is locatable in the port and is configured to monitor the position of at least one opposing ram contained in the BOP. At least one of the rams includes a detection feature on a lower surface of the ram which is distinguishable from the rest of the ram body, other features of the BOP, and any debris in the bore of the BOP. The detection feature is detectable by the sensor assembly. The detection feature may include a visual indicator.

What is claimed is: 
     
         1 . A ram blowout preventer (“BOP”) assembly, comprising:
 a body comprising a vertical bore extending through the body, a ram cavity intersecting the bore, and a port located below the ram cavity; 
 a pair of opposing rams movable laterally into and out of the BOP vertical bore; and 
 a sensor assembly located in the port and configured to monitor the position of at least one opposing ram. 
 
     
     
         2 . The assembly of  claim 1 , wherein each opposing ram comprises a detection feature located on a lower surface of the ram and configured to be detected by the sensor assembly. 
     
     
         3 . The assembly of  claim 2 , wherein the detection feature comprises a visual indicator. 
     
     
         4 . The assembly of  claim 2 , wherein the detection feature comprises a radio frequency identification (“RFID”) tag. 
     
     
         5 . The assembly of  claim 1 , wherein the sensor assembly is configured to be calibrated depending on a velocity of sound of a fluid in the vertical bore. 
     
     
         6 . The assembly of  claim 1 , wherein the sensor assembly is configured to monitor the position of each opposing ram during movement of each ram. 
     
     
         7 . The assembly of  claim 1 , further comprising another port configured to provide for fluid communication with the vertical bore. 
     
     
         8 . The assembly of  claim 7 , wherein the another port is a choke or kill port. 
     
     
         9 . The assembly of  claim 1 , comprising multiple sensors located in the port configured to monitor the position of each opposing ram. 
     
     
         10 . The assembly of  claim 1 , where the sensor assembly is powered by a power source local to the blowout preventer assembly. 
     
     
         11 . The assembly of  claim 1 , wherein the opposing rams are each one of a shear ram, a pipe ram, variable-bore ram, blind shear ram, or a blind ram. 
     
     
         12 . The assembly of  claim 1 , wherein the sensor is configured to be retrofitted to the port. 
     
     
         13 . A blowout preventer (“BOP”) ram detection assembly for detecting the position of a ram in a BOP assembly, the detection assembly comprising:
 a ram moveable within the BOP assembly and comprising a detection feature located on a lower surface of the ram; 
 a sensor assembly locatable in the BOP assembly and configured to detect the position of the ram by detecting the detection feature. 
 
     
     
         14 . The assembly of  claim 13 , wherein the detection feature comprises a visual indicator. 
     
     
         15 . The assembly of  claim 13 , wherein the detection feature comprises a radio frequency identification (“RFID”) tag. 
     
     
         16 . The assembly of  claim 13 , wherein the sensor is configured to be calibrated depending on a velocity of sound of a fluid in the vertical bore. 
     
     
         17 . The assembly of  claim 13 , wherein the sensor assembly is configured to monitor the position of the ram during movement of the ram. 
     
     
         18 . The assembly of  claim 13 , wherein the detection feature is retrofittable to the ram. 
     
     
         19 . The assembly of  claim 13 , further comprising a plurality of detection features. 
     
     
         20 . A method for monitoring the position of a rams within a blowout preventer (“BOP”), comprising:
 providing a detection feature on a lower surface of the ram; 
 providing a sensor assembly in a port located in the BOP below the ram; 
 moving the ram within the BOP; and 
 monitoring the position of the ram by detecting the detection feature with the sensor assembly.