Systems and methods for cutting a tubular member

Abstract

A closure device for cutting a tubular member includes a housing, and a cutting member disposed in the housing, wherein the cutting member is coupled to a heating element, wherein the cutting member is configured to transfer heat to a tubular member from the heating element to cause a loss of mechanical integrity of the tubular member as the cutting member physically engages the tubular member.

What is claimed is: 
     
         1 . A closure device for cutting a tubular member, comprising:
 a housing; and   a cutting member disposed in the housing, wherein the cutting member is coupled to a heating element;   wherein the cutting member is configured to transfer heat to a tubular member from the heating element to cause a loss of mechanical integrity of the tubular member as the cutting member physically engages the tubular member.   
     
     
         2 . The closure device of  claim 1 , wherein the cutting member is configured to unequally distribute a thermal flux from the heating element to the tubular member along a partial circumference of the tubular member. 
     
     
         3 . The closure device of  claim 1 , wherein the cutting member is configured to transfer heat to a tubular member from the heating element using thermal conduction when the cutting member physically engages the tubular member. 
     
     
         4 . The closure device of  claim 1 , further comprising a retaining member frangibly coupling the heating element to the cutting member. 
     
     
         5 . The closure device of  claim 1 , wherein the heating element comprises an induction heating element. 
     
     
         6 . The closure device of  claim 1 , wherein the heating element forms a cutting edge of the cutting member. 
     
     
         7 . The closure device of  claim 6 , further comprising a thermal insulator disposed between the heating element and the cutting member. 
     
     
         8 . The closure device of  claim 1 , further comprising a power supply connected to the heating element and configured to store and selectably transfer energy to the heating element. 
     
     
         9 . A closure device for cutting a tubular member, comprising:
 a housing;   a heating element disposed in the housing; and   a cutting member slidably disposed in the housing;   wherein the heating element is configured to unequally distribute a thermal flux along a circumference of the tubular member when the cutting member physically engages the tubular member.   
     
     
         10 . The closure device of  claim 9 , wherein the cutting member is configured to transfer heat to a tubular member from the heating element using thermal conduction when the cutting member physically engages the tubular member. 
     
     
         11 . The closure device of  claim 9 , wherein the closure device comprises a ram blowout preventer and the cutting member comprises a ram block. 
     
     
         12 . The closure device of  claim 11 , further comprising:
 a telescoping member extending between a bonnet and a slidable piston of the blowout preventer, wherein the telescoping member is configured to extend and retract as the piston is displaced through the blowout preventer; and   a power cable electrically connected with the heating element, wherein the power cable is disposed about the telescoping member.   
     
     
         13 . The closure device of  claim 12 , wherein the bonnet comprises a recess extending therein, and the telescoping member extends between the recess and the slidable piston. 
     
     
         14 . The closure device of  claim 9 , further comprising a power supply connected to the heating element and configured to store and selectably transfer energy to the heating element. 
     
     
         15 . The closure device of  claim 14 , wherein the power supply comprises a capacitor array. 
     
     
         16 . The closure device of  claim 14 , further comprising:
 a sensor disposed in the housing and configured to detect physical engagement between the cutting member and the tubular member; and   a controller connected to the sensor and power supply, wherein the controller is configured to cause the power supply to transfer energy to the heating element in response to receiving a signal from the sensor indicating physical engagement between the cutting member and the tubular member.   
     
     
         17 . The closure device of  claim 9 , wherein the heating element comprises an inductive heating element. 
     
     
         18 . A method for cutting a tubular member, comprising:
 engaging an engagement portion of a tubular member with a cutting member;   energizing a heating element;   transferring heat from the heating element to the engagement portion of the tubular member via thermal conduction between the cutting member and the tubular member; and   physically cutting the tubular member with the cutting member.   
     
     
         19 . The method of  claim 18 , wherein the engagement portion extends along only a portion of the circumference of the tubular member. 
     
     
         20 . The method of  claim 18 , further comprising unequally distributing a thermal flux along a circumference of the tubular member. 
     
     
         21 . The method of  claim 18 , further comprising physically engaging the tubular member with the heating element, wherein the heating element is coupled to the cutting member. 
     
     
         22 . The method of  claim 18 , further comprising frangibly decoupling the heating element from the cutting member in response to the heating element fusing to the tubular member.