Method and apparatus for removing plugs from subsea equipment through the use of exothermic reacting chemicals

Abstract

A method of servicing subsea equipment comprising positioning a reaction chamber about the subsea equipment having a plug therein, wherein positioning the reaction chamber substantially isolates an area about the subsea equipment from an environment external to the reaction chamber, providing one or more reactants to the reaction chamber, and allowing a reaction to proceed between the reactants, wherein the reaction produces sufficient heat to eliminate the plug. A system for removing plugs from subsea equipment comprising a support vessel, a reaction chamber supported by the support vessel and positioned adjacent the subsea equipment having a plug therein, wherein the reaction chamber is configured to substantially isolate an area about the subsea equipment having a plug therein from an environment external to the reaction chamber, and one or more exothermically-reacting chemical reactants present within the reaction chamber.

1 . A method of servicing subsea equipment comprising:
 positioning a reaction chamber about the subsea equipment having a plug therein, wherein positioning the reaction chamber substantially isolates an area about the subsea equipment from an environment external to the reaction chamber;   providing one or more reactants to the reaction chamber; and   allowing a reaction to proceed between the reactants, wherein the reaction produces sufficient heat to eliminate the plug.   
   
   
       2 . The method of  claim 1 , wherein the subsea equipment comprises a pipeline, a tubular, a riser, a flow conduit, a valve, a collar, a joint, a connection, a fitting, a spool, a wellhead, a template, a manifold, an instrument, a gauge, or combinations thereof. 
   
   
       3 . The method of  claim 1 , wherein the plug comprises a hydrate. 
   
   
       4 . The method of  claim 1 , wherein the plug comprises a paraffin wax. 
   
   
       5 . The method of  claim 1 , wherein the reactants are provided to the reaction chamber by one or more hoses extending from a support vessel to the reaction chamber. 
   
   
       6 . The method of  claim 1 , wherein the reaction chamber comprises a material suitable for thermally insulating an interior portion of the reaction chamber from the environment external to the reaction chamber. 
   
   
       7 . The method of  claim 1 , wherein the reactants comprise ammonium chloride, sodium nitrite, hydrogen peroxide, ammonium hydroxide, hydrochloric acid, a metallic ion-containing solution, or combinations thereof. 
   
   
       8 . The method of  claim 1 , wherein the reactants comprise ammonium chloride and sodium nitrite. 
   
   
       9 . The method of  claim 1 , wherein the reaction between the reactants will yield non-toxic, non-environmentally hazardous end products. 
   
   
       10 . The method of  claim 1 , further comprising providing to within the reaction chamber a catalyst, a retarder, an accelerator, an additive, or combinations thereof. 
   
   
       11 . A method of servicing subsea equipment comprising:
 locating a plug in the subsea equipment;   substantially isolating an area about the subsea equipment containing the plug; and   heating the substantially isolated area to remove the plug.   
   
   
       12 . The method of  claim 11 , wherein the heating is produced via an exothermic reaction. 
   
   
       13 . The method of  claim 12 , further comprising monitoring a change in temperature about the subsea equipment. 
   
   
       14 . The method of  claim 13 , further comprising controlling the progression of the exothermic reaction in response to the monitoring the change in temperature. 
   
   
       15 . A system for removing plugs from subsea equipment comprising:
 a support vessel;   a reaction chamber supported by the support vessel and positioned adjacent the subsea equipment having a plug therein, wherein the reaction chamber is positioned to substantially isolate an area about the subsea equipment having a plug therein from an environment external to the reaction chamber; and   one or more exothemmically-reacting chemical reactants present within the reaction chamber.   
   
   
       16 . The system of  claim 15 , further comprising a one or more conduits extending between the support vessel and the reaction chamber, wherein the one or more conduits supply the one or more chemical reactants to the reaction chamber. 
   
   
       17 . The system of  claim 15 , wherein the subsea equipment comprises a pipeline, a tubular, a riser, a flow conduit, a valve, a collar, a joint, a connection, a fitting, a spool, a wellhead, a template, a manifold, an instrument, a gauge, or combinations thereof. 
   
   
       18 . The system of  claim 16 , further comprising a pump coupled to the one or more flow conduits. 
   
   
       19 . The system of  claim 16 , further comprising one or more remotely operated vehicles to position the reaction chamber adjacent the subsea equipment having a plug therein. 
   
   
       20 . The system of  claim 16 , further comprising means for locating the plug in the subsea equipment.