Bismuth method of abandoning a well

Abstract

A well abandonment tool for deployment in a well tubing, comprising an upper section, including a connector to allow the tool to be deployed on slickline or wireline a housing including a chamber containing bismuth a receiver and processor, capable of receiving a signal from the surface to actuate a permanent sealing process a lower section, including a release means capable of releasing the upper section of the tool from a lower section of the tool a tubing cup seal capable to making a seal against the inside of the well tubing to contain moltenbismuth until it solidifies a tubing bridge plug or anchor capable of securing the tool inside the well tubing the tool also including a heat source capable of melting the bismuth to a flowable state, actuated by the receiver and processor such that when the tool has been secured in the well tubing, the bismuth melting process can be initiated, and the upper housing released from the lower housing to recover the upper housing, and bismuth being melted by the heating means and caused to flow into the well tubing above the tubing cup seal to form a plug.

1 . A well abandonment tool for deployment in a well tubing, comprising:
 an upper section, including, and
 a connector to allow the tool to be deployed on slickline or wireline, 
 a housing including a chamber containing bismuth, and 
 a receiver and processor, capable of receiving a signal from the surface to actuate a permanent sealing process; and 
   a lower section, including:
 a release means capable of releasing the upper section of the tool from a lower section of the tool, 
 a tubing cup seal capable to making a seal against the inside of the well tubing to contain molten bismuth until it solidifies, and 
 a tubing bridge plug or anchor capable of securing the tool inside the well tubing; 
   the tool also including a heat source capable of melting the bismuth to a flowable state, actuated by the receiver and processor;   such that when the tool has been secured in the well tubing, the bismuth melting process can be initiated, and the upper housing released from the lower housing to recover the upper housing, and bismuth being melted by the heating means and caused to flow into the well tubing above the tubing cup seal to form a plug.   
     
     
         2 . A tool according to  claim 1 , wherein the receiver is an acoustic receiver capable of receiving a coded acoustic signal from a transmitting tool. 
     
     
         3 . A tool according to  claim 1 , wherein the receiver receives electrical signals conducted by a wire connection from the surface. 
     
     
         4 . A tool according to  claim 1 , wherein the heat source is a housing containing thermite, provided with a ignitor and a battery pack to initiate a thermite reaction. 
     
     
         5 . A tool according to  claim 1 , wherein the heat source is an electric element. 
     
     
         6 . A tool according to  claim 1 , wherein the ignitor includes a secondary back up such as a timer in addition to the electrical wet connector. 
     
     
         7 . A tool according to  claim 1 , wherein the ignitor includes a secondary back up such as a hydrostatic pressure switch in addition to the electrical wet connector. 
     
     
         8 . A tool according to  claim 1 , wherein the ignitor includes a secondary low temperature alloy part which has to melt to operate a switch in addition to the electrical wet connector. 
     
     
         9 . A tool according to  claim 1 , wherein the bismuth in the retrievable running tool could provide the connecting means to the lower section, so when it melts the running tool is automatically released from the lower section. 
     
     
         10 . A tool according to  claim 1 , wherein a flux is provided, releasable together with the molten bismuth to improve the bonding of the bismuth to the steel tubulars and the top of the lower section. 
     
     
         11 . A tool according to  claim 1 , wherein bismuth beads are conveyed in a container above the heat source. 
     
     
         12 . A tool according to  claim 1 , wherein bismuth is cast around the heat source for deployment. 
     
     
         13 . A method of using a tool according to  claim 1 , including depositing bismuth beads on the heat source. 
     
     
         14 . A method of using a tool according to  claim 13 , wherein bismuth beads are deposited from surface using gravity. 
     
     
         15 . A method of operating in a well using a tool according to  claim 1 , including deploying multiple tools to produce multiple bismuth metal to metal seals placed on top of each other to make a metal to metal seal of unlimited length.