Bismuth and cement method of abandoning a well and means of real time verification of the bismuth and cement placement process

Abstract

A method of abandoning a well, where the well is at least a length of tubing, and a first annulus outside the tubing, comprising the steps of puncturing a hole or holes in the tubing, the holes in the tubing giving access to the first annulus immediately outside the tubing, heating the inside of the tubing, depositing bismuth in proximity to the region inside the tubing which is heated, such that bismuth melts, the quantity of bismuth being sufficient that a first portion of the bismuth remains in the tubing, while a second portion of bismuth flows through the holes in the tubing into the first annulus, where it flows to the non-heated section allowing the bismuth to cool and solidify to form a plug in the tubing and the annulus

1 . A method of abandoning a well, the well comprising at least a length of tubing, and a first annulus outside the tubing, comprising:
 puncturing a hole or holes in the tubing, the holes in the tubing giving access to the first annulus immediately outside the tubing;   heating the inside of the tubing; and   depositing bismuth in proximity to the region inside the tubing which is heated, such that bismuth melts, the quantity of bismuth being sufficient that a first portion of the bismuth remains in the tubing, while a second portion of bismuth flows through the holes in the tubing into the first annulus, where it flows to the non-heated section allowing the bismuth to cool and solidify to form a plug in the tubing and the annulus.   
     
     
         2 . A method according to  claim 1  wherein the well further comprises a second tube concentric with the length of tubing, and a further annulus outside the second tube, and including the steps of
 puncturing a hole or holes in the second tube, the holes in the tubing giving access to the further annulus immediately outside the second tube 
 the quantity of bismuth being sufficient that a first portion of the remains in the tubing, while a second portion of bismuth flows through the holes in the tubing into the first annulus, while a third portion of bismuth flows through the holes in the second tube into the further annulus. 
 
     
     
         3 . (canceled) 
     
     
         4 . A method of abandoning a well according to  claim 1 , wherein the holes are punctured by mechanical means. 
     
     
         5 . A method of abandoning a well according to  claim 1 , wherein the holes are punctured by explosive means. 
     
     
         6 . A method of abandoning a well according to  claim 1 , wherein the holes are punctured by a laser means 
     
     
         7 . A method of abandoning a well according to  claim 1 , wherein the holes are punctured by thermite plasma means 
     
     
         8 . A method of abandoning a well according to  claim 1 , wherein the inside of the tubing is heated using a thermite heat source 
     
     
         9 . A method of abandoning a well according to  claim 1 , wherein the inside of the tubing is heated using an electrical heat trace heat source 
     
     
         10 . A method of abandoning a well according to  claim 1 , wherein the bismuth is deposited in the forms of bismuth beads deposited on the heat source. 
     
     
         11 . A method of abandoning a well according to  claim 10 , wherein the bismuth beads are conveyed in a container above the heat source. 
     
     
         12 . A method of abandoning a well according to  claim 10 , wherein the bismuth beads are deposited from surface using gravity 
     
     
         13 . A method of abandoning a well according to  claim 1 , wherein the bismuth is cast onto the heating element and conveyed into the well by the heating element. 
     
     
         14 . A method of abandoning a well according to  claim 1 , including the steps of
 puncturing additional holes into the tubing above the region the bismuth has solidified circulating cement inside the tubing and a first annulus and/or further annuli above the solidified bismuth.   
     
     
         15 . A method of abandoning a well according to  claim 14 , wherein there is included the step of
 deploying a disposable choke inside the tubing before cement is circulated to restrict the flow of cement to ensuring the controlled placement of the cement.   
     
     
         16 . A method of abandoning a well according to  claim 15 , wherein the disposable choke is gravity deployed. 
     
     
         17 . A method of abandoning a well according to  claim 15 , wherein the disposable choke is deployed on a metal clad fibre optic cable. 
     
     
         18 . A method of abandoning a well according to  claim 15 , wherein the choke area is formed by the OD of the chokeand ID of the tubing. 
     
     
         19 . A method of abandoning a well according to  claim 14  wherein a disposable fibre optic cable provides distributed sensor feedback of the cement process. 
     
     
         20 . A method of abandoning a well according to  claim 19  wherein the disposable fibre optic cable provides distributed temperature feedback of the cement process. 
     
     
         21 . A method of abandoning a well according to  claim 19  wherein at least one disposable battery powered acoustic transmitters is combined with the metal clad fibre optic cable. 
     
     
         22 . A method of abandoning a well according to  claim 21  wherein the disposable fibre optic cable in combination with disposable acoustic transmitters the disposable fibre optic cable provides distributed acoustic feedback of the cement process, providing both cement bond and cement density measurements. 
     
     
         23 . A method of abandoning a well according to  claim 19  wherein the tool housing containing the acoustic transmitter could include a heater and bismuth to make a metal-to-metal seal inside the housing once the cement has set. 
     
     
         24 . A method of abandoning a well according to  claim 19  wherein the fibre optic cable has a shear release mechanism to enable the fibre optic cable above the cement to be retrieved back to surface. 
     
     
         25 . A choke according to  claim 15 , the choke comprising a hollow tube having discs disposed long the length of the inside of the hollow tube, such that the tube allows a through flow which is restricted by the discs, the hollow tube being suspended by a fibre optic cable terminating at the lower end of the hollow tube, the fibre optic cable including sensors. 
     
     
         26 . A choke according to  claims 25  wherein the sensors include acoustic sensors, and acoustic transmitters are included in the choke.