Thermite method of abandoning a well

Abstract

A method of conveying materials or tools into a well, the well including a plurality of lengths of concentric tubing, comprising the step of permitting at least one cartridge to free-fall under gravity into the well. No line may be connected to the cartridge. The cartridge is selected from a group of cartridges which may comprise, a cartridge including thermite, hermetically sealed from well fluids, a cartridge including low temperature alloy, hermetically sealed from well fluids, a cartridge formed from low temperature alloy, a cartridge including a detonator triggered by impact, a cartridge including a detonator triggered by an electronic or mechanical clock, a cartridge formed from tungsten carbide, a bridge plug cartridge including slips to retain the bridge plug in a position against the wall of well tubing, a thermal barrier material, or a shock absorber that absorbs energy from subsequent cartridges being dropped.

1 . A method of conveying materials or tools into a well, the well including a plurality of lengths of concentric tubing, comprising the steps:
 permitting at least one cartridge to free-fall under gravity into the well.   
     
     
         2 . The method according to  claim 1 , wherein no line is connected to the cartridge. 
     
     
         3 . The method according to  claim 1 , wherein the cartridge is selected from a group of cartridges which may comprise:
 a cartridge including thermite, hermetically sealed from well fluids;   a cartridge including low temperature alloy, hermetically sealed from well fluids;   a cartridge formed from low temperature alloy;   a cartridge including a detonator triggered by impact;   a cartridge including a detonator triggered by an electronic or mechanical clock;   a cartridge formed from tungsten carbide;   a bridge plug cartridge including slips to retain the bridge plug in a position against the wall of well tubing;   a thermal barrier material; and   a shock absorber that absorbs energy from subsequent cartridges being dropped.   
     
     
         4 . The method according to  claim 1 , wherein the cartridges are automatically fed into the top of the well. 
     
     
         5 . A cartridge for use in a well, adapted to be allowed to free fall under gravity through the well, wherein the cartridge comprises a housing hermetically sealed from well fluids. 
     
     
         6 . The cartridge according to  claim 5 , wherein the cartridge houses either thermite, a low temperature alloy, or a heat-shielding material. 
     
     
         7 . The cartridge according to  claim 5  wherein for the bottom of the cartridge being pointed. 
     
     
         8 . The cartridge according to  claim 7 , wherein the top of the cartridge has a concave shape corresponding to the pointed bottom end. 
     
     
         9 . The cartridge according to  claim 5  further comprising a bridge plug which includes slips which are capable of being activated to retain the bridge plug in a position against the wall of well tubing. 
     
     
         10 . The cartridge according to  claim 5  further comprising a collapsible section which absorbs shock from items which fall on top of the cartridge. 
     
     
         11 . The cartridge according to  claim 5  further comprising which includes a detonator capable of triggering a thermite reaction. 
     
     
         12 . The cartridge according to  claim 11 , wherein the cartridge includes an electronic or mechanical clock to trigger the detonator. 
     
     
         13 . The cartridge according to  claim 11 , wherein the detonator is triggered by the action of the cartridge being brought to a halt in the well after being allowed to free fall down the well. 
     
     
         14 . The cartridge according to  claim 11 , wherein the detonator is triggered by the action of another cartridge being dropped on it from above. 
     
     
         15 . A cartridge for use in a well, formed predominantly of low temperature alloy or of tungsten carbide.