Method of abandoning a well

Abstract

A method of abandoning a well, said well comprising at least two concentric conduits ( 28,30 ) defining a main bore and at least one annular chamber ( 40 ) there between, comprising the steps of providing a perforation in one or more of the conduits, pumping out the fluiti from the annular chamber and/or main bore to create a fluiti-free void, inserting sealing material in the annular chamber and/or main bore to seal it/them. There is also provided an apparatus for abandoning a well having at least two concentric conduits defining at least one annular chamber there between, the apparatus including a pump ( 50 ) and a perforation forming device ( 42 ).

1 . A method of abandoning a well, said well comprising at least two concentric conduits defining a main bore and at least one annular chamber there between, comprising the steps of: 
 providing a perforation in one or more of the conduits,    pumping out the fluid from the annular chamber and/or main bore to create a fluid-free void,    inserting sealing material in the annular chamber and/or main bore to seal it/them.    
   
   
       2 . A method according to  claim 1  wherein sealing material is inserted into the bore of the innermost conduit to seal it.  
   
   
       3 . A method according to  claim 1  wherein a tube is introduced and the fluid pumped to the surface through the tube.  
   
   
       4 . A method according to  claim 1  wherein the fluid is pumped downwards into the well.  
   
   
       5 . A method according to  claim 1  wherein the sealing material is inserted in the annular chamber before the fluid from the annular chamber is pumped out.  
   
   
       6 . A method according to  claim 1  wherein perforations are formed in at least one conduit and the annular chamber or chambers are sealed at one level in the well, and then further perforations are formed in a greater number of conduits at a second higher level in the well.  
   
   
       7 . A method according to  claim 6  wherein after forming the further perforations in the greater number of conduits at the second higher level, the annular chambers between these conduits are sealed.  
   
   
       8 . An apparatus for abandoning a well having at least two concentric conduits defining at least one annular chamber there between, the apparatus including a pump and a perforation forming device.  
   
   
       9 . An apparatus according to  claim 8  wherein there is also provided a valve unit capable of securing itself in an innermost conduit and including a check valve to permit the one-way flow of fluids.  
   
   
       10 . An apparatus according to  claim 8  wherein the pump and the valve unit are separable.  
   
   
       11 . An apparatus according to  claim 8  wherein there is provided a cable on which the pump may be lowered into the well.  
   
   
       12 . An apparatus according to  claim 8  wherein the perforation forming device is incorporated into the pump.  
   
   
       13 . An apparatus according to  claim 8  wherein the perforation forming device is incorporated into the valve unit.  
   
   
       14 . An apparatus according to  claim 8  wherein the cable includes a through bore.  
   
   
       15 . (canceled)