Remote plugging device for wells

Abstract

Remote cement plugging device ( 10 ) and method of use. The device has at least one means ( 60 ) for perforating at least one hole through a wall of a first well casing, and means to inject cement into an annulus between the inner well casing and a second well casing. The perforating means has at least one punch ( 65 ) actuated by compressed fluid (hydraulic, pneumatic) to form the hole(s), and thereafter the cement is delivered to the annulus between the inner and outer/intermediate casings to form the cement plug without the need to withdraw the device from the well casing.

1 . A remote plugging device for well operations, including at least one perforating means for perforating at least one hole through one or more casings of a well, and sealant injection means to inject sealant into an annulus between at least one of said one or more well casings and at least another of said well casings or a further well casing,
 wherein the perforating means includes at least one punch actuated by pressurised fluid to perforate the at least one hole, and thereafter the sealant is delivered to the annulus to form a sealant plug without need to withdraw the device from the one or more well casings.   
   
   
       2 . A device as claimed in  claim 1 , wherein the at least one punch is actuated by hydraulic or pneumatic pressure. 
   
   
       3 . A device as claimed in  claim 1 , wherein the at least one punch is extended and retracted by at least one double acting hydraulic or pneumatic piston. 
   
   
       4 . A device as claimed in  claim 1 , wherein the at least one punch is extended by hydraulic or pneumatic pressure and retracted by at least one resilient biasing means. 
   
   
       5 . A device as claimed in  claim 4 , wherein the at least one resilient biasing means includes at least one return spring. 
   
   
       6 . A device as claimed in  claim 1 , further including an outlet for sealant flow provided adjacent one of said at least one perforation means. 
   
   
       7 . A device as claimed in  claim 1 , further including at least one packer assembly whereby, when the device is inserted into the well, the at least one packer assembly is expanded to hold the device by pressure against a bore of the one or more well casings. 
   
   
       8 . A device as claimed in  claim 7 , including a fluid pressure accumulator provided within or proximate to a leading nose end of the device, the accumulator providing fluid pressure to the at least one packer assembly in the event of a failure of the device. 
   
   
       9 . A device as claimed in  claim 7 , wherein the at least one packer assembly is actuated by compressed or pressurised fluid. 
   
   
       10 . A device as claimed in  claim 9 , wherein the compressed or pressurised fluid is a hydraulic or pneumatic supply. 
   
   
       11 . A device as claimed in  claim 1 , wherein said at least one punch includes a breakaway shaft such that in the event of the punch being jammed in the hole, the punch can be positively retracted and a working end of the punch sheared off. 
   
   
       12 . A device as claimed in  claim 1 , wherein the at least one perforation means includes at least one resilient packer that absorbs shock induced on the punch when the casing is perforated. 
   
   
       13 . A device as claimed in  claim 12 , wherein the at least one resilient packer is formed of silicon rubber, rubber, nitrile, PEEK, UHMPE, HFPE, Nylon, other ultra high density synthetic material, or combinations thereof. 
   
   
       14 . A device as claimed in  claim 1 , wherein the perforation means is arranged to consecutively perforate holes through a multiplicity of well casings of said one or more well casings, and the sealant is arranged to be injected between at least one of said multiplicity of well casings and said further well casing. 
   
   
       15 . A method of sealing a well riser, including the steps of:
 a) inserting a remote plugging device into a riser;   b) supplying pressurised fluid to the plugging device;   c) perforating at least one hole through at least a first well casing wall using at least one respective punch actuated by the fluid; and   d) pumping a sealant through said at least one hole into an annulus between the first casing wall and an outer casing or an intermediate casing to form a plug seal.   
   
   
       16 . A method as claimed in  claim 15 , wherein the sealant contains cement or drilling mud. 
   
   
       17 . A method as claimed in  claim 15 , further including the step of retracting the at least one punch by hydraulic or pneumatic pressure, or by using at least one resilient biasing means. 
   
   
       18 . A method as claimed in  claim 15 , further including retaining at least one said at least one punch extended after perforating the casing. 
   
   
       19 . A method as claimed in  claim 15 , wherein:
 the step of perforating said at least one hole includes perforating through a multiplicity of well casing walls including said first well casing wall; and   the pumping step includes injecting the sealant into the annulus being between at least one of said multiplicity of well casing walls and said outer casing or said intermediate casing.   
   
   
       20 . A method as claimed in  claim 15 , further including utilising at least one packer to provide an initial seal between the device and the first well casing against hydrocarbon leakage prior to pumping sealant into the at least one hole.