Well abandonment tool and method of use
AssigneeWinterhawk Well Abandonment Ltd.
InventorDale Kunz
Life of this patent
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Abstract
A tool is provided for use in closing and sealing the cased bore of a well to be abandoned. The tool is run into the bore, the tool having a stack of pleated rings slidably mounted on a tubular mandrel. The tool is engaged with the casing and a charge of hot asphaltic sealant is discharged from a conveyed container to flood the stack and tool annulus. The stack is compressed axially to partly flatten and radially expand the rings to frictionally engage the surrounding casing, the rings and sealant sealing the bore. Further, the rings can expand the heated casing for sealing casing/cement interfaces. The sealant solidifies and creates an impermeable mass sealing against surfaces of the mandrel, stack and casing.
Claims25
A downhole tool conveyed into a casing of a well on a string of pipe extending downhole into the cased well from surface, comprising:
- a tubular mandrel releasably connected to the string of pipe;
- a stack of pleated rings slidably mounted on the mandrel;
- a first compression plate slidably mounted on the mandrel at one end of the stack;
- a second compression plate releasably mounted on the mandrel at the other end of the stack with the stack of pleated rings sandwiched therebetween;
- a radially expandable first locking assembly releaseably slidable on the mandrel and adjacent the first compression plate, the first locking assembly selectively actuable to expand into locking engagement with the casing to thereby positionally fix the first compression plate and first end of the stack, the mandrel and second compression plate being axially movable relative to the first compression plate to compress the stack;
- a radially expandable second locking assembly, releaseably secured to the mandrel adjacent the second compression plate for co-movement axially with the mandrel to forcibly compress the stack between the first and second compression plates for axially compressing the pleated rings and radially expanding the pleated rings into engagement with the casing;
- and
- frangible connection between the second locking assembly and the mandrel so that they move together until a resistive force by the compressed stack reaches a pre-determined extent, wherein the second locking assembly is released from the mandrel and is actuated to expand into locking engagement with the casing to thereby lock the compressed stack in compression.
A method for blocking fluid communication along a well at a sealing location, the well completed with casing, the method comprising:
- conveying a tool having stack of pleated steel rings downhole to the sealing location in the casing and forming an annular space therebetween;
- filling the stack and annular space with a charge of sealant;
- and then
- axially compressing the stack to expand the ring radially to engage the casing.
Dependencies are inferred from the claim text.