Method and apparatus for cleaning oil wells

Claim 3

The method of claim 1 wherein said tool is initially set so that raising the tool allows the fluid deposited into the well hole to flow through the tool into the liner and lowering the tool prevents fluid from flowing through the tool or between the tool and liner thereby forcing the fluid through the liner perforations.

Claim 4

The method of claim 2 wherein the tool is converted while in the well hole so that raising the tool draws fluid into the liner through the vacuum created in the liner and tool and lowering the tool forces fluid through the tool and up the pipe string to the surface.

Claim 5

The method of claim 3 wherein the tool is converted while in the well hole by lowering a standing valve on a wire line to engage a check valve on the tool so as to lock the check valve into open position.

Claim 6

The method of claim 4 additionally including the steps of retrieving the standing valve with a wire line and raising the tool to the surface, the tool allowing fluid from above to flow therethrough when raised so as to come up dry.

Claim 7

A tool for cleaning, unplugging and unclogging the perforations in the casing liner set in a well hole oil producing zone comprising: means for centering the tool in the liner; a first tubular section mounted above said centering means and having at least one opening in the sidewall thereof; a second tubular section mounted above said first tubular section and having at least one opening disposed in the sidewall thereof, resilient annular cup means mounted on said section above and below said opening; a check valve mounted above said second tubular section preventing fluid below the valve within said sections from passing upwardly when the tool is lowered, and allowing fluid deposited above the valve to pass downwardly when said tool is raised in the well hole; said cup means forcing fluid in the liner below said means through said opening in said first tubular section into said first tubular section and upwardly out of said opening in said second tubular section and through the perforations in the liner when said tool is lowered in the well hole; a standing valve selectively mounted above said check valve for converting said tool while in the well hole from producing pressure in the liner below said tool to producing a vacuum in the liner below said tool, including means for rendering said check valve inactive; and said cup means and standing valve creating a vacuum therebelow after conversion of said tool, allowing fluid to pass through said perforations into the liner when said tool is raised, and forcing fluid through said openings in said first tubular section into said tool and upwardly through said standing valve to the surface when said tool is lowered.

Claim 8

A tool for cleaning, unplugging and unclogging the perforations in the casing liner set in a well hole oil producing zone comprising: means for centering the tool in the liner; a first tubular section mounted above said centering means and having at least one opening in the sidewall thereof; a second tubular section mounted above said first tubular section and having at least one opening disposed in the sidewall thereof, resilient annular cup means mounted on said section above and below said opening; a check valve mounted above said second tubular section preventing fluid below the valve within said sections from passing upwardly when the tool is lowered, and allowing fluid deposited above the valve to pass downwardly when said tool is raised in the well hole; said cup means forcing fluid in the liner below said means through said opening in said first tubular section into said first tubular section and upwardly out of said opening in said second tubular section and through the perforations in the liner when said tool is lowered in the well hole; a standing valve selectively mounted above said check valve for converting said tool while in the well hole from producing pressure in the liner below said tool to producing a vacuum in the liner below said tool, including means for rendering said check valve inactive; and said cup means and standing valve creating a vacuum therebelow after conversion of said tool, allowing fluid to pass through said perforations into the liner when said tool is raised, and forcing fluid through said openings in said first tubular section into said tool and upwardly through said standing valve to the surface when said tool is lowered.

Claim 9

The tool of claim 6 aDditionally including liner inner wall scratching means carried by said tool.

Claim 10

The tool of claim 6 additionally including retriever means selectively attached to said standing valve and a wire line for lowering said retriever means and standing valve down to said tool to convert said tool, said retriever means being lowered into the hole and releasing said standing valve upon engagement with said tool and thereafter withdrawn from the well hole, said retriever means being lowered by said wire line back into said hole upon completion of said cleaning operation so as to attach said standing valve and thereafter be withdrawn therewith from the well hole, whereby said tool may be raised dry.

Claim 11

The tool of claim 6 wherein said cup means comprises a plurality of individual sealing cups, each of said cups preventing fluid flow in one direction upon movement of said tool and cups relative to the perforated liner, the cups first adjacent said opening in said second tubular section oriented so as to prevent fluid pumped through said opening from flowing between said tool and the liner so as to force the fluid through the liner perforations and into the formation.

Claim 12

The tool of claim 9 wherein at least the lowermost cup is oriented so as to prevent fluid below said cups from flowing upwardly between said tool and said liner when said tool is lowered.

Claim 13

The tool of claim 10 wherein at least the uppermost cup is oriented so as to prevent fluid deposited above the tool from flowing downwardly between said tool and liner when said tool is lowered.