Process and device for separation of pipes or columns fixed in the ground
AssigneeWirth Maschinen-und Bohrgerate-Fabrik GmbH
InventorsPeter Heinrichs, Fritz Tibussek
Life of this patent
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Abstract
To separate relatively long upright pipes (13) which have a relatively large diameter, the lower end thereof being fixed in the ground, in particular of support legs (3) of an off-shore oil bore or conveying platform (100), a cutting unit is lowered down into the pipe (13) to a separation point. The cutting unit (40) acts gradually from the inside across the periphery to the internal periphery of the pipe (13) and cuts through the pipe (13) by removing metal. A bore tool head (60) is mounted upstream of the cutting unit (40), viewed from the lowering position, and is used to bore out material in the pipe such as ocean bed or concrete.
Claims27
A method for separating an upright pipe having a lower end embedded in and supported by anchoring material extending into and about the lower end to maintain the pipe in an upright position with the pipe having an open upper end extending above the anchoring material, said method comprising the acts of:
- inserting a cutting and augering unit into said pipe through said open upper end, and lowering said unit toward a separation point along said pipe below a top surface of the anchoring material;
- augering and removing the anchoring material as said cutting and augering unit approaches said separation point;
- separating said upright pipe by advancing a cutting portion of said cutting and augering unit from the inside of said pipe radially through to the outside of said pipe;
- and,
- signaling that said separation is complete.
A device for separating an upright pipe having a lower end embedded in and supported by anchoring material extending into and about the lower end to maintain the pipe in an upright position said device comprising:
- an auger for augering anchoring material having a bit end and a fastening end, said auger being positioned within said pipe, with said bit end below said fastening end and adjacent said anchoring material;
- a cutting unit positioned above and supporting said auger at said fastening end, said cutting unit including at least one radially extendable cutting arm for separating the pipe;
- a mechanical piston/cylinder drive positioned above and supporting said cutting unit said drive actuating said cutting arm and being pivotally connected thereto;
- an extendable hollow shaft positioned above and supporting said mechanical drive;
- a supply line for pressurizing said mechanical piston/cylinder drive;
- and,
- a signal mechanism for determining when the cutting arm has cut through the pipe so that said mechanical drive can be depressurized.
A cutting apparatus for separating a leg of an offshore oil rig platform, the leg being a longitudinally extending pipe with a lower end driven into and extending below the ocean floor and an upper end projecting above the ocean surface, the leg being supported by anchoring material extending into and around the lower end of the pipe, and the leg having a desired separation point below the ocean floor within the anchoring material, the apparatus comprising:
- an auger for loosening and displacing anchoring material having a bit end and a fastening end, said auger positioned within said pipe, with said bit end below said fastening end and adjacent said anchoring material;
- a cutting unit positioned above and supporting said auger at said fastening end, said cutting unit including at least one radially extendable cutting arm for separating the pipe;
- a mechanical piston/cylinder drive positioned above and supporting said cutting unit, said drive actuating said cutting arm and being pivotally connected thereto;
- an extendable hollow shaft positioned above and supporting said mechanical drive;
- a supply line for pressurizing said mechanical drive;
- and,
- a signaling mechanism for determining when the cutting arm has cut through said pipe so that said mechanical drive can be depressurized.
A method of separating a leg of an offshore oil rig platform, the leg being a longitudinally extending pipe with a lower end driven into and extending below the ocean floor and an upper end projecting above the ocean surface, the leg being supported by anchoring material extending into and around the lower end of the pipe, and the leg having a desired separation point below the ocean floor within the anchoring material, the method comprising the steps of:
- inserting a cutting and augering unit into the upper end of the pipe, lowering said cutting and augering unit toward the desired separation point near the lower end of the pipe, and rotating said cutting and augering unit as said unit is being lowered;
- displacing the anchoring material using an augering portion of said cutting and augering unit as said unit rotates and descends until said unit reaches the desired separation point;
- extending a cutting portion of said cutting and augering unit radially from the inside of the pipe as said cutting and augering unit is rotated, causing separation of the pipe;
- and, signaling that said separation is complete.
Dependencies are inferred from the claim text.