Weatherford/dmc, Inc.

Edmond D Chammas

Edwin C Lewis, Ii

An improved chemical cutting apparatus for cutting objects in well bores such as, for example, tubing in the bore of an oil or gas well. The apparatus is properly positioned relative to the object to be cut by means of a casing collar locator, and an igniter is fired which in turn activates a gas generator. Pressure from the gas generator axially displaces a slidable piston having suitable anchor means connected thereto. Movement of the piston causes the anchor means to move into contact with the object to be cut, thereby anchoring the apparatus relative to such object. Pressure generated in the gas generator is communicated through a passageway in the slidable piston and forces a chemical cutting agent into a chamber containing a reactant. The reaction of the chemical cutting agent and reactant increases the pressure and temperature within the chamber thereby displacing along the axis a second slidable piston. Movement of the second slidable piston exposes radial exhaust orifices thereby allowing the reacting elements in the chamber to escape with great velocity and to contact the object to be cut in incendiary fashion. The improvement according to the present invention resides in the provision of pressure relief means intermediate the gas generator and the chemical cutting agent for diverting a portion of the gas away from the chemical cutting agent so as to reduce the likelihood of release of the chemical cutting agent in the event the apparatus is mishandled or malfunctions.

Chemical cutting apparatus

A chemical cutting apparatus and method for cutting objects in well bores such as, for example, tubing in the bore of an oil or gas well. The apparatus is properly positioned and an igniter is fired activating a gas generator. The resultant pressure axially displaces a slidable piston having one or more wedges pivotally connected thereto. Movement of the piston anchors the apparatus relative to the object to be cut. The pressure is then communicated through the slidable piston forcing a chemical cutting agent into a chamber containing a reactant. The resultant reaction increases the pressure and temperature thereby displacing along the axis a second slidable piston. Movement of the second slidable piston exposes radial exhaust orifices thereby allowing the reacting elements in the chamber to escape with great velocity and to contact the object to be cut. The second slidable piston is then held firmly in place. The chamber containing the reactant and the member having the radial exhaust orifices are made of a suitable material which will not enter into the reaction.

Chemical cutting apparatus for use in wells

A chemical cutting apparatus and method for cutting objects in well bores such as, for example, tubing in the bore of an oil or gas well. The apparatus is properly positioned relative to the object to be cut by means of a casing collar locator and an igniter is fired, which in turn activates a gas generator. Pressure from the gas generator axially displaces a slidable piston having one or more wedges pivotally connected thereto. Movement of the piston both pivots and extends the wedge, thereby bringing the wedge into contact with the object to be cut and anchoring the apparatus relative to the object to be cut. The pressure generated in the gas generator is communicated through a passageway in the slidable piston and forces a chemical cutting agent into a chamber containing a reactant. The reaction of the chemical cutting agent and reactant increases the pressure and temperature within the chamber thereby displacing along the axis a second slidable piston. Movement of the second slidable piston exposes radial exhaust orifices thereby allowing the reacting elements in the chamber to escape with great velocity and to contact the object to be cut.

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Houston, TX, United States of America

Edmond D Chammas