Method and device for joining oilfield tubulars
AssigneeShell Research Limited
InventorsAlan Edgar John Bliault, Francis Alexander Cumming, Mark Seth Laws
Life of this patent
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Abstract
A method for joining well and other oilfield tubulars by amorphous bonding comprises the steps of positioning a body of amorphous material (16) between adjacent and surfaces of a pair of oilfield tubulars (3, 4) that are to be joined and using induction heating to melt the amorphous material and create on cooling a metallurgical bond between the tubulars (3, 4). Throughout the heating and bonding process the tubulars (3, 4) are fixed in axial alignment with each other using clamp means which include a mandrel (1) which is inserted into the interior of the tubulars (3, 4) so that the bonding process can be performed in a sealed chamber (17, 18) which is filled with an inert gas.
Claims7
A method for joining oilfield tubulars, the method comprising the steps of:
- providing a first oilfield tubular having an end surface and an inner surface, and a second oilfield tubular having an end surface and an inner surface;
- placing the end surface of said first tubular adjacent to the end surface of said second tubular;
- positioning a body of welding material between said adjacent end surfaces;
- arranging a welding device near said adjacent end surfaces and said welding material, which device is equipped with an internal mandrel, an external clamp mechanism, an external seal mechanism, and an inert gas injection mechanism;
- inducing the external clamp mechanism to press the end surfaces against the body of welding material such that the end surfaces of the tubulars are maintained in an accurately defined axially aligned position relative to each other;
- activating the external seal mechanism to create a sealed external chamber that surrounds the end surfaces of the tubulars and the body of amorphous material;
- activating the inert gas injection mechanism to fill the sealed external chamber with an inert gas;
- heating the body of welding material such that it melts and on cooling a metallurgical bond is created between the end surfaces of the tubulars;
- allowing the joined tubulars to cool down;
- releasing the clamp and seal mechanisms;
- and
- removing the joined tubulars from the welding device;
- characterized in that the welding device is an amorphous bonding device which is equipped with an induction heating coil, that the body of welding material is a body of amorphous material which is heated by the induction coil and that the mandrel is equipped with axially spaced seals that are expanded against the inner surfaces of the oilfield tubulars to form a sealed internal annular chamber inside the tubulars which is filled with an inert gas during the step of inducing the heating coil to melt the amorphous material.
A device for joining oilfield tubulars comprising:
- an external clamp mechanism and a mandrel that is insertable into the interior of tubulars, each said tubular having an end surface and wherein the end surfaces are placed adjacent to each other, to press the end surfaces against a body of welding material between the tubulars such that the end surfaces are maintained in an accurately defined axially aligned position relative to each other;
- an external seal mechanism for creating a sealed external chamber that surrounds the end surfaces and the body of welding material;
- an inert gas injection mechanism for filling the sealed external chamber with inert gas;
- means for heating the body of welding material such that it melts and on cooling a metallurgical bond is created between the end surfaces of the tubulars;
- and
- means for moving the tubulars into and from the device;
- characterized in that the device is an amorphous bonding device which is equipped with an induction heating coil and that the mandrel is equipped with axially spaced seals that are in use expanded against the inner surfaces of the oilfield tubulars to form a sealed internal annular chamber inside the tubulars during the amorphous bonding process.
Dependencies are inferred from the claim text.