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US 11,377,704 B2Granted
High performance material for coiled tubing applications and the method of producing the same
AssigneeTenaris Coiled Tubes, LLC
InventorsMartin Valdez, Jorge Mitre, Bruce A. Reichert
Life of this patent
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Abstract
Embodiments of the present disclosure are directed to coiled steel tubes and methods of manufacturing coiled steel tubes. In some embodiments, the final microstructures of the coiled steel tubes across all base metal regions, weld joints, and heat affected zones can be homogeneous. Further, the final microstructure of the coiled steel tube can be a mixture of tempered martensite and bainite.
Claims45
A method of forming and heat treating a tube for use as all or part of a coiled tubing string in a wellbore, the method comprising:
- bias welding a plurality of base metal steel strips together end to end to form a plurality of welded strips and longitudinally welding the plurality of strips to form a length of a tube, said length of the tube having one or more microstructures, wherein the plurality of base metal steel strips comprises a C—Mn steel, a B—Ti steel, or a Cr—Mo steel;
- and
- after forming the tube, performing a full body heat treatment along the length of the tube thereby modifying the one or more microstructures of the tube to create a treated tube with a final microstructure across all (a) base metal regions, (b) bias weld joints, and (c) heat affected zones, wherein performing the full body heat treatment along the length of the tube comprises at least one cycle each of austenitization, quenching, and tempering, wherein the at least one cycle each of the austenitization, quenching, and tempering comprises:
- an austenitization cycle performed at temperatures at or above 900 degrees C. to achieve dissolution of iron carbides in the tube and at or below an upper temperature threshold to limit a grain size to below 20 μm;
- a quenching cycle performed after the austenitization cycle to achieve an as-quenched microstructure comprising more than 90 volume % martensite;
- and
- a tempering cycle performed at temperatures between 550 degrees C. and 720 degrees C. to achieve a yield strength of the tube of greater than about 80 ksi;
- wherein the final microstructure of the treated tube comprises more than 90 volume % tempered martensite and 0 volume % to less than about 10 volume % bainite across the base metal regions, the bias weld joints, and the heat affected zones of the treated tube;
- wherein the final microstructure is homogeneous across all the base metal regions, the bias weld joints, and the heat affected zones;
- and
- wherein a yield strength of the treated tube is greater than about 80 ksi.
8 more elements
A method of forming and heat treating a tube for use as all or part of a coiled tubing string in a wellbore, the method comprising:
- bias welding a plurality of base metal steel strips together end to end to form a plurality of welded strips and longitudinally welding the plurality of strips to form a length of a tube, said length of the tube having one or more microstructures, wherein the plurality of base metal steel strips comprises a C—Mn steel, a B—Ti steel, or a Cr—Mo steel;
- and
- after forming the tube, performing a full body heat treatment along the length of the tube thereby modifying the one or more microstructures of the tube to create a treated tube with a final microstructure across all (a) base metal regions, (b) bias weld joints, and (c) heat affected zones, wherein performing the full body heat treatment along the length of the tube comprises at least one cycle each of austenitization, quenching, and tempering, wherein the at least one cycle each of the austenitization, quenching, and tempering comprises:
- an austenitization cycle performed at temperatures at or above 900 degrees C. to achieve dissolution of iron carbides in the tube and at or below an upper temperature threshold to limit a grain size to below 20 μm;
- a quenching cycle performed after the austenitization cycle to achieve an as-quenched microstructure comprising more than 90 volume % martensite;
- and
- a tempering cycle performed at temperatures between 550 degrees C. and 720 degrees C. to achieve a yield strength of the tube of greater than about 80 ksi;
- wherein the final microstructure of the treated tube comprises more than 90 volume % tempered martensite and 0 volume % to less than about 10 volume % bainite across the base metal regions, the bias weld joints, and the heat affected zones of the treated tube;
- wherein the final microstructure comprises a uniform distribution of fine carbides across all the base metal regions, the bias weld joints, and the heat affected zones;
- and
- wherein a yield strength of the treated tube is greater than about 80 ksi.
8 more elements
A method of forming and heat treating a tube for use as all or part of a coiled tubing string in a wellbore, the method comprising:
- bias welding a plurality of base metal steel strips together end to end to form a plurality of welded strips and longitudinally welding the plurality of strips to form a length of a tube, said length of the tube having one or more microstructures, wherein the plurality of base metal steel strips comprises a C—Mn steel, a B—Ti steel, or a Cr—Mo steel;
- and
- after forming the tube, performing a full body heat treatment along the length of the tube thereby modifying the one or more microstructures of the tube to create a treated tube with a final microstructure across all (a) base metal regions, (b) bias weld joints, and (c) heat affected zones, wherein performing the full body heat treatment along the length of the tube comprises at least one cycle each of austenitization, quenching, and tempering, wherein the at least one cycle each of the austenitization, quenching, and tempering comprises:
- an austenitization cycle performed at temperatures at or above 900 degrees C. to achieve dissolution of iron carbides in the tube and at or below 1000 degrees C. to limit a grain growth;
- a quenching cycle performed after the austenitization cycle to achieve an as-quenched microstructure comprising more than 90 volume % martensite;
- and
- a tempering cycle performed at temperatures between 550 degrees C. and 720 degrees C. to achieve a yield strength of the tube of greater than about 80 ksi;
- wherein the final microstructure of the treated tube comprises more than 90 volume % tempered martensite and 0 volume % to less than about 10 volume % bainite across the base metal regions, the bias weld joints, and the heat affected zones of the treated tube;
- wherein the final microstructure is homogeneous across all the base metal regions, the bias weld joints, and the heat affected zones;
- and
- wherein a yield strength of the treated tube is greater than about 80 ksi.
8 more elements
Dependencies are inferred from the claim text.