The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 02, 2008
Filed:
Apr. 27, 2007
Yuji Arai, Amagasaki, JP;
Kunio Kondo, Sanda, JP;
Hisashi Amaya, Kyoto, JP;
Akihito Yamane, Amagasaki, JP;
Yuji Arai, Amagasaki, JP;
Kunio Kondo, Sanda, JP;
Hisashi Amaya, Kyoto, JP;
Akihito Yamane, Amagasaki, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
(1) A steel pipe that is expanded radially in a state wherein it was inserted in a well such as an oil well, characterized in that the non-uniform wall thickness ratio E(%) before expanding satisfies the following expression {circle around (1)}.0≦30/(1+0.018α)  {circle around (1)} Wherein α is the pipe expansion ratio (%) calculated by the following expression {circle around (2)}.α=[(inner diameter of the pipe after expanding−inner diameter of the pipe before expanding)/inner diameter of the pipe before expanding]×100  {circle around (2)} (2) A steel pipe that should be expanded radially in a state wherein it is inserted in a well, such as an oil well, characterized in that the eccentric non-uniform wall thickness ratio is 10% or less. When the embedding-expanding method is performed with use of the steel pipe of (1) or (2), lowering of collapse strength of the expanded steel pipe is prevented and bending thereof can be decreased.