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:
Jun. 18, 2002
Filed:
Nov. 03, 2000
Richard W. DeLange, Kingwood, TX (US);
Ed Evans, Spring, TX (US);
Richard Griffin, Houston, TX (US);
Grant Prideco, LP, The Woodlands, TX (US);
Abstract
An oilfield tubular string A comprising a plurality of elongate joints having one or both ends threaded. The joints may be connected by a coupling including a generally sleeve shaped coupling body having a tapered upstream thread profile and a tapered downstream thread profile for threaded engagement with a mating profile of a respective joint. The coupling body includes a low stress flex groove having a selected box thread runout bevel angle, and all transitions in the flex groove between surfaces are radiused to greater than 0.100 inches to minimize stress risers. A pin-in-box connection between tubular joints includes mating tapered threads engagement of end shoulder and and a low stress flex groove The present invention allows the elongate joints to be used as both a casing string and a drill string, thereby saving significant time and expense.