Grant Prideco, Inc.

Richard C Griffin

Richard W Delange

Gregory K Otten

Merle Edward Evans

Donna S Anderson

Ed Evans

William W Starodub

The threaded connection between the pin and the box ends of two pipes is sealed externally and internally to protect the threads in the connection from exposure to corrosive fluids. Seals are provided at each axial end of the threads. External seals are formed by metal-to-metal engagement between the pin and box and a third metal body secured circumferentially about the pin. The metal body may be fashioned into a desired annular pin seal surface to mate with and seal with the box at full makeup of the connection. The metal body can be removed and replaced as required to repair or reconstructed the pin seal surface.

Replaceable corrosion seal for threaded connections

The threaded connection between the pin and the box ends of two pipes is sealed externally and internally to protect the threads in the connection from exposure to corrosive fluids. Seals are provided at each axial end of the threads. The external seals may be formed by metal-to-metal engagement between the pin and box or may be provided by an annular, elastomeric ring engaging the pin and box of the connection. A threaded compression ring may be used to compress the elastomeric seal between the pin and box. The seals protect dynamically loaded threaded connections from fatigue-induced failure in corrosive environments.

Corrosion seal for threaded connections

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.

Growing community of inventors

Houston, TX, United States of America

Richard C Griffin