Shell Oil Comapny

Exxon Production Research Company

National Oilwell, Inc.

Stewart A Fox

Jack E Miller

Bryan Lane

Richard H Gunderson

James D Smith

Joe R Fowler

Jerome Q Burns

William T Asbill

A rugged screw-threaded pipe connector for handling corrosive or contaminating fluids under high pressure in a pipeline or pipe riser surrounded by a body of water and subject to high static or dynamic stresses and bending forces. The connector is provided with coarse threads having stabbing flanks and with load flanks adapted to support high loads. The connector is provided with multiple sealing means arranged within the body of the connector that isolate the threads from fluids outside the connector or within the bore of the connector.

Multiple-seal underwater pipe-riser connector

A tubular pin member is received within a tubular box member. The pin member includes a reduced diameter portion forming a shoulder having an annular groove in the shoulder. A metal seal ring of aluminum bronze is shrink fitted onto the outer diameter wall of the annular groove. The tubular box member and the tubular pin member have cooperable connection means connecting the tubular members. The metal seal ring sealingly engages the box thereby establishing a metal-to-metal seal between the tubular members. Pressure in the flow bore of the tubular members applies a force to the inner diameter of the metal seal ring to enhance the metal-to-metal sealing engagement between the seal ring and the outer diameter wall and the box.

Connection seal

A fatigue-resistant threaded connector for connecting adjacent sections of a tubing string subject to cyclic dynamic stress variations is disclosed. The connector comprises a pin member which is threadedly engageable with a corresponding box member. In its preferred embodiment, the connector is radially preloaded. The connector has tapered threads with a straight load path having substantially no eccentricity. The preferred thread form is a modified buttress thread having a zero (or near zero) degree load flank, a 45 degree stab flank, and a large root radius. Additionally, the thread may include a small stab flank relief to reduce stress concentrations, and a differential between the pitch of the pin threads and the pitch of the box threads to compensate for the Poisson's ratio effect of the radial preload. The connector utilizes an elliptical stress relief groove at the base of the pin threads and elliptical contours on all thickness transitions to reduce peak stresses. The fully assembled and preloaded connector has a maximum stress-concentration-factor of less than 1.5 and its weight is less than 2.5 times the weight of an equivalent length of tubing.

Fatigue-resistant threaded connector

Growing community of inventors

Houston, TX, United States of America

Stewart A Fox