Hydril Company

Hunting Oilfield Services, Inc.

Doyle E Reeves

Donald J Ortloff

Thomas L Blose

Keith C Mott

K Darrel Chelette

John J Staudt

A method for manufacturing pipe joints for connecting two pipe sections in a well bore allows the pipe joint to have increased resistance to compressive and torsional forces. Each pipe joint has a box member for matingly engaging a pin member, the pin member being threadingly connected to the box member to create the pipe joint. Threads are created for the pin member on a tapered exterior surface of a pipe, the threads being axially disposed between a pin end terminal surface and an external shoulder. A tapered surface having a recess is created for the box member on an interior of a pipe, the tapered surface being axially located between a box end terminal surface of the pipe and an internal shoulder, the recess being axially located just behind the box end terminal surface of the pipe. Threads are cut into the tapered surface of the box member, the threads beginning behind the recess and traveling axially away from the box end terminal surface. Since the threading pass for the box member begins behind the recess, threads are not cut through the box end terminal surface giving, this surface an increased contact area. When the pin member and the box member are threadingly connected, the box end terminal surface engages the external shoulder of the pin member. The increased area of the box end terminal surface gives the pipe joint increased compressive and torsional resistance.

Method for manufacturing a flush/semi-flush threaded connection

Metal-to-metal seals for pin and box member tubular joints are disclosed where mating annular surfaces are machined at slightly different angles such that the bearing load from initial contact is entirely on the leading edge of the pin annular surface and the trailing edge of the box annular surface. The mismatch of the sealing surfaces is selected for any particular seal geometry such that at final make-up, the bearing load has a relatively even distribution across the entire sealing surface in contact, thus broadly distributing make-up bearing stresses and minimizing any resulting tendency for galling that may occur, in particular for joints having relatively thick walls for both pin and box members.

Tubular coupling with metal to metal seal

An improved threaded connection adapted to secure adjacent conduits in a continuous flow conduit forming relationship. The threaded connection employs a tapered or wedge shaped thread with angled or tapered thread load flanks to obtain superior mechanical strength by controlling stress levels in the connection. To insure proper make-up of the connection the dimension of the thread structure is controlled to prevent trapping of thread lubricant during rotational make-up which may produce false torque make-up values.

Tubular connection

A tubular connector for adjoining two adjacent joints comprising a first pin end on a first joint, a second pin end on a second joint and a tubular coupling member with suitable threads for mating with both pin ends. Each pin end is tapered and includes wedge threads. The wedge threads achieve a metal-to-metal seal upon makeup by providing a root-and-crest bearing surface prior to makeup. As an addition, a metal-to-metal conical seal can be provided in front of the most forward thread revolution on the pin ends. Further as an addition, an elastomeric seal can be provided in a circumferential groove just forward of the conical seal for making a compound seal therewith. A corrosion barrier ring can be included in the coupling member for filling the gap between the tip ends of the two pin ends being joined.

Metal-to-metal wedge thread coupling connector

A threaded pipe connection is disclosed of the wedge-shaped thread type that avoids high stress concentrations in the box between the first thread and the end of the box by making the length of the box between the first thread and the end of the box equal to or greater than 5% of the pipe diameter and by providing clearance between the crest of the first full thread on the box and the root of the last thread on the pin and between the crest of the last full thread on the pin and the root of the first full thread on the box.

Threaded pipe connection having wedge threads

A threaded pipe connection is disclosed that has threads the flanks, roots, and crests thereof form thread seals when the connection is made up and that has a seal ring of resilient material that is trapped in a cavity between a groove in either the box or the pin and the thread seals to provide a secondary seal.

Threaded pipe connection with compressible seal ring

A joint and male and female tubular elements are disclosed where the threads of the female and male members have negative load flanks and have two or more radial steps axially separated one from another by a reverse angle torque shoulder having one or two adjacent conical sealing surfaces. The reverse angle torque shoulder serves as a positive assembly stop. The negative load flank angle of the threads and the reverse torque shoulder angle combine to interlock the male and female members and to prevent differential radial separation of the conical sealing surfaces when the joint is exposed to internal pressure, external pressure or both. Tapered threads and sealing surfaces and interference threads may advantageously be used in joint construction. Tapered conical sealing surfaces where the taper of the member having the thinner wall thickness at the seal surface is inclined at a smaller angle with respect to the axis of the threaded connection than the complementary conical seal surface of the mating member, may advantageously be used so that the bearing load across the entire axial width of the male and female sealing surfaces has a relatively even distribution at final make-up.

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Houston, TX, United States of America

Doyle E Reeves