Pipe joints or couplings – With casing – lining or protector – Lined
Reexamination Certificate
1999-02-24
2001-08-14
Barrett, Suzanne Dino (Department: 3627)
Pipe joints or couplings
With casing, lining or protector
Lined
C285S333000, C285S383000
Reexamination Certificate
active
06273474
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to threaded pipe connections and, more particularly, to a corrosion-resistant threaded connection assemblies for use with clad pipe such as can be used as oil and gas well tubing and casing, piping in chemical and other plants, oil and gas pipelines, and the like.
2. Description of the Prior Art
There are numerous instances where piping and pipelines are used for transporting fluids that are highly corrosive to materials such as carbon steel from which such pipe and pipelines are typically made. In particular, in the production of oil and gas, there is a growing need for corrosion-resistant alloy pipe, e.g., tubing, because of the continuing increase in the drilling of oil and gas wells into pay zones that produce highly corrosive fluids. To overcome the corrosion problems, and as well known to those skilled in the art, it is common to use lined steel pipe, which liners may be made of plastic, stainless steel, or other corrosion-resistant materials.
A typical multiple-walled composite pipe, e.g., a lined steel pipe, is a dual or double-walled pipe in which the inner wall is a liner tube made of a corrosion-resistant material, e.g., stainless steel, or some other corrosion-resistant material (metal alloy) that serves as a conductor for the corrosive fluid, and an outer wall or pipe that is designed to provide strength to withstand the internal pressures of the corrosive fluid, as well as external forces such as external pressure, mechanical loading, etc.; e.g., carbon steel that may be corrosion-prone.
Obviously, particularly in the case of tubing or casing, there are limitations on the length of such double-walled pipes due to conditions to which the pipes are subjected on site. Thus, in the case of tubing or casing strings and in the production of oil and gas, each joint of pipe is usually about 30-40 feet long while the tubing or casing string itself may be thousands of feet long. Accordingly, and as is well known in making up such tubing or casing strings, successive joints of tubing/casing are connected together using couplings until the desired length of string is achieved.
Typically, in these multiple-walled composite pipes, the inner tube or liner made of the corrosion-resistant material does a highly effective job of protecting the corrosion-prone outer tube or pipe. Indeed, methods of successively internally cladding corrosion prone pipe with a corrosion-resistant material are well known to those skilled in the art. The problem is not with the clad pipe, but rather where successive joints of the clad pipe are adjoined to one another by means of a coupling. For many years, the goal has been to create a “holiday-free” interface at the junction of the clad pipe and the coupling. It serves no purpose to connect clad pipe utilizing a coupling that is subject to corrosion since such a connection will sooner or later fail because the coupling will fail.
The prior art is replete with pipe couplings and assemblies ostensibly designed to overcome the problem of eliminating corrosive attack at the junction of the pipe and the coupling. However, insofar as is known to Applicants, none of these solutions have been readily embraced by the oil and gas industry, either because of cost factors, failures caused by corrosion, or lack of sufficient structural integrity at the pipe/coupling juncture.
In U.S. Pat. No. 5,282,652, there is disclosed a corrosion-resistant pipe coupling structure comprising a tubular coupling member having axially opposite ends thereof. Internal screw threads form boxes that engage male screw threads forming pins provided on the axially opposing end parts of two pipes to be connected, the internal surface of each of the pipes being resistant to corrosive fluids. An intermediate annular projection is provided on the inner surface of the coupling member and directed radially inwardly thereof to be abuttingly interposed between the opposing end parts of the pipes. The structure is characterized in that the intermediate annular projection is made of a corrosion-resistant material, at least in a radially intermost part thereof.
U.S. Pat. No. 4,026,583 also discloses corrosion-resistant tubing or casing for use in the oil and gas industry.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a corrosion-resistant threaded connection assembly.
Another object of the present invention is to provide a workpiece for use in making a corrosion-resistant, threaded tubular member.
Still a further object of the present invention is to provide a method of forming a workpiece for use in making a corrosion-resistant threaded tubular member.
Yet another object of the present invention is to provide a corrosion-resistant threaded tubular member.
Still a further object of the present invention is to provide a method of forming a corrosion-resistant tubular member.
The above and other objects of the present invention will become apparent from the drawings, the description, and the claims.
In one embodiment, the present invention provides a corrosion-resistant threaded connection assembly comprising a first tubular member having an outer tube of corrosion-prone material, e.g., carbon steel, and an inner tubular lining of corrosion-resistant material, e.g., stainless steel or some other corrosion-resistant metal alloy, the first tubular member including a first pin connection. The outer tube has a first end and a second end. The first pin connection comprises a nose portion formed on a first ring of corrosion-resistant material—e.g.—a metal alloy, secured to the first end of the outer tube of corrosion-prone material, thereby forming a first annular securing locus. The first ring of corrosion-resistant material defines a first annular, axially facing end surface and a first radially outwardly facing, annularly extending thread-free pin shoulder formed on the corrosion-resistant ring. A first axially extending, externally threaded portion providing male threads is formed at least partially on said outer tube and extends axially inwardly of the pin shoulder and first end surface, the first securing locus being disposed intermediate the first end surface and the end of the externally threaded portion distal the first end surface. The assembly further includes a second tubular member comprising a coupling having a first end and a second end, the coupling having a first box connection formed in the first end and a second box connection formed in the second end. The coupling further includes an internally disposed annularly extending section of corrosion-resistant material disposed intermediate the first and second ends of the coupling. Each of the box connections comprises a radially inwardly facing, annularly extending box shoulder formed on the section of corrosion-resistant material. Each of the box connections further includes an axially extending, internally threaded portion providing female threads complementary to the male threads of the first pin connection and extending axially outwardly of the thread-free box shoulder. The pin and box shoulders are sized and configured such that when respective ones of said first pin connections are threadedly received in the first and second box connections, the pin and box shoulders are in metal-to-metal sealing engagement.
In yet another embodiment of the present invention, there is provided a workpiece for use in making a corrosion-resistant threaded tubular member. The workpiece includes an outer metal tube of corrosion-prone material having a first end, a second end, and an inner surface. A first ring of corrosion-resistant material is secured to the first end of the metal tube, a first annular securing locus being formed between the first ring and the first end of the metal tube. An inner metal tubular lining of corrosion-resistant material is disposed in the outer tube, the metal lining having a first end, a second end, and an outer surface, the outer surface of said lining overlying said inner surface of said tube and sa
DeLange Richard W.
Hashem Ghazi J.
Barrett Suzanne Dino
Bushman Browning
Grant Prideco, L.P.
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