Sumitomo Metals Develops CLEANWELL® DRY, Environmentally Friendly OCTG Premium Connection
-Achieving Both Utmost Performance and Environmental Responsiveness-

Sumitomo Metal Industries, Ltd. (Sumitomo Metals) has developed CLEANWELL® DRY, an environmentally-friendly premium connection of VAM® (*1) used in connecting oil country tubular goods (OCTG), jointly with Vallourec( *2). CLEANWELL® DRY premium connection enables oil and gas development with no discharge of products that are harmful to the environment.

CLEANWELL® DRY was used for the first time in an offshore drilling rig (*3) in the North Sea, the area with the most stringent environmental regulation in the world, and was highly evaluated by the customer.

1. Background
Exploration wells that are used to extract crude oil or natural gas are usually located at a depth of 2,000 to 3,000 meters but, with the recent trend of deeper drilling, they can now be located as deep as 8,000 to 10,000 meters.

Premium connections that connect OCTG have to bear underground heat as well as pressure caused by weights of themselves. The deeper a well is, the higher the heat and pressures are. Tubular connections are required to perform without any damage and maintain gas-tightness even under a harsh environment.

There are occasions that OCTG be loosened and sealed during the running process. The specification requires that tubular connections prevent galling( *4) and maintain gas-tightness, after being loosened and sealed for a specified number of times.

When a connection is connected to a pipe, the thread surface is coated with grease called "dope" (*5). Previously, whenever the connection was sealed, the dope left on the contact surface of the thread was cleaned off with water, and new dope was applied again. This was necessary to satisfy the specifications for both anti-galling performance and gas-tightness. As the dope contains heavy metals such as lead and zinc, there was a concern that, when sealing the connection, heavy metals might run off and result in a detrimental impact on marine creatures or humans. In addition, the extrusion of the dope inside OCTG may drop and become accumulated inside the well, thereby causing trouble in exploration operations. Besides the hard working environment, cleaning and application of the dope burdens operations in terms of efficiency.

In recent years, more stringent environmental regulations have been introduced worldwide and some areas have already restricted the use of dope. Thus, connections that satisfy specifications on anti-galling performance, without the use of dope, had been greatly desired.

2. Development details
Sumitomo Metals and Vallourec have successfully developed CLEANWELL® DRY by developing the following three surface coating treatment technologies, based on their technologies in advanced tribology (*6) and anticorrosion performance.

  (1) The inner surface of a connection is plated with a specific metal plating with high anti-galling performance and is then coated

        with a excellent lubricating solid film.
  (2) Threading area in pipe edge is coated with a transparent anti-corrosion solid film.
        * These films are manufactured on a dedicated production line at Sumitomo Metals' Wakayama Steel Works. Once formed,

          the films show the same connection performance to dope, even after being loosened and sealed several times.
  (3) Film repair technologies have also been developed in order to cope with damage caused by problems in delivery and storage.

The above technologies not only prevent environmental contamination caused by dope driftage, but also enable the elimination of dope-cleaning and dope-coating operations at drilling sites or in the storage of tubes. Consequently, they have attracted market attention as being operator-friendly or facilitating automatic operation.

3. Future development
Shipments of dope-free CLEANWELL® DRY connections have begun primarily to North Sea oil wells. Going forward, these products are expected to be used in offshore oil well development in the Barents Sea, part of the Arctic Sea, where environmental regulations are the most stringent in the world.

CLEANWELL® DRY is a super-high-end product that supports deep-well development under stringent environmental regulations. Sumitomo Metals will expand marketing and sales activities in offshore oil fields in the North Sea and other parts of the world as well as in oil fields in the Middle East and other desert areas.

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<Terms>
*1 VAM®
VAM® is the brand name of a premium connection for seamless pipes. Sumitomo Metals and Vallourec have jointly developed the technology for VAM®, which has captured the largest market share of 40% in high-grade OCTG worldwide. VAM® has the world's best service network of 137 repair shops in 46 countries for cutting threads of the VAM® product line.

*2 Vallourec
  (1) Head office : France
  (2) Sales : 6,437 million euro (2008)
  (3) Number of employees : 18,561 (2008)
   Sumitomo Metals and Vallourec have been business partners of VAM®, the world-renowned premium connection, for over 30 years.

*3 Offshore drilling rig
An offshore drilling rig is a large structure over the ocean housing equipment and workers for drilling oil wells or natural gas extraction wells from under the water.

*4 Galling
Galling is material transfer from one metallic surface to another, at the time of friction and sliding movement of both materials. When galling occurs at the thread and seal area of a connection, the connection may become unable to demonstrate the specified performance.

*5 Dope
A grease that contains heavy metals such as lead, zinc, and copper and is manufactured in compliance with the American Petroleum Institute's (API) standard.

*6 Tribology
Tribology is the science and technology of studying friction, lubrication and wear. The word "tribology" derives from the Greek "tribos" meaning "friction." Application areas include bearings, hair conditioners, and other diverse fields.