Sumitomo Metals Receives the Imperial Invention Prize from the Japan Institute of Invention and Innovation for its super-high strength low alloy steel oil country tubular goods

On June 17, 2008, Sumitomo Metal Industries, Ltd. (Sumitomo Metals) received the Imperial Invention Prize, the highest honor of the National Commendation for Invention, together with the National Commendation for Invention Prize, from the Japan Institute of Invention and Innovation for its super-high-strength low alloy steel oil country tubular goods. It is the first time for Sumitomo Metals and the first in about 20 years for the steel industry to receive the Imperial Invention Prize. The invention contributes to the prevention of the greenhouse effects, by helping increase the stable supply of natural gas, a cleaner energy source that is a source of less carbon dioxide than primary energy sources it replaces.

1. Summary of the invention
The tubular goods are special in that they are valuable for their unprecedented strength and sour-gas resistance, two features of importance for exploration for oil and natural gas resources.

In many parts of the world there has been a shift in the focus in energy demand from oil to natural gas, due to increasing need to reduce emission of greenhouse gases such as carbon dioxide. Natural gas is usually found in an extremely severe environment of wells that are at a few thousand meters below the surface of the ground, that is, much deeper than oil wells, and is often associated with acidic gases such as hydrogen sulfide (sour environment), requiring more corrosive resistance than needed for tubular goods used in other environments. Sumitomo Metals' award-winning products provide both higher strength to withstand the higher stratum pressures and their own hanging weight at the well head, and corrosion resistance. It has been widely recognized that high-strength steels suffer from sulfide stress cracking ("SSC"; see Note 1), one form of hydrogen embrittlement of steel (see Note 2) in sour environments. Historically, 110ksi (see Note 3) (758MPa) had been the highest yield strength for the similar tubular goods, of a grade used for sour service. Conventional steels could not provide high strength and high corrosion resistance at the same time.

Behind the award granted to Sumitomo Metals is the company's finding that inclusions (see Note 4) that are contained in such tubular steel goods have a highly detrimental effect on SSC resistance by becoming sites of corrosion pits on the steel surface in sour environments. Sumitomo Metals has succeeded in reducing the size of inclusions to prevent pitting corrosion and SSC occurrence.

In 2003 this invention was used to develop 125ksi (862MPa) grade sour-resistant tubular pipe, the first material of that kind in the world, which underwent qualification testing through collaborative research with British Petroleum in the UK and StatoilHydro in Norway. The newly-developed high-strength product has enabled exploitation of deep, highly-corrosive natural gas sour wells (4,000-6,000 meters depth) for the first time.

The invention contributes to the prevention of the greenhouse effects, by helping increase the stable supply of natural gas, a cleaner energy source that is a source of less carbon dioxide than primary energy sources it replaces.

2. Recipients of the awards
The Imperial Invention Prize:
Tomohiko Omura, Senior research engineer of Corporate Research & Development Laboratories
National Commendation for Invention Prize:
Hiroshi Tomono, Representative Director and President

3. Commendation ceremony
(1) Date: Tuesday, June 17, 2008, 15:00 to 16:00
(2) Place: Hotel Okura, Orchard Room (South Wing 2nd Floor)

[Reference]
National Commendation for Invention Prize
For the purpose of contributing to the progress of science and technology and the development of industry, this Commendation has, since 1919, been held to commend persons who have accomplished extremely excellent inventions replete with originality, persons who have rendered distinguished services in regard to the working of inventions, and persons who have greatly contributed to the promotion of excellent technology and to the guidance and development of human resources. The activities have been supported by the Ministry of Education, Culture, Sports, Science and Technology, Ministry of Economy, Trade and Industry, Patent Office, Japan Economic Federation, Japan Chamber of Commerce and Industry, Japan Patent Attorney Association, and Asahi Shimbun.

Of particular note, the Japan Institute of Invention and Innovation (JIII) has been honored to receive the Imperial Bounty every year by virtue of the Imperial Household's deep understanding of the JIII's invention encouragement activities and, in commemoration of this honor, the Imperial Invention Prize has been presented to the person who has achieved the most distinguished invention.
(Note: English translation from the Japanese text on the website of the Japan Institute of Invention and Innovation)

[Terms]
Note 1: Sulfide stress cracking (SSC):
Hydrogen embrittlement caused by hydrogen sulfide (H2S)

Note 2: Hydrogen embrittlement:
Embrittlement due to hydrogen entering

Note 3: ksi
Kilo-pounds per square inch, a unit of stress or pressure
1ksi = approximately 0.7kg/mm2

Note 4: Inclusion
Materials such as oxide and nitride that are generated during melting of steel and remain inside. These materials greatly influence the toughness property of steel.