Dr. Merlin Seifert, Daniel Kipp
The technology in oil and gas exploration is continuously developing. Using directional drilling, new oil and gas deposits - up to depths of 5 km and distances of 10 km away from the rig - can be tapped. This has the advantage that different deposits can be reached from the same rig.
With the help of extremely sensitive measurement tools near the drill bit, its current position can be monitored. The measuring devices are divided into two subgroups:
MWDs use earth's magnetic field to define the three-dimensional position of the drilling tool as well as the drilling direction, whereas LWDs determine information about the geological structure of the formation.
To explore resources deep under the seabed, steels showing the combination of excellent corrosion resistance and strength, are required especially for drill string components e.g. drill collars, internals and connectors.
Nonmagnetic stainless steels (nonmags) fulfil the increasing requirements of the oil and gas industry. Due to their special properties, such as high corrosion resistance against aggressive media, high strength, and low relative magnetic permeability, these stainless steels are the best choice for components of MWDs and LWDs as well as drill collars.
Furthermore, the earth's magnetic field remains unaffected by the use of nonmags. Hereby, precise measurements for determination of the drill bit position are possible.
Nonmags are based upon a combination of high chromium, manganese, molybdenum and nitrogen content plus small amounts of nickel to ensure a stable austenitic microstructure. A homogeneous austenitic microstructure is the prerequisite to guarantee a specific magnetic permeability of μr < 1.01.
Properties of nonmagnetic stainless steels from Deutsche Edelstahlwerke are achieved via sophisticated thermo-mechanical processing, which includes detailed temperature control.
Specific and application-oriented development resulted in grade 509, which broadens the nonmag portfolio of Deutsche Edelstahlwerke. Due to its chemistry, 509 is the perfect compromise between corrosion resistance and strength. It thus performs better in more aggressive media than lower alloyed grades, while reaching high strength level requirements. In addition, 509 displays an excellent resistance against intergranular corrosion according to ASTM A 262 practice A and E and can withstand stress corrosion cracking to a certain extent. A surface treatment also improves SCC resistance to higher limits. With regard to pitting corrosion 509 shows excellent properties as well, since PREN is as high as 28 - 33 (PREN: Pitting resistance equivalent number %Cr + 3.3x %Mo + 16x %N).
All DEW nonmags are also available as metal powder for additive manufacturing. Interested in nonmagnetic stainless steel? Contact DEW today to find out more.
Deutsche Edelstahlwerke (DEW) is one of the world’s leading producers and processors of special steel long products and belongs to the SCHMOLZ + BICKENBACH Group. In the three materials groups – engineering steel, tool steel and stainless, acid and heat resistant steel – Deutsche Edelstahlwerke offers international customers a uniquely wide range of product dimensions, from drawn wire with a diameter of 4.5 mm to open-die forgings with a diameter of 1,100 mm. As a partner with technical competence in steel, Deutsche Edelstahlwerke develops innovative, individual special steel solutions for complex high-tech applications and offers services ranging from steelmaking to extensive steel processing and steel finishing.
Nonmagnetic stainless steels - or nonmags - are based upon a combination of high chromium, manganese, molybdenum and nitrogen content plus small amounts of nickel to ensure a stable austenitic microstructure. A homogeneous austenitic microstructure is the prerequisite to guarantee a specific magnetic permeability of μr < 1.01.
Contact DEW today to find out more about their nonmagnetic steels, which are also available in powder form for additive manufacturing.