API ERW Casing Pipe

ERW (Electric Resistant Welded) steel pipe refers to a straight seam welded pipe manufactured by high-frequency resistance welding process. ERW casing, also called TUF pipe, is made of large-diameter ERW steel pipe and is used to fix oil and natural gas wells or oil wells. This article will introduce ERW casing in detail, continue reading to learn more.

The surface of ERW casing protects the well from shallow water and shallow air, supports wellhead equipment and protects other layers of casing. ERW casing technology separates different levels of pressure to protect drilling fluid circulation and production casing. To install explosion-proof devices, leak-proof devices and tail pipes in the boreholes. Oil casings transport oil and natural gas from underground storage formations. Used to protect wells and layer drilling mud. In the production of ERW casing, the outer diameter usually ranges from 114.3 mm to 508 mm.

Features of ERW Casing:

1. High dimensional accuracy, good surface quality, uniform wall thickness, and high extrusion resistance of the casing;

2. The base material has few impurities, uniform structure, good material toughness, and high casing toughness, which can meet the needs of special well conditions in oil fields;

3. Large diameter span. Compared with seamless casing, it has certain economic advantages in large diameter (above 219mm) specifications.

Anti-Corrosion Measures for ERW Casing:

1. First, ensure that water quality meets standards and strictly monitor and manage water quality. Implement cleaning and injection, strengthen main water pipeline cleaning, ensure that the water quality in the station and at the bottom of the well reaches standards, and reduce corrosion sources from entering the annular space;

2. For newly put into production water injection wells, annulus protection liquid is mainly used for disinfection, and a system is established to conduct it regularly;

3. In view of the accelerated effect of mechanical scratches on oil casing corrosion, it is recommended to install a rubber ring at the oil pipe coupling or a centralizer at a severely deviated part of the well to prevent the oil pipe from scratching the casing and the oil pipe during operation and water injection. . One side contacts the housing;

4. In view of the serious corrosion of bacteria under scale and the slow growth and killing of SRB at high temperatures, high-temperature water or steam of 100 degrees Celsius can be regularly injected into the annulus to kill SRB under scale;

5. Before the corrosion of water injection well casing is effectively controlled, it is not recommended to promote the use of cathodic protection and coated casing.

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