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Petroleum casing technical specifications and anti-corrosion

Writer: admin Time:2021-07-07 14:17 Browse:

Anti-corrosion countermeasures of oil casing
1. First, make sure that the water quality meets the standards, and strictly monitor and manage the water quality. Implement cleaning and separate injection, strengthen the cleaning of main water pipelines, ensure that the water quality in the station and the bottom of the well meets the standard, and reduce the introduction of corrosion sources into the annular space;
2. For water injection wells that have been newly put into production, adopt annulus protection liquid mainly for sterilization, and form a system to do it regularly;
3. In view of the accelerated effect of mechanical scratches on the corrosion of oil casing, it is recommended to add a rubber ring to the tubing coupling or add a centralizer to the severely deviated part to prevent the tubing from scratching the casing during operation and water injection. One side touches the casing;
4. In view of the severe corrosion of bacteria under the scale and the slow growth and killing of SRB at high temperature, high temperature water or steam of 100 degrees Celsius can be injected into the annulus regularly to kill the SRB under scale;
5. It is not recommended to promote the use of cathodic protection and coated casing before the corrosion in the casing of the water injection well is effectively controlled.
Technical specifications of oil casing
(1) Domestic casing is in accordance with SY/T6194-96. The length of casing is variable, and its range is 8-13m. However, casing pipes no shorter than 6m can be provided, and the quantity shall not exceed 20%.
(2) The inner and outer surfaces of the casing shall not have folds, hair lines, delamination, cracks, creasing and scarring. These defects should be completely removed, and the depth of removal must not exceed 12.5% ​​of the nominal wall thickness.
(3) The outer surface of the coupling shall not have defects such as folding, hairline, delamination, cracks, creasing, and scarring.
(4) The surface of the casing and coupling thread should be smooth, without burrs, tears and other defects that are sufficient to interrupt the thread and affect the strength and tight connection.