API Spec 5CT1988によると、H-40、J-55、K-55、N-80、C-75、L-80、C-90、C-95、P-101、およびQ-125を含む10種類のケーシング鋼グレードがあります。ケーシングには、スレッドとカップリング、または次のパイプエンドフォームのいずれかに供給されます：カップリングの有無にかかわらず、フラットエンド、ラウンドスレッド、カップリングの有無にかかわらず、ストレートスレッド、特別なエンドワーク、シーリングリングの構造。
Countermeasure of oil casing anticorrosion
1. First do a good job of water quality standards, strict water quality testing and management. Clean and separate injection should be carried out to strengthen the cleaning of the main water pipeline, so that the water quality in the station and at the bottom of the well can reach the standard and reduce the introduction of corrosion sources into the annular space.
2. For newly put into production of water injection Wells, annular protective fluid mainly used for sterilization should be added, and a system should be formed to add it regularly;
3. In view of the accelerated effect of mechanical abrasion on oil casing corrosion, it is recommended to add a rubber ring to the tubing coupling or a centralizer to the severely inclined part of the well to avoid scratching the casing and one side of the casing during the operation and water injection process;
4. In view of the serious corrosion of bacteria under scale and the slow growth and killing of SRB at high temperature, high-temperature water or steam at 100 degrees Celsius can be injected into the annulus regularly to kill SRB under scale;
5. Cathodic protection and coated casing are not recommended to be popularized until the corrosion in the casing of water injection well is effectively controlled.
