Oil casing flange is a steel pipe used to support the well wall of oil and gas wells, which is used for the drilling process and the normal operation of the whole oil well after well completion. Several layers of casing shall be used for each well according to different drilling depth and geological conditions. Cement shall be used for cementing after casing running. It is different from and drill pipe and can not be reused. It is a disposable consumable material. Therefore, the consumption of casing accounts for 70% of the oil well pipe. Casing can be divided into conduit, surface casing, technical casing and oil layer casing according to the use situation.
Application of oil casing flange
1. Oil casing flange is a kind of large-diameter pipe, which plays the role of fixing the oil and gas well wall or well hole. The casing is in the borehole and fixed with cement to prevent the borehole from separating the rock stratum and borehole collapse, and the drilling mud circulates to facilitate drilling and production.
2. Oil casing flange is mainly used to support the well wall during drilling and after well completion, so as to ensure the progress of drilling process and the normal operation of the whole oil well after well completion. Anti corrosion Countermeasures of oil casing
1. First, pay attention to the water quality standard, and strictly inspect and manage the water quality. Clean up and separate injection shall be implemented, and the cleaning of main water pipeline shall be strengthened to ensure that the water quality in the station and at the bottom of the well meets the standard, and reduce the introduction of corrosion sources into the annular space.
2. For the newly put into operation water injection wells, annulus protection fluid mainly for sterilization shall be added, and a system shall be formed to add it regularly.
3. In view of the accelerating effect of mechanical scratch on the corrosion of oil casing flange, it is recommended to add a rubber ring on the coupling or a centralizer at the part with serious well deviation to avoid scratching the casing and contacting the casing on one side during operation and water injection.
4. In view of the serious corrosion of bacteria under the scale and the slow growth and killing of SRB at high temperature, 100 ℃ high-temperature water or steam can be injected into the annulus regularly to kill SRB under the scale.
5. Before the corrosion in the casing of water injection well is effectively controlled, it is not recommended to promote the use of cathodic protection and Atlas casing.
