ERW casing is a large diameter pipeline, which can fix oil and gas wells or wells. The casing is inserted into the wellbore and fixed with cement to prevent the wellbore from separating the formation from the wellbore, thus preventing drilling mud circulation for drilling convenience.



Different types of casing are used in oil recovery: ERW casing surface protects wells from shallow water and shallow air, supports wellhead equipment and maintains other layers of casing. Technical ERW casing separates different levels of pressure to ensure normal circulation of drilling fluid and protection of production casing. In order to install explosion-proof device, leak-proof device and tail pipe in drilling hole. Oil and gas are exported from the reservoir below the surface by the oil-bearing casing. It is used to protect wells and stratify drilling mud. ERW casing production, external diameter is usually 114.3 mm to 508 mm.


Anticorrosion measures of ERW casing


1. First of all, water quality standards should be well established, and water quality detection and management should be strictly enforced. Cleaning and dispensing, strengthening the main water pipe cleaning work, so that the quality of the bottom water in the station meets the standards, reducing the introduction of corrosion sources in the annular space;


2. For new injection wells, a sterilization-based environmental protection solution is adopted and a system is formed.


3. In view of the acceleration of casing corrosion caused by mechanical wear, it is suggested that a rubber ring be added to the pipe joint or a centralizer be added to the serious part of the well in order to avoid damage to the pipeline. During operation and water injection. One side contact sleeve;


4. For serious bacterial corrosion and slow growth and killing of SRB at high temperature, high temperature water or steam at 100 degrees Celsius can be injected regularly to kill scales under SRB.


5. Cathodic protection and coated casing should not be popularized until the corrosion in the casing of injection wells has not been effectively controlled.