steel casing is a thin-walled steel Pipe used in Oil pipelines, oil wells, and natural gas wells. Can withstand high pressure, high temperature and corrosive media. Below are some of the major steel casing standards.
1. API 5CT
API5CT is a petroleum casing standard formulated by the American Petroleum Institute, including H40, J55, K55, N80, L80, C90, C95, P110, Q125 and other grades of casing.
- ISO 11960: Petroleum casing standard formulated by the International Organization for Standardization, similar to api 5ct, including different grades of casing.
3.GB/T 9711.1: Petroleum casing standards formulated by the china National Standardization Organization, including L175, L210, L245, L290, L320, L360, L390, L415, L450, etc.
4.SY/T6194: Petroleum casing standard formulated by China Petrochemical Industry Standards, including casing and Tubing types, used for different depths and oil well conditions. These standards stipulate the size, chemical composition, mechanical properties, quality requirements, etc. of oil casing to ensure its safety and reliability in the Oil and Gas extraction process.
Types of steel casing
Steel casing can be divided into: conduit, ground casing, technical casing and oil layer casing according to its purpose.
Guide sleeve: Mainly used for ocean and desert drilling to separate seawater and sand to ensure smooth drilling.
Surface casing: mainly used for first drilling, drilling through weak surface strata to bedrock. In order to Seal this part of the formation and prevent collapse, it is necessary to seal it with surface casing.Surface oil casing protection drill
The well is protected from contamination of shallow water and gas zones, supports Wellhead equipment and maintains the Weight of other casing layers.
Technical casing – Separates different levels of pressure to facilitate the normal flow of drilling fluids, protects production casing, and allows the installation of explosion protection devices, anti-leak devices and liner pipes in drilling.
Reservoir Oil Casing (Production Casing): Extracts oil and gas from reservoirs below the surface and is used to protect drilling wells and layer drilling mud. When producing oil casing, the outer Diameter is usually 114.3 mm to 508 mm.
Steel casing steel grade
According to the strength of the steel itself, steel casing can be divided into different steel grades, namely J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc. Different well conditions and well depths require different steel grades. In corrosive environments, the casing itself is also required to be corrosion-resistant. In places with complex geological conditions, casings are also required to have collapse resistance.
How to choose the right steel casing?
When choosing steel casing, you need to consider the following factors:
- material: high-quality anti-corrosion and wear-resistant materials should be selected, such as polyurethane, chlorinated polyvinyl chloride, polyester, etc., to ensure the anti-corrosion and wear-resistant performance of the casing.
- specifications: According to the diameter and Length of the oil pipe that needs to be protected, select the casing of the corresponding specifications to ensure that it can completely cover the oil pipe.
- Thickness: Thickness is one of the important indicators to measure the quality of casings. Casings with moderate and uniform thickness should be selected to ensure their strength and wear resistance.
- Production technology: Use casings with exquisite production technology, tight braiding layer, smooth surface and no burrs to ensure reliable quality.
