API 5CT refers to the technical specification for steel pipes used in oil pipelines and oilfield drilling. This standard specifies the size, weight, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage requirements for oil pipelines and oilfield drilling steel pipes. These specifications are formulated to ensure the quality and safety of oil pipelines and steel pipes used in oilfield drilling, and to promote the healthy development of the petroleum industry.
The API 5CT standard has clear requirements for the chemical composition of steel pipes used in oil pipelines and oilfield drilling. These requirements vary mainly based on the steel grade and purpose of the steel pipe.
| Carbon (C) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | phosphorus and sulfur (P+S) |
| ≤0.35% | ≤1.35% | ≤0.020% | ≤0.015% | ≤0.030% |
The total content of does not exceed Oil casing and tubing under API 5CT standards are mainly manufactured through the following production methods: hot-rolled seamless steel pipes, cold-drawn seamless steel pipes, welded steel pipes, heat treatment, and non-destructive testing.
The characteristics of API 5CT are mainly reflected in the following aspects:
1. High strength and high durability: API 5CT has high yield point and tensile strength, and can withstand operation under high pressure and high temperature conditions.
2. Good sealing performance: API 5CT has excellent sealing performance and can effectively prevent leakage.
Anti-corrosion performance: The surface of API 5CT casing has undergone anti-corrosion treatment, which can effectively prevent corrosion and oxidation. This allows it to maintain its performance and reliability for long periods of time in harsh environments.
3. High specifications and appearance quality requirements: The internal and external surfaces of API 5CT petroleum casing must not have defects such as folding, hair lines, separation layers, cracks, folding, and scarring. These defects should be completely removed to a depth not exceeding 12.5% of the nominal wall thickness. In addition, the thread surface of oil casing and couplings should be smooth, and no burrs are allowed to affect the strength and tight connection of other defects.
4. Strict manufacturing and inspection standards: API 5CT standards stipulate the material requirements, manufacturing processes and process control requirements for drilling line pipes. These requirements include the tensile strength, yield strength, elongation, impact energy and hardness of line pipes to ensure the safe operation of line pipes under high pressure, high temperature and harsh environments.
Petroleum casing and tubing under API 5CT standards are widely used in drilling and completion operations in the oil and gas industry. The following are the main application areas of API 5CT: Drilling operations: Drill pipe: API 5CT drill pipe is used to connect the drill bit, transmit rotational torque and bit pressure to the drill bit, and is also used to transport drilling fluid (mud). Casing: API 5CT casing is divided into various types, such as surface casing, technical casing and production casing, each of which has different wall thickness and steel grade to adapt to different formation conditions and drilling needs. Well completion operations: Tubing: used to extract oil and natural gas from the formation after well completion. Line Pipe: Used in the construction of these transmission pipelines.
