Characteristics of OCTG pipes

Oil well pipes (including OCTG casing), also known as special oil pipes, are steel pipes specially used for oil and natural gas extraction. Most of them are seamless pipes, but welded pipes also account for a considerable proportion.

Oil well pipe standards
The drill pipe that implements the API-5CT standard is the pipe that connects the drilling motor and the drill bit during the drilling process. The outer diameter is generally 2-6.5 inches (50-165mm), and the length is generally between 5-14m. Casing is used as the structural wall or lining of an oil/gas well to protect the well or surrounding groundwater from contamination and can be up to 26 inches in diameter. Casing accounts for more than three-quarters of oil-specific pipe shipments.

How oil well pipe works
Drilling fluid flows through the drill string to the drill bit to cool it. At the same time, the drilled earth and rock cuttings and drilling fluid form mud, which is transported to the surface through the annulus (the gap between the casing and the drill string). Due to the harsh working environment, most drill strings use seamless pipes.

Characteristics of oil well pipes
1. Oil well pipes play an important role in the petroleum industry:
① Oil well pipes are used in large amounts and are costly. There is great potential to save expenses and reduce costs.
② The mechanical and environmental behavior of oil well pipes has an important impact on the adoption of advanced technologies and production increase in the petroleum industry.
③Oilfield pipes suffer huge losses due to failure, and their safety, reliability and service life are crucial to the petroleum industry

2. Basic characteristics of oil well pipes
Oil well pipes are not ordinary metallurgical products. On the contrary, special metallurgical products that have been deeply processed (pressure processing, welding, machining, heat treatment, surface treatment, etc.) on the basis of seamless pipes, rods or plates actually belong to the category of mechanical products. In order to meet the usage requirements, in addition to strict requirements on chemical composition, metallurgical quality, mechanical properties, residual stress, etc., there are also strict requirements on outer diameter, inner diameter, wall thickness, roundness, straightness and thread parameters, as well as the sealing performance of the finished product. and structural integrity.

OCTG casing：https://www.eastern-steels.com/products/casing.html