Tubing naturally has a smaller diameter than casing, except for the 4 1/2-inch diameter. An outer diameter of 114.3 mm (4 1/2 inches) is considered a threshold and can be either casing or tubing. Anything smaller is called tubing, anything larger is casing.
Purpose: Casing is primarily used to reinforce and protect the wellbore from collapsing under the pressure of surrounding formations. It ensures the integrity of the well and prevents any structural failures. Tubing, on the other hand, is designed to transport fluids like oil and gas from the reservoir to the surface.
Size: Casing generally has a larger diameter compared to tubing. Casing sizes typically range from 4 1/2 inches to 20 inches in diameter, while tubing is usually between 1 1/2 inches and 4 1/2 inches in diameter.
Length: Casing tends to be longer than tubing, often reaching lengths of up to 40 feet or more. Tubing, however, is typically shorter, usually between 25 and 30 feet in length.
Thickness: Casing is constructed with thicker walls compared to tubing. This added thickness is necessary to withstand the weight of the surrounding rock formations and the pressure of the fluids within the well. The thickness of casing can vary depending on the depth and pressure of the well, typically ranging from 0.25 to 1 inch. Tubing, being primarily a conduit for fluids, has thinner walls, typically ranging from 0.10 to 0.25 inch.
Material: Casing is predominantly made of steel, chosen for its strength and durability under various well conditions. The grade and type of steel used for casing are selected based on factors such as well depth, pressure, and corrosive environment. Tubing, however, can be made from a variety of materials including steel, plastic, or composite materials, depending on the specific requirements of the well and the fluids being transported.
Tubing and casing from Vigor are all produced in accordance with API 5CT and 5B standards, and all tubing and casing can be customized according to your needs. If you are interested in Vigor's products, please do not hesitate to get in touch with us.
