An oil and gas rig, whether onshore or offshore involves a large network of interconnected pipes and tubes. These pipes and tubes are present both underwater and on the ground. Hence, they have to withstand various environmental conditions.
Casing tubing involves the outer tubes which surround the inner main tubes. These tubes generally line the wellbore and are important for preventing the soil and groundwater from getting contaminated by the drilling mud and extracted fluids. Besides, this outer structure forms the core of a support system which is important to keep the wellbore steady even under high loads.
The casing process works simultaneously with the drilling process. First, the drilling is done. Then after a while, the drill is taken out and the casing is cemented. The procedure is repeated thereafter.
The Importance Of Casing Tubing
In a country like UAE having numerous oil wells, casing tubing becomes a lot more important as it forms the core of the oil well construction. Besides preventing the soil and groundwater from getting contaminated, it also helps to transport the oil from the well to the surface.
Both tubing and casing can be seen as individual structures also. While the tubing forms the inner portion of a casing tubing arrangement, casing forms the outer supporting feature. Due to this, tubing generally has a smaller diameter than that of the casing. There is also a threshold value of 114.3 mm for the diameter. A tube of this diameter can be considered both as tubing as well as casing. Any diameter above this threshold value corresponds to casing while any diameter below this value corresponds to tubing.
The shape of casing is generally like a funnel, with a broad face at the top and a narrow face at the bottom. The casing comes in various shapes and sizes, depending upon its use. Not only is it applied in vertical drilling operations but it is also important for horizontal drilling ones.
Casing Tubing Material
The casing in an oil well may be made up of various types of materials, some of which are listed below:
- Carbon Steel: ASTM A106 Gr. B, API 5L Gr. B, X42, X52, X60, X65, X70, X80(PSL1 / PSL2). These can be used in high heat, extreme cold, and even for transporting steam at a high temperature.
- Carbon Steel Alloy Low Temp: ASTM A333 Gr.6. These form the cover tubing of many other tubes.
- Carbon Steel Alloy High Temp: ASTM A335 Gr P1/P5/P9/P11/P22. These are known for their high tensile strength and smooth internal finish.
- Austenitic Stainless Steel: ASTM A312 Gr TP304/304L, A312 Gr TP316/316L,A312 Gr TP321, A312 Gr TP347. These are fireproof and provide the much-needed fire protection to keep your oil plant safe.
- Duplex & Super Duplex: ASTM A790 S31803, ASTM A790 S32760/S32750.They can be used for a wide range of subsea applications along with the extraction process.
While these materials are the most widely used ones, you can also get the casing in custom alloys depending upon your requirement. There are several suppliers in UAE such as New World Horizon General Trading L.L.C, AOSS, Trio-Tech Tools, etc. who can provide high-quality casing tubing in Dubai at competitive prices.