Huaxi Steel - Casing & Tubing
Casing & Tubing is a steel pipe column installed in the drilling wellbore, which is combined with the well wall through cementing to form a stable wellbore structure. It belongs to the "trunk pipeline" of the oil and gas well, extending from the wellhead to the target formation, and is used to maintain the integrity of the wellbore, isolate different formations (such as water layers, high-pressure layers, etc.), and provide a channel for subsequent production.
- Outer diameter: 1.315"- 20"
- Wall thickness: 0.133"-0.500"
- Length: R1(group1), R2(group2), R3(group3)
- API 5CT J55, K55, N80, L80-1, L80-9Cr, L80-13Cr, P110
- API standard thread
- STC (short round thread)
- LTC (long round thread)
- BTC (trapezoidal thread)
- Special thread (Premium Connection)
- Metal-to-metal seal (such as VAM, FOX, Hydril).
- High pressure and bending resistance, suitable for high temperature and high pressure (HPHT) wells.
Representative brands:
- VAM® (Vallourec)
- TMK (Russian Steel Pipe Company)
- Hydril Wedge (National Oilwell)
Conductor Casing
Conductor casing is the first boundary between the surface and the subsurface. It helps prevent well collapse, keeps away the groundwater, and most importantly provides structural support. Conductor casing is installed in the ground by either drilling it or hammering it down. It is available in sizes ranging from 18″ to 36″.Surface Casing
The purpose of surface casing is primarily environmental and to ensure safety. It helps in separating the freshwater zones, offers protection from blowout, and supports the wellhead and blow out prevention (BOP) equipment. Therefore surface casing is required to maintain very high safety standards. It is responsible for supporting the next casing in line. It may vary in size depending on the purpose, but the most common size of surface casing is 13 3/8”.
Intermediate Casing
Intermediate casing is not always required in all types of oil and gas production. If used, it is placed between the surface and the production casing. It is available in sizes ranging from 13 3/8” to 16”.
Production Casing
Production casing helps provide structural integrity and pressure control of the hydrocarbon-bearing sections, mainly during the production of oil.
Production Liner
Production liners can be suspended from the production casing or one of the previous casings. They help in reducing the cost significantly as the liner is not required to run through the full depth of the well. Liners can be pre-perforated to help save time and cost.
Tubing
Tubing is inserted inside the wellbore through the oil well casing pipe, which helps the transportation of the hydrocarbons to the surface. It is pipe either used for transporting natural gas or crude oil to the facilities for further processing after the drilling is complete. Similar to the drill pipe and casing, tubing is subjected to high pressure during the extraction process, and needs to be thick, strong, and sturdy. Production tubing is available in various sizes ranging from ¾” to 4 ½”.