OCTG Pipe – Drill Pipe，Casing，Tubing，Production Standards

OCTG Pipe – OCTG Meaning

OCTG stands for Oil Country Tubular Goods. OCTG Pipe is the lifeline of the oil industry, ensuring the safety and efficiency of the oil extraction and transportation industry.

OCTG Pipe – Three Types

Drill pipe

Drill pipe, consisting of a caliper, drill bit, drill rod, and casing, is primarily used to transmit power torque and transport drilling fluid. Heavy-duty seamless pipe is typically used for this purpose. OCTG pipe requires exceptional strength due to its heavy load. During drilling, the drill pipe must withstand not only its own weight but also the internal pressure of the drilling fluid, as well as the high torque required for drilling and drill bit selection.

Casing

The casing is the most critical and fundamental component of an OCTG, comprising 77% of the entire piping system. It is lowered into a drilled well, cement is injected between the wellbore walls, and the casing forms a permanent seal. Its core function is to prevent collapse, isolate the formation, and seal the wellbore, preventing leaks. Large-diameter pipes with thick walls are typically used, requiring extremely precise threaded connections.

Tubing

The diameter of the tubing is typically smaller than the casing because it is inserted into the casing to transport oil and natural gas to the surface, the third stage of the wellbore process. The tubing is then connected using tubing threads to form an extremely long continuous pipeline that can penetrate deep underground. Tubing has extremely high requirements for corrosion resistance and high temperature resistance.

OCTG Pipe Production Standards

API 5CT is the global standard for the OCTG pipeline industry. It is a standard developed and issued by the American Petroleum Institute. Although other oil and gas producing countries and international organizations have also developed their own standards, the content of the standards is similar to that of the API.

Common Steel Grade

API 5CT H40、API 5CT K55、API 5CT R95、API 5CT P110

API 5CT J55、API 5CT N80、API 5CT L80、API 5CT Q125

We sell all of the above steel grades of API 5CT pipe. If you require OCTG pipe or OCTG pipe threads, please contact PANDAPIPE by clicking below. PANDAPIPE is a pipe manufacturer and distributor, a company you can trust.

Physical Properties Of Steel Grades

Different steel grades have different Yield Strength, Tensile and Hardness max. If you want to purchase 5CT standard OCTG Pipe but don’t know which steel grade to use, you can refer to the figure below.

OCTG Pipe Threaded Connection

OCTG threads primarily adhere to the API 5CT standard. So why am I giving OCTG threaded connections a separate heading, rather than placing them under “Production Standards,”? Because I want to emphasize the importance of OCTG  threaded connections!
Threaded connections are more than just screwing; they are the weakest link in oil and gas extraction, the most vulnerable to leaks and fractures!