The Role of OCTG Pipes in The Oil And Gas Industry

OCTG pipe is the abbreviation of oil-specific pipe. It refers to a type of steel pipe specially used for oil and gas extraction, most of which is the seamless pipe, but the welded pipe also account for a considerable proportion. OCTG pipes mainly include casing pipe, tubing and drill pipe, which withstand high pressure, high temperature and corrosive fluids under different working conditions to ensure the safety and efficiency of oil and gas extraction.

Oil well pipes are mainly used in the exploration and extraction of oil and gas, including tubing, casing pipe and drill pipe. Tubing is used to transport oil from the oil layer to the ground, casing pipe is used to fix the wall of the oil well, and drill pipe is used for oil well drilling. The following will give you a detailed introduction to the role of OCTG pipes in the oil and gas industry.

1. Oil and gas transportation and downhole fluid management

Oil pipes are mainly used to transport underground oil, natural gas or injection fluids to the ground to form a closed channel to improve extraction efficiency. Since oil wells may contain corrosive media (such as hydrogen sulfide H₂S, carbon dioxide CO₂ and high salt water), oil pipes need to have good corrosion resistance and pressure resistance.

To prevent leakage, oil pipes are usually connected with precision threads or special joints to ensure sealing. In high-temperature and high-pressure oil wells, offshore platforms and oil fields in acidic environments, the material selection of oil pipes is particularly important, and corrosion-resistant alloys or special coatings are usually used to extend the service life.

2. Drilling operations and power transmission

The drill pipe is one of the core components in drilling operations. It connects the drilling rig and the drill bit, and is responsible for power transmission, drilling fluid circulation and high torque loads during the drilling process. The drill pipe must have high strength, fatigue resistance and wear resistance because it rotates continuously during the drilling process and is subjected to huge axial tension and torque.

In order to improve the durability of the drill pipe, its surface is usually phosphated, galvanized or ceramic sprayed to enhance corrosion resistance. In deep well, horizontal well and directional well drilling, high-strength and flexible drill pipe can significantly improve drilling efficiency and operation safety.

3. Well support and stable oil well structure

OCTG casing pipe is installed inside the wellbore after drilling is completed. Its main function is to support the wellbore wall, prevent the wellbore wall from collapsing, and isolate the fluids in different formations. The downhole environment is complex, and the formation pressure may cause the wellbore to be unstable. The existence of the casing pipe can provide structural support to ensure the integrity of the wellbore.

At the same time, the casing pipe can also prevent the mutual penetration between groundwater, oil layers and gas layers, avoiding resource waste and environmental pollution. According to the different installation positions, the casing pipe can be divided into surface casing pipe, intermediate casing pipe and production casing pipe, which work together to ensure the long-term stable operation of the wellbore.

Summary

OCTG pipe is the basic equipment for oil and gas extraction. Generally, the OCTG pipe is drilled through the drill pipe to form a hole. After reaching the oil layer, the casing pipe is lowered and cement is injected into the annular space between the casing pipe and the wellbore wall to maintain the wellbore wall and seal the oil, gas and water layers. Then, the oil layer is opened with a perforating gun according to the requirements of oil field development to form a channel, and the oil pipe is lowered. The oil is raised from the bottom of the oil well to the wellhead by using a suitable induction method. It can be seen that OCTG pipe plays an important role in the oil and gas industry, which not only determines the success rate of drilling, but also affects the safety, economy and service life of the entire oil well.