The selection of pipelines in the construction of oil and gas pipelines needs to take into account a variety of factors. The following are several common types of pipelines and their applicable situations:

Steel pipe

Features

High strength: It can withstand high pressure and external loads, and is suitable for long-distance, large-diameter oil and gas transportation, ensuring the safety and stability of the pipeline during high-pressure transportation.

Good corrosion resistance: By adopting anti-corrosion coatings and cathodic protection measures, it can effectively resist corrosion in soil, water and other environments, and extend the service life of the pipeline.

Good toughness: It can adapt to a certain degree of geological deformation and natural disasters such as earthquakes, and reduce the risk of pipeline rupture.

Good connection performance: It can be connected in a variety of ways such as welding and flange connection. The connection is firm and the sealing is good, which can effectively prevent oil and gas leakage.

Applicable scenarios

Long-distance pipelines: such as cross-border and cross-regional oil and gas transmission trunk lines, such as the West-East Gas Transmission Pipeline, etc., steel pipes can meet the transportation requirements of high pressure and large flow.

Subsea pipelines: With its high strength and corrosion resistance, it can operate stably in complex submarine environments, such as the submarine pipeline of the Liwan 3-1 gas field in the South China Sea in China.

Urban gas trunk pipe: In the urban gas supply system, steel pipe can be used as the trunk pipe to undertake the task of transporting high-pressure gas and provide a stable gas source for the city.

Polyethylene pipe (PE pipe)

Features

Corrosion resistance: It has excellent chemical corrosion resistance, no additional anti-corrosion measures are required, and it can resist the erosion of acid, alkali, salt and other substances in the soil.

Good flexibility: It has strong flexibility and can bend with the changes in terrain, which is convenient for construction and can adapt to a certain degree of foundation settlement.

Wear resistance: The surface is smooth and has good wear resistance, which can reduce the wear of oil and gas on the inner wall of the pipeline during transportation and reduce friction resistance.

Convenient connection: Hot melt connection or electric fusion connection is adopted, the connection process is simple, the connection quality is reliable, and the sealing of the pipeline can be effectively guaranteed.

Applicable scenarios

Urban gas branch pipes and household pipes: In the distribution and household connection of urban gas, PE pipes are widely used for their corrosion resistance, good flexibility and convenient connection, such as gas branch pipes and household pipes in urban communities.

Rural biogas pipelines: In rural biogas delivery systems, PE pipes can adapt well to rural environmental conditions and ensure the safe delivery of biogas.

Short-distance oil and gas gathering and transportation pipelines: In short-distance gathering and transportation systems inside oil and gas fields, PE pipes can be used to collect and transport low-pressure oil and gas.

Glass fiber reinforced plastic pipe (FRP pipe)

Features

Extremely corrosion-resistant: It has a high tolerance to various corrosive media such as acids, alkalis, and salts, and is particularly suitable for transporting highly corrosive oil and gas.

Light weight: The weight is only 1/4 to 1/5 of that of steel pipes, which is easy to transport and install, and can reduce construction difficulty and cost.

Good insulation performance: It has good insulation performance, can effectively prevent electrochemical corrosion and lightning induction, and improve the safety of pipelines.

Smooth inner wall: The inner surface is smooth and the hydraulic friction coefficient is small, which can reduce energy loss during oil and gas transportation and improve transportation efficiency.

Applicable scenarios

High-sulfur oil and gas field pipelines: In oil and gas fields with high sulfur and other corrosive media, FRP pipes can effectively resist corrosion and ensure the safe operation of pipelines, such as the gathering and transportation pipelines of some acidic gas fields.

Sewage treatment pipelines: In the sewage treatment system of oil and gas fields, FRP pipes can be used to transport sewage containing corrosive substances.

Coastal oil and gas pipelines: In the humid and high-salt environment of the coast, the corrosion resistance of FRP pipes gives it a clear advantage and can be used for oil and gas transportation and gathering pipelines in coastal areas.

The preferred pipeline for oil and gas pipeline construction needs to be determined according to specific engineering needs and conditions. If there are no special restrictions, steel pipes are generally preferred for long-distance and large-scale oil and gas transportation. The main reasons are as follows:

Outstanding pressure bearing capacity: Steel pipes have high strength and rigidity and can withstand the transportation requirements of oil and gas under high pressure. In long-distance transportation, in order to improve transportation efficiency and reduce costs, higher transportation pressures are usually used. Steel pipes can adapt well to this high-pressure environment and ensure the safe operation of pipelines. For example, in large-scale long-distance pipeline projects such as the West-East Gas Pipeline, steel pipes can withstand pressures of up to 10MPa and above, ensuring the long-distance and stable transportation of natural gas.

Adapt to complex environments: Steel pipes have good toughness and can adapt to a variety of complex geological conditions and environmental factors. Whether in mountainous areas, deserts, swamps or earthquake-prone areas, steel pipes can rely on their good physical properties to resist external forces such as soil stress, ground subsidence, earthquakes, and reduce the risk of pipeline rupture and leakage. For example, in the construction of pipelines across mountainous areas, steel pipes can withstand the stress caused by terrain undulations and geological changes.

Stable material supply: The production technology of steel pipes is mature and the market supply is sufficient. The steel industry is a basic industry with a complete production process and quality control system, which can ensure the supply of pipes required for large-scale pipeline construction. Moreover, steel pipes have a full range of specifications and models, which can be selected and customized according to different engineering needs.

Mature maintenance technology: Steel pipes have a long history of application in oil and gas pipeline construction, and the relevant maintenance and detection technologies are very mature. There are a variety of effective anti-corrosion, detection and repair technologies to choose from, such as coating anti-corrosion, cathodic protection, ultrasonic detection, magnetic flux leakage detection, etc., which can promptly detect and deal with problems in the pipeline and extend the service life of the pipeline.