When choosing this type of steel pipe for a specific industry application, the following aspects can be considered:

1. Industry standards and specifications

Different industries have specific standards and specifications for the use of steel pipes. For example, in the oil and gas industry, API standards (such as API 5L, etc.) are often followed, which have detailed provisions on the size, material, performance, etc. of steel pipes.

The chemical industry may control the quality and performance of steel pipes based on domestic standards such as GB/T 9711.

The construction industry has standards such as GB/T 13793 and JG/T 141, which stipulate the technical requirements for steel pipes for construction.

When selecting steel pipes, it is necessary to ensure that the selected steel pipes fully meet the standards and specifications of the industry to ensure the quality and safety of the project.

2. Working environment and medium

Temperature and pressure: If the steel pipe needs to work in a high temperature and high pressure environment, such as in the pipeline system of an oil refinery, the steam transmission pipeline of a power plant, etc., it is necessary to select a steel pipe material with good high temperature strength and stability. Such as chromium-molybdenum alloy steel (such as 15CrMo, 12Cr1MoV, etc.), this type of material can still maintain high strength and creep resistance at high temperatures, meeting the use requirements in high temperature and high pressure environments.

Corrosive media: When steel pipes are used to transport fluids containing corrosive media such as acids, alkalis, and salts, such as various corrosive material transportation pipelines in the chemical industry, seawater transportation pipelines in seawater desalination plants, etc., appropriate anti-corrosion measures and steel pipe materials must be selected according to the specific characteristics of the corrosive medium. For pipelines that transport strong acidic media such as sulfuric acid and hydrochloric acid, steel pipes lined with corrosion-resistant plastics such as polytetrafluoroethylene (PTFE) and polypropylene (PP) can be selected, or steel pipes made of high-alloy stainless steel (such as 316L, 904L, etc.) can be selected. These materials have good resistance to acidic media corrosion. For pipelines that transport alkaline media, ordinary carbon steel has good tolerance to alkaline media under certain conditions, but if the alkalinity is strong or there are special requirements, stainless steel pipes can also be selected.

Wear environment: In some scenarios where fluids containing solid particles need to be transported, such as tailings transportation pipelines in the mining industry and coal powder transportation pipelines in thermal power plants, steel pipes will face serious wear problems. In order to improve the wear resistance of steel pipes, steel pipes with wear-resistant coatings on the inner surface can be selected, such as ceramic coated steel pipes, tungsten carbide coated steel pipes, etc. These wear-resistant coatings have the characteristics of high hardness and good wear resistance, which can effectively resist the erosion and wear of solid particles and extend the service life of steel pipes. In addition, high-hardness alloy steel pipes, such as manganese steel, chromium-molybdenum alloy steel, etc., can also be selected. After special heat treatment, their hardness and wear resistance are significantly improved to meet the use requirements in wear environments.

3. Performance requirements of steel pipes

Mechanical properties: Depending on the use scenarios of steel pipes in specific industries, there are different requirements for their mechanical properties. In the construction industry, steel pipes used for building structural support, such as columns of high-rise buildings and supporting structures of bridges, need to have high strength and good toughness. Higher strength can ensure that the steel pipe will not be deformed or damaged under the weight of the building and various loads; good toughness enables the steel pipe to absorb energy and avoid brittle fracture when it is subjected to natural disasters such as earthquakes, wind disasters or other unexpected impacts, thereby ensuring the structural safety of the building. In the oil and gas industry, pipelines used for long-distance transportation of oil and gas need to have good fatigue resistance in addition to having high strength to withstand the pressure of oil and gas in the pipeline. Due to the long-term flow of oil and gas in the pipeline, certain pressure fluctuations and friction will occur on the inner wall of the pipeline, which will cause fatigue damage to the pipeline material. If the fatigue resistance of the pipeline is insufficient, cracks will gradually appear on the inner wall of the pipeline over time and continue to expand, which may eventually cause the pipeline to rupture and cause serious accidents such as oil and gas leakage. Therefore, for oil and gas pipelines, good fatigue resistance is one of the key factors to ensure its long-term safe and stable operation.

Process performance: In specific industry applications, the process performance of steel pipes has an important impact on their processing and use effects. In the oil and gas industry, when steel pipes are used for oil well casings and oil pipes, their connection performance is crucial. The working environment of oil wells is complex, and steel pipes need to be reliably connected underground to withstand various loads such as high pressure, high temperature, and formation stress. Therefore, this type of steel pipe usually adopts special threaded connection methods, such as API standard BC and TC. These threaded connection methods have been verified by long-term practice and have good sealing, connection strength and torque resistance, which can ensure the safe and reliable operation of steel pipes in oil wells. In the construction industry, the welding performance of steel pipes used in building structures is an important process performance indicator. During the construction process, steel pipes are often required to be connected into various structural forms by welding, such as frame structures, truss structures, etc. Good welding performance can ensure that the weld and the parent material can be well fused during the welding process of the steel pipe to form a firm connection joint, and no welding defects such as cracks, pores, and slag inclusions will appear after welding. This is crucial to ensure the overall strength and stability of the building structure. In order to meet the welding performance requirements of steel pipes for construction, steel with good weldability is usually selected as the raw material of steel pipes, such as carbon structural steels such as Q235 and Q345 and low-alloy high-strength structural steels. These steels have good weldability in chemical composition and mechanical properties, and can meet the process requirements of steel pipe welding in building structures.

4. Size and specifications

Pipe diameter and wall thickness: Specific industries have clear requirements for the pipe diameter and wall thickness of steel pipes. In long-distance oil and gas pipelines, the pipe diameter is determined by the transportation volume and transportation distance. For example, for large-scale cross-regional natural gas transmission pipelines, in order to meet the large gas transmission volume demand, steel pipes with larger pipe diameters, such as steel pipes with specifications of 1016mm and 1219mm, are usually selected. At the same time, the choice of wall thickness should comprehensively consider factors such as the working pressure of the pipeline, the characteristics of the transmission medium, and the environmental conditions of the pipeline. In high-pressure natural gas transmission pipelines, in order to withstand higher internal pressures, steel pipes with larger wall thicknesses need to be selected to ensure the structural strength and safety of the pipeline. Generally speaking, the wall thickness will be within a certain range according to the pipe diameter and working pressure. For example, for a high-pressure natural gas transmission pipeline with a diameter of 1016mm, the wall thickness may be selected between 14.6mm and 25.4mm. In the water supply and drainage pipeline system of the construction industry, the selection of pipe diameter and wall thickness is mainly determined by factors such as the type and scale of the building, and the design flow and working pressure of the water supply and drainage system. For indoor water supply and drainage pipelines in general residential buildings, in order to meet the needs of daily water and drainage, the pipe diameter usually chooses smaller specifications, such as DN20, DN25, DN32, etc. (DN represents nominal diameter). At the same time, considering the relatively low working pressure of the water supply and drainage system, as well as the installation and maintenance requirements of the pipeline, the wall thickness will also choose relatively thin specifications to reduce costs and reduce the weight of the pipeline. For example, for a DN25 PPR (random copolymer polypropylene) water supply pipe, the wall thickness may be selected between 2.3mm and 3.5mm, and the specific wall thickness will be reasonably determined according to the use environment and design requirements of the pipeline.

Length: The length requirements of steel pipes vary depending on the industry application scenarios. In the construction industry, the length of steel pipes used to build scaffolding usually has a variety of specifications to meet the needs of different building structures and construction processes. Common scaffolding steel pipe lengths include 3m, 4m, 6m and other specifications. Shorter 3m and 4m length steel pipes are suitable for building some scaffolding with lower height and more compact structure, or for adjusting and reinforcing local positions of scaffolding. The 6m length steel pipe is widely used in the construction of large scaffolding, which can reduce the number of joints of steel pipes and improve the overall stability and construction efficiency of scaffolding. In the oil and gas industry, the length of steel pipes used for long-distance transmission pipelines is usually longer. This is to reduce the number of welded joints of the pipeline, reduce the risk of welding quality, and improve the overall sealing and safety of the pipeline. Generally speaking, the single length of steel pipes for oil and gas transmission pipelines is between 12m and 14m. For example, the common API 5L standard steel pipes usually have a single length of 12.2m. Such a length design is not only convenient for the production, transportation and installation of steel pipes, but also can effectively reduce the number of pipeline welding joints, thereby improving the reliability and service life of the pipeline system.

5. Quality and Reliability

Quality system certification: Choosing a steel pipe supplier with relevant quality system certification is an important prerequisite for ensuring the quality of steel pipes. For example, ISO 9001 quality management system certification is an internationally recognized quality management standard. Enterprises that have passed this certification indicate that they have established a sound system in quality management and can ensure the stability and reliability of product quality. In the steel pipe industry, many well-known steel pipe manufacturers have passed ISO 9001 quality management system certification, which provides a strong guarantee for the quality of the steel pipes they produce. In addition, some specific industries also require steel pipe suppliers to have industry-specific quality certifications. In the oil and gas industry, API Spec Q1 quality system certification is a widely recognized industry standard. This certification requires companies to establish and implement an effective quality management system in the design, development, production, installation and service of oil and gas industry products. Steel pipe suppliers that have passed API Spec Q1 quality system certification can better meet the strict requirements of the oil and gas industry in terms of quality and reliability.

Production process and equipment: Advanced production technology and sophisticated production equipment are key factors in producing high-quality steel pipes. In the production process of SSAW Steel Pipes, the forming process has an important influence on the quality of steel pipes. For example, the use of advanced three-roll forming process can make the steel strip more evenly stressed during the rolling process, thereby effectively controlling the roundness and straightness of the steel pipe. Compared with the traditional forming process, the three-roll forming process can significantly improve the dimensional accuracy and appearance quality of the steel pipe, providing better conditions for subsequent welding and processing procedures. The welding process is the core link in the production of SSAW steel pipes, and its quality is directly related to the overall performance of the steel pipe. The modern advanced SSAW steel pipe welding process adopts multi-wire submerged arc welding technology, which can significantly improve the welding speed and deposition efficiency by increasing the number of welding wires and reasonably adjusting the position of the welding wires. At the same time, multi-wire submerged arc welding technology can also improve the forming quality and internal quality of the weld, making the chemical composition of the weld metal more uniform and the mechanical properties more excellent. In addition, the advanced welding equipment is equipped with a high-precision welding parameter control system and a weld tracking system, which can monitor and adjust the various parameters in the welding process in real time to ensure the stability and reliability of the welding quality. In addition to the forming and welding process, the production equipment of the steel pipe also has an important influence on the product quality. For example, high-precision steel strip leveling equipment can effectively eliminate the residual stress and shape defects generated by the steel strip during the rolling process, so that the steel strip can meet higher flatness requirements. This is crucial to ensure the forming quality and dimensional accuracy of the steel pipe. In addition, advanced non-destructive testing equipment such as ultrasonic flaw detectors and radiographic flaw detectors can conduct comprehensive and detailed inspections of the welds and parent materials of the steel pipe, and timely discover internal defects such as pores, slag inclusions, cracks, etc. Through the analysis and evaluation of the test results, corresponding measures can be taken to repair or scrap the steel pipe, thereby ensuring that the quality of the steel pipe shipped from the factory meets the relevant standards and requirements.

In offshore energy transportation, due to the complex marine environment, the performance requirements for steel pipes are relatively strict. The following types of steel pipes are widely used:

SSAW steel pipe (spiral seam submerged arc welded steel pipe)

Large-diameter demand satisfaction: Offshore energy transportation, especially long-distance oil and gas transportation, requires large-diameter pipelines to ensure sufficient transportation volume. SSAW steel pipes can be spirally formed to produce large-diameter steel pipes using narrower steel strips, with a maximum diameter of up to 3600mm, which can well meet the demand for large-diameter pipelines in offshore energy transportation.

Good strength and toughness: In the offshore environment, steel pipes need to withstand the pressure from internal oil and gas, the pressure from external seawater, and the effects of natural forces such as wind, waves, and earthquakes. SSAW steel pipes have high strength and good toughness through reasonable material selection and advanced welding technology, and can maintain structural stability under complex stress conditions, effectively preventing accidents such as pipeline rupture and leakage.

Cost-effectiveness advantage: Since the production process of SSAW steel pipes is relatively mature and the production efficiency is high, large-scale production can be achieved. At the same time, its raw materials are highly adaptable and can be produced using steel strips of different specifications, thereby reducing the cost of raw materials. These factors make SSAW steel pipes have good cost-effectiveness advantages while meeting the requirements of offshore energy transportation, and can save a lot of money for the project.

LSAW Steel Pipe (straight seam submerged arc welded steel pipe)

High precision and high quality: Offshore energy transportation has extremely high requirements for the quality and precision of steel pipes. During the production process of LSAW steel pipe, straight seam welding process is adopted. The weld length is relatively short, the welding process is easier to control, and the dimensional accuracy and weld quality of the steel pipe can be effectively guaranteed. The deviation range of its pipe diameter and wall thickness is small, the internal quality of the weld is uniform, and the defect incidence rate is low, which can meet the high precision and high quality requirements of offshore energy transportation for steel pipes.

Excellent corrosion resistance: The marine environment has the characteristics of high salinity, high humidity and strong corrosiveness, which poses a severe challenge to the corrosion resistance of steel pipes. LSAW steel pipes usually use high-quality steel as raw materials, and carry out special anti-corrosion treatment on the surface, such as hot-dip aluminum plating, zinc-nickel alloy plating, epoxy powder coating, etc. These anti-corrosion treatment methods can form a dense and uniform protective film on the surface of the steel pipe, effectively isolating the steel pipe from the contact with the external corrosive medium, thereby significantly improving the corrosion resistance of the steel pipe and extending its service life in the offshore environment.

Adapt to special working conditions: In offshore energy transportation, some special working conditions have special requirements for the performance of steel pipes. For example, when oil and gas are extracted in deep sea areas, steel pipes need to withstand extremely high external seawater pressure; in the extraction of some oil and gas fields containing corrosive gases such as hydrogen sulfide and carbon dioxide, steel pipes need to have good resistance to hydrogen sulfide stress corrosion cracking (SSCC) and carbon dioxide corrosion. LSAW steel pipes can be customized according to different special working conditions by adjusting the chemical composition of steel, optimizing heat treatment processes, and adopting special anti-corrosion measures, so that the performance of steel pipes can be customized to meet the use requirements under various special working conditions and ensure the safe and reliable transportation of offshore energy.

Seamless steel pipes

High strength and pressure bearing capacity: Offshore energy transportation, especially in the high-pressure oil and gas transportation link, requires steel pipes to have extremely high strength and pressure bearing capacity. In the production process of seamless steel pipes, through perforation, pipe rolling and other processes, there is no weld on the pipe wall of the steel pipe, thereby avoiding possible defects and weak links at the weld. This makes the seamless steel pipe have a uniform and consistent organizational structure and high strength, which can withstand greater internal pressure, effectively prevent accidents such as pipeline rupture and leakage under high pressure, and ensure the safety and reliability of offshore energy transportation.

Good fatigue resistance: In the offshore environment, steel pipes are subject to a variety of dynamic loads, such as pipeline vibration caused by wind and waves, pressure fluctuations during oil and gas transportation, etc. These dynamic loads will cause fatigue damage to the steel pipe material. Over time, the fatigue damage will gradually accumulate, causing cracks in the steel pipe and eventually fatigue fracture. Seamless steel pipes have good fatigue resistance due to their uniform organizational structure and the absence of defects such as welds. Under the same dynamic load conditions, the fatigue life of seamless steel pipes is relatively long, which can effectively resist the accumulation of fatigue damage, reduce the probability of pipeline accidents caused by fatigue fracture, and provide long-term and stable operation guarantee for offshore energy transportation.

High precision and corrosion resistance: Offshore energy transportation also has high requirements for the dimensional accuracy and corrosion resistance of steel pipes. In the production process of seamless steel pipes, advanced production equipment and precise process control can ensure that the steel pipes have high dimensional accuracy, and the deviation range of the pipe diameter and wall thickness is small, which can meet the high-precision requirements of offshore energy transportation for steel pipes. At the same time, seamless steel pipes can select suitable steel materials according to different use environments and transportation media, and carry out corresponding surface treatments, such as hot-dip plating, coating, passivation, etc. These surface treatment methods can form a dense and uniform protective film on the surface of the steel pipe, effectively isolating the steel pipe from the contact with the external corrosive medium, thereby significantly improving the corrosion resistance of the steel pipe, extending its service life in the offshore environment, and ensuring the long-term stable operation of offshore energy transportation.

In the field of offshore energy transportation, compared with other types of steel pipes, SSAW steel pipes (spiral seam submerged arc welded steel pipes) have many significant advantages:

1. Excellent mechanical properties

High strength and high toughness: The offshore environment is complex, and the steel pipe needs to withstand the internal oil and gas high pressure, external seawater pressure, and dynamic loads generated by wind, waves, earthquakes, etc. During the production process, SSAW steel pipes are strictly screened for raw materials and advanced welding and heat treatment processes to make them have the characteristics of high strength and good toughness. This enables it to maintain structural integrity under various complex stress conditions, effectively reduce the probability of accidents such as pipeline rupture and leakage, and ensure the safety and reliability of offshore energy transportation.

Good fatigue resistance: In offshore energy transportation, steel pipes are subjected to alternating loads for a long time, such as pipeline vibration caused by wind and waves, pressure fluctuations during oil and gas transportation, etc., which can easily lead to the accumulation of fatigue damage and then cause fatigue fracture. Due to the special structure of the spiral weld of SSAW steel pipe, the weld can disperse stress and reduce the occurrence of stress concentration when subjected to alternating loads. At the same time, the advanced production process ensures the uniformity of the internal organizational structure of the steel pipe and further improves its fatigue resistance. Therefore, SSAW steel pipes can better resist fatigue damage, extend the service life of the pipeline, and reduce maintenance costs during the long-term operation of offshore energy transportation.

2. Adapt to large-diameter requirements

Large-diameter production advantages: Offshore energy transportation usually requires large-diameter pipelines to meet the needs of efficient and large-scale oil and gas transportation. SSAW steel pipe adopts spiral forming process in the production process, which can produce large-diameter steel pipes with narrow steel strips. Compared with some other production processes, such as straight seam submerged arc welded steel pipe (LSAW), the production of large-diameter steel pipes may be limited by the width of raw materials, and splicing and other methods are required to meet the pipe diameter requirements, which will increase the complexity and cost of the production process to a certain extent. SSAW steel pipe can more flexibly produce various large-diameter specifications of steel pipes through spiral forming process, with a maximum diameter of up to 3600mm, which can well meet the demand for large-diameter pipelines for offshore energy transportation and provide reliable pipeline support for large-scale oil and gas transportation.

Structural stability under large diameter: In the case of large diameter, the structural stability of steel pipes is crucial to ensure the safety of offshore energy transportation. Due to the unique structure of the spiral weld of SSAW steel pipe, the force of the steel pipe in the circumferential direction is more uniform. When the steel pipe is subjected to internal pressure, external seawater pressure and various other loads, the spiral weld can effectively disperse the stress and avoid stress concentration in local areas, thereby improving the structural stability of the steel pipe under large diameter. In contrast, some straight seam welded steel pipes may be more prone to stress concentration in large diameters due to the relatively concentrated distribution of welds, thus affecting the overall structural stability and safety of the steel pipe. Therefore, the good structural stability of SSAW steel pipes in large diameters enables them to reliably undertake the transportation tasks of large-diameter pipelines in offshore energy transportation, providing strong guarantees for the efficient and safe transportation of offshore energy.

3. Significant cost-effectiveness

Raw material cost advantage: SSAW steel pipes have strong flexibility and adaptability in the selection of raw materials. It can use steel strips of different widths and thicknesses as raw materials, and can make full use of some relatively narrow steel strips and process them into large-diameter steel pipes through spiral forming process. This wide adaptability to raw materials gives SSAW steel pipes greater choice in raw material procurement, and can flexibly adjust the raw material procurement strategy according to market price fluctuations, thereby effectively reducing raw material costs. In contrast, some other types of steel pipes, such as LSAW steel pipes, have high requirements for the width of raw materials when producing large-diameter products. They may need to purchase wide steel plates of specific specifications, which limits the flexibility of raw material procurement to a certain extent and may lead to relatively high raw material costs. Therefore, the advantages of SSAW steel pipes in terms of raw material costs enable them to save a lot of money for the project while meeting the needs of offshore energy transportation, thereby improving the overall economic benefits of the project.

Production efficiency and cost control: The production process of SSAW steel pipes is relatively mature, and the production process has a high degree of automation. During the production process, the steel strip can quickly produce a long length of steel pipe through continuous spiral forming and welding processes. Compared with some other types of steel pipe production processes, such as some seamless steel pipes, the production process is relatively complicated, requiring multiple processes such as perforation, pipe rolling, and sizing, and the production efficiency is relatively low. However, due to the characteristics of its production process, SSAW steel pipes can produce a large number of products in a shorter time, thereby improving production efficiency. High production efficiency can not only meet the large demand for steel pipes in offshore energy transportation projects, but also help reduce the production cost of unit products. In the case of large-scale production, fixed costs (such as equipment depreciation, plant leasing, etc.) can be spread over more products, thereby reducing the fixed costs borne by each unit product. At the same time, high production efficiency can also reduce manual intervention in the production process, reduce the probability of quality problems and production accidents caused by human factors, further improve product quality stability and the safety of the production process, and indirectly reduce production costs. Therefore, the advantages of SSAW steel pipes in production efficiency and cost control make it highly competitive in the offshore energy transportation market, and can provide high-quality, low-cost steel pipe products for projects, ensuring the smooth implementation and efficient operation of offshore energy transportation projects.

4. Good corrosion resistance

Special weld structure and corrosion resistance: The spiral weld structure of SSAW steel pipes not only has a positive effect on its mechanical properties, but also has unique advantages in corrosion resistance. Compared with some straight seam welded steel pipes, spiral welds form a continuous and relatively uniform distribution on the surface of the steel pipe. This distribution allows the anti-corrosion treatment on the surface of the steel pipe, such as the application of anti-corrosion coating, hot-dip galvanizing and other processes, to be more evenly covered on the weld and the surface of the parent material, reducing the risk of local corrosion caused by uneven coating thickness or leakage. At the same time, the spiral weld forms a structure similar to a diversion inside the steel pipe. When transporting oil and gas containing corrosive media, the medium flows more smoothly in the pipeline, reducing the accumulation and residence time of the medium at the weld, thereby reducing the possibility of corrosion at the weld. Therefore, the special spiral weld structure of SSAW steel pipe provides a good anti-corrosion foundation for it in offshore energy transportation, helps to extend the service life of the pipeline, and ensures the safe and reliable operation of offshore energy transportation.

Supporting anti-corrosion measures and effects: In order to further improve the corrosion resistance of SSAW steel pipes in offshore energy transportation, a series of supporting anti-corrosion measures are usually taken according to the specific use environment and the characteristics of the transport medium. Common anti-corrosion measures include surface coating protection, cathodic protection, and the addition of corrosion inhibitors. In terms of surface coating protection, coating materials with good corrosion resistance, wear resistance and adhesion are usually selected, such as epoxy powder coating, polyethylene coating, polyurethane coating, etc. These coating materials are evenly covered on the surface of the steel pipe through special coating processes, such as electrostatic spraying, thermal spraying, etc., to form a dense protective film, which effectively isolates the steel pipe from the contact with the external corrosive medium, thereby significantly improving the corrosion resistance of the steel pipe. For example, epoxy powder coating has excellent chemical corrosion resistance, wear resistance and good adhesion, and can form a hard and dense protective film on the surface of the steel pipe, effectively resisting the erosion of corrosive media such as seawater, oil and gas, and is widely used in the anti-corrosion treatment of offshore energy transportation pipelines. In terms of cathodic protection, sacrificial anode method or impressed current method is usually used for cathodic protection of steel pipes. The sacrificial anode method is to use a metal or alloy with a lower potential than the protected metal as an anode, and connect it to the protected steel pipe to form an electrochemical corrosion cell. In this battery, the anode metal will preferentially undergo oxidation reaction and continuously dissolve due to its low potential, thereby providing electrons for the steel pipe, reducing the potential on the surface of the steel pipe and entering the corrosion-free zone, thereby achieving the purpose of preventing the steel pipe from corroding. Commonly used sacrificial anode materials include magnesium alloy, aluminum alloy, zinc alloy, etc. These materials have the characteristics of low potential, large capacitance, and easy shedding of corrosion products, and can provide effective cathodic protection for steel pipes in different seawater environments. The impressed current method is to apply cathodic current to the protected steel pipe through an external power supply, so that the potential on the surface of the steel pipe is reduced and enters the corrosion-free zone, thereby achieving the purpose of preventing the steel pipe from corroding. When using the impressed current method for cathodic protection, it is usually necessary to set auxiliary anodes near the steel pipe, such as high-silicon cast iron anodes, magnetic iron oxide anodes, mixed metal oxide anodes, etc. These auxiliary anodes have good conductivity, corrosion resistance and low consumption rate, and can stably provide cathodic current to the steel pipe during long-term cathodic protection. At the same time, it is also necessary to equip the corresponding power supply equipment and control system, such as rectifier, constant potentiostat, etc. These equipment can automatically adjust the output current according to the potential change of the steel pipe surface, so that the potential of the steel pipe surface is always kept within the set protection potential range, thereby ensuring the effect of cathodic protection. In terms of adding corrosion inhibitors, suitable corrosion inhibitors are usually selected and added to the conveying medium according to the properties and composition of the conveying medium. Corrosion inhibitor is a chemical substance that can form a protective film on the metal surface to inhibit metal corrosion. The mechanism of action of corrosion inhibitors mainly includes adsorption, film formation and chemical reaction. In terms of adsorption, corrosion inhibitor molecules can form a tight adsorption film on the metal surface by physical adsorption or chemical adsorption, thereby preventing the contact between the corrosive medium and the metal surface, and achieving the purpose of inhibiting corrosion. In terms of film formation, corrosion inhibitor molecules can react chemically on the metal surface to generate an insoluble protective film, such as a passivation film, a precipitation film, etc. These protective films can effectively isolate the metal from the contact with the corrosive medium, thereby inhibiting the corrosion of the metal. In terms of chemical reaction, corrosion inhibitor molecules can react chemically with certain components in the corrosive medium, thereby changing the properties and composition of the corrosive medium and reducing the corrosiveness of the corrosive medium to the metal. For example, when transporting oil and gas containing hydrogen sulfide, some nitrogen-containing and sulfur-containing organic corrosion inhibitors are usually added. These corrosion inhibitors can form a dense adsorption film or precipitation film on the metal surface, effectively preventing hydrogen sulfide from contacting the metal surface, thereby inhibiting metal corrosion. By taking the above series of supporting anti-corrosion measures, the corrosion resistance of SSAW steel pipes in offshore energy transportation has been significantly improved, and they can operate stably for a long time in harsh marine environments and complex transportation media conditions, effectively extending the service life of the pipeline, reducing maintenance costs, and ensuring the safety, reliability and economy of offshore energy transportation.