Land oil and gas transportation

Detection cost: Land oil and gas pipelines usually use technologies such as intelligent pipe cleaning detection and magnetic flux leakage detection. The price of intelligent pipe cleaners is relatively high. Each detection requires the configuration of appropriate pipe cleaners according to the length and diameter of the pipeline, and the cost may range from tens of thousands to hundreds of thousands of yuan. In addition, professional detection equipment and personnel are required to regularly inspect the pipeline, and labor costs and equipment maintenance costs cannot be ignored. The detection cost of long-distance and large-diameter oil and gas pipelines is relatively higher.

Maintenance cost: Once a pipeline leaks or other failures occur, the maintenance cost mainly includes material costs, labor costs, and production stoppage losses caused by maintenance. For small-scale corrosion perforation and other problems, the maintenance materials are mainly patching plates, welding materials, etc., and the cost is relatively low; but if a large area of ​​pipeline damage occurs, the pipe section needs to be replaced, involving pipe procurement, transportation, on-site welding, etc., and the cost may be as high as millions or even tens of millions of yuan. At the same time, the loss of production stoppage is calculated based on the oil and gas transportation volume and market price, which may bring huge economic losses.

Anti-corrosion maintenance cost: Land oil and gas pipelines mostly use coating anti-corrosion combined with cathodic protection. Regular maintenance of the coating requires repainting or repairing damaged parts. The coating materials and construction costs are calculated based on the area of ​​the pipeline, and the cost per kilometer per year may be thousands to tens of thousands of yuan. The maintenance of the cathodic protection system includes anode replacement, potential detection, etc. The cost of anode materials, detection equipment and labor costs may also cost thousands of yuan per kilometer per year.

Marine Engineering

Detection cost: As mentioned above, detection technology is limited and difficult in deep-sea environments. Based on the detection technology of underwater robots, the equipment procurement cost is high, and each detection requires a professional diving support team and ship, and the detection cost is extremely high. The cost of each detection may be as high as millions of yuan, and the detection frequency is relatively low compared to land pipelines because the detection is difficult and has a greater impact on the pipeline.

Maintenance cost: SSAW Steel Pipe maintenance operations in marine engineering are difficult, requiring professional underwater maintenance equipment and technicians. Equipment such as underwater welding robots are expensive, and maintenance materials also need to be specially customized to adapt to the marine environment. The cost of a maintenance may be as high as tens of millions of yuan or even higher, not including indirect losses caused by the suspension of offshore operations due to maintenance, such as the loss of production suspension of offshore oil and gas production platforms.

Anti-corrosion maintenance cost: The marine environment is highly corrosive, and SSAW steel pipes have high anti-corrosion requirements. The maintenance cost of the 3LPE anti-corrosion coating and thermal spray zinc-aluminum coating used is high. Regular inspection and repair of the coating, as well as maintenance of the cathodic protection system, may cost hundreds of thousands of yuan per kilometer per year or even higher. In addition, the attachment of marine organisms may also affect the anti-corrosion effect, and cleaning up marine organisms will also incur additional costs.

Building structure

Inspection cost: The inspection of SSAW steel pipes used for building structures mainly adopts conventional means such as appearance inspection and ultrasonic inspection. The inspection equipment is relatively simple and low-cost compared to land oil and gas pipelines and marine engineering. For large-scale construction projects, the labor cost and equipment use cost of regular inspections may range from tens of thousands to hundreds of thousands of yuan per year, depending on the scale of the building and the amount of steel pipes used.

Maintenance cost: If the SSAW steel pipes in the building structure are damaged, they are mostly local deformation, corrosion and other problems. Maintenance is mainly to repair the damaged parts or replace local components, and the material and labor costs are relatively low. The maintenance cost is usually calculated based on the degree of damage, generally ranging from thousands to tens of thousands of yuan. Compared with land oil and gas pipelines and marine engineering, the maintenance cost is significantly lower.

Anti-corrosion maintenance cost: SSAW steel pipes in building structures are mostly painted for corrosion protection, and the paint surface is regularly maintained, such as touch-up and rust removal. The coating cost and construction cost are relatively low, and the cost per square meter per year may range from tens to hundreds of yuan. The overall anti-corrosion maintenance cost is relatively low in several applications.

Municipal water supply and drainage

Detection cost: Common methods for municipal water supply and drainage pipeline detection include closed-circuit television detection (CCTV) and sonar detection. The detection equipment and labor costs depend on the length and complexity of the pipeline. Generally, the detection cost per kilometer ranges from thousands to tens of thousands of yuan. For water supply and drainage pipelines in old urban areas, the detection cost may be relatively high due to the complex pipeline layout and different pipe diameters.

Maintenance cost: Leakage or blockage in water supply and drainage pipelines is common. Maintenance costs mainly include pipe replacement, repair materials, labor costs, etc. For the maintenance of small-diameter pipes, the cost is relatively low, which may be several thousand yuan; but for large-diameter pipes or when large-scale pipe reconstruction is required, the cost may rise to hundreds of thousands of yuan. In addition, water may need to be stopped during the maintenance process, which will affect the lives of residents, and indirect costs must also be considered.

Anti-corrosion maintenance costs: Municipal water supply and drainage pipes mostly use anti-corrosion measures such as cement mortar lining and epoxy coal tar coating. Cement mortar lining generally does not require frequent maintenance, and the regular maintenance cost of epoxy coal tar coating is relatively low, and the cost per kilometer per year may be around several thousand yuan. In general, the anti-corrosion maintenance cost of SSAW steel pipes in the field of municipal water supply and drainage is at a medium level among various applications.

To determine the inspection cycle of SSAW steel pipes, it is necessary to comprehensively consider factors such as the environment, service life, and transportation medium in the application scenario.

Onshore oil and gas transportation

Based on the corrosiveness of the transportation medium: If the transportation medium contains highly corrosive components such as hydrogen sulfide and carbon dioxide, the pipeline corrosion rate is fast and the inspection cycle should be shortened. For example, in natural gas pipelines containing high concentrations of hydrogen sulfide, a comprehensive inspection may be required every 1-2 years. With the help of intelligent cleaning detection technology, corrosion and cracks on the inner wall of the pipeline can be accurately detected. For light crude oil pipelines with weaker corrosiveness, the inspection cycle can be appropriately extended to 3-5 years.

Based on the service life of the pipeline: In the first 5 years of a newly built pipeline, the inspection cycle can be set to 3-5 years due to the new material and relatively strict manufacturing process control. As the service life increases, the pipeline is affected by internal and external factors, and its performance gradually decreases. The inspection cycle of pipelines over 10 years should be shortened to 1-3 years, so as to detect potential defects in time and ensure safe transportation.

Reference operating pressure and temperature: Pipelines with high operating pressure and large temperature fluctuations are prone to fatigue damage and other problems due to the large stress. For high-temperature and high-pressure oil and gas pipelines with working pressure exceeding 10MPa and temperature above 100℃, non-destructive testing such as magnetic leakage detection may be performed every year to monitor pipeline integrity; while for pipelines with relatively stable pressure and temperature, the inspection cycle can be appropriately relaxed.

Marine Engineering

Consider the seawater corrosion environment: Seawater is highly corrosive, especially in deep sea areas. Low temperature, high salt and high pressure accelerate the corrosion of steel pipes. For SSAW steel pipes in shallow sea areas, such as pipelines for nearshore marine aquaculture facilities, underwater ultrasonic testing technology is required every 2-3 years to check the integrity of the coating and the change in pipe wall thickness; deep-sea oil and gas pipelines are difficult to detect and costly, so the inspection cycle is usually 3-5 years, but some parameters will be monitored in real time with the online monitoring system.

Combined with the importance of pipelines: key pipelines that undertake the main oil and gas transportation tasks, such as the main pipelines connecting offshore oil and gas platforms and land terminals, have a shorter inspection cycle, generally a comprehensive inspection every 2-3 years, covering underwater robot inspection, potential inspection and other means. For some auxiliary pipelines, such as non-critical connecting pipelines inside the platform, the inspection cycle can be extended to 4-6 years.

Pay attention to the complexity of sea conditions: in areas with severe sea conditions, fast currents and easy to be affected by storms, the pipeline is at high risk of impact and wear, and the inspection cycle needs to be shortened. For example, in offshore wind power foundation steel pipe piles in typhoon-prone sea areas, appearance inspection and necessary non-destructive testing may be required every year; for pipelines in relatively stable sea conditions, the inspection cycle can be appropriately extended.

Building structure

Based on the design life of the building: If the design life of the building is 50 years, the SSAW steel pipe structure can be ultrasonically inspected every 3-5 years in the first 10-15 years to check for deformation, internal defects, etc. As the building service life increases and approaches the end of the design life, the inspection cycle is shortened to 1-3 years to ensure the safety of the building structure.

Consider environmental erosion factors: For buildings in corrosive environments such as humidity and acid rain, such as seaside buildings and industrial plant buildings, steel pipes are prone to rust and corrosion. The inspection cycle is generally 2-3 years, mainly for appearance inspection and coating integrity inspection. For buildings in dry and clean environments, the inspection cycle can be extended to 4-5 years.

Combined with changes in usage functions: If the usage function of a building changes, such as from ordinary office to heavy equipment storage, the load-bearing requirements of the SSAW steel pipe structure will increase, and structural inspection and evaluation must be carried out in a timely manner. The inspection cycle may be shortened to 1-2 years based on the evaluation results to monitor the performance changes of the structure under the new load.

Municipal water supply and drainage

Based on water quality: For pipelines that transport sewage, industrial wastewater and other poor water quality, the inspection cycle is usually 1-2 years due to the large amount of impurities, acid and alkali substances in the water, and the risk of corrosion is high. CCTV inspection, sonar inspection and other means are used to check whether the pipeline has leakage, blockage, corrosion and other problems. For pipelines that transport clean tap water, the inspection cycle can be extended to 3-5 years.

Reference pipeline operation status: Pipelines that often have leakage, burst pipes and other faults indicate that their operation is poor, and the inspection cycle should be shortened to less than 1 year to timely troubleshoot and solve the problem. For pipelines that operate stably and have no obvious faults, the inspection cycle can be carried out according to normal standards.

Consider urban development plans: With urban development, some areas may carry out projects such as road reconstruction and underground space development. The municipal water supply and drainage SSAW steel pipes involved may be affected by surrounding construction. During this period, more frequent inspections are required, even every six months. After the construction is completed, the inspection cycle can be adjusted according to the actual situation.