Abstract

With the continuous development of China's pipeline industry, a third-generation pipeline technology system represented by the China Russia East Gas Pipeline has been formed, and the overall technical level with pipeline transportation as the strategy source has entered the world's first tier. By systematically summarizing the technological development status of China's pipeline transportation engineering design and construction, material equipment, transportation and storage, and safety maintenance, this article analyzes the opportunities and challenges faced by the development of oil and gas storage and transportation technology under the new energy security strategy of "four revolutions and one cooperation", and looks forward to the development directions of traditional oil and gas storage and transportation technology upgrading, digital transformation, new energy storage and transportation, and unconventional pipeline technology. In the face of new situations and requirements, pipeline enterprises should provide strong support for ensuring national energy security and improving the construction of modern energy systems while ensuring the safe and efficient transportation of oil and natural gas.

Since the establishment of the People's Republic of China, with the development of the petroleum industry and national economy, China's pipeline industry has gone through three main stages: self-reliance and hard work entrepreneurship from the 1950s to the early 1980s, technology introduction and capacity improvement from the mid-1980s to the late 1990s, and independent innovation, transformation and upgrading from the early 21st century to the present. As of the end of 2021, the total length of China's long-distance oil and gas pipelines has reached 14.8 x 10⁴ km, including 8.76 x 10⁴ km of natural gas pipelines, 3.13 × 10⁴ km of crude oil pipelines, and 2.91 × 10⁴ km of finished oil pipelines; 22 LNG receiving stations with a total receiving capacity of 10225×10⁴ t/a; There are 30 gas storage facilities with a capacity of 540.09 × 10⁸ m³ and a peak shaving capacity of approximately 149.69×10⁸ m³. China is the third largest pipeline country in the world, with over 95% of its onshore oil and gas being transported through pipelines, benefiting nearly 7×10⁸ people. Oil and gas pipelines have become an important energy lifeline for economic development and people's livelihoods. In 2019, in order to implement the new energy security strategy of "four revolutions and one cooperation" and deepen the reform of the oil and gas system, the Central Committee of the Communist Party of China and the State Council made decisions and deployed the establishment of the National Oil and Gas Pipeline Network Group Co., Ltd. (referred to as the National Pipeline Network). Chinese pipeline enterprises, represented by the national pipeline network, shoulder the mission and responsibility of implementing the national energy security strategy, leading pipeline technology innovation, promoting energy system transformation, and achieving sustainable and high-quality development under the "dual carbon" goals.

1. Development Status

After years of technological breakthroughs and engineering construction practice, China's pipeline transportation technology has made significant progress. In recent years, the construction process of China's oil and gas storage and transportation infrastructure has continued to accelerate, forming a third-generation pipeline technology system represented by the China Russia East Gas Pipeline Project (referred to as the China Russia East Line). A series of core achievements with independent intellectual property rights have been formed in the fields of design and construction, materials and equipment, transportation and storage, safety maintenance, etc., and the overall technical level has entered the world's top tier.

1.1 Design and Construction Technology

In terms of construction technology for high-grade and large-diameter gas pipelines, China has achieved a leading position globally. We have established a relatively mature pipeline design standard and technical system, and developed pipeline design theories and methods for special areas such as strong earthquake fault zones, high mountain canyons, rivers, lakes, seas, permafrost, deserts, and Gobi. The concept and technology of pipeline design have been comprehensively improved, gradually evolving from traditional stress based pipeline design to strain and reliability based pipeline design. Modern methods such as multidisciplinary collaboration, digital modeling, and cloud platform services have greatly improved the efficiency and effectiveness of pipeline design. Pipeline welding has gradually developed from traditional manual welding and relying solely on manual construction to fully automated welding machine mechanized construction flow operation, establishing construction methods that are suitable for various complex terrains, and forming non excavation crossing technologies such as directional drilling, shield tunneling, and pipe jacking under complex geological conditions. For the first time internationally, the China Russia East Gas Pipeline Project has been designed and constructed using a combination of 1422mm large diameter, X80 high steel grade, 12MPa high pressure, and 380×10⁸ m³/a large capacity parameters. This has achieved the comprehensive application of innovative technologies such as fully automatic welding, fully automatic ultrasonic testing, and fully mechanized anti-corrosion joint repair.

1.2 Material and Equipment Technology

Pipeline enterprises have collaborated with material and equipment manufacturers to carry out a series of localization breakthroughs, and have achieved breakthroughs in the localization of key materials and equipment for oil and gas storage and transportation. We have established a complete chain of X70/X80 steel pipes and fittings from basic research to industrial application, and domestically produced X80 steel pipes and fittings have been widely used in pipeline engineering construction. As of now, the construction mileage of China's X80 pipeline has reached 1.9×10⁴ km, exceeding the total mileage of foreign X80 pipelines. We have achieved independent manufacturing of 22 key equipment in 6 categories, including a 20MW electric drive compressor unit, a 30MW gas drive compressor unit, a 2500kW oil pump unit, a 1422mm large-diameter fully welded ball valve, and a PCS system. We have also achieved large-scale application in key projects such as the China Russia East Line, the West East Gas Pipeline 3, and the China Russia crude oil pipeline. We have established application testing platforms such as the National Energy Oil and Gas Pipeline Technology and Equipment Research and Development (Testing) Center, achieving a virtuous cycle of integrated promotion of industry, academia, research and application. The localization rate of the entire pipeline core equipment has reached 95%, and the procurement cost has been reduced by more than 30%, breaking foreign monopolies and promoting the development of national industries, providing solid guarantees for the construction of China's energy strategic channel and independent and controllable energy security.

1.3 Transportation and Storage Technology

More than 80% of the crude oil produced in China is easily condensable and highly viscous. At the same time, the geological environment along the oil and gas pipeline network is complex and variable, with a high proportion of high consequence areas along the pipeline, and it is difficult to control multiple sources and sinks. In the process of solving the technical problems of oil and gas transmission engineering, China's technical level in the field of crude oil flow assurance and centralized regulation of super large and complex oil and gas pipelines has taken the lead in the world. We have established a technical system for ensuring the flow of easily condensable and high viscosity crude oil, independently developed drag reducing agents and nano pour point depressants, developed customized drag reducing agents and pour point depressants, and industrial application technologies. We have proposed a flow evaluation method for crude oil pipelines based on limit states, and achieved sequential and intermittent transportation of various crude oils with significant differences in pour point and viscosity. We overcame the key technology of centralized regulation, developed an integrated platform and control software for oil and gas pipeline network regulation. The total mileage of long oil and gas pipelines under centralized regulation and operation exceeded 9×10⁴ km, becoming the control center of long oil and gas pipelines with the most complex dispatching and operation environment in the world, and realizing the centralized regulation and optimal deployment of "one network in China".

1.4 Safety Maintenance Technology

In response to the demand for safe and reliable operation of oil and gas pipelines, a pipeline integrity technology system with risk pre control as the core has been established, achieving full lifecycle management of oil and gas pipeline network systems. The pipeline failure rate has decreased from 0.87 times (/10³ km·a) in 2006 to the current 0.30 times (/10³ km·a). We have developed a series of specialized internal testing technologies and equipment, including three-axis high-definition magnetic leakage, electromagnetic control array, geometric deformation, centerline surveying, drilling and oil theft. The overall level of technical indicators is comparable to that of foreign countries, and can comprehensively cover all sizes of pipe diameters, meet the engineering testing requirements of metal loss, deformation, centerline surveying and mapping of pipeline bodies, and significantly reduce testing costs. Three generations of oil pipeline leakage monitoring technologies have been developed, including negative pressure wave method, acoustic wave method, negative pressure wave combined with flow balance method, and pipeline safety warning technology based on different fiber optic sensing principles. We have established a pipeline geological hazard protection technology system that integrates investigation and identification, risk assessment, monitoring and early warning, and engineering prevention and control. We have developed a series of technologies for pipeline risk assessment, defect detection, leakage monitoring, and safety warning. We have led the development of three ISO international standards: ISO 19345-1-2019 "Specification for Pipeline Integrity Management of Petroleum and Natural Gas Industry Pipeline Transportation Systems - Part 1: Full Life Cycle Integrity Management of Offshore Pipelines", ISO 19345-2-2019 "Specification for Pipeline Integrity Management of Petroleum and Natural Gas Industry Pipeline Transportation Systems - Part 2: Full Life Cycle Integrity Management of Offshore Pipelines", and ISO 20074-2019 "Geological Hazard Risk Management of Land Pipelines in Petroleum and Natural Gas Industry Pipeline Transportation Systems". Our industry influence and international discourse power have significantly increased.

2. Facing the Situation

Since the 13th Five Year Plan, China's pipeline transportation technology has developed by leaps and bounds, forming a relatively complete oil and gas storage and transportation technology system, and establishing a relatively complete modern pipeline industry system. With the rapid progress of a new round of technological revolution and industrial transformation, cross disciplinary and interdisciplinary technologies are accelerating their integration, and the revolution in oil and gas energy consumption, supply, technology, and system is constantly deepening. The pipeline industry and technological development have entered a period of transformation and innovation. At a new historical starting point, in order for the pipeline industry to achieve high-quality and sustainable development, it is necessary to deeply implement the new energy security strategy, coordinate and solve the synergistic problems between safety, efficiency, value, and low-carbon in the development process, and make every effort to build "safe pipelines, green pipelines, development pipelines, and friendship pipelines", providing lasting impetus for social and economic development.

2.1 Oil and Gas Production Reform brings New Opportunities for the Development of Pipeline Transportation Technology

In recent years, under the background of oil and gas system reform and state-owned enterprise reform, the national pipeline network has been committed to building a "national network", promoting the formation of an X+1+X oil and gas market system, opening up the fast lane of energy development, and bringing new opportunities to the pipeline industry and technological development. As a pillar industry of China's modern energy system, pipelines have industrial advantages, technological advantages, and basic advantages. They should adhere to serving national strategies, serving the needs of the people, and serving the development of the industry. They should effectively play the role of the "1" in X+1+X, establish a knowledge system and a diversified heterogeneous scientific integration system that meets various needs of the pipeline system, solve the comprehensive coordination and economic balance problem between the national energy strategy mission and the development of enterprises themselves, continuously expand the technological boundaries and development space of pipelines, drive the entire oil and gas industry chain and even the energy industry chain to move towards high-end, and release higher value synergy.

2.2 The "Dual Carbon" Development Strategy points out New Directions for Creating Value in Pipeline Networks

The energy sector is the main battlefield for achieving carbon peak and carbon neutrality, while new energy and the "dual carbon" strategy are the driving forces and engines for sustainable development of pipeline networks. The new energy security strategy of "four revolutions and one cooperation" is driving profound changes in the energy consumption structure, and the goal of carbon neutrality will accelerate the transformation of the energy structure. The "14th Five Year Plan for Modern Energy System" points out that during the "14th Five Year Plan" period, China will promote the construction of a modern energy system from three aspects: enhancing the security and stability of the energy supply chain, promoting green and low-carbon transformation of energy production and consumption methods, and improving the modernization level of the energy industry chain. The investment in energy research and development will increase by more than 7% annually, and the number of new key technology breakthrough areas will reach about 50. This has injected strong impetus into accelerating the transformation and upgrading of the oil and gas industry, promoting the integration and development of traditional pipeline transportation technology with CCUS and hydrogen energy transportation. The national pipeline network should grasp this important window period, play the main role of scientific and technological innovation, explore and build a new mode of coordinated development of pipeline network, power grid and information network, promote the deep integration of oil and gas pipeline network and energy Internet, and form a multi wheel energy supply system driven by coal, oil, gas, nuclear, new energy and renewable energy.