【Ten Years of Rapid Development in Chemical Equipment】1298-2023: 4 Firsts Achieved! Operation of the natural gas pipeline under the seabed in Jiaozhou Bay, Qingdao

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On November 28, 2023, the natural gas pipeline beneath Jiaozhou Bay in Qingdao was officially put into operation. Since then, Qingdao has changed from being the end point for natural gas transported via the \"West-to-East Gas Transmission\" pipeline to becoming the starting point for liquefied natural gas (LNG) supply. This pipeline can meet the city’s medium- to long-term natural gas demand in the future, providing solid support for achieving coal-free heating in the main urban area on the east coast of Qingdao. 　　This pipeline has set four firsts in China’s urban gas industry: it is the urban gas pipeline with the longest distance over water (12 kilometers) ； The first urban gas pipeline to pass directly under the cross-sea bridge ； The first urban gas pipeline laid using the land-to-sea directional drilling technique (with a crossing length of 1402 meters and a depth of 45.2 meters) ； The horizontal directional drilling crossed the longest urban gas pipeline (2482 meters). 　　Once completed and put into operation, this pipeline will have a gas transmission capacity of 3.6 billion cubic meters per year. It will meet the gas demand of various projects along its route, including those in the SCO Demonstration Zone, high-tech zones, as well as large-scale gas-powered power generation projects and coal-to-gas conversion projects. It will also be able to satisfy the city’s gas needs for the next 20 years. Each year, it will enable the substitution of 5.36 million tons of coal, resulting in a reduction of 5 million tons of carbon emissions, 21,600 tons of sulfur dioxide emissions, and 4,320 tons of dust emissions, thereby further contributing to Qingdao’s achievement of its \"dual carbon\" goals. 　　It is reported that the total investment in this project amounts to 1.45 billion yuan. It was officially launched on December 30, 2021, with the construction of its main route completed by December 2022. The pipeline starts from the Jiaozhou distribution station on Sinopec’s East Main Pipeline, passes through Jiaozhou City and Chengyang District, enters the sea west of Nügukou Bridge, comes ashore via the Zhenping Road pressure regulation station, connects with the city’s \"three horizontal and four vertical\" sub-high pressure gas pipelines, and extends southward to Huadian Qingdao Power Plant. 　　The total length of this pipeline is 72 kilometers, of which about 60 kilometers are on land and approximately 12 kilometers run beneath the seabed of Jiaozhou Bay. The geological conditions and marine environment along its route are complex and variable, a situation that is rare in China. Bi Hongbo, deputy general manager of Qingdao Energy China Resources Gas Co., Ltd., the company responsible for the construction of this project, explained that the entire pipeline crosses more than 60 towns, streets, and administrative villages. It passes through 35 railways, highways, national roads, municipal roads, and other types of roads, as well as over 50 large and small rivers and ponds. The directional drilling for the Dagu River was carried out at a depth of 27 meters below the river surface, which is equivalent to the height of nine floors; the horizontal length of this pipeline is 2,482 meters, setting a new record for the longest horizontal directional drilling distance for urban gas pipelines with a diameter of 1,016 millimeters in China. 　　“To advance the project construction, we have deployed a total of 39 construction units, over 314 sets of equipment, 21 vessels, and more than 600 construction workers. For the first time, a smart chemical plant management model was adopted, with on-site ‘task mapping’ in place’ ； By utilizing domestically leading fully automatic welding machines and fully mechanized anti-corrosion patching technologies, the one-time pass rate for welds exceeds 98%. ”Huang Cheng, assistant to the general manager of CNPC Pipeline Bureau and the general contractor for the project, said. Faced with the difficulties and obstacles in the construction process, the participating units worked together, conducted repeated site inspections, and optimized the route design ； Land-sea combined transport, multi-channel material allocation ； After several revisions to the plan, the construction strategy was finalized. By carrying out work in intervals and advancing tasks sequentially, the construction of the main line as well as its commissioning were ultimately completed on schedule. 　　Taking the official commissioning of the natural gas pipeline under the Jiaozhou Bay as an opportunity, Qingdao Energy Group will, on the basis of ensuring the safe and efficient operation of the submarine pipeline, accelerate the construction of major projects such as LNG strategic reserve facilities and related pipelines, in order to establish a safe and stable energy supply system, a well-connected pipeline distribution network, and a flexible and efficient reserve and peak-shaving system.