Thread Content
The major technical pilot project for the coal-to-gas transmission pipeline in Xinjiang was successfully completed and approved. Author/Source: Yaha Coal Chemical Industry; Date: June 24, 2019; Clicks: 9. Recently, the “Major Technical Pilot Project for the Coal-to-Gas Transmission Pipeline in Xinjiang,” carried out by Sinopec Petroleum Engineering Design Co., Ltd., finished all its research tasks and was successfully approved by experts in Beijing. The technical achievements resulting from this research – including techniques for crack prevention and strain design of X80 steel under the conditions of coal-to-gas production, methods for controlling the welding properties of X80 steel, strategies for optimizing the wall thickness of large-diameter pipe fittings, and technologies for soft sealing in large-diameter ball valves – will provide technical support for Sinopec in the construction and safe operation of large-diameter, high-strength steel coal-to-gas pipelines. It is understood that the Xinjiang coal-to-gas transmission pipeline project is the largest coal-to-gas transmission pipeline in the world planned and constructed by Sinopec. This project represents a significant step in converting coal into clean energy; it involves a large-scale regional transfer of energy, and it holds great importance for alleviating the imbalance between domestic natural gas supply and demand, optimizing the energy structure, and building an environment-friendly society. Unlike existing high-strength long-distance pipelines, the new gas pipeline is the first high-pressure, high-strength steel long-distance pipeline for coal-to-gas conversion, both domestically and internationally. It features a high design pressure (12 MPa), a large diameter (1219 mm), and a high steel grade (X80). The medium transported is coal-to-gas gas containing hydrogen. To determine appropriate criteria for the crack resistance toughness of X80 steel used in transporting this gas, to establish an accurate design model based on strain theory, and to address issues such as unstable quality of the circumferential welds, excessively thick wall thicknesses in tees, and the tendency of non-metallic materials in fully welded ball valves to fail under pressure, various studies and tests are required for verification. Therefore, this project imposes high requirements on pipeline materials, fittings, valves, and welding processes. This pilot project was proposed in July 2013; after multiple reviews by Sinopec’s headquarters’ Engineering Department, Science and Technology Department, Development Planning Department, the New Pipeline Company, as well as experts from within and outside the industry, it was ultimately designated as a major technical pilot project. It comprises 4 research topics and 9 sub-areas, with all research work to be carried out by Petroleum Engineering Design. After 6 years of intense efforts, the technical personnel overcame a series of technical challenges associated with coal-to-gas pipelines. For the first time in China, systematic research was conducted on high-strength, large-diameter coal-to-gas pipelines, covering aspects such as pipe materials, welding, fittings, and pipeline valves. Internationally, for the first time, full-scale blast tests under coal-to-gas operating conditions were carried out, as well as full-scale (D1219 mm) bending tests on X80 steel pipes designed based on strain criteria, and evaluations of soft-sealing materials for high-pressure, large-diameter fully welded ball valves used in coal-to-gas applications. The resulting set of technical requirements, testing methods, and acceptance standards have been successfully applied in key projects such as the Qianjiang-Shaoguan section of the Xinjiang coal-to-gas transmission pipeline project, ensuring the quality of engineering construction and enhancing China Petrochemical’s technical capabilities in pipeline construction. Among them, the major technological achievements in the field of new gas technology were fully utilized in the construction of the E’an-Cang gas pipeline, a key project under the supervision of the State Council. These achievements provided solid technical support for the successful commissioning of the pipeline on November 15th, thereby ensuring a stable supply of natural gas for Hebei Province.