The West-East Gas Transmission Project has taken corresponding measures in terms of spiral steel pipe anti-corrosion, pipeline design, and construction, and coping with complex environments to ensure pipeline safety
During the design and construction process of the West-East Gas Transmission Project, we always consider the safe selection of pipelines with different wall thicknesses as the first consideration. According to the natural environmental conditions along the pipeline of the project and the requirements for pipeline reliability, the combined protection method of external anti-corrosion coating and reinforced current cathodic protection is adopted for pipeline anti-corrosion. The pipeline outer anti-corrosion layer adopts three layers of PE anti-corrosion, and a total of 42 cathodic protection stations are set up along the entire line.
The current situation assessment, predictive assessment, and comprehensive assessment of the dangers of various geological disasters were carried out. The danger level was divided, the main geological disaster types and danger levels were determined, the suitability of the land was evaluated, and suggestions for countermeasures and measures for preventing and controlling geological disasters were proposed; the activity of the main faults along the pipeline was evaluated, and the pipeline seismic calculation was carried out for the pipeline passing through the high-intensity area in the preliminary design. The station engineering design was designed according to the seismic intensity of the area; the preliminary design carried out the seismic design for 8 active faults intersecting with the pipeline.
At the same time, by the relevant provisions of the design specifications, different design coefficients are used to ensure the safety of pipelines and environments passing through different regions. For complex and difficult areas where the pipeline passes, the design safety factor of the pipeline is partially increased to ensure the safety of the pipeline in special areas. The width of the West-East Gas Pipeline construction operation zone is 28 meters (plain) and 18 meters (mountainous areas); the cross-section of the trench is generally trapezoidal, the width of the upper opening of the excavation does not exceed 5 meters, and the depth of the trench generally does not exceed 2.5 meters.
To ensure the safety of pipelines passing through large rivers, mountains, and other areas, crossing, tunnel crossing, and top pipe crossing are adopted; for different areas where the pipeline passes, appropriate pipeline protection measures are taken, such as in the desert Gobi areas of Xinjiang and Gansu, wind and sand fixation is the main focus, and in the Henan-Anhui plain and the Jiangnan water network area, pipeline stability is the main focus, etc.
During the construction of the West-East Gas Pipeline, great attention was paid to environmental protection along the route.
The ecological environment along the West-East Gas Pipeline project is complex and changeable. We have carried out the project “Research on the Safety, Restoration, and Components of the Ecological Environment in the Areas Along the Long-distance Pipeline”, systematically analyzed the relationship between pipeline construction and the ecological environment along the route, put forward requirements for ecological environment protection and restoration, and drew specific technical diagrams for ecological environment protection and restoration.
In the construction of the pipeline, the QHSE management system of all parties involved in the project construction is established and improved, to achieve the harmonious unity of pipeline construction and quality, health, safety, and environment. Reduce the damage to the natural environment during construction operations, eliminate any environmental pollution accidents during work, and discharge various pollutants after meeting the relevant national standards.
For example, in the protection of cultural relics of Zhongshan Grottoes in Shaanxi Province, where the pipeline passes, the blasting and trenching are minimized, the amount of blasting charges is controlled, and necessary test explosions are carried out. In special cases, trenches can be excavated manually to meet the requirements of cultural relics protection; when the pipeline passes through the forest area at the top of Dajian Mountain, which is lush with trees, the design does not hesitate to adopt tunnel construction and increase the investment in pipeline engineering in some areas to avoid damage to the trees; for special locations such as loess ridges along the pipeline, targeted special designs are carried out, and gray soil backfilling is used to widen the ridges and engineering and water conservation measures such as interception and drainage ditches and vegetation are built; in the design and construction, the centralized stacking and protection of waste slag generated by tunnel construction are considered; appropriate engineering construction measures such as diversion and drainage, filling and plugging, deep burial, and water-blocking walls are adopted to ensure pipeline safety and reduce soil erosion.
These seemingly small practices have laid a solid foundation for environmental protection, which also creates conditions for pipeline safety.
Post time: Sep-10-2024