【Ten Years of Rapid Development in Chemical Engineering Equipment】The First Long-Distance Casing Directional Drilling Crossing for Water Supply Pipeline Projects in China from 1974 to 2022
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This post was last edited by Desert Fish on 2022-12-25 at 14:29. Witnessing the ten-year rapid development of chemical processing equipment, we celebrate the prosperity and strength of modern China. More people’s participation makes things even more lively; Haichuan becomes even better with you in it. This is just a tentative contribution – we welcome everyone to engage more actively in discussions on this forum. Replies will be rewarded; feel free to discuss! ------------------------------------------------- The main water supply pipeline for the urban-rural eastern corridor of the Yinchuan metropolitan area has recently been successfully laid beneath Lihong Highway and Qingshuigou in Litong District, Wuzhong City, thereby removing the final obstacle to the flow of water from the Jinji Water Treatment Plant to the fourth water distribution plant in Wuzhong City. For this crossing, advanced horizontal directional drilling technology used in China was employed; the application of horizontal directional drilling with large-diameter inner tubes for a single crossing in water supply pipeline projects is a first of its kind, and this method is also new in China. On May 25, 2022, after more than two months of relentless efforts, the main water supply pipeline for the urban-rural east line in the Yinchuan metropolitan area was successfully laid beneath Lihong Highway and Qingshuigou in Litong District, Wuzhong City, thereby removing the final obstacle to the flow of Yellow River water from the Jinji Water Treatment Plant to Wuzhong City’s fourth water distribution plant. For this crossing, advanced horizontal directional drilling technology used in China was employed; the diameter of the pipes drilled using this method is the largest of its kind in the country. Moreover, it is the first time that horizontal directional drilling with inner tubes of such large diameter has been used for crossing in a water supply pipeline project, and this approach is also new in China.
Before reaching Wuzhong City, the Yellow River water must pass through a water conveyance pipeline with a length of 9.51 kilometers and a diameter of 1.2 meters. Crossing the Lihong Highway and Qingshui Gou represents the final obstacle for the Yellow River water to reach the Fourth Water Distribution Plant in Wuzhong City. Yinlihong Avenue is a major road connecting urban and rural areas in Wuzhong City, with heavy traffic loads; Qingshui Gou serves as the main channel for flood discharge during the rainy season. Large-scale excavation and pipe jacking are not suitable, as they involve high construction costs and significant risks. After multiple comparisons and evaluations of different options, Ningxia Water Resources and Hydropower Engineering Bureau Co., Ltd. and all the participating units decided to use advanced horizontal directional drilling techniques in China for the construction work. By means of guided drilling, twelve stages of hole expansion, and pipe pulling back, the crossing projects for the Lihong Highway and Qingshui Gully were completed, thereby avoiding any impact on road traffic and flood discharge in the gully.
The total length of the horizontal directional drilling passage is 456 meters, with a maximum penetration depth of 15 meters. The ’tube in tube’ method is employed, whereby a steel pipe with a diameter of 1.4 meters is welded around a 1.2-meter-diameter main water supply pipe. This setup enables passage through complex geological formations such as clay layers, sand layers, and gravel layers; the outer casing acts like a shield to protect the water pipeline from being compressed or deformed.
This directional drilling project began with guided drilling and gradual hole expansion on March 20, 2022. The most critical step, namely the retraction of the pipeline, started on May 23, 2022, and was completed by 7 p.m. on May 25, marking the successful passage of the final barrier in the eastward water supply project that allows Yellow River water to reach the Wuzhong Fourth Water Plant. It also serves as a reference for similar projects in the future.