Huayuan News
At 23:00 on June 10, 2014, Huayuan successfully completed the pullback for the horizontal directional drilling (HDD) crossing of the Yellow River as part of the Bo’ai–Zhengzhou–Xuedian natural gas pipeline project. This marked the eighth time that Huayuan had successfully crossed the Yellow River.
The Zhengzhou Yellow River HDD crossing project involved a total crossing length of 2,621.76 meters, with a pipeline diameter of 610 mm and wall thickness of 12.5 mm. The crossing path passed mainly through medium sand layers.
The entry point was located east of Lupo Village in Wangcun Town, Xingyang City, Henan Province, while the exit point was in Wen County, Jiaozuo City, Henan Province — adjacent to Chenjiagou, the birthplace of Chen-style Taijiquan, a major school of Chinese martial arts.
Most of the pipeline was installed through sandy formations with poor stability and high permeability, posing considerable construction challenges.
To address issues such as excessive crossing length, insufficient drill rig torque, low drill pipe stiffness, and difficulty in bit positioning, Huayuan abandoned the traditional single-ended pilot drilling method. Instead, it adopted a dual-rig simultaneous drilling approach, with rigs drilling from both entry and exit points toward each other for precise underground docking.
Using the DX-I guidance system and pilot hole docking technology independently developed by Huayuan, along with its latest magnetic beacon tracking instrument, the team overcame challenges posed by long crossing distances and river currents affecting bit positioning. Ultimately, the drill bits met successfully along the designed bore path, and the pilot hole was completed as planned.
During the reaming phase, the dual-rig synchronized reaming technique was employed to solve issues arising from limited torque and pipe stiffness, ensuring smooth and coordinated hole enlargement.
Given the crossing’s predominantly sandy formations, there was a high risk of borehole collapse and pipe sticking, especially over such a long distance. Using traditional pullback methods with only one rig could have caused drill pipe breakage due to excessive resistance.
To mitigate this, Huayuan used its independently developed 500-ton pipe thruster to assist the pullback. Ultimately, with the combined pulling force of the rig and pushing force of the thruster, the pipe was successfully pulled into place, completing the HDD crossing safely and efficiently.
