Press Release
At 7:30 on January 23, 2021, after 23 days and nights of underground traversing, a “Metallic Loong” with a length of 3,120 meters emerged from the ground. The crude oil pipeline HDD crossing work at Guci Waterway South Line for the Refining and Chemical Integration Project of Zhejiang Petrochemical Co., Ltd., which was undertaken by Huayuan Group, was successfully completed.
This crossing work set a new record of crossing hard rock layers with Φ813 pipelines. A total of 327 drill rods were pulled back, employing a multi-to-one pipeline welding method with four pipes per segment, totaling 66 segments. The first-pass welding success rate was 100%, achieving a remarkable start for the Zhejiang Petrochemical Co., Ltd pipeline crossing project.
For the directional drilling crossing project of Guci Waterway, the entry point is located on the west side of Zhenghe Shipyard on Cezi Island, and the exit point is located on the east side of Mamu Huasheng Ranch. This large-scale waterway directional drilling crossing included three pipelines: from north to south, they are the submarine cable casing, Main Pipeline II (North Line), and Main Pipeline I (South Line). The pipeline specifications for the crossing segment were Φ813×20.6mm L415M longitudinal submerged arc welded steel pipes. The design pressure was 6.0 MPa, with normal temperature transportation. The corrosion protection for this crossing was achieved through three-layers PE reinforced anti-corrosion coating.
The primary geological formations encountered during the crossing were ignimbrite, with an average saturated compressive strength of 123 MPa and a maximum value of 148 MPa.
Since the commencement of this project on November 26, 2019, Huayuan Group has overcome challenges such as the installation of large-diameter and long-distance casings, slurry leakage in the submarine fault zone, seabed drill-bits intersection, reaming of high-hardness and large-diameter rocks, narrow prefabrication sites, and scratches on the anti-corrosion layer. It has given full play to the company's technological advantages and innovation capabilities, organized carefully, deployed meticulously, and advanced steadily. It has successfully completed the first HDD crossing of the crude oil pipeline for Zhejiang Petrochemical Co., Ltd., and accumulated experience for the subsequent eight directional drilling crossings of crude oil pipelines.
