What are the applications of horizontal directional drilling (HDD) in geological exploration?
Oct 27, 2025| Today, Drillto Trenchless Co., Ltd., a manufacturer of HDDs, will introduce HDDs. HDDs have a wide range of applications in geological exploration, specifically in the following areas:
1. Evaluating the engineering properties of surrounding rock along ultra-long, deep tunnels
HDDs enable continuous coring along the project axis, overcoming the limitations of traditional tunnel exploration, which relies on a single hole. For example, during the construction of the Sichuan-Tibet Railway, explorers used this technology to determine the geological conditions of over 100 tunnels. The longest single hole reached 1,888 meters, with coring continuity exceeding 95% and trajectory deviation controlled within 0.5‰, providing a direct view of the geological conditions along the tunnels.
2. Accurately Ascertaining Underground Mineral Resources
HDD technology combines geological exploration coring techniques with horizontal directional drilling, supplemented by in-hole testing, to provide a direct and accurate understanding of underground mineral resource deposits. During the exploration of the Zoige uranium field, a major breakthrough was achieved in the implementation of small-diameter controlled directional drilling technology for geological drilling. This technology enabled directional branch drilling with "one base, multiple holes, and one hole, multiple branches," minimizing disturbance to the fragile ecological environment of the plateau.
III. Efficiently Completing Exploration Tasks in Complex Geological Conditions
Horizontal directional drilling rigs offer significant advantages in areas with complex geological conditions. For example, in the Guangdong-Hong Kong-Macao Greater Bay Area water supply project, this technology achieved a single-hole, continuous drilling record of 1,888.88 meters, accurately identifying karst development characteristics along the water supply tunnel. Its key features include:
Significantly Increased Operation Length: The domestic record is 1,888.88 meters
High Coring Continuity: Accurately Recovering Geological Information
Precise Trajectory Control: Trajectory Deviation is Controlled to Within 0.5‰
Strong Drilling Capability in Complex Formations: Applicable to Hard Rock Formations Such as Granite and Gneiss
IV. Providing Geological Support for Major Engineering Construction
In major engineering construction projects, horizontal directional drilling rigs can provide early geological surveys, providing a basis for the development of construction plans. For example, during the construction of a major national water diversion project, prospectors used this technology to determine the geological conditions of each mountainous area involved in the canal. Furthermore, beneath the main channel of the Shiziyang River, the underwater geological conditions were explored, providing crucial geological support for the project.
V. Promoting Innovation and Development in Geological Exploration Technology
The application of horizontal directional drilling rigs has driven innovation and development in geological exploration technology. For example, in the Datong-Jinan Waterway Diversion Project, horizontal directional full-hole coring drilling technology was employed, resulting in a borehole exceeding 2,000 meters deep. This breakthrough in small-diameter diamond wireline continuous coring in engineering surveys has revolutionized the exploration of deep-buried long tunnels and chambers.
