How to Prevent Problems in Horizontal Directional Drilling
May 06, 2026| I. Prevention Measures for Guiding Deviation
1. Precise Layout: Before construction, use a total station or GPS to verify the entry point, exit point, and rig positioning three times to ensure the deviation is ≤0.1°.
2. Anti-Magnetic Interference: When constructing near high-voltage lines or substations, use an artificial magnetic field guidance system or switch to gyroscope guidance to avoid magnetic azimuth distortion.
3. Real-time Correction: Measure trajectory data every 3 meters of drilling. If a lateral deviation >0.3 meters is detected, immediately adjust the drilling parameters.
II. Prevention Strategies for Mud Spillage
1. Geological Prediction and Improvement: For fault zones and fractured areas along the drilling path, reinforce the strata in advance using high-pressure jet grouting + compaction grouting to improve overall integrity.
2. Optimize Design Parameters: Increase the entry and exit angle (recommended ≥8°) and radius of curvature, and shorten the shallow buried section length; ensure the pressure of the overlying soil layer is greater than the mud column pressure to prevent mud surge.
3. Mud Control: Use non-dispersible, low-solids mud to balance viscosity and fluidity; follow the "high at both ends, low in the middle" pump flow adjustment principle during drilling to avoid pressure buildup.
III. Drill Tool Damage Prevention Measures
1. Appropriate Selection and Inspection: Use super roller cone reamers or rock cutterheads in hard rock sections; have a professional team perform non-destructive testing on drill pipe threads and shoulder surfaces before construction.
2. Load Balancing Control: Reduce the height of the first male thread by 70% to distribute the load more evenly across all threads; apply low-friction thread grease to high-stress areas to reduce stress concentration.
3. Operating Procedures: Strictly prohibit operations exceeding torque and tension limits; control drilling speed to avoid impact operations such as skipping or sudden drilling.
IV. Prevention Methods for Drag-back Obstruction
1. Sufficient Hole Enlargement: The final hole diameter should be at least 20% larger than the pipe's outer diameter, and at least three stages of enlargement should be performed to ensure a smooth, stepless borehole.
2. Assistance System Configuration: For long-distance (>500m) or large-diameter projects, equip with a combination of pipe pusher and pipe tamping hammer for assistance; use a hydraulic emergency traction machine to deal with sudden pipe detachment accidents.
3. Optimization of Delivery Trench: Set a reasonable slope (recommended 1:20) and inject highly lubricating mud to reduce frictional resistance.
V. Borehole Wall Instability and Surface Settlement Control
1. Dynamic Matching of Mud Pressure: Simulate formation stress through BIM modeling and set the optimal mud pressure range to make the borehole wall stress state close to the original state.
2. Flow Rate Control: Maintain the mud flow state as laminar (Reynolds number <2000) to reduce the scouring effect on the borehole wall.
3. Drilling Portal Reinforcement: Steel sheet piles or cement-soil mixing piles will be used to reinforce the entry and exit points to prevent disturbance-induced settlement.
4. Monitoring and Early Warning: Distributed fiber optic sensors will be deployed to monitor surface settlement in real time and control it within 15mm.
VI. Comprehensive Management and Support Measures
1. Personnel Training: Personnel will receive at least 40 hours of technical and safety training before starting work, focusing on strategies for dealing with complex geological formations.
2. Equipment Maintenance: A drilling tool life assessment system will be established, and vulnerable parts will be replaced regularly to prevent fatigue fracture.
3. Emergency Response Plan: Specific emergency plans will be developed for situations such as stuck drill bit, broken drill bit, and slurry leakage. Retrieval tools (such as male and female drill bits) will be provided.
