How to Detect Deviation in Horizontal Directional Drilling Rigs
May 20, 2026| I. Real-time Monitoring: Measurement While Drilling (MWD) System
1. The drill bit is equipped with a probe (containing a fluxgate sensor and accelerometer). Data is automatically collected every 3 meters of drilling, and the following key parameters are transmitted back in real time:
Depth: Current vertical depth of the borehole;
Inclination: Angle between the drill bit and the horizontal plane;
Azimuth: Angle of the drilling direction relative to true north;
Tool Face Angle: Current orientation of the drill bit, used to guide correction operations.
2. Data is transmitted wirelessly or via wired connection to a ground receiver. The directional control software generates a 3D trajectory model, which is compared with the designed path to automatically identify whether the lateral/longitudinal deviation exceeds ±0.3 meters.
II. Periodic Verification: Ground Measurement
1. After each drilling section (e.g., every 10 drill rods), the entry point, exit point, and key points of the surface trajectory are re-measured using a total station or GPS to calibrate the equipment baseline.
2. In complex areas (such as those crossing roads or densely packed pipelines), ground beacon points are set up, and the probe position is calibrated using an artificial magnetic field to improve positioning accuracy.
III. Enhanced Detection in Special Environments
1. Anti-interference Detection: Near high-voltage lines and metal structures, wired sensors or gyro-guided systems are used to avoid distortion of wireless signals due to electromagnetic interference.
2. Two-way Drilling Connection Detection: In long-distance projects, drilling is carried out synchronously at both ends. The overall trajectory consistency is verified by comparing the coordinates of the intermediate meeting point.
IV. Data Recording and Analysis
1. All measurement data must be recorded in the Directional Drilling Construction Record Form, including the thrust, torque, pump pressure, and mud parameters of each drill rod, to facilitate tracing deviation trends.
2. If continuous deviation or abrupt change is found, construction is immediately suspended to analyze whether it is caused by changes in the strata, equipment failure, or operational errors.
