How does HDD rely on IMU to achieve trenchless precision crossing?

In complex underground engineering fields such as horizontal directional drilling, accurate attitude and azimuth measurements directly determine drilling efficiency and trajectory accuracy.

The ER-MIMU-091 MEMS IMU is designed for harsh oil drilling, mining and horizontal directional drilling (HDD) environments. Compared with fiber optic gyro IMU, ER-MIMU-091 maintains navigation-level accuracy while significantly reducing costs and has better anti-vibration performance, making it suitable for harsh working conditions at the drilling site.

After adding algorithms, it can perform measurement while drilling, and obtain information such as azimuth, well inclination, and tool face angle through calculation. It is the core unit of advanced gyro tools.

Navigation-level high-precision indicators

Gyroscope zero bias instability <0.01°/hr, angular random walk as low as 0.0025°/√h. Accelerometer zero bias stability is 50ug, zero bias repeatability is 100ug, and second-order nonlinear coefficient is < 100 μg/g².

High-precision measurement data can ensure that the azimuth cumulative error is controllable during long-term drilling. It can provide strong support for solving information such as azimuth, well inclination, tool face angle, etc.

Miniaturization and high reliability

Adopting the latest MEMS gyroscope technology, the cylindrical design with a diameter of only Φ30 mm and a length of 120 mm makes it easy to integrate into space-constrained downhole instruments, probes or drill bit guide short sections.

The all-solid-state and built-in inner platform design makes it excellent in shock and vibration resistance. It provides standard (-40°C ~ +80°C) and high temperature (-40°C ~ +125°C) versions, with an internal integrated advanced temperature compensation algorithm to ensure the stability of key parameters and measurement accuracy under drastic temperature changes underground.

Horizontal Directional Drilling (HDD) Guidance:

In HDD construction for trenchless pipeline laying, the ER-MIMU-091 uses a high-precision self-seeking gyro installed in the probe behind the pilot drill bit to measure the angular velocity component of the earth's rotation. Combined with the accelerometer, it can provide azimuth, pitch and roll angle information in real time through solution. The drill bit is precisely controlled to move forward along the designed trajectory to ensure that the pipeline accurately passes through obstacles and reaches the predetermined exit point.

MWD and continuous attitude measurement (well inclination/tool face angle):

Integrated in the MWD short section, the ER-MIMU-091 three-axis gyro measures the rotational angular velocity of the drill tool around three axes in real time, and provides continuous azimuth, well inclination, and tool face data after solution combined with accelerometer information.