Design and analysis of north seeker based on downhole drilling orientation

Rapid miniaturization has been a hot and difficult point in the recent research on inertial directional north seekers. Micromechanical gyroscopes have the advantages of low cost, medium precision, micro size, low power consumption, high overload resistance, and high reliability. The north-seeking system based on MEMS gyroscope can reduce the cost, reduce the size, and reduce the difficulty of use. As MEMS technology becomes more and more mature, the accuracy of MEMS north seekers gradually improves, and MEMS north seekers are also widely used in mining and drilling and other industries.

1.The role of north seeker in underground

In recent years, compared with other industries, the production and operating environment of the mining industry has been relatively complex, and there is an urgent need for intelligent safety monitoring systems to ensure the safety of production operations. At the current stage, personnel positioning systems and intelligent safety monitoring systems are systems that must be equipped in the mining industry. The operation of these systems plays an active role in ensuring personnel safety. Combined with the actual underground environment of coal mine and the need for position and pose monitoring during the cutting operation of shears, the arrangement of north finder and non-carrier communication (UWB) equipment in this combined positioning scheme is mainly based on the needs of underground geological environment and measurement accuracy. In the underground transportation roadway, the visibility is high, the dust concentration is low, but the space is relatively narrow, so the north finder positioning scheme is adopted to realize the positioning of the fixed base station without carrier communication (UWB). In the process of using the carrier-free communication (UWB) to dynamically position the shearer's cutting operation attitude, at least three sets of positioning nodes need to be set up to meet the settlement requirements for the attitude angle during the operation of the shearer. In order to improve the settlement accuracy , an inclination sensor and a north seeker are simultaneously installed on the shearer to measure the attitude angle of the shearer when it is running, to meet the demand for positioning accuracy.

2.North finding system of drilling

Overall scheme of drilling hole orientation instrument: the azimuth angle (the angle between the geographical true north direction) and the inclination angle are two key parameters of drilling hole positioning. The north seeking system first conducts the north seeking operation and obtains the initial reference of inclination angle and azimuth angle. Based on the initial attitude value, three-axis MEMS gyro and three-axis accelerometer are used for attitude tracking.

During drilling construction, the drilling rig arrives at the designated drilling site. According to the designed azimuth and inclination angle, the operator roughly predetermined the orientation and inclination angle of the drilling rig, and then placed inertial directional north finder at the horizontal position near the drilling site for north seeking operation; After north finding is completed, the orienteer is placed on the guide rail of the rig to display the current rig attitude information (inclination angle and azimuth angle), and then the rig attitude is adjusted until the rig reaches the design angle.

Summary

Ericco company has more mature technical support and theoretical foundation for the north finder applied in drilling and mining industry, not only providing low-cost optical fiber north seeker ER-FNS-03, but also MEMS north finder : cost efficient MEMS north finder ER-MNS-05, smallest size MEMS north finder ER-MNS-06. On this basis, a new MEMS three-axis north seeker ER-MNS-09, a drilling and mining tool, is introduced, which not only can find the north autonomously, but also has self-alignment and attitude measurement functions. In shape and volume is also a great breakthrough, it can be put into the probe to explore, if you are interested, welcome to contact us.