Direction and position measurement in HDD using two magnetic fields

In the horizontal directional drilling (HDD) system, MWD (measurement while drilling) magnetic surveying technology is widely used. However, this system suffers from the interferences to the geomagnetic field and the accumulated errors. To guide the drilling process in this situation, a method for measuring direction and position of the drilling bit by combining two magnetic fields is proposed. To realize this system, a utility algorithm is established. Simulation experiments were implemented to prove the feasibility of the method and the errors were analysed.