Non-magnetic drill pipes are supporting equipment for measurement while drilling (MWD) in directional drilling. They play roles such as reducing external interference on MWD devices, signal transmission, conveying power media for downhole motors, and transferring power from drilling rigs. As an important component of underground directional drilling tools in coal mines, they feature low magnetic permeability, high tensile strength, and excellent torsional resistance. They provide a non-magnetic environment free from Earth’s magnetic interference for downhole measurement systems, ensuring that the magnetic field at the probe is almost equal to the nearby Earth’s magnetic field. This enables accurate identification of the borehole’s geomagnetic direction and guarantees the measurement accuracy of the system.

A set of non-magnetic drill pipes usually consists of upper non-magnetic drill pipes, probe outer pipes, and lower non-magnetic drill pipes. The term “upper” and “lower” refers to their distance from the surface—those closer to the surface are called “upper,” and those farther are called “lower.” The probe is installed inside the probe outer pipe.

Non-magnetic drill pipes are mainly used in horizontal directional drilling systems for underground coal mine roadways.