MWD，which means Measure While Drilling, originally meant to measure well trajectory parameters while drilling, including: well inclination, azimuth, tool face angle, and auxiliary parameters such as temperature. Today's MWD can not only measure geometric parameters such as well inclination, azimuth and tool face, but also can measure mechanical parameters such as bit pressure, bit torque and downhole vibration, as well as the natural gamma density, resistivity and porosity of the formation，geological parameters such as measurement, referred to MWD technology.
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