High Quality Content by WIKIPEDIA articles! MWD stands for Measurement While Drilling in the oil & gas industry. The simplest way to describe MWD is to relate it to the measurements a pilot takes. A pilot needs to know the direction they are flying (North, South, East, or West), the angle they are flying at (up, down, or horizontal), and what type of skies they will be flying through (rough, choppy, cloudy, rainy, etc.). Like a pilot a directional driller needs to know these items about the ground formations that they are drilling through. MWD provides this information. Previous to MWD measurements were taken at various parts of the drilling process, but MWD has allowed these measurements to be sent to the surface continuously while the hole is being drilled. This allows for faster drilling, more accurate drilling, and safer drilling.