Well logging acquires in-situ measurements of rock and fluid properties along the wellbore to quantify reservoir quality, fluids, and well integrity. It underpins petrophysics, geomechanics, ...

LWD acquires formation evaluation and wellbore data in real time while the bit is cutting rock. Sensors housed in drill collars measure gamma ray, resistivity, density, neutron porosity, sonic, NMR, ...