A Mudlogger  collects and monitors information from drilling operations, such as drilling data, gas and samples, using a range of equipment and laboratory techniques including binocular microscopes, ultraviolet fluorescence and hand specimen analysis.  They monitor drilling parameters including speed of rotation, rate of penetration, pump rate, pit levels, cutting rate and lag time, and mud flow rate.<br><br>
Mudloggers are contracted to an oil company and or a service company and are based and usually work on a rotary drilling rig for fossil fuel, hydrothermal energy, or water. They feed information and advice back to the drilling team for operational purposes, which is then reported back to the oil company. Mudloggers are also known as logging geologists or mudlogging geologists.