Positive Pressure container, Explosion Proof Container, mud logging unit, mud logging cabin, dnv2.7-1 certified, zone 1 / zone 2 classification, hazardous zone rated
Mud Logging unit, mud logging cabin
Since its commercial introduction in 1939, the mud logging unit has become a hub for monitoring formation responses to the drilling process. Initially, the mud logger's mandate was to record the depth and describe the lithology of formations encountered by the drill bit then determine whether those formations contained hydrocarbons. However, the scope of mud logging has expanded as additional sensors brought more data into the logging unit—such as gas chromatographs, weight-on-bit and mud pit level indicators. Basic mud logging services now typically track drilling rates, lithology, visual hydrocarbon indicators, total combustible gas in mud and individual hydrocarbon compounds in the gas along with numerous drilling parameters. The mud logger monitors and evaluates a broad range of surface indicators to compile a concise record of subsurface geology, hydrocarbons encountered and significant drilling events. These days, the term surface logging is sometimes used to encompass a range of enhanced mud logging services that incorporate advanced sensor and computing technology to provide monitoring for wellbore stability and early kick detection.
The practice of mud logging relies heavily on the mud circulation system. High-pressure mud pumps draw mud, or drilling fluid, from surface tanks and direct it downhole through the drillpipe. The mud exits the drill string through nozzles in the bit. As a bit drills through the subsurface, the rock it grinds—along with water, oil or gas in the formation—is carried back up the hole by the drilling fluid. Upon reaching the surface, the fluid exits through a flowline above the blowout preventer and is deposited over a vibrating mesh screen at the shale shaker, which separates formation cuttings from the liquid mud. The liquid portion of the drilling fluid falls through the screens to the mud pits, ready to be pumped back into the well; the rock cuttings on the shaker screen provide the basis for determining downhole lithology.