Mudlogging or Mud Logging is a geology-related profession in the oilfield. When a well is drilled the oil company often hires a mudlogging company to set up a small, portable lab and living quarters at the edge of the well location. Mudloggers analyze samples of rock and drilling mud that are returned up-hole from the drill bit.
Mudlogging involves staying away from home for often weeks on end. Unlike the roughnecks, which often rotate on 7-14 day shifts, a mudlogger or team of two mudloggers will remain with the well from the time it is started or until "TD" or total depth is reached.
It is for that reason that one must have a stable relationship at home or be single. Being away from home for weeks on end in remote locations such as offshore can be taxing on a family.
Mudlogging involves the use of highly technical instruments such as as gas chromatograph and requires a good computer background.
Many small mudlogging companies, mostly those who service the land-based drilling market, will hire and train non geologists. However, that being said, it helps if you have a degree in geology since much of the job deals with the identification of types of rocks and communicating professionally with other geologists.
Companies like Baker Hughes and Sperry Sun require applicants to have a geology degree. Smaller companies like Selman and Associates for example, will train non-geologists to be mudloggers.
For anyone considering applying to one of the "mom and pop" or small logging companies it helps to have some background in the oilfield service industry, at least a high school or technical school education and strong math and science skills. Read up on the oilfield as much as you can so that you understand the process of drilling an oil or gas well in detail. Then study up on the types of sedimentary rocks and read introductory geology textbooks and basic petroleum geology books.
One good book that is used by companies like Schlumberger in their training programs is "A Primer Of Oilwell Drilling" by Ron Baker. Another is "A Nontechnical Guide To Petroleum Geology, Exploration, Drilling and Production". You may find these in the links below.
If you are hired you may spend several months working with an experienced employee as his sample catcher. Your job will be to go out to where the drilling mud is being pumped up from the well bore and catch a screen full of rock cuttings, wash them, and assist the mudlogger in identifying them.
In addition you will probably help him rig up and rig down the mudlogging equipment, and do odd jobs.
Only after working with an experienced logger for several months will you transition to holding down your own shift or "tour".
When you are hired you will usually start out working the night shift as "second man". Eventually, after a year or more of experience you will be able to "break out" on your own and run a job as lead hand.
Mudlogging is not for everyone. It is a job that demands extraordinary attention to detail, knowledge of many different disciplines such as electronics, computers and geology and requires working in often harsh and challenging remote environments. It can pay well but if you cannot stand being away from the comforts of your home for long periods and living in cramped, noisy conditions it is not a good job for you.