Mudloggers play a vital role in the drilling of oil and gas, gathering information and creating a detailed well log, so a passion for geology and excellent communication skills are required

As a mudlogger, you'll monitor and record drilling activity, providing information about the well status during the extraction of oil or gas.

The data you collect and monitor, the 'mudlog', influences important decisions about the efficiency and placement of the well sites.

You'll use a range of equipment and laboratory techniques, such as binocular microscopes, ultraviolet fluorescence and thin section analysis to create mud logs showing a geological record of the site being drilled.

Drilling parameters that are monitored include:

  • speed of rotation
  • rate of penetration
  • oil and gas shows (whether oil or gas is present)
  • pit levels
  • cutting rate
  • mud-flow rate.

Mudloggers ensure that accurate samples are taken at the right intervals and record any issues encountered during the drilling. They mainly work offshore and are contracted to an oil company via a service company. Less commonly, mudloggers work in water well and mineral exploration.

Mudloggers may be known as:

  • logging geologists
  • mudlogging geologists
  • mudlogging technicians.

Mudlogging is also known as hydrocarbon well logging.


Tasks carried out by a mudlogger include:

  • working in wellsite units collecting, processing, logging and analysing geological samples
  • using various laboratory techniques to evaluate detailed and complex data for signs of oil or gas
  • monitoring computer recordings of drillings
  • interpreting information and feeding it back to the drilling team to enhance safety and success
  • operating and maintaining a real-time computer-based data acquisition system, the advanced logging system (ALS), which records all aspects of rig activity
  • undertaking some on-site maintenance, for which a knowledge of electrical and mechanical systems is useful
  • taking on the primary health and safety role for the well through constant monitoring of all critical drilling parameters
  • predicting dangerous situations, such as over-pressured formations
  • assisting the wellsite geologist during coring operations
  • reporting to the wellsite geologist and the oil company in written reports
  • frequently acting as a drilling engineer, collating and then logging details of drilling operations in oil company computer systems.


  • Pay for mudloggers during training is usually modest until training is completed, when a typical starting salary is roughly £25,000 to £30,000.
  • Once you've built up experience as a mudlogger, you can expect to earn around £45,000. You might even be able to reach a salary of £70,000.

Benefits usually include free accommodation, food and travel when you're working away from home. Travel expenses are paid by the employer and, if you're frequently using air travel, you'll soon tot up air miles. Hardship posts may attract a premium.

Multinational service companies tend to offer the best pay, working conditions and opportunities for progression.

Income figures are intended as a guide only.

Working hours

Mudloggers frequently work 12 hours a day, seven days a week, sometimes for up to four weeks at a time. However, it's more likely that you'll spend two weeks offshore on the rig and two weeks at home.

What to expect

  • Work is usually in teams of four, based in units or self-contained laboratories, which are the safest and most comfortable working areas on the rig.
  • Self-employment or freelance work, obtained via contracting companies, is sometimes possible with experience and is becoming increasingly common in mudlogging.
  • Jobs are available in restricted locations. The nearest opportunities are with North Sea oil rigs. Work in the Middle East, Africa and other regions may be possible.
  • Weather conditions can be bad and life on the oil rig, living closely with colleagues even during periods when you are off-duty, can be intense. A typical offshore installation could house 50 to 100 men and women in compact, but comfortable, living quarters. Facilities are generally good and typically include a gym, satellite television and other leisure facilities.
  • An increasing number of rigs have separate facilities for women, although it is rare to find female mudloggers in the Middle East and the Gulf of Mexico.
  • The oilfield has a broad mix of cultures and backgrounds and creates intense physical and mental pressures. Consider how you feel about living in close quarters with others for long periods of time or spending long periods away from family and friends before entering this career.
  • There is usually no requirement for mudloggers to move to their employer's location, as they are generally employed by service companies. This is often cited as a plus point to the offshore lifestyle.


Most mudloggers have a degree in geology, but relevant degree subjects include physical, mathematical or applied science and engineering. Joint degrees with geology are also acceptable.

In particular, the following subjects may be helpful:

  • applied physics
  • chemistry
  • geochemistry
  • geophysics or geotechnology
  • mineral, mining or petroleum engineering
  • petroleum geology
  • physics.

The minimum entry requirement is usually a degree as it provides the necessary scientific understanding. However, HNDs in geology or similar subjects are accepted by some companies, particularly if coupled with significant relevant practical experience.

A pre-entry postgraduate qualification is not needed.

A high level of health and fitness is also required and this is assessed by a medical to international standards. Some forms of colour blindness and levels of deafness can rule out applicants, though this is rare.


You will need to show evidence of the following:

  • good computer skills
  • the ability to work with sophisticated technology
  • the capacity to absorb a range of technical information in areas such as geology, chemistry, mechanics, electricity, electronics and computer science
  • strong mathematical skills
  • analytical and critical thinking
  • decision-making ability
  • excellent oral and written communication skills
  • the ability to work independently with minimal supervision and also as part of a team
  • the capability to cope in stressful conditions.

English is the accepted international language of the oil business. Ability in other languages (principally French and German) can be useful.

The working conditions of exploration and production may prove very difficult for graduates with certain physical disabilities, but there are equivalent opportunities in shore-based work, such as seismic analysis, geology and process engineering. If you have questions about your own situation, contact an employer before making your application.

Work experience

While pre-entry experience is not essential, vacation work and practical experience in the industry will improve your chances of finding employment.


The exploration and extraction business is worldwide and many of the jobs are based overseas. Major employers recruit internationally with many applicants coming from the United States and Europe, so UK graduates are competing with nationals of other countries.

Smaller mudlogging companies may recruit globally, although there is a tendency to recruit locally where possible.

When there is a demand for oil exploration, vacancies for mudloggers are correspondingly high and you may be able to find work anywhere in the world. However, the oil industry is strongly affected by economic trends.

In good years, major employers welcome speculative applications. Some advertise on graduate recruitment websites. Recruitment can vary between no positions advertised at all, to hundreds available in any one year.

Recruitment, training patterns and job titles vary from company to company in the extraction phase. In particular, some employers do not distinguish at entry level between petroleum, drilling and support engineering. Instead, they prefer to recruit people with wide potential and deploy them after training where individual preference and company need coincide.

Look for job vacancies at:

Many companies, particularly the larger ones, welcome speculative applications as they do not always advertise their vacancies.

Recruitment agencies are not widely used in mudlogging, but for information on specialist recruitment agencies handling vacancies in oil exploration services, visit the Recruitment & Employment Confederation (REC).

Professional development

Training varies from company to company but will almost certainly involve a course in general oil well drilling. This will cover:

  • drilling equipment and techniques
  • training in the physics and mechanics of oil-bearing rocks
  • downhole pressure and its corresponding effects on the safety of the well.

Training in computer systems, such as the advanced logging system (ALS), is normally carried out on the job.

There is no professional accreditation associated with mudlogging. It sometimes leads on to more senior work in the oil industry, for which professional institution accreditation does exist.

Safety and survival training is obligatory and varies depending on location. To work in UK waters you'll need to obtain a BOSIET (Basic Offshore Safety Induction and Emergency Training) certificate. This usually takes three days to complete and is valid for four years.

The course covers basic knowledge of safety and emergency procedures when working offshore and travelling by helicopter. Subsequent refresher courses are mandatory.

More information on training in the oil and gas industry can be found at OPITO. The Energy Institute also offers relevant training programmes - for more information, see Energy Institute Training.

Career prospects

Mudlogging is sometimes seen as an entry point into the industry and regarded as an ideal position from which to gain knowledge and observe the practices and operation of an oil rig.

However, some companies employ senior mudloggers who have been in the profession for years.

Larger multinational companies tend to offer better conditions and opportunities to progress.

Some mudloggers move on to the role of data engineer or crew chief, which is a senior member of the mudlogging crew. Whereas a mudlogger collects the rock samples and analyses them, the data engineer or crew chief monitors the drilling and collates and analyses the data. They also field questions from oil companies on related matters to the drilling operations. Mudloggers typically serve two to three years before being promoted to this role.

There are ex-mudloggers in all positions throughout the drilling industry.

Some opt for related oil careers such as directional drilling or wellsite geology. Others leave to gain an MSc or PhD leading to more specialist careers.

Occasionally, mudloggers enter areas such as human resources and marketing in the oil industry.