Mudloggers keep records of drilling operations to provide information about well status for the extraction of oil or gas. They help to increase the efficiency and placement of wells and the data they collect and monitor informs crucial decisions. They 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 and/or gas is present); pit levels; cutting rate; and mud flow rate.

The mudlogger ensures that accurate samples are taken at the right intervals and records any issues encountered during the drilling. They mainly work offshore and are contracted to an oil company via a service company. Less commonly they work in water well and mineral exploration. Mudloggers may also be known as logging geologists, mudlogging geologists or mudlogging technicians. Mudlogging is also known as hydrocarbon well logging.


Typical Work Activities

  • 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 companies’ computer systems.


Technical Skills

  • Good computer skills.
  • The ability to work with sophisticated technology.
  • The ability to absorb a wide 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.
  • Good oral and written communication skills.
  • The ability to work independently with minimal supervision and also as part of a team.
  • The ability 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. A high level of health and fitness is also required and this is assessed by a stringent medical to international standards. Some forms of colour blindness and levels of deafness can rule out applicants, though this is rare.


Career Development

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/crew chief, which is a senior member of the mudlogging crew. Whereas a mudlogger collects the rock samples and analyses them, the data engineer/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.



Original content at


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s