The role of a wellsite geologist offers worldwide opportunities for passionate geologists with drilling knowledge

Wellsite geologists study and classify rock cuttings from oil and gas wells in order to determine how drilling should be started and how it should proceed. They use specialised tests, core samples and rock-cutting data to build up knowledge of the structure being drilled.

They are experienced geologists, deciding when tests should be carried out and, ultimately, when to stop drilling. They send reports and logs of completed drilling to the operations geologist and offer advice to oil company representatives.

They also incorporate health and safety requirements in daily geological operations.

Wellsite geologists liaise with drilling engineers, petroleum engineers and mudloggers during the course of projects.


The work is based entirely on-site and usually involves the following:

  • evaluating offset data before the start of drilling
  • analysing, evaluating and describing formations while drilling, using cuttings, gas, formation evaluation measurement while drilling (FEMWD) and wireline data
  • comparing data gathered during drilling with predictions made at the exploration stage
  • advising on drilling hazards and drilling bit optimisation
  • taking full responsibility for making decisions about suspending or continuing drilling
  • advising operations personnel on-site and in the operations office
  • acting, in effect, as the representative of the onshore oil company geology team
  • supervising mudlogging, FEMWD and wireline services personnel and monitoring quality control in relation to these services
  • keeping detailed records, writing reports, completing daily, weekly and post-well reporting logs and sending these to appropriate departments
  • maintaining up-to-date knowledge of measuring while drilling (MWD) tools, such as gamma and resistivity, as geosteering becomes increasingly important
  • communicating regularly with onshore operations offices.


  • Typical starting salaries for those employed by oil and gas companies ranges anywhere from £25,000 and £45,000.
  • At a senior level, you can expect to earn £35,000 to £120,000, sometimes with up to 50% extra in allowances and bonuses.
  • New consultant wellsite geologists can earn between £350 and £450 per day. Those with experience can earn between £800 and £1,000 per day.

Salaries vary according to experience, where you are working in the world and what type of organisation you work for.

Income figures are intended as a guide only.

Working hours

This is not a secure profession, as work depends entirely on drilling activity. Most wellsite geologists work around 150 days a year, but this could vary between 50 and 200. You'll be paid on a day-by-day basis.

In the North Sea, working hours are normally 12 hours on, 12 hours off continuously for two weeks, followed by a break ashore of two to three weeks.

Career breaks are possible but part-time work is rare.

What to expect

  • Work on offshore rigs is physically hard, often undertaken in dirty, noisy and bad weather conditions.
  • Almost all wellsite geologists are self-employed.
  • There are currently very few women working in this area.
  • In the UK, activity, and therefore work, is currently located mainly off the east coast of England and Scotland, but exploration is also being carried out in the western approaches, the Irish Sea and west of the Shetlands. Work is available on rigs throughout the world, some in very remote and hard-to-reach places.
  • Although there are still a few rigs where living conditions are basic, on most they are very good, with meals and a laundry service provided. Gyms and snooker rooms are also often available.
  • Alcohol and recreational drugs are not allowed on rigs.
  • Considerable disruption to your personal and home life is to be expected.
  • Travel to rigs by helicopter is normal, sometimes at short notice, so flexibility is required.
  • Travel to sites in some parts of the world can be complex and difficult.


An honours degree in geology or in another earth science containing a substantial amount of geology is normally required. Joint degrees with geology, including sedimentology, are acceptable.

Entry may also be possible with one of the following subjects:

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

Becoming a wellsite geologist with a HND only or without a degree is generally not possible. An MSc in geology can be helpful. Search for postgraduate courses in geology.

This is not generally a graduate appointment and at least two years of experience as a mudlogger, or logging geologist, is required, though five years is more usual. Experience with a measuring while drilling (MWD) company is also useful.

Competition for posts changes depending on the state of the market.


You will need to show evidence of the following:

  • excellent oral and written communication skills
  • the ability to work independently, as well as within a team of multidisciplinary professionals
  • analytical and critical-thinking skills
  • confidence in giving an opinion
  • the ability to evaluate complex information and make decisions at any hour, day or night
  • an understanding of the activity that is taking place in the well and its implications
  • sensitivity to different cultures and ways of working
  • leadership and supervisory skills
  • practical skills
  • the ability to work with sophisticated technology
  • strong mathematical and scientific analytical skills
  • the ability to get on well with others in and outside a working environment (you will be working and living with the same set of people, without respite, for several weeks)
  • competence in IT, with the ability to use standard office programs and specialised software
  • the ability to cope with working under pressure.

A current driving licence is important since much of the work is on remote sites. Good colour vision is also required.

All rig personnel, including wellsite geologists, are required to pass several tests of physical fitness and survival. Offshore fire qualifications are normally required.


Very few people in this role work directly for oil or gas companies. Most are employed on a contracting basis for specialist consultancies who supply wellsite geologists as and when required.

The companies that specialise in geological services are small to medium-sized. These provide most opportunities for wellsite geologists.

Other companies may offer wellsite geology as another service alongside drilling services. They mainly employ independent consultants on a daily rate, so wellsite geologists are actually self-employed and, therefore, responsible for meeting their own training and insurance costs.

The major consultancy groups tend to recruit regionally. However, this is a global industry and many UK wellsite geologists seek positions abroad where conditions may be more basic, but rates are still reasonably high. Many contracts are short term but well paid.

Longer term contracts can give more security but are often less well paid. The exploration and extraction business is worldwide and therefore British nationals compete with those from other countries.

Look for job vacancies at:

In good years, the main specialist companies welcome speculative applications. However, most wellsite geologists are recruited by recommendation from others.

Get more tips on how to find a job, create a successful CV and cover letter, and prepare for interviews.

Professional development

There is no formal wellsite geology qualification. Some mudlogging and consultancy companies offer training in certain aspects, such as wireline/formation evaluation, but others have stopped doing this, since they tend to lose staff to consultancy.

As an independent consultant, you would be expected to put yourself through such courses, at your own cost, in order to keep your skills up to date.

A wellsite geologist will generally have undertaken training in a range of areas before beginning work, but regular updating will be required. These areas include:

  • wellsite and offshore safety management
  • safety management systems
  • risk assessment
  • control of substances hazardous to health (COSHH)
  • wellsite operations
  • wellsite geological procedures
  • formation evaluation of wireline
  • abnormal pressure interpretation
  • FEMWD (formation evaluation measurement while drilling) logs.

Several of the geological services organisations that recruit staff also run training courses delivered at their premises or in-house at a company site or other venue.

A range of courses are offered by training providers such as:

Career prospects

Before securing a post as a wellsite geologist, you'll have probably gained a minimum of two (but more likely five) years' experience as a mudlogger or measuring while drilling (MWD) engineer.

You may also have a relevant MSc and direct experience of working as a geologist for an oil company.

As an independent consultant, you'll be largely responsible for your own career development. The best way to maintain some continuity of work is to develop a good working relationship with one or two oil companies and become their preferred contractor.

Professional accreditation is not currently an issue but may be required in the future as part of competency assurance.

Graduates considering wellsite geology should aim for chartered geologist (CGeol) status, which can be applied for through the Geological Society upon gaining at least five years' experience.

Some wellsite geologists go on to become operations geologists for oil companies, which may be on a long-term contract requiring relocation or on a rotating contract. Others might undertake further training (usually self-funded) and become petrophysicists or reservoir engineers for oil companies.