Wellsite Geologist Services: an introduction

1. Wellsite geologist

Wellsite geologist (or WSG for short) is the title of an oil company on site field geologist. We are supervisors representing the geology and geophysics department of the company at the wellsite.

Among other things, we analyse the drill cuttings coming out of the borehole as a form of formation evaluation.

We are often consultants and as such offer our advice to the oil company. Depending on the situation we must take some decisions alone or together with the office in town. An example of this is when there is the need to stop drilling operations for casing or coring.

The company man (Co-Man), or drilling supervisor, and the wellsite geologist are usually the only oil company representatives at the rig. Both are oil company supervisors, but the geologist oversees a few teams while the company man supervises the entire drilling operation.

The geologist works under the supervision of operations and petroleum geologists. They are located in the town offices and are the ones to whom we report.

We are the main contact point between the oil rig and the geology and geophysics team in town. We communicate and discuss their intentions, plans and concerns to the teams at the wellsite.

Wellsite Geologist Sample Observation at mudlogging Unit

2. What does a wellsite geologist do?

We have many responsibilities and duties at the wellsite and the following list mentions a few of them. The job might be arguably well paid, depending on market conditions, but the pressure on us is real and often high.

2.1. Drill cuttings analysis and descriptions

One of the standard duties is the description of drill cuttings coming out of the borehole. The description is often standardized and defined by each oil company.

By analysing drill cuttings the oilfield geologist can identify and classify the drilled rock. Evaluating cuttings also allows for checking borehole stability and confirming the presence of hydrocarbons. This analysis is also important to help drilling optimization.

Cuttings are analysed and described using a stereoscopic microscope under white reflected light. To help identify the presence of hydrocarbons, a UV Box (Ultraviolet Box) is also used. Hydrocarbons will have a variable, but identifiable, brightness when exposed to ultraviolet light.

Several other tests are performed to carry out the formation evaluation. Such tests involve chemicals such as hydrochloric acid, to detect calcium carbonate content, and phenolphthalein, to detect the presence of cement and differentiate it from the formation.

Drill cuttings Sample for Observation

2.2. Data, correlations and decisions

The wellsite geologist analyses offset logs and data to correlate with the current well. Correlations are done using data provided by sources such as MWD/LWD, wireline logs, gas and cuttings.

This ensures the formations being drilled in the borehole are recognized and identified. This can help you predict the distance to the reservoir and calibrate the current geological models. You will be able to foresee important events like significant gas changes, drilling breaks and potential hazards which occurred in offset wells.

You may find the older offset logs usually printed in paper or in a pdf format. The raw data is usually in a LAS file format, which is the most common for the mudloggers and LWD/MWD services to distribute. There are other data formats, but it depends on what software you are using and what’s the best format to import and distribute.

You will need to advise the office and wellsite teams on the best course of action in several scenarios. As the field geologist you have the responsibility of advising the teams to either carry on or stop drilling. Nowadays this is usually a decision made together with the office in town, but it varies from oil company to oil company.

One such example is selecting at which depth drilling operations must stop in order to set casing or take a core sample. Besides the services already mentioned, sometimes biostratigraphy services are also needed to identify the right depth.

2.3. Team supervision

There are a few teams and services which we supervise. These are the mudlogging, MWD and LWD, wireline logging, core handling, micro and nano paleontologists. The geologist performs quality control and assurance of these services and the data they provide.

These requirements can change from oil company to oil company, but in most cases that's how it works.

Looking at the Rig Camp from the Side

2.4. Coring operations

The geologist will be the key figure at the wellsite as we’ll have to decide with the office in town when to stop normal drilling operations, as we approach coring point. Again, we need to use several correlations, drill cuttings and other formation evaluation methods for this. When we reach coring point we start to pull out of hole to proceed with the coring operation itself.

We evaluate the few cuttings coming out of the wellbore while cutting the core. When the core is at surface, we take core chips from each meter (3 feet) of the entire core to evaluate the presence of hydrocarbons and to decide if coring operations should continue or stop in order to resume regular drilling operations (usually reaching the Total Depth). We must handle, or supervise the handling, of the core on surface ensuring proper markings and saw cutting as per oil company standards.

2.5. Casing point approach

The role of the geologist, for this operation, will be similar to the coring point approach as our main focus will continue to be analysing drill cuttings and correlating data with offset wells.

We must also ensure that there are no permeable / porous formations close to the bottom of the hole when we reach casing point, or in the rathole immediately below the casing shoe, as that increases substantially the risk of having losses during the cement job that will be performed after running the casing itself.

2.6. Geosteering / Horizontal drilling

With the increase in horizontally drilled wells the geologist is very closely involved in the real time directional drilling decisions necessary for a successful geosteered well.

Geosteering involves good communication, on approaching and remaining within the reservoir, also between the petrophysicists and reservoir engineers in town and the company man and directional drillers on the rigsite.

2.7. Reporting and software

We also have several reports to prepare daily, weekly, and at the end of the well. Some of the daily reports are the Daily Geological Report and the Lithology Log. These reports are updated with geological data, ongoing operations and important events.

There is also an End of Well Report or Final Well Report. This is produced and completed during the course of operations at the wellsite. They are delivered as updates to the operations and petroleum geologists during drilling operations.

When drilling operations end these reports continue to be completed in the offices in town. They are updated until the end of all wellsite operations and only end when all the data from the entire well is obtained. Final completion of these reports will be carried out by the onshore geology team or the oilfield geologist, if asked to.

There are several software packages available for us and these are usually provided by the oil company. Training on how to use them is one of the geological consultant's responsibilities.

For example, some of these software packages will allow you to produce the lithology logs, composite logs and other types of logs which may be required.

Some companies may also have their own daily report producing software instead of it being just a word document.

2.8. Safety and communicating

HSE (Health, Safety and Environment) is a key aspect at the wellsite. The geologist is a leader and sets the example at all times encouraging others to work in safe conditions. Safety is one of the most important aspects of the entire operation, I can't stress that enough.

Communication is also key to the success of the operations. We communicate frequently with both the onshore office and the teams at the wellsite. This can reduce misunderstandings and mistakes. Make your teams feel comfortable enough to ask you anything in case of any doubts.

A silly question is always better than any kind of mistake. Mistakes in the oil fields tend to cost substantial amounts of money or even lives.

Satelite Dish Garden at the Rig Camp in the Desert

2.9. Meetings and daily schedule

On a typical day, the schedule for the wellsite geologist will involve many calls and some meetings. It can all change depending on who the client is and what particular situations come up.

The standard would be to call the operations geologist around three times per day (morning, afternoon and at night) for updates on the general operations. This is something you need to discuss and decide as it will vary.

Rig meetings, at least after each shift takes over, will take place to keep everyone up to speed on what happened during the last 12 hours, what’s happening at the moment and what’s to come regarding operations.

These are standard meetings and calls that happen naturally when all is going according to plan. In general, if anything, and I mean anything, happens that delays operations and/or is not as planned you MUST immediately call the operations geologist to inform the subsurface team. This ensures everyone is on the same page, updated and well informed in order to take decisions, if needed, on the plan forward.

Big Red Truck at the Wellsite ready for the Rig move

3. Travel schedule and rotation

This part applies to pretty much anyone who’s going to work in a rig, be it onshore or offshore. I’m just giving you my point of view on the job I’m currently doing.

The schedule and rotation will vary from oil company to oil company and work depends on the market conditions. As a geological consultant you usually get paid on a day rate basis only. Service companies on the other hand usually pay a part A (fixed monthly lump sum) and a part B (Daily Rate).

If there is plenty of drilling activity you might have a lot of work, but during a downturn you may stay at home for a long time. In a perfect scenario you would work roughly 6 months in a year having the other 6 months of time off.

You can be assigned a rotation of 2/2 (2 weeks on / 2 weeks off), 3/3 or 4/4. These are the standard rotations, but in Norway for example you can get 2/4. It is common for people to have a second job back home with a 2/4 rotation.

The geologist will either be alone on 24 hour permanent call or work on a 12 hour day or night shift if there’s two of us on site. In some areas the standard now is to have 2 wellsite geologists on 12 hour shifts. This seems to be the way most companies are headed.

Even if you are on 24 hour permanent call, some companies now prefer to have a separate witness for wireline logging jobs. That will either be a specialized consultant who used to be a wireline engineer or perhaps a petrophysicist or geologist from the town office.

Sometimes oil companies decide to get another geology consultant just during reservoir operations.

Looking at Quiet Sea in the Evening

4. Training and qualifications

To become a geologist you will usually need a Bachelors Degree in geology or any other degree that makes you an Earth Scientist.

I remember senior geologists mentioning a time when you didn’t even need a degree to do it. That’s definitely not the case now.

A Masters Degree may help you for an entry level position, depending on market conditions. It may also help you against the competition during downturns. Industry experience and networking, however, will help you much more.

Specific training can also help you get the job. There are several reputable consultancy companies which can train you in Operations and Wellsite Geology, for example. Search online and you will find 3 to 5 day courses, but you may need to travel to another country for training.

These are courses that you will have to pay for yourself as a consultant. If you work already for an oil company as staff then the company might want you to attend, in which case they will pay for it. This may be the case if you are to take the role of an operations geologist.

There are other important courses besides wellsite and operations geology. Those would be safety related courses (HSE), wireline and LWD formation evaluation, and abnormal pore pressure interpretation.

Usually companies also require you to have previous field experience in certain key positions, like mudlogging.

You need to get a medical certificate that’s adequate for the country you’ll be sent to work in. They seem to be getting more standardized and I imagine in a few years we will have only one type of certificate valid worldwide.

Offshore survival courses may also have specific details which vary from company to company and country to country. Some training facilities may have more learning modules than others, so be sure to always enrol in survival courses that are as complete as possible and allow you to work worldwide.

View from the Rig Camp

5. Skill sets you will need

As I’ve said before, sometimes there will be considerable pressure on us and you need to be able to deal with it. You may have to take difficult decisions on your own and at any time, depending on the situation and the oil company.

Some oil companies will give you the freedom, and very high responsibility, of taking important decisions. Others will want to make decisions together as a team. More and more this is a joint effort and the onshore team will also be evaluating the more complex situations, day or night. After all it’s in everyone’s best interest that the operation runs as smoothly as possible.

You will have to work with multicultural and multidisciplinary teams. Being social and knowing more than one language is a big bonus here as you will be living with these people at the wellsite for weeks.

Good computer skills, hardware and software, are a great bonus these days as well. Especially in an age when everything tends to become more and more digital and automated.

Critical and analytical thinking are very important. For example, you need to know when the data you are looking at is good and reliable or if it’s poor quality. Mathematical skills are also vital for data analysis.

Desert Sunset

6. How to start working in wellsite geology

This is one of the most frequent questions I get asked.

Keep in mind that I’m talking from a European perspective. From what I have read it seems things might be different in North America, but since I’ve never worked there I can’t say for sure.

As I mentioned before, we are usually consultants. Consultants normally work through agencies who have contacts and can find contracts for you. These contracts are for assignments and projects with oil companies.

Both agencies and oil companies will prefer you to have some previous field experience.

What does that mean?

It means you need to start working in the oilfields some years before, to get some experience. It’s unlikely you will get hired straight out of university for a job that requires you to supervise a few teams if you don’t know what they do and how they do it.

Hill in the Desert

6.1. The traditional path of mudlogging

Although I now work as a consultant geologist, I started out in mudlogging. I did it for almost six years.

If you are here reading this you are probably a mudlogger, have been one in that past or at least know what a mudlogger is.

I’ll still have to explain what mudlogging and a mudlogger is for anyone who doesn’t know.

6.2. Working in mudlogging

mudlogging services are composed by a team who collects several sets of geological and digital data from the wellbore while monitoring several other parameters at the same time. The team is divided into sample catchers, mudloggers and data engineers. Most of the time it’s just mudloggers and data engineers. There are other positions, like pressure engineer, but these are not a constant.

There will be 2 of each to cover the 24 hour period, so they’ll work 12 hour shifts. In some cases the oil company may only want one data engineer and two mudloggers. In this situation, the mudlogger should have experience as they’ll take the data engineer’s responsibilities when alone. Other team member combinations are possible and vary depending on the oil company requirements.

The team works in a container unit that connects to a multitude of sensors spread throughout the rig and which are constantly acquiring data. Even when there’s no drilling operations.

In this unit they also process the rock samples that come out of the borehole during drilling operations. That means washing the samples, preparing them for observation, performing several standardized tests and packing them for transportation.

Describing Cavings

6.3. Sample catcher, mudlogger and mudlogging data engineer

A Sample Catcher does just that. They catch and prepare the rock samples. This is the most basic position and it’s meant for inexperienced people to learn about the rig and the oilfield work environment.

The usual career progression for geologists is to start as a sample catcher and from there progress to mudlogger. I was hired directly as a mudlogger and had a couple of weeks of training before being sent to work in a rig. If you don’t have training you’ll probably be sent to the wellsite as a sample catcher for a couple of weeks to learn the basics.

The mudlogger usually has a university background in geology, earth sciences or engineering. There will be more responsibility here as you need to monitor the wellbore for gas and volumes. At the same time you need to keep an eye on the unit's equipment and system. You will produce some reports, create the mudlog, describe drill cuttings, mentor the sample catcher and help the data engineer.

As you learn more about operations, and the mudlogging unit’s system and sensors, you will get promoted to the position of data engineer. If the company needs personnel you may get pushed to data engineering much sooner than expected.

The data engineer is the most experienced figure of the mudlogging team. The number of duties and responsibilities are endless. They’ve been through the other positions and act as mentors for the mudlogger and sample catcher.

You are responsible for anything and everything in the mudlogging unit. You need to know how to do all the reports, calibrate, maintain and fix all the equipment from the unit and it's operating system.

The role to work in wellsite geology will come at some stage after you get experienced as a data engineer. Keep in mind that this depends on the market conditions. You may need to look for another company or agency if the current one doesn’t have such a position.

In reality all of these positions are preparing you.

For what, you might ask?

As I mentioned in the beginning you will be a supervisor. You need to supervise the mudlogging team and the data they produce to ensure it has quality. You should also mentor them.

6.4. Other paths to the profession

Not everyone starts out how I did. I have met other geologists who have never worked as mudloggers.

Some had worked in logging while drilling (LWD) or even wireline logging and were hired for their on site experience and geology degrees.

Remember when I said that agencies and oil companies prefer you to have field experience? Well in some countries I’ve met guys who were hired straight out of university by their national oil companies. They were not consultants, they were oil company staff. They were sent as trainees to learn about the rig and the work itself, but had little initial knowledge compared to the mudloggers whom they were supposed to eventually supervise.

6.5. Other challenges

Getting to be a wellsite geologist can take time and the path may not be easy. You will need persistence and determination to get there.

Timing and market conditions are important. During a downturn there’s probably zero chance someone’s going to hire you as a new geological consultant when so many experienced ones are out of a job.

Luck also plays an important factor. I’ve seen skilled people who never made the transition for one reason or another.

The last challenge is getting a personal recommendation from a senior geologist. This is someone you have impressed with your hard work and commitment over time and not a person you've just met. If you’ve proven yourself the senior geologist will recommend you directly to an agency he/she has contact with.

This is what will, most likely, get you working with an agency as a consultant.

7. Beyond the role - working as an operations geologist

With enough experience you might transition to operations geologist. In this role you will stay in the office in town and supervise the geologists at the rig. You'll check their reports, monitor operations unfold, help plan future wells, keep the clients and investors informed, decide on equipment to be sent to the rig, etc.

The operations geologist is usually alone on 24 hour call for the duration of his/her hitch and stays at the oil company office. During critical operations there may be two of them to cover 24 hours. If you are a consultant you will probably work in a rotation system like people at the rigsite, but you may be required to relocate if you are staff.

It’ll be up to you to decide if you want to make the transition or just prefer the field work at the wellsite. I know quite a few geologists who preferred to stay at the rigsite.

Keep in mind that with the right Masters Degree you can also work as a petroleum geologist, petrophysicist, reservoir engineer, etc. in the office in town. Although it’s always good to have some field experience, in these positions that's usually not a requirement.

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