NAME: Fernando Ziegler
CURRENT TITLE: Geophysics Consultant
AREA OF EXPERTISE: Pore pressure, fracture pressure, wellbore stability, seal capacity, hydrocarbon column height estimates, rock physics, geomechanics, drilling operations
YEARS OF EXPERIENCE: 11 years
Master of Science in Geophysics – University of Houston
Bachelor of Science in Physics – The University of Texas at Austin
What’s your job like?
As a pore pressure and wellbore stability specialist, my job consists of compiling information from various sources, whether I am working on a pre-drill model or working in drilling operations.
Working on a pre-drill model means being part of various interactions between geologists, geophysicists, petrophysicists, drilling and completion engineers, management, and sometimes potential or current partners, and then taking that information and applying it to my models. The work I do for geoscientists includes calculating a pore pressure, different stresses, and elastic rock properties for an existing well or estimating them for a proposed well, calculating hydrocarbon column height estimates to help identify potential opportunities from farm-ins and lease sales, and analyzing different proposed locations and targets. The work I do for engineers includes using my estimated pore pressure and fracture pressure for a proposed well and working in well planning, such as assisting with the proposed mud weights, casing string setting depths, and proposed injectivity tests for the different hole sections.
During drilling operations, I continue with interactions not only with the people in the previous paragraph, but now also with the personnel involved directly in drilling operations such as operations geologists, mudloggers, mud engineers, and drilling supervisors, and using the information they provide to monitor the pore pressure and wellbore stability in that well as it is being drilled. For the geoscientists, I compare the well being drilled with the pre-drill model and make the necessary adjustments, if needed. For the engineers, I provide regular real-time pore pressure and fracture pressure updates, review the results from injectivity tests, and sometimes even assist in remediation of well control, lost circulation, and wellbore breathing situations when any one of such events occur.
What’s a typical day like?
On any given day, the day may be totally different from the previous one, and I like that.
All the pore pressure and fracture gradient work I have done has always involved working with integrated groups of geoscientists and engineers from various organizations and technology groups, so most of my days vary depending on the project I am working on. This means that some days I may be interpreting data from my desk while on others days I may be interacting with different people involved in a given project, sometimes informally in somebody’s office and sometimes more formally in the case of a peer review or when presenting to management.
Most recently, I have been more involved in actual drilling operations. A lot of this involves doing real-time pore pressure, fracture pressure, and wellbore stability monitoring, writing a summary of the activities and events of the previous day and a forecast for the projected activity and potential event(s) expected during the day, and reviewing these with the different people involved in drilling operations during a morning meeting. Most of the time, that means the rest of the day is spent monitoring. In the case of an unexpected event such as an influx or losses, it then comes to contacting the appropriate people involved in drilling operations and providing recommendations on how to mitigate or solve the issue at hand.
Everything about my job is fun. I enjoy working with all of the various individuals involved in a given project. Ultimately, there are a lot of people involved in drilling a wellbore safely and efficiently and being able to interact with them is key for me to do a successful job.
I like how during drilling operations things move either really slow or really fast, and if an unexpected drilling event occurs decisions need to be made to figure out how to best mitigate or solve the issue at hand. Of course, to contrast, a bit of a break comes when drilling operations are not taking place, where I get to focus on pre-drill pore pressure and wellbore stability analyses or hydrocarbon column height estimates. This variation also allows me to work on other things such as teaching an introductory course to peers or working on new ideas that may potentially improve my workflow.
The other fun aspect of my job is looking at projects in new geographical areas, because I benefit and learn so much each single time. Every area has its own set of stress regimes, overpressure mechanisms, geological issues, set of units, and languages to sift through.
Depending on the area, the amount and quality of data can differ. Sometimes one doesn’t have the necessary well logs or the well logs are not digitized, and one has to digitize them themselves, or the closest offset is very far away and not very representative. Sometimes the data are not useful because they are from a different field or are not deep enough to where the proposed target is. Sometimes there is very coarse seismic interval velocity data originally used for imaging and one has to go back and pick the interval velocities from scratch if the necessary information is still available.
To me, a pre-drill pore pressure and wellbore stability analysis are like putting a puzzle together with a lot of missing pieces. My job is to try to determine what the whole picture says. To add to the excitement, the next puzzle will be missing some pieces as well and may ultimately look entirely different from the previous puzzles I have worked on, but the job is to still determine what the whole picture tells says.
During drilling operations, the challenging part is accounting and accommodating for everything involved in a given hole section. Various formations may behave differently after being drilled and they have their own set of issues. In a given section, one can be dealing with a formation that gave an influx while another deeper formation may have instability issues or losses, with the challenge being deciding what to do to mitigate the most recent issue without aggravating the previous one or impacting the rest of the hole section.
What’s your advice to students?
Learn how to make and give a presentation: No matter what you do, you will have to make a presentation to peers or management. This will vary between one slide or the whole set of slides, or may be something interactive. Spend some time practicing what you are going to say and overcoming any fears you may have in speaking in front of people. Learn a little about information design and data visualization.
Network and talk to people: The people you go to school with and those you meet during your professional career will be the same people you will eventually work with. These interactions will continue for the rest of your career inside and outside the office.
Ask questions: It is perfectly acceptable to not know something. Inside and outside of your organization, you will always find someone who knows the subject well and will be delighted to go over things with you.
Venture outside your comfort zone: Take the opportunity when you are given the option to take on a new assignment. It may make you a more well-rounded geoscientist. Working with different business units exposes you to different areas around the world. Learn a little bit about the business you are involved in and what other people do.
Don’t burn any bridges: People change organizations or companies and if you have networked and talked to people, then people will know who you are and what you do. Some of those people will become managers. You will have a harder time during your career if you burn your bridges with individuals or companies if you ever plan to change organizations or companies.