September 2023 Meeting

Monday, September 11, 2023
6:00 - 7:30 pm

For those attending in-person this meeting will be held at the following location:
Pellissippi State Community College
Ned R. McWherter Technology Building, Room 129

Note: ETGS members participating virtually will receive an email with info for attending/logging into the meeting.


September Presentation

Petroleum Systems Analysis and the Shale Revolution: A Career Perspective



Tony McClain


Petroleum Systems Analysis (PSA) is a geological sub-discipline or "technical specialist" role in most oil and gas companies. The technical work is very different from what most geologists do in oil industry jobs. Most are "prospecting" geologists, doing the standard analyses associated with the task of finding and developing oil and gas prospects. These tasks typically involve structural geology, stratigraphy (with emphasis on sedimentary geology and processes), as well as log analysis and seismic analysis. All of these tasks are brought together in various maps of the subsurface: structure maps, reservoir isopach maps, porosity and/or "net pay" maps, etc., and documentation of all surrounding oil and gas drilling activity that may inform the risk level of the prospect being proposed. PS analysts do work that supports the prospecting geoscientists. This work involves basin modeling, in order to understand the generation history and movement (migration) of petroleum fluids in the basin over time, as well as geochemistry, in order to understand the nature and quality of the source rock. They also do geochemistry of the oil and gas in the basin in order to characterize the quality (composition) of the oil and/or gas for which prospectors are searching. Ultimately, PSA is a risk assessment exercise to ensure every prospect has each of the 5 elements that a "working petroleum system" requires: 1) source, 2) reservoir, 3) trap, 4) seal, 5) charge access.

In the early to mid 2000s, the advent of the "shale revolution" not only changed the world order in terms of the United States' place on that world stage, but it raised the profile and value of the petroleum systems specialist and their work. The shale revolution turned prospecting work on its head - the source rock (shale) was now also the reservoir! Now, everyone wanted to know, in detail, all about the geochemistry and maturity of source rock-shales that were being considered as drilling targets. Petroleum systems analysis became a sought-after and highly valued skill-set in the industry. Serendipitously, I had just made a career-direction change from a prospector role to a petroleum systems analyst role in 2005, just as the shale revolution was getting under way. The impact of the shale revolution on the discipline of petroleum systems analysis and on the trajectory of the U.S. oil industry on the world stage will be discussed.


Tony McClain grew up in Oak Ridge, Tennessee during the 60s and 70s. After high school, and a brief period pursuing his first love - baseball, he discovered a new passion when he took his first geology class at Florida State University. He was "hooked" from day one. He went on to earn B.S. and M.S. degrees in geology (BYU/'82 and Texas A&M/'85, respectively) before embarking on a nearly 36 year career in the oil industry from early 1985 to late 2020, retiring back home to Oak Ridge in October of that year. After working the first 15+ years with ARCO Oil and Gas Company, BP acquired ARCO where he finished the last 20+ years of his career. He worked in most of the onshore U.S. petroleum basins during his career, and after the beginning of the shale revolution, focused on exploration and development of many shale plays including the Eagle Ford of South Texas, the Haynesville of East Texas/North Louisiana, the Bakken Shale of the Williston Basin, and the Wolfcamp and Bone Spring plays in the Permian Basin. He also worked on shale plays in Mexico and Canada.

Like most of us, he feels fortunate to have had a career in a subject that would have been his hobby, had it not been his job. Tony and his wife Jana have been married 43 years, have three sons and 9 grandchildren.



Greetings! We hope you will join us for the next ETGS in-person/virtual meeting, and that you, your family, and your colleagues are staying healthy and well. 

As a courtesy, please mute your cell phone or the microphone in your laptop/tablet to minimize background noise and feedback echoes. We will try to mute all participants until the presentation is finished. Please use the chat feature to type comments or questions during the presentation. We recommend that you send questions for the speaker to "everyone" so all participants can see the question. After the presentation, the speaker will answer questions.  During this Q&A period, you may unmute if you wish to ask a question verbally.

We will create an attendance list based on the participant names we can see during the meeting. This is helpful for those who need to document participation to support Professional Geologist registrations. It is not always possible to tell who is participating, especially for those joining by phone, so please email your name to etgs@live.com to be listed on the attendance sheet. Let us know exactly how your name should appear on the list.

Thank you for your patience and understanding as we continue adapting to this hybrid format. As always, we welcome and appreciate your feedback and suggestions for improvement.


ETGS News:

  • New ETGS mugs are available! If you would like to purchase a mug, email etgs@live.com and include "ETGS Mug" in the subject line.


ETGS Coffee & Beer Mugs...

Sure to be a collector's item!

We look forward to seeing you at the next meeting.

ETGS is a volunteer organization. We need your help to continue serving those interested in the geology of East Tennessee and beyond. Please email us at
etgs@live.com if you would consider assisting in one of the following open positions. It is a great opportunity to expand your personal and professional network.

David Carlone

Vice President

J. Brad Stephenson

Seaira Stephenson

Webmaster/Social Media Coordinator
Bob Gelinas



Page updated August 28, 2023