Archive of Texas PTTC Workshops
Ellison Miles Geotechnology Institute and the Texas Region PTTC Presents a 2-Day Workshop

Rocks, Pores, and Capillary Pressure:
The Hole Story on How to Understand Reservoirs and Seals
by Thinking Like Oil and Gas

Tuesday and Wednesday, March 1–2
Ellison Miles Geotechnology Institute
Brookhaven College, Farmers Branch, Dallas, Texas

Presenter: Dr. Charles L. Vavra, North Star Geological Services, LLC

Workshop Description
This practical two-day course combines creative analogies, real-world case studies and hands-on exercises to examine critical, but commonly misunderstood, rock properties such as pore geometry and capillary pressure and their impact on reservoir quality, fluid distributions and petrophysical response. Capillary pressure concepts are developed and used to evaluate reservoir quality, seal capacity, fluid distribution and saturations. The influence of rock composition, mineral location and pore geometry on wireline log response and formation damage are reviewed. Real-world examples illustrate how operators who didn’t understand the rocks missed significant reserves, and how the reserves were later “discovered” by operators who “thought like oil and gas”.

About the Presenter
Charles L. Vavra is president of North Star Geological Services, LLC, Lucas, Texas. Dr. Vavra has over 20 years experience in exploration and development of conventional and unconventional oil and gas fields in the United States and around the world. Chuck specializes in pore-level characterization of reservoirs and seals, petrographic and diagenetic studies, and identification of missed pay and hidden reserves. He is a certified petroleum geologist, a member of AAPG, SEPM, and SIPES and is a licensed professional geologist in Texas. Chuck received his B. Sc. and Ph.D. from Ohio State University.

For more information, please call Dennis Maddox at 972-860-4630 or e-mail

For more information about this and other PTTC workshops, please contact Sigrid Clift at
512-471-0320 or e-mail