WEBINAR: What the heck is petrophysics?

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Please note this webinar will be held in during five seperate 1.5 hour sessions (12:00 p.m. - 1:30 p.m. CST) beginning on Tuesday, January 29 and concluding on Tuesday, February 26.

Upon registration you will received login details.

If you are registering for this WEBINAR after any of the sessions you will reeive the recorded link of session one and instructions to join the remaining sessions.


This webinar offers, in five sessions, an introduction to common openhole petrophysical measurements. The course is designed to be a high-level survey of the measurements that exist in millions of wells worldwide, and that are still made in wells being drilled today. The measurements are presented in the context of a generic workflow rather than being grouped by their underlying physics.

The course assumes no knowledge of petrophysical measurements or their interpretation, although the course may help those with some knowledge in those areas to put that information into a more coherent framework.

This webinar is intended to pique one’s interest in petrophysics, and to help people decide if their interest warrants attendance at more detailed introductory courses such as The Discovery Group’s Basic Openhole Log Interpretation, which will be offered through PTTC in March of 2019, in Houston.


  • Addresses the borehole environment in which each measurement can be made;

  • Presents a “cocktail party explanation” of the physics of each measurement and the subsurface volume which is measured;

  • Shows the indirectness of each measurement as they attempt to predict formation properties;

  • Details the methods which derive the formation properties from the measurements;

  • Focuses on the traditional interpretation targets of lithology, porosity, and fluid saturation;

  • References other formation properties of interest, such as mechanical and acoustic properties;

  • Introduces a variety of interpretation techniques in the context of the availability of newer, more extensive, data.


  • The borehole environments and wellsite operational sequence in which the measurements are made;

  • Description of the common openhole measurements; acoustic, nuclear, and electrical;

  • Determination of lithology, porosity, fluid saturation, and other properties from those measurements;

  • Use of algorithmic and graphical techniques to determine those properties from the measurements that are made, and the parameters necessary for the calculations;


This webinar is presented in five 1.5-hour sessions, one session per week in consecutive weeks.


The topics shown for each session are best estimates based on previous presentations of the course. Notes will be provided prior to the sessions so that participants can preview the material to be covered.

Questions and comments based on the experience of the class participants are welcome, and often provide insights to local conditions and methods which would not otherwise be presented. In this webinar format, questions will be addressed in the last 15 minutes of each session.

Session 1

  • Course Logistics, materials and locations
  • Definitions; the openhole acquisition environment
  • Generic workflow in context of the measurements and related equations
  • Correlation/Reservoir measurements: Gamma ray, SP, Caliper, Tension

Session 2

  • Porosity & Lithology measurements:
  • Acoustic slowness, Bulk Density, Photoelectric Effect, Neutron Porosity
  • Nuclear magnetic resonance (NMR)

Session 3

  • Common porosity measurements used together:
  • Pairs of measurements for porosity and lithology
  • Triads of measurements for lithology
  • Elemental Spectroscopy for lithology

Session 4

  • Resistivity measurements
  • Estimating fluid content and production:
  • Archie’s equation and Bulk Volume Water

Session 5

  • Putting the interpretations together:
  • Pattern recognition (graphical) solutions and prediction of calculation parameters.
  • Buckles, Pickett, Hingle plots, and combined as a “gameboard” for simultaneous parameter prediction.


Daniel A. Krygowski is a Senior Petrophysical Advisor at The Discovery Group, in Denver, Colorado, USA. In this role, he has worked petrophysical interpretation projects in a variety of international and US domestic locations. Currently he is spending most his time providing and developing training courses in basic and intermediate openhole petrophysics. The courses include the common instructor-led formats, as well as longer-term, lower intensity formats that allow participants to spend more time with the course material while delving deeper into areas of personal interest.

Since the late Cretaceous, Dan has taught the AAPG Basic Well Log Analysis course with Dr. George Asquith. In recent years, Rick Lewis, with Schlumberger, has joined George and Dan in instruction in the course. In 2004, the AAPG published Basic Well Log Analysis, co-authored by Dan and George, with Steve Henderson and Neil Hurley. The book is the second edition of George’s similarly-named book which was one of AAPG’s all-time best sellers, and the second edition has also become an AAPG best seller.

Dan earned a BA in Physics from the State University of New York at Geneseo. He then earned MS and Ph.D. degrees in Geophysics from the Colorado School of Mines, where he focused on petrophysics under Dr. George R. (Dick) Pickett.

After completing his formal education, Dan worked for Cities Service Company (now part of Occidental Petroleum), Atlantic Richfield (now part of bp), Petrophysical Solutions, Landmark Graphics (a Halliburton company), and Chevron. At several of those companies, he held positions in petrophysics and petrophysical software development, with both technical and management responsibilities. He joined The Discovery Group in late 2006.

Dan has been active in the Denver Well Logging Society, serving two terms as Director, and terms as Vice-President Technology, and Vice-President Membership. Dan is a member of SPWLA, AAPG, SPE, DWLS, and RMAG.

Dan can be reached at: DanKrygowski@Discovery-Group.com - 303.831-1515 x207 office - 303.862.0110 cell

Produced for PTTC by PIKA Industries LLC


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