Evaluation of Organic Shale Reservoirs

Rick Lewis 


The participant will develop a basic understanding of the geology and evaluation of organic shale reservoirs. The goal will be the development of skills for a basic evaluation of a gas shale reservoir. Towards that end, several spreadsheets will be distributed and demonstrations will aid the student in these analyses.

The subject will be subdivided into Reservoir Quality (RQ) and Completion Quality (CQ).

RQ addresses whether the organic shale is a reservoir. Does the prospective shale reservoir have what adequate matrix properties to produce hydrocarbons subsequent to a hydraulic stimulation—hydrocarbon in place, viscosity, and matrix permeability? Both log and core analysis for petrophysical parameters will be described in detail, and gas- and oil-producing shales will both be examined.

CQ addresses whether the organic shale can be effectively stimulated. Does the stress and mineralogy permit the development of adequate hydraulic stimulation surface area, and will these fractures remain conductive over time?

At the conclusion of the class, the participants should have an appreciation of what it takes for an organic shale to be a reservoir. They should also have the knowledge and tools to permit a basic evaluation of a perspective shale reservoir using triple combo logs and, if possible, core analysis.


  • Introduction to organic shale reservoirs
  • Geology of organic shale reservoirs
  • Typical log responses for organic shales
  • Mechanisms for liquids production
  • Mineralogy determination
  • Kerogen/TOC/adsorbed gas quantification
  • Porosity and saturations
  • Quantifying hydrocarbon in place
  • Permeability of organic shales
  • Geomechanics/stress for laminated reservoirs

Learning Level

Intermediate as a geoscientist. Beginner with regards to organic shales.

Course Length

1 Day

Who Should Attend

Geoscientists and engineers who are interested in the description and evaluation of organic shales as a reservoir. Prior experience with organic shales is not necessary.


Engineers are responsible for enhancing their professional competence throughout their careers. Licensed, chartered, and or/ certified engineers are sometimes required by government entities to provide proof of continued professional development and training. Training credits are defined as Continuing Education Units (CEUs) or Professional Development Hours (PDH). Attendees of SPE training courses earn 0.8 CEUs for each day of training. We provide each attendee a certificate upon completion of the training course.


Rick LewisRick Lewis, Petrophysics Technical Manager, Unconventional Reservoirs for Schlumberger Oilfield Services. Lewis was the developer of the gas shale evaluation workflow that was initially fielded ten years ago and has been applied to more than 3000 wells in North America. In his current position, he manages a group responsible for the continual improvement for this workflow, for its introduction and application to the international market, and for the development of workflows for the evaluation of liquids-producing shales. Lewis is also the interface to the Schlumberger research and engineering groups for the development of evaluation technologies for unconventional reservoirs. Prior to this assignment, Lewis was responsible for wireline interpretation development for the central and eastern United States. He is located in Dallas, Texas, USA. He has also worked for Shell Oil and the U.S. Geological Survey. Lewis received a BS degree from UCLA and MS and PhD degrees from Cal Tech, all in geology.