N003 Geological Interpretation of Well Logs

Course Facts

Course Code:
5 days
4.0 Continuing Education Units
40 Professional Development Hours
Certificate Issued Upon Completion


Business Impact: The ultimate objectives of this course are to be able to use sets of well logs to establish robust correlation schemes, guide well placement and derive property inputs for geological modelling. These skills will enable participants to reduce risk, understand uncertainty, improve success rates, and reduce costs throughout the E&P life cycle.

This course is an introduction to the principles and applications of conventional well logs. It shows how combinations of logs can be used to interpret mineralogy, lithology, facies, depositional environments and key sequence stratigraphic markers such as flooding surfaces. Sessions start by considering the individual measurements but as the course progresses there is an increasing emphasis on combinations of measurements and the trends with depth. The climax of the course is an exercise to produce a robust correlation scheme using data from three wells. The correlation scheme is then used to choose the location for a fourth well designed to intersect the best developed reservoir.

Duration and Training Method

This is a five-day classroom course which uses a combination of lectures and self contained exercises based on real data sets.

Participants receive a complete set of lecture notes and a copy of the text book “Geological Interpretation of Well Logs” by Malcolm Rider and Martin Kennedy.

Participants will learn how to:
1. Differentiate the functions, physical principles, and limitations of logging tools used in a standard logging suite and their applications for geological interpretation.
2. Demonstrate the differences between logs acquired using wireline conveyance and logs acquired whilst drilling.
3. Use well logs to determine lithologies,  interpret facies, and stratigraphic and structural features.
4. Determine shale volume, porosity, and water saturation from well logs.
5. Correlate between wells using well logs, integrating other available down-hole data.
6. Analyse well logs and cores, together with other available data, to produce a coherent geological evaluation.
7. Employ dipmeter and borehole imaging tools and analyse their interpretation patterns to indicate structural and stratigraphic features.

In this class, each individual logging tool is described in terms of basic functions, physical principles and geological interpretation. Log data is then used as a complementary set for lithology interpretation, facies recognition, log sequence analysis and correlation. The following timetable is only a guide and may vary depending on the instructor and experience level of the class.

Day 1:

  • Introduction
  • Logging Environment
  • Introductory Worksession
  • Simple Gamma Ray
  • Worksession: Caliper and Gamma
  • Spectral Gamma Ray

Day 2:

  • Worksession: Spectral Gamma Ray
  • Resistivity – Theory and Tools
  • Worksession: Resistivity
  • Resistivity – Geology
  • Sonic Logging
  • Worksession: Sonic
  • Well tying and Modern Sonic Logs

Day 3:

  • Density Logs
  • Worksession: Density
  • Neutron Logs
  • Density Neutron Combination
  • Lithology
  • Worksession: Lithology
  • Dipmeter

Day 4:

  • Core Photos – log comparison
  • Image Logs
  • Worksession: Image logs
  • Facies and Sequences from Logs
  • Worksession: Sequence Analysis
  • Correlation

Day 5:

  • Stratigraphy and Correlation with logs
  • Worksession: Correlation
  • NMR
  • Basic Petrophysics
  • Worksession: Basic petrophysical workflow

    Who should attend

    This course best suits those beginning to acquaint themselves with logs or those who do not use logs all the time and need a refresher. The course is aimed primarily at inexperienced Geologists and Geophysicists, whether in exploration or exploitation, but is also good for Technologists, Reservoir and Petroleum Engineers and new-hire Petrophysicists. 

    Prerequisites and linking courses

    N003 is considered essential for all geoscientists to attend, due to its nature and direct relevance to all key aspects of the Oil and Gas industry. There are no formal prerequisites for the class, however it is advantageous to have a basic knowledge of Geology and Petroleum Systems.

    For an entry-level petrophysics class, see N083 (Introduction to Petrophysics and Reservoir Evaluation) and for a more petrophysical view of the interpretation of well logs, see course N121 (Modern Petrophysical Well Log Interpretation).

    To build on the learnings of N003, it is recommended to follow with N517 (Well Log Sequence Stratigraphy for Exploration and Production), N451 (Practical Oil-Finders Guide to Siliciclastic Sequence Stratigraphy (Wyoming)), or N011 (High Resolution Sequence Stratigraphy: Reservoir Applications (Utah)).

    Click on a name to learn more about the instructor

    Jenny Garnham

    Martin Kennedy

    Larry Maple

    Related Subjects

    "This was one of the most effective classes I've taken. I feel excited to get back into my log data next week."