Oil and Gas

Oil and Gas | Petrophysics

Quantitative Log Analysis and Petrophysics

Course Code: N360
Instructors:  Martin Kennedy
Course Outline:  Download
Format and Duration
5 days


The course introduces the principles and practice of petrophysics as applied to conventional reservoir rocks (clastics and carbonates). It defines the petrophysical properties: porosity, permeability and water saturation and goes onto explain what controls them and how they can be reliably estimated. The course also considers some of the more artificial properties that are based on the above and shows how they are used to characterize petroleum reservoirs.

Duration and Training Method

This is a classroom course, comprising lectures supported by exercises of varying complexity. Most exercises will use real data from a variety of different reservoir types. All exercises can be completed using calculators and graphs (computers and special software are not required).

Course Overview

Participants will learn to:

  1. Be able to define porosity, water saturation and permeability and appreciate the difference between total and effective porosity models.
  2. Understand how porosity is measured in the laboratory and how it can be estimated from density and other physical properties measured by logging tools.
  3. Have a qualitative understanding of how porosity tools work: density, sonic, neutron porosity and NMR.
  4. Define electrical resistivity and what determines it in porous solids (Archie equation).
  5. Understand how resistivity is measured in the borehole and how resistivity measurements can be used to estimate water saturation.
  6. Appreciate what controls permeability, how it is measured and how it determines deliverability in wells.
  7. Calculate reservoir average properties and use them to characterize reservoirs.
  8. Have a qualitative understanding of what controls the distribution of oil and gas in a reservoir.

The course starts with an introduction which includes an overview of the course and some useful tools and techniques. The rest of the course goes through the outputs of a petrophysical interpretation in the order they are typically generated: shale volume, porosity, saturation and permeability. Each property is defined, before explaining how it is measured on rock samples and why it is important. At the same time the logs that are most commonly used to estimate it are introduced and the way(s) they are transformed is described.

Day 1:
1.1 Petrophysical properties and data
1.2 Physical Properties of Rocks
1.3 Measuring porosity and permeability on core samples
1.4 Fundamentals of Logs and Log Analysis
1.5 Some Useful Tools and Techniques

Gamma-ray, SP and Shale Volume.
2.1 Clay minerals and why they are important in petrophysics
2.1 Shale and Clay Volume
2.2 Natural Gamma-ray Activity
2.3 SP

Day 2:
Density and Porosity
3.1 Introduction
3.2 Density and the density log
3.3 Porosity from Density
3.4 More on Porosity

More Porosity Logs
4.1 Neutron Porosity
4.2 Sonic
4.3 NMR
4.4 Estimating porosity and shale volume from sonic and neutron logs
4.5 Combining Measurements

Day 3:
Resistivity and Saturation

5.1 Introduction
5.2 Resistivity Tools
5.3 Water Saturation
5.4 Resistivity and Saturation: Archie equation.
5.5 Modifi cations to the Archie equation (conductive minerals)

Day 4:
Hydrocarbon Eff ects on Logs

6.1 Specifi c eff ects of hydrocarbons on logs
6.2 Accounting for Hydrocarbon Eff ects
6.3 Accounting for Invasion
6.4 Fluid Substitution

7.1 Introduction, diff erent types of permeability
7.2 Controls on permeability
7.3 Estimating Permeability from Logs

Net, Pay and Averaging
8,1 Why Average?
8.2 Cut-off s and how they are chosen
8.3 Problems.
Brief introduction to uncertainty

Day 5:
Fluid Distribution: Controls and Models

9.1 Introduction and Fundamentals
9.2 Water in Porous Rocks
9.3 Measuring Capillary Pressure Curves.
9.4 Real Fluids in Real Rocks
9.5 Contacts and Free water Level
9.6 The Saturation Height Function
Conclusion and the Future

The course is designed to give participants an appreciation of the practice of petrophysics. Anyone who uses petrophysical properties in their day to day work would benefit from attending. Petrophysicists at the start of their careers would also benefit from attending but it is not intended to cover the more advanced tools and techniques.

Martin Kennedy

Martin Kennedy, is a consultant petrophysicist based in Perth, Western Australia. He began his career as a wireline-logging engineer. After leaving the field, Kennedy worked in R&D, for government and for several mid-sized British independents before moving to Perth as Woodside’s Chief Petrophysicist in 2003. He left after six years to concentrate on training and consulting. His career has spanned everything from field studies to quick-look evaluations as well as managing the petrophysics skill-pool for two companies. Kennedy has worked on most of the classic petroleum provinces outside North America (and a few within) as well as some more exotic areas. He now consults for a wide range of companies ranging from small Independents to Majors and specializes in areas that do not readily yield to standard techniques. His particular interests are carbonates; the way logging tools interact with geology; image logs; and interpreting old logs, bad logs, and bad/old logs. Kennedy holds a degree in chemistry from Bristol U. and a PhD degree in electrical engineering from Edinburgh U.

Affiliations ans Accreditation
PhD Edinburgh University - Electrical Engineering
BSc Bristol University - Chemistry

Courses Taught
N003: Geological Interpretation of Well Logs
N030: Rocks & Fluids: Practical Petrophysics (Isle of Wight, England)
N360: Quantitative Log Analysis and Petrophysics

CEU: 4.0 Continuing Education Units
PDH: 40 Professional Development Hours
Certificate: Certificate Issued Upon Completion
RPS is accredited by the International Association for Continuing Education and Training (IACET) and is authorized to issue the IACET CEU. We comply with the ANSI/IACET Standard, which is recognised internationally as a standard of excellence in instructional practices.
We issue a Certificate of Attendance which verifies the number of training hours attended. Our courses are generally accepted by most professional licensing boards/associations towards continuing education credits. Please check with your licensing board to determine if the courses and certificate of attendance meet their specific criteria.