Well-logging Analysis

AAPG SC-UI conducted short course about Well Logging Analysis on September 27th 2014, at Pertamina DEX Room FMIPA UI. We invited Mr. Budi Abrar from Petronas as the speaker for this course. It was attended by 80 participants, and it was very nice to meet our fellow AAPG SC-Trisakti came to our course.

This course mainly discussed the use and application of every logging analysis like Neutron log, Sonic log, Density log, and Resistivity log. Density log is very useful as it has high accuracy and exhibits small borehole effect. Neutron log is used to measure hydrogen index and porosity. Neutron log when it combined with the bulk density can give the best possible answer for lithology and porosity.

The application for Sonic log itself are for seismic, mechanical properties, fracture identification, and identify porosity and lithology. In resistivity, the values can be high if there are hydrocarbon and tight zone. It doesn’t always mean hydrocarbon exist when the resistivity value is high, it can be tight zone. There are also water saturation calculation which related to Archie law. In petrophysics, secondary porosity has differences with sonic log and density log.

For quicklook evaluation, here are the list that we get to do:

  1. Check log data for consistency
  2. Identify coals, tight streaks and washouts
  3. Identify reservoir
  4. Compute total porosity
  5. Identify fluid types based on logs
  6. Compute apparent porosity PHIA
  7. Compute formation water resistivity
  8. Compute water saturation in all reservoir
  9. Identify fluid contact using pressure test from formation tester tool
  10. Write summary