Rock Typing and Permeability · Module K2
Core data, the basis of everything
Every permeability curve is checked against core, so the core has to be on a known basis first. This module pairs plugs to log depths, finds and enters the core depth shift, corrects air permeability for gas slippage with a lab Klinkenberg value or the Heid correlation, applies overburden factors from stress tests rather than defaults, and matches the porosity kind of the plugs to the log. It closes with the basis line that should sit beside every fit.
- Level
- Advanced
- Position
- Module 2 of 8
- Video
- About 19 minutes, narrated
- Format
- Narrated video lesson with captions and slide reading view; with the certified option, a quiz whose pass unlocks the next module.
What the module covers
- Pairing plugs to log samples
- Finding and entering the core depth shift
- Gas slippage and the Heid correlation
- Lab Klinkenberg values against a correlation
- Overburden factors from stress tests
- Effective or total porosity on both axes
Learning outcomes
After the module you should be able to:
- Put plugs on a stated depth, permeability and porosity basis, and write that basis beside every fit.
- Correct air permeability for slippage and stress, and say which values were measured
- Check that plug porosity and log porosity are the same kind before fitting
A short preview
Air passes through a plug more easily than oil or water would, because gas molecules slip along the pore walls, and the effect grows as the pores get smaller. The Heid correlation corrects for it. At a lab mean pore pressure of 40 psi, a plug reading 0.1 mD with air comes down to about 0.053 mD, nearly half, while a 100 mD plug moves only to about 95 mD. Stress acts the same way. On the course well, measured permeability factors at reservoir stress run from about 0.9 in the best rock to 0.65 in the tightest, so one default multiplier leaves tight plugs reading high.
Who it is for
Petrophysicists, reservoir engineers and geoscientists who build permeability curves from core and logs, define rock types, and carry permeability into net pay, k·h and saturation-height models.
Prerequisites: The Intermediate track, or working experience with shale volume, porosity and water saturation; Advanced modules A2 and A4 help but are not required. The hands-on steps use the Rock Typing, Permeability estimate, NMR and Neural network permeability workspaces in Formation Evaluation, all available from the Starter plan.
Take the module in the Learning Hub
Rock Typing and Permeability: Specialty course, sold separately: eight modules that turn core plugs and logs into a permeability curve you can defend, from plugs on a stated basis through transforms, NMR and rock types to net pay, k·h and the saturation-height hand-off. The lesson opens in the Learning Hub once the track is purchased; graded quizzes and the certificate come with the certified option.