Rock Typing and Permeability · Module K5
The three discriminators
Rock typing starts with a number computed from each plug's porosity and permeability. The module derives the reservoir quality index and flow zone indicator, the Winland R35 pore-throat radius and the Lucia rock-fabric number, explains the question each one answers, and works a plug by hand to match the workspace. It names the unit trap in each and shows where the three disagree on the same plugs.
- Level
- Advanced
- Position
- Module 5 of 8
- Video
- About 18 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
- Reservoir quality index and normalized porosity
- Flow zone indicator and the unit-slope line
- Winland R35 and port-size classes
- Lucia rock-fabric number for carbonates
- Low porosity and vuggy plugs
- Where the three discriminators disagree
Learning outcomes
After the module you should be able to:
- Choose the discriminator for the question asked, check it by hand against the workspace, and name its unit trap.
- Compute FZI and R35 for one plug by hand and match the workspace
- Choose flow units, port size or carbonate fabric to suit the question asked
A short preview
Take a plug at 20 percent porosity and 100 millidarcies. Its reservoir quality index, 0.0314 times the square root of k over φ, is about 0.70 µm. Divide by the normalized porosity, 0.20 over 0.80, and the flow zone indicator is 2.81 µm. Winland's regression puts the pore-throat radius of the same plug near 6 µm, a macroport. Enter the porosity as a fraction where the equation expects percent and the radius grows about 53 times, to some 325 µm: a megaport that no 100 mD sandstone has.
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.