Advanced Petrophysics · Module A5
Natural Fractures and Dual-Porosity Systems
Recognising natural fractures and handling dual-porosity systems in interpretation: fracture types and their indicators on conventional and image logs, aperture and the cubic law, matrix–fracture transfer, the effect on saturation logs, and bounding fracture uncertainty with explicit upside and downside cases.
- Level
- Advanced
- Position
- Module 5 of 8
- Video
- About 20 minutes, narrated
- Format
- Narrated video lesson and slide reading view; with the certified option, a quiz whose pass unlocks the next module.
What the module covers
- Fracture types, origins and significance
- Fracture porosity versus matrix porosity
- Fracture indicators on conventional and image logs
- Aperture, permeability and the cubic law
- Dual-porosity, dual-permeability systems and matrix–fracture transfer
- Upside and downside fracture cases
Learning outcomes
After the module you should be able to:
- Recognise natural fractures and treat dual-porosity systems in interpretation.
- Identify open, closed and healed fractures from log and image evidence
- Explain how fractures change flow and saturation interpretation
- Bound fracture uncertainty explicitly
A short preview
Flow through a fracture rises with the cube of its aperture: between parallel plates the flow per unit width goes as w³/12 for a given pressure gradient and viscosity. Halve the aperture and the flow falls by a factor of eight. Apertures estimated from image logs or core are uncertain, so fracture permeability is better carried as a wide, explicitly bounded range than as one value, and its contribution to the uncertainty compared honestly with the matrix's.
Who it is for
Experienced petrophysicists and geoscientists who interpret complex reservoirs and present interpretation risk to asset teams and management.
Prerequisites: The Intermediate Petrophysics track, or several years of interpretation work.
Take the module in the Learning Hub
Advanced Petrophysics: Eight advanced modules with narrated lessons; quizzes and certificate eligibility come with the certified option. The lesson opens in the Learning Hub once the track is purchased; graded quizzes and the certificate come with the certified option.