This document discusses a study investigating fluid flow behavior in vuggy carbonate rocks using glass bead proxy cores. Glass beads were packed and sintered to create porous media with controlled vugs. Computerized tomography scans were used to characterize the cores and estimate porosity. Permeability was measured using pressure transducers. Results included porosity, permeability, and vug volume measurements. Future work proposed modeling two-phase flow, adding shale boundaries, and measuring additional properties like contact angle and capillary rise.

1. Investigating the Petrophysics of Vuggy Carbonate
Rocks Using Glass-bead Proxy Cores
Dayeed Khan, Hasan Khan, Dr. Ayaz Mehmani and Prof. Maša Prodanović
Motivation
Almost 60% of world’s oil is held in
carbonate reservoirs, making the study of
fluid flow behavior through carbonate rocks
a very important research topic. Currently
very little is known about the two-phase flow
behavior in vuggy carbonates due to the
complexity in textural and chemical
properties of the solid phase. A controlled
reconstruction technique using glass beads
will allow the two-phase flow properties be
investigate in well-defined porous media.
Methods
Packing/Material:
• 1 mm glass beads used as grains
• Graphite mold used as a lubricating mold
• Cheese cloth and salt used to
introduce vugs into the core
Sintering:
• Glass bead with softening point 650 °C
• Exposure time 25 minutes
• Exposure temperature 775 °C
Computerized Tomography (CT):
• CT machine was used to make axial scans of
cores
• Resolution 250 microns
• Images generated images were used to
estimate porosity and processed for
segmentation
Basic Image Processing:
• MATLAB used to generate TIF files
• ImageJ used to segment the porosity
associated with the vugs (Otsu threshold
method)
• ImageJ used to create a 3D image of the
cores and individual vugs
Porosity:
• Used Helium porosimeter to calculate
the effective porosity
• Estimated porosity using CT scan
(using X-ray attenuation values)
Permeability:
• Transducers were used to measure the
pressure across the core
Results (Core Characterization)
Porosity
Permeability
Volume of Vugs
Future Work
• Modelling 2-phase flow in vuggy
carbonates
• Creating shale boundaries within a
core and model 2-phase flow
• Nuclear Magnetic Resonance
measurements
• Measure contact angle
Capillary Rise
48.2mm
61.5mm
Pressure
Outlet 1
Pressure
Outlet 2
Ø = CTglass - CTtotal
CTglass - CTwater
CTglass = 2500, CTwater = 25
Vuggy
Shale
Layers
*
*4 pressure points