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