Abstract
Correlations for petrophysical parameters and saturation dependent transport properties
are usually grouped by “rock type”. This is a broad classification including quantitative
measures such as porosity, permeability, pore and throat size distributions, pore
connectivity and qualitative descriptions of rock fabric and texture. Rock typing is based
on conventional core analysis data (porosimetry, permeametry, mercury injection
capillary pressure (MICP)), special core analysis (SCAL), wireline logs (electrofacies),
description of cuttings and depositional environment, and thin-section analysis. The
broad nature of this classification has obvious limitations and fails to fully capture the
complex dependence between pore space geometry and topology (rock micro-structure)
and petrophysical properties.
We propose an alternate classification for rocks based on high resolution X-ray computed
microtomography which is complementary to the conventional approach and allows the
establishment of a more direct relationship between rock micro-structure and
petrophysical properties. Petrophysical properties are computed directly from 3D
microtomographic images of clastic and carbonate cores drawn from a wide range of
reservoirs. The computed petrophysical properties are used to test empirical correlations
between permeability and other important petrophysical parameters (e.g., hydraulic
radius, drainage capillary pressure, NMR response, grain size and sorting) for various
rock types. We find that the most universally robust correlations are based on the critical
pore radius determined from drainage capillary pressure data. The results clearly
demonstrate the potential for digital imaging and computations on 3D images to develop
improved correlations for petrophysical properties
are usually grouped by “rock type”. This is a broad classification including quantitative
measures such as porosity, permeability, pore and throat size distributions, pore
connectivity and qualitative descriptions of rock fabric and texture. Rock typing is based
on conventional core analysis data (porosimetry, permeametry, mercury injection
capillary pressure (MICP)), special core analysis (SCAL), wireline logs (electrofacies),
description of cuttings and depositional environment, and thin-section analysis. The
broad nature of this classification has obvious limitations and fails to fully capture the
complex dependence between pore space geometry and topology (rock micro-structure)
and petrophysical properties.
We propose an alternate classification for rocks based on high resolution X-ray computed
microtomography which is complementary to the conventional approach and allows the
establishment of a more direct relationship between rock micro-structure and
petrophysical properties. Petrophysical properties are computed directly from 3D
microtomographic images of clastic and carbonate cores drawn from a wide range of
reservoirs. The computed petrophysical properties are used to test empirical correlations
between permeability and other important petrophysical parameters (e.g., hydraulic
radius, drainage capillary pressure, NMR response, grain size and sorting) for various
rock types. We find that the most universally robust correlations are based on the critical
pore radius determined from drainage capillary pressure data. The results clearly
demonstrate the potential for digital imaging and computations on 3D images to develop
improved correlations for petrophysical properties
| Original language | English |
|---|---|
| Pages (from-to) | 1-12 |
| Journal | SCA2005-08 P081 |
| Publication status | Published - 2005 |
| Event | International Symposium of the Society of Core Analysts 2005 - Toronto Canada Duration: 1 Jan 2005 → … |