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It splits into two components:
subject to condition:
LaTeX Math Block |
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\phi_e = \phi_{\rm opn} + \phi_{\rm cls} |
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LaTeX Math Block |
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\phi_e(\mathbf{r}, \ p) = \phi_{e0ei}(\mathbf{r}) \exp \left[ \int_{p_i}^p c_\phi(p) \, dp \right] |
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This leads to the effect of Porosity Shrinkage.
Since the pore compressibility is very low (~ cϕ = 0.5 ÷ 1.5 GPa-1) for all and has a weak dependence on reservoir pressure for subsurface rocks in petroleum reservoirs the LaTeX Math Block Reference |
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can be written as:
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\phi_e(\mathbf{r}, \ p) = \phi_{e0ei}(\mathbf{r}) \cdot \left[ 1 + c_\phi \, (p-p_i) + 0.5 \, c_\phiphi^2 \, (p-p_i)^2 \right] |
Most Subsurface E&P Disciplines (except Petrophysics) usually omit index "e" and denote Effective porosity as .Effective porosity at the initial formation pressure is usually denoted as LaTeX Math Inline |
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body | \phi_i.See also
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Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petrophysics (PP) / Volumetric Rock Model
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