Volumetric value of Oil In Place (OIP) recalculated to NTP conditions:
(1) | V_{\rm STOIP} = \int_{\Omega} \left[ \frac{s_o({\bf r}) }{B_o} + \frac{R_v \, s_g({\bf r})}{B_g} \right] \phi_e({\bf r}) dV |
where
\Omega | Petroleum reservoir |
{\bf r} = (x,y,z) | Position vector to some location in a reservoir |
dV = dx \, dy \, dz | Volume element of a reservoir |
p_i({\bf r}), \, T_i({\bf r}) | Initial formation pressure and temperature at location {\bf r} |
\phi_e({\bf r}) | Effective porosity at location {\bf r} |
s_o({\bf r}), \, s_g({\bf r}) | Current Oil saturation and Gas saturation at location {\bf r} |
B_o(p_i, T_i), \, B_g(p_i, T_i) | Oil FVF and Gas FVF at Initial formation pressure and temperature |
R_s(p_i, T_i), \, R_v(p_i, T_i) | Solution GOR and Vaporized Oil Ratio at Initial formation pressure and temperature |
For practical implementation of
(1) one needs to build a Dynamic Flow Model (DFM) and perform a numerical integration.
See Also
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petroleum Geology / Petroleum Reservoir / Hydrocarbon In Place (HCIP) / Oil In Place (OIP) / Stock-Tank Oil In-Place (STOIP)