Total volume of subsurface natural gas reserves in NTP conditions.
| (1) | V_{\rm STOIIP} = \int_{\Omega} B^{-1}_o(p_i({\bf r}), T_i({\bf r})) s_o({\bf r}) \phi_e({\bf r}) dV |
where
{\bf r} = (x,y,z) | Position vector to some location in reservoir |
p_i({\bf r}), T_i({\bf r}) | Initial formation pressure and temperature at location {\bf r} |
\phi_e | |