| (1) | {\rm RS} = \left< c_t \, \phi \, h \, A \right> = \int_{V_\phi} c_t \cdot \phi \cdot dV = \int_{V_\phi} c_t \cdot \phi \cdot dh \, dA |
where
< .. > | spatial averaging |
|---|---|
V_\phi = \int_V \phi_e \, dV | total connected pore volume |
V = \int_V dh \, dA | total rock volume containing reservoir |
dA | infinitesimal element of reservoir drainage area |
dh | infinitesimal element of reservoir thickness |
\phi_e({\bf r}) | |
c_t({\bf r}) |
For the homogeneous reservoir it simplifies to:
| (2) | {\rm RS} = c_t \, \phi \, V = c_t \, \phi \, h \, A |
where
A= \int_V \phi \, dA | reservoir drainage area |
|---|
It plays important role in production analysis and pressure testing as it relates the initial formation pressure p_i and current formation pressure p_e(t) as:
| (3) | p_e(t) = p_i - \frac{Q_t^{\uparrow} - Q_t^{\downarrow} }{\rm RS} |
where
Q_t^{\uparrow} | cumulative offtakes |
|---|---|
Q_t^{\downarrow} | cumulative intakes |
See Also
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Well Testing / Pressure Testing