Estimated Ultimate Recovery
Natural Depletion
(1) | EUR = \frac{Q_o}{V_o} = \frac{ (p_i - p_{wf \, min}) \, c_t}{(1-s_{wi})\, B_o} = \frac{ (p_i - p_{wf \, min}) }{(1-s_{wi})\, B_o} \, \big( c_r + s_{wi} c_w + (1-s_{wi})c_o \big) |
Water flooding
(9) | EUR = E_S \, E_D = E_{SV} \, E_{SH} \, E_D |
Sweep effciency
Total sweep | Areal sweep | Vertical sweep | ||||||
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V_{sweep} – sweep volume V_\phi – pore volume | A_{sweep} – sweep area A_\phi – pore area | h_{sweep} – sweep thickness h_\phi – pore thickness |
Displacement efficiency
(13) | E_D = \frac{1-s_{wi}-s_{or}}{1-s){wi}} |
Gas flooding
WAG flooding
Water and gas flodding.
Motivation = increas displacement as residual oil saturation to gas sweep is less than to water sweep s_{org} < s_{orw} .
Chemical EOR
CО2 injection
Reference
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