A proxy model of watercut YW in producing well with reservoir saturation and reservoir pressure :
{\rm Y_{Wm}} = \frac{1 - \epsilon_g}{1 + \frac{M_{ro}}{M_{rw}} \cdot \frac{B_w}{B_o} }, \quad \epsilon_g = \frac{A}{q_t} \cdot M_{ro} \cdot \left[ \frac{\partial P_c}{\partial r} + (\rho_w-\rho_o) \cdot g \cdot \sin \alpha \right] |
where
Water formation volume factor | Oil formation volume factor | ||||
Relative water mobility | Relative oil mobility | Current formation pressure | |||
Water density | Oil density | Standard gravity constant | |||
Total sandface flowrate | Cross-sectional flow area | Deviation of flow from horizontal plane | |||
capillary pressure |
If capillary effects are not high or saturation does not vary along the streamline substantially , then .
If flow is close to horizontal then gravity effects are vanishing too: .
In these cases simplifies to:
{\rm Y_{Wm}} = \frac{1}{1 + \frac{M_{ro}}{M_{rw}} \cdot \frac{B_w}{B_o} } = \frac{1}{1 + \frac{k_{ro}}{k_{rw}} \cdot \frac{\mu_w }{\mu_o } \cdot \frac{B_w}{B_o}} |
The models and can also be used in production analysis assuming homogeneous reservoir water saturation :
s_w(t) = s_{wi} + (1-s_{wi}) \cdot \rm E_{Dow}(t) = s_{wi} + (1-s_{wi}) \cdot \rm RFO(t)/E_S |
where
current oil recover factor | |
cumulative oil production | |
STOIIP | |
sweep efficiency | |
initial water saturation | |
residual oil saturation to water sweep |
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Well Testing (WT) / Flowrate Testing / Flowrate / Water cut (Yw)
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