The qOW plotis based on the following correlation between oil production rate and water production rate:
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where
q_W | water production rate | q_O | oil production rate | ||
p^*_1 | formation pressure in oil pay reservoir | J_{1W} | water productivity index of oil & water reservoir | J_{1O} | oil productivity index of oil pay reservoir |
p^*_2 | formation pressure water reservoir | J_{2W} | water productivity index of water reservoir |
For the case of water reservoir pressure is higher than that of oil+water reservoir: b > 0 \Leftrightarrow p^*_2 > p^*_1
For the case of water reservoir pressure is lower than that of oil+water reservoir: b < 0 \Leftrightarrow p^*_2 < p^*_1
In practical applications, the equation (1) is often considered through the weighted average values:
(4) | <q_W> = a \, \cdot <q_O> + \, b |
where
<q_W>, \ <q_O> | are weighted average of q_W and q_O |
There are different ways to calculate weighted average of the dynamic variable, for example:
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See Also
Petroleum Industry / Upstream / Production / Subsurface Production / Field Study & Modelling / Production Analysis / Watercut Diagnostics