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1    
  r o b w . (5.9)
0
1   b w

Potential oil extraction and ρ r o, ρ b w are estimating in
reservoir engineering laboratories. Let‟s compare formula (5.8)
with Krylov‟s formula that listed next:
=k DEk SE. (5.10)
From this comparison follows that displacement
efficiency defines potential oil-extraction and sweep efficiency can
be outlined by F 1(æ) dependency.
Displacement efficiency k DE- the ratio of the oil displaced
from the flooded reservoir to the initial volume of oil in the
reservoir. Displacement efficiency in general depends of depends
on the ratio of oil viscosity to water viscosity and permeability
coefficient.
Sweep efficiency k SE - the ratio of volume of the reservoir
which water passed to the initial oil-saturated volume of reservoir.
In other words the ratio of the rock volume covered by
displacement to the total volume of the oil-saturated rock. It takes
into account oil losses along the horizontal and through the
thickness of the reservoir. It also can be represented as a product of
the following coefficients:
k SE = k 1 k 2 k 3 k 4,
where k 1 - coefficient that takes account of non-uniformity of
reservoir (0.7-0.8); k 2 - coefficient that takes account of lens-shape
of formation and its interruption (0.7-0.9); k 3 - coefficient that
takes account of kinematics of filtration flow (0.7-0.8); k 4 -
coefficient that takes account of oil losses in the rows that cut the
area (0.8 -0.9).
Auxiliary function F 2(æ) estimate oil content in wellbore
fluids. In general, this function can be found as:

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