Neftegaz.RU #3-17 ENG

OFS
FIG. 3. Fluid flow rate dependency from hydraulic fractures number
amounts 5.3 percent, efficiency
factor at average for the field
equals 0.96. Oil viscosity at surface
conditions is 0.87 g/cm 3 .
The exponential decline factor:
(4)
where – production at the start of
the calculation period;
– production at the end of the
calculation period.
At the same time oil flow rate is
calculated by the equation:
where – time.
(5)
table 3. This dependency is given in
the figure 3.
As one can see in the figure 3,
when there are more than 8
fractures, no significant fluid flow
rate increase is observed and
when hydraulic fractures number
increases subsequently the diagram
is flattened.
Let us consider the impact of some
of the parameters on multi-stage
hydraulic fracturing indicators. The
figure 4 demonstrates dependencies
of fluid flow rates from a number of
hydraulic fractures for various half of
the length values.
When there is large number of
hydraulic fractures, the impact of
a fracture dimensions reduces
significantly and the length of the
well horizontal borehole has more
considerable impact (Figure 5).
Drilling of longer horizontal boreholes
gives significant effect when more
intensive flood pattern formation is
applied.
Flow rates decline shall be
considered in the process of multistage
hydraulic fracturing designing.
Premature products flooding may
occur when layout of the nearest
injection wells is not taken into
consideration.
When exponential speed of flow rates
decline is specified let us calculate
cumulative oil production for 3 years
[3]. For four wells which have already
been drilled the average decline
speed amounts 0.56. Initial flooding
FIG. 4. Dependencies of fluid flow rates from a number of hydraulic fractures for various half of
the length values
FIG. 5. Dependencies of fluid flow rates from a number of hydraulic fractures in HW having
various length values
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