Page 331 - Principles of Applied Reservoir Simulation 2E

316 Principles of Applied Reservoir Simulation

30.4 Fluid Withdrawal Constraints

Fluid withdrawal from explicit pressure controlled production wells can
be constrained as follows:
a. A minimum oil production rate can be specified;
b. A maximum oil production rate can be specified; and
c. A maximum liquid (water plus oil) withdrawal rate can be speci-
fied.
A positive value of QO for a pressure controlled production well is used
as the minimum allowed oil production rate. If the calculated oil production rate
drops below the minimum allowed value, the well is shut in.
A positive value of QW for a pressure controlled production well is used
as the maximum allowed oil production rate. If the calculated oil production rate
exceeds the maximum allowed value, calculated production will be reduced to
the allowed value. Production from each connection is proportionally reduced
by the ratio of allowed to calculated oil production rates.
A positive value of QT for a pressure controlled production well is used
as the maximum allowed liquid withdrawal rate. If the sum of oil and water
production exceeds the maximum allowed value, calculated production is
reduced to the allowed value. The reduction is made by multiplying production
from each connection by the ratio of allowed-to-calculated liquid withdrawal
rates. IMPORTANT: When used to control total liquid withdrawal, the units
of QT are STB/Day.

30.5 Fluid Injection Constraints

Fluid injection into explicit pressure controlled injection wells can be
constrained as follows:
a. A maximum water injection rate can be specified; and
b. A maximum gas injection rate can be specified.
A negative value of QW for a pressure controlled water injection well is
used as the maximum allowed water injection rate. If the calculated water
injection rate exceeds the allowed value, calculated water injection will be