Page 313 - Intelligent Digital Oil And Gas Fields

Smart Wells and Techniques for Reservoir Monitoring 261

w
iteratively samples em and minimizes the misfit between the dynamic smart
s,i
well response and the observed production profile (e.g., water cut, pressure,
GOR) that renders, for example, the modeled liquid rate profile that
matches the well completion profile from the ICV segmentation. By further
calculating the water flow rates per ICV segment, any type of water flooding
optimization can be facilitated. To quantify the uncertainty in the smart well
model response (i.e., the virtual PLT profile), the optimization method can
further be integrated into multiple stochastic realizations of reservoir
properties.

7.6 SMART WELL MODELING AND CONTROL
For wellbore modeling, the oil and gas well deliverability per segment
can be calculated using inflow and outflow well performance analysis. Most
of the commercial simulators can reproduce the effect of an ICV in a
wellbore. Konopczynski and Ajayi (2004) have described the fundamental
concepts to evaluate the well performance for single- or multiple-zone res-
ervoirs using ICVs. The IPR and Vogel expressions can be easily used under
the same assumptions that are used under radial and Darcy’s flow conditions.
We show a methodology to estimate ICV performance as follows:
• Estimate maximum well rate potential from an IPR/Vogel model.
• Productivity index, PI¼Q/(P res P wf ).
• Calculate the pressure drop across the choke (P out P in ) required deliv-
ering the expected rate reduction/increase.
• Determine the flow trim characteristic by lab testing the flow coefficient
at each choke position of pressure drop.
• Carry out in the lab the mechanical design of the flow trim for the desired
well behavior.
The Perkins model (1993) is the most applicable equation to predict the
subcritical pressure drop across a valve using Eq. (7.3):

Q Q ρ r ffiffiffiffiffiffi
1
jj
P out P in ¼ ¼ C γ mix Q tot (7.3)
Cv Cv ρ Cv
wstd
where
P out is the flowing BHP at the outlet (psi) of the ICV,
P in is the flowing BHP at the inlet of the valve (psi),
C is the conversion factor,
Q is the total fluids in USG/min,