Abstract
After perforating a gas
zone with through tubing perforation method, other possible gas zones are also
perforated from bottom to top accordingly. However, if one of these zones is
highly saturated with water, water might flow through the perforations where
gas production is possible. In this study, the water flux from upper
perforation to lower perforations where gas is available was simulated by using
TOUGH + RealGasBrine simulator. The effects of permeability, pressure
differences between zones, and salinity on water flux through gas zone were
investigated in this study. Permeability affects the behavior of water flux and
its amount to gas zone significantly. Similarly, these effects were seen for
the cases with pressure differences between zones and salinity in water zone
even though these effects are less than those observed in permeability cases.
It was observed that the duration of exposure of gas zone to water flux should
be kept minimum by applying well completion operations quickly to isolate water
zone and stop water flux from this zone to gas zone. After isolating water zone
with well completion operations, gas production simulations from gas zone were
conducted at a constant production pressure of 5 MPa. It was observed that gas
production from gas zone was retarded and water production from gas zone was
higher compared to the original cases without any water invasion. Even in a
long term of gas production, it is possible to observe the remarks of previous
water flux from upper zone after analyzing water saturation distribution