Page 269 - Formation Damage during Improved Oil Recovery Fundamentals and Applications

240 Xingru Wu

(A) (C)

Stage a: Preflush Stage c: Overflash
(B) (D)

Preflush fluid
Inhibiting
fluid
Overflush
fluid
Stage b: Scale inhibitor
Figure 5.13 Procedure of a typical scale-squeeze operation.

treatments may result in reduced productivity as it partially blocks the
flow paths in near wellbore regions. For subsea wells, squeeze treatments
can either be bullheaded from the processing facility, which are suscepti-
ble to plugging by particles and debris, and have the potential to collect
flowline debris such as wax, scale, and corrosion products. Maintaining
the integrity of the squeeze package over long distances of flowline is also
an issue. Additionally, in the offshore environment, some hydrate inhibi-
tors can exacerbate the severity of scaling (Kan and Tomson, 2012).

5.5 SUMMARY
Inorganic deposition in the formation can significantly reduce the
well productivity, and proactive actions should be taken to prevent the
scaling of a formation in the near wellbore region or within the produc-
tion facilities. Even through the formation brine in the reservoir condi-
tion is stable, solids can precipitate when pressure drops or mixed with
the injected fluids. If the deposition occurs in the deep reservoir or far
away from the production/injection well, the matrix can end up with a
reduced permeability, but its impact on production performance is not
dramatic. When the precipitation occurs at the near wellbore region, the