Nanotechnology for corrosion control Silsesquioxane based nanofillers for iron carbonate film enhancement

Carbon dioxide internal corrosion is one of the most common degradation
mechanisms occurring in oil and gas exploration and production environments
when carbon steel is the material of construction. Both general and localized
attack can lead to severe production cuts and safety incidents and these are
commonly mitigated via the use of corrosion inhibitors, the deployment of
which significantly increases the operational expenditure.
When environmental conditions are favourable, a naturally growing corrosion
product known as iron carbonate precipitates onto the internal pipe wall
providing protection from degradation but only when it is well adherent to the
surface and compact. To date, research trying to take advantage of the
protective abilities of these naturally growing films is limited.
The aim of this research is to encourage the iron carbonate kinetics of
formation but also its mechanical properties via the addition of a hybrid
organic-inorganic molecule to mimic the formation of a nanocomposite. This
should allow for the modified iron carbonate to better resist mechanical
removal in order to sustain its naturally inherent steel protection properties
over a wider range of environmental conditions.
Electrochemical results show how the addition of a silsesquioxane-based
nanofiller acts as nucleating agent and accelerates the build-up of the iron
carbonate corrosion products. Mechanical properties such as hardness and
modulus extracted from nanoindentation tests ascertain that the modified
corrosion products are more robust.
This thesis describes a novel approach relying on the protectiveness of the
corrosion layer growing in situ in oil and gas transport systems to mitigate
carbon steel dissolution in specific environmental conditions. It is anticipated
that the benefits of such a batch treatment of the nanofiller would be greater
than for conventional film-forming inhibitors.