|
|
Corrosion in Multiphase Environments
|
|
|
|
Many service applications involve the exposure to multiphase environments that contain produced, process or condensed water in combination with hydrocarbon liquid and dissolved gases such as H2S, CO2, O2 and other species. Under such conditions, many factors must be considered when assessing the system corrosivity. These include environmental parameters such as partial pressure of the acid gases, temperature, chloride content and the amount of buffering salts in solution. They indicate the corrosivity of the aqueous phase.
|
My Saved Article
Many
service applications involve the exposure to multiphase environments that
contain produced, process or condensed water in combination with hydrocarbon
liquid and dissolved gases such as H2S, CO2, O2
and other species. Under such conditions, many factors must be considered when
assessing the system corrosivity. These include environmental parameters such
as partial pressure of the acid gases, temperature, chloride content and the
amount of buffering salts in solution. They indicate the corrosivity of the
aqueous phase. However,
the physical and chemical properties of the liquid hydrogen carbon phase are
also important since, in some cases, this phase can offer significant
protection from corrosion. Finally, it is also important to take into account
the mechanical forces acting in the system produced by flow in the environment.
These forces will determine the flow regime and the degree of mixing as well as
the wall shear stress on the exposed surfaces that can remove normally
protective surface films. In
most cases, substantial water must be present in liquid hydrogen carbon phase
to sustain corrosion to a significant degree. However, under certain
circumstances, particularly those associated with stagnant conditions or where
the liquid hydrocarbons possess little physical persistence on the metal
surface, substantial corrosion can exist.  Ref.: Efird, K. D., Predicting corrosion of steel in crude
oil production, Materials Performance, Vol. 30, No. 3,
March 91, pp 63-66
|
|
|
|
|
|