Physical modeling and mathematical simulation of fluid flow inside an oil/water separator tank and it effect on flow accelerated corrosion

The physical separation of oil/water in the oil production process is carried out in separation tanks, where the separation of water carries aggressive compounds, which cause significant corrosion damage to inner walls of the separator tank. The flow behavior of such fluids, causing a gradual detachment and entrainment in some zones of the walls of the separator, this phenomenon is known as Flow Assisted Corrosion. In this paper the design and construction of a physical scale model (1/26) of an original separator tank was made which flowed a NACE ID-196 brine combined with kerosene and added with H₂S at distinct flow rates, with the objective of observing this phenomenon. Similarly, a solid separator geometry prototype was built in the SolidWorks software later to carry out virtual simulations with ANSYS Fluent software to be able to compare with experimental results. The effect of flow rate (flow accelerated corrosion) on the surface of API 5L X-70 (steel use in this work) on the corrosion rate was evaluated and the corrosion products formed have been characterized using Scanning Electron Microscopy (EDX), X-ray Diffraction (XRD) and Linear Polarization technique (values of corrosion rate). XRD analysis showed that the corrosion products are mainly composed of a mixture of oxides and sulfides.