Horizontal Rotating Cylinder—A Compact Apparatus for Studying the Effect of Water Wetting on Carbon Dioxide Corrosion of Mild Steel

Abstract

Water wetting is a crucial issue in carbon dioxide (CO 2) corrosion of multiphase flow pipelines made from mild steel. This study demonstrates the use of a novel benchtop apparatus, a horizontal rotating cylinder, to study the effect of water wetting on CO 2 corrosion of mild steel in two-phase flow. The setup is similar to a standard rotating cylinder except for its horizontal orientation and the presence of two phases-typically water and oil. The apparatus has been tested by using mass-transfer measurements and CO 2 corrosion measurements in single-phase water flow. CO 2 corrosion measurements were subsequently performed using a water/hexane mixture with water cuts varying between 5% and 50%. While the metal surface was primarily hydrophilic under stagnant conditions, a variety of dynamic water wetting situations was encountered as the water cut and fluid velocity were altered. Threshold velocities were identified at various water cuts when the surface became oil-wet and corrosion stopped.

Fluid structure governing the corrosion behavior of mild steel in oil–water mixtures

“…Currently, ex-situ examination of corrosion products is one of the most effective methods to interpret the corrosion mechanism in a high-pressure condition [16,25,[27][28][29]. Although attempts have also been made to understand corrosion in oil-water fluids by means of in-situ electrochemical methods [30,31], they are not applicable to localised corrosion phenomena [19,32] and they generally need a special control of the fluid to capture electrochemical signals in such badly conductive and unstable media [31,33]. A direct observation at the oil/steel interface by wire beam electrode [34,35] can reflect the localised corrosion process, but its resolution is much worse than the water droplets in emulsions.…”

Corrosion Control in CO2 Enhanced Oil Recovery From a Perspective of Multiphase Fluids

“…Flow loop tests indicated that the corrosion rate was retarded under intermittent water wetting conditions compared to continuous water wetting (Li et al, 2006). In a flow condition, the intermittent wetting behavior closely depends on the flow pattern characteristics (Nesic and Carroll, 2003). Several studies have demonstrated that with increasing flow rate, the steel surface can be changed from continuous water wetting to intermittent wetting or even continuous oil wetting (Nesic and Carroll, 2003;Cai et al, 2012), hence reducing the corrosion risk at the pipeline bottom.…”

“…In a flow condition, the intermittent wetting behavior closely depends on the flow pattern characteristics (Nesic and Carroll, 2003). Several studies have demonstrated that with increasing flow rate, the steel surface can be changed from continuous water wetting to intermittent wetting or even continuous oil wetting (Nesic and Carroll, 2003;Cai et al, 2012), hence reducing the corrosion risk at the pipeline bottom. The intermittent wetting by oil and water at steel surface has been verified by various sensors in flow loop tests (Fordham et al, 1999;Zong et al, 2010;Luo et al, 2017).…”

A study on the behavior of CO2 corrosion on pipeline using computational fluid dynamics, experimental and artificial neural network approach

“…Nesic [10], Nesic and Carroll [11] and Li et al [12] concentrated on the characteristics of water wetting (water with CO 2 and H 2 S gases). Their study indicated that water wetting at the bottom of steel pipe due to the higher density of water compared to the oil and the corrosion rate in the pipelines is dependent on the wetted area.…”