Produced Water Quality and Corrosion Inhibitor Audit: A Case Study of Operational Issues
The corrosion of Oil & Gas Industry hydrocarbon-processing infrastructure has the potential to cause untold damage to equipment, potentially leading to deferred production, spills and the resulting financial penalties from these and more importantly significant HES implications.
Most corrosion issues relating to hydrocarbon processing and produced water treatment equipment are preventable through the correct selection of materials of construction, operation of plant equipment the use of chemical corrosion inhibitors, and other mitigating practices such as pigging.
However, the use of corrosion inhibitors can have detrimental effects on the processed fluids, potentially leading to stabilised emulsions and problems of oil and water separation resulting in high BS&W in the crude oil or poor produced water quality. Furthermore, asset protection against corrosion, and optimisation of treatment chemical utilisation, are key areas that should be considered as there is the potential to save the plant operator OPEX costs in both the short and longer terms.
This paper details a case study where an oil producer had issues during the field deployment stage of a new corrosion inhibitor injection program. During early phased injection of the corrosion inhibitor, at the satellite jackets production wellheads; overboard produced water quality (OBWQ) was measured to be deteriorating, with increasing oil in water (OIW) readings as the new inhibitor program was being rolled out across the field. The deployment of this corrosion inhibitor was halted when OIW readings became uncontrollable with measured readings of >100 ppm and a visible oil sheen on the sea’s surface.
Oil Plus was contracted to review why the deployment of the new corrosion inhibitor injection program failed, and to implement procedures to better execute field-wide deployment of the new corrosion inhibitor program, for long term protection of the production infrastructure.
The audit of the oil producer’s production infrastructure, the selection of the corrosion inhibitor and its deployment in the field for asset protection against internal corrosion will be discussed in this paper.