Practical Wash Water & Demulsifer Optimization at Khurais Crude Processing Facility

Abstract

This paper covers practical demulsifer and wash water approach followed by Saudi Aramco Khurais producing facility to optimize the chemical and water consumption. This Paper is intended to: Share practical demulsifer and wash water optimization approach. Highlight how this approach enhanced the separation process and how it already helped Saudi Aramco to meet the product quality with minimal operating costs by optimizing operating parameters in the field. The basic idea of the optimization is to relax the oil - emulsified water separation in HPPT by allowing water carry over to the downstream equipment and vessels through minimizing the demulsifer dosage on the production header to increase the retention time. The optimization process includes manipulating different key parameters (controlled variables) which are demulsifer dosing rate (on production header and dehydrator), wash water dosing rate, de-salting train mixing valves differential pressure and transformers voltage with continues monitoring and corrective actions based on the export specification of BS&W and salts within pre-defined internal limits to avoid having off-spec product (Trial and Error) This approach resulted in decreasing the operating costs by reducing overall demulsifer dosage by 50%, and allowing the overall separation efficiency to be increased contributing towards enhanced separation. Various graphs included showing the full impact of optimizing the operating parameters on improved separation in dehydrator. From the water conservation, this process resulted in reducing non-potable wash water consumption for crude washing purposes by more than 20,000 gallon/day without compromising the crude specification. This optimization resulted in cost saving equivalent to around US$ 650,000 due to significant demulsifer reduction. Sustaining such an optimum performance proves to be a challenge and in this regard, the team is focusing heavily on the monitoring efforts that are equipped with the advisory features on what to do should the deviation exist from the stipulated target. This includes, among others, the alerting feature for immediate corrective actions by the team. Overall, this initiative succeeded in maintaining the facility crude quality specifications of BS&W and salts while reducing chemical operating costs, creating positive environmental impacts by saving non-potable wash water while increasing the assets utilization and reliability effectively.