Cathodic Protection of Process Vessels

Paper ID: C2025-00077 ABSTRACT: Gas & Oil Separation Plants (GOSPs) have oil trains designed to process wet crude oil and associated gas for separation into dry and stabilized crude oil, high-pressure gas, low-pressure gas & disposal water. GOSPs employ several process vessels in each train for this separation. Each train consists of high-pressure production trap (HPPT), low-pressure production trap (LPPT), Water Oil Separator (WOSEP), a dehydrator, desalter vessels, and a crude stabilizer.
Internal corrosion control and management is essential for these vessels to support operation. Cathodic protection (CP) by galvanic anodes plays a crucial role in ensuring that these vessels remain protected from corrosion during their life.
Aluminum anodes, zinc anodes and high temperature zinc anodes are used for CP. Specially designed Anode Monitoring Systems (AMS) are used for monitoring including the anode consumption.
Challenges are accelerated anode consumption, failure of electrical isolation and vessel internal members draining CP current, corrosion of the internals, etc.
This paper presents approaches followed , including design practices, monitoring, field issues and associated remedial actions, etc. In addition, how the data from field survey is used to estimate the CP system status and life of anodes, etc. to manage internal corrosion of Saudi Aramco’s process vessels.