Portuguese oil and gas major tags alarm rationalisation

London -- Created in 2000 from former state-owned Portuguese oil and gas company Petrogal, Galp Energia Group’s remit is to build a national oil and gas company compliant with modern international standards.

The group’s Oporto Refinery has an annual production setup comprising: Fuels 3,700 ktpa; Lube Oils 150 ktpa; Aromatics and solvents 440 ktpa; Lubricants 1.5 ktpa; Paraffins 10 ktpa; Asphalt 150 ktpa; and Sulphur 10 ktpa.

The refinery implemented a Fisher Rosemount DCS in 1991. Since that time, consistent with internal security standards, alarms had been configured in three levels: hardware, system and process. Alarms at the first two levels are generated automatically by the DCS while the latter are defined by those responsible for each area and configured by the PC&A team.

Alarms were configured without overall rationalisation and without a specific tool to collect and analyse alarms and find redundancies between them. This resulted in over 5,000 tags configured with alarms (each tag can have up to six or more alarms) in the refinery, a number that grew along with each new project.

Since the DCS was not able to store alarms for a long period of time, incident analysis was difficult and slow; each specific alarm had to be searched for by hand in a log file running hundreds of pages.

Before the implementation of an alarm-management project, operators were forced into a reactive approach toward alarms, especially during upsets like maintenance or emergency shutdowns. Operators were dealing in some cases with five alarms per operator every 10 minutes – compare this with the EEMUA standard of one alarm per operator per 10-minute interval.

Oporto’s process control and automation (PC&A) team identified two ways in which a solution could be found: A system embedded in the new DeltaV DCS to which the facility was migrating in 2005, or a separate system for alarm management, able to capture all alarms independent of the DCS platform.

The company chose the second option, in order to be able to manage alarms for both DCSs in a consistent manner and to add a degree of independance to the system, as it would be used as an important tool to analyze incidents.

According to Lluvet Santos, who led Oporto’s PC&A team, the process of choosing one product was not easy as there are many in the market.

“We narrowed our choices to three leading products, considering such relevant aspects as does it provide detailed analysis of all alarms, operator responses and active alarm durations and does it integrate alarms and events with process data?

The team, he said, also wanted a system that produced KPI reports based on EEMUA standards, generated/exported data to MS Excel as well as being a common tool in the refinery and easy to maintain.

Having considered these issues, the company installed a Matrikon ProcessGuard and also bought the alarm MOCCA (Management of Change Configuration Assistant) package during implemetation.

Alarm rationalisation is being carried out by PC&A team and plant management with almost 500 tags analysed since March, 2006. The process has been slower than expected, however, as all shifts have to analyse the conclusions of each alarm-rationalisation meeting.

“When there are operators that have never attended a meeting, we begin with a short presentation of the present alarm situation in their plant, our objectives, the tools to help achieve the objectives and our famous “MOCCA sheet” where we register all the alarms, causes and consequences of each alarm configured,” said Santos.

Data on the combined performance level of the Aromatics (FAR) and Water Treatment (ETAR) plants in the Oporto Refinery show that the performance level of FAR/ETAR went from stable/reactive to robust in four months, with 261 tags rationalised.

“Based on our successes to date, we are expanding the program of alarm analysis and rationalisation to all plants at Oporto Refinery – Fuels, Lube Oils, Power and Blending plants. Our goal for 2007 is to rationalise all tags with alarms in the refinery, with the expectation of similar results to those achieved in the FAR/ETAR plants,” Santos concluded.