Yokogawa working together with Chevron in Cape Town.
Chevron began marketing product in South Africa in 1911. It now markets products here under the Caltex brand, which began as a partnership between Chevron and Texaco in 1936. The 100 000 barrel-per-day Cape Town refinery produces gasoline, diesel, jet fuel, LPG and asphalt. Chevron South Africa recently initiated a project to replace the existing Centum XL control system at the Cape Town Refinery with Yokogawa’s CS3000 FIO hardware and upgrade the control network to Vnet/IP.
Project background
The basis for the project is to ensure the refinery’s DCS (distributed control system) retains high reliability and the required availability. The risk of availability of the current control system is increasing due to its age which could result in increased maintenance costs and unplanned plant shutdowns or production losses. The intent is to replace the existing Centum XL control stations that have been in service in excess of 15 years with the latest Yokogawa CS3000 hardware and upgrade the control network to a faster and more efficient VNet/IP.
In June 2008 Yokogawa SA was appointed as the principal contractor with overall responsibility for the project. Ilitha was appointed as sub-contractor for the design and installation with the installation being awarded to RSI. Chevron appointed Phillip Venter as its project manager with the Yokogawa project manager reporting directly to him.
Project summary
The main objective is to upgrade the control system live, which requires hot cutovers during the switchover from the old to the new system. This ensures there is no downtime on the plant and that all instruments and controls can be tested immediately after the cutover. Structured and formal project management and engineering procedures were developed and are being followed to ensure all the process requirements are implemented and all the risks are mitigated. The execution procedure culminates in a thorough risk assessment process involving all the key stakeholders.
Reliability, maintenance, advanced control, construction and operations representatives have all been assigned to the project to ensure every Chevron requirement is met. Prior to the hot cutover of each control station the current program is re-configured for the CS3000. A formal process is followed to ensure all the control logic and functionality is retained and complies with the software configuration standard.
After the approval of the design, the Yokogawa CS3000 hardware is installed into the DCS panels and they are acceptance tested. The hot cutover process does not interrupt the continuous operation of the plant and is carried out on an individual I/O point basis. To achieve this, the field wiring is transferred from the old DCS to the new and at the same time the existing configuration (program) is disabled and the new configuration activated. To ensure there is no disruption to the plant, control valves need to be bypassed until they are successfully cutover.
Key success factors
Project manager Phillip Venter says: “There are several factors that I believe are major contributors to the ongoing success of this project. From the RFQ stage of the project there has been excellent teamwork between Yokogawa and Chevron, we shared the vision of successfully completing the project within schedule and budget, with no production loss and zero incidents.
“Having the entire Yokogawa team in one location on site has drastically improved the efficiency of the team. This, coupled with each team member’s personal commitment to the project has made it a pleasure to work with Yokogawa.”
Statistics to date (April 2010)
* Overall project progress – 78% complete.
* 16 out of 24 FCSs cutover – 67% complete.
* 4520 of 7118 I/O cutover – 64% complete.
* 20 out of 24 FCSs installed – 83% complete.
* Incident free man-hours on site – 35 050.
* Project within budget and scheduled for completion in Jan 2011.
For more information contact Charles van Haght, Yokogawa South Africa, +27 (0)11 831 6300, [email protected], www.yokogawa.com/za
Tel: | +27 11 831 6300 |
Email: | [email protected] |
www: | www.yokogawa.com/za |
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