Technical excellence: delivered

AlderleyServices Case Study:

Control System Upgrade and Commissioning

Nigeria

Alderley were contracted by an oil and gas operator in Nigeria to provide an upgrade to a crude oil control system that was initially supplied by Alderley in 2001. This crude oil control system is located on a separation and processing platform offshore Nigeria and is used to monitor export crude oil from the platform which is fed into the Floating Storage and Offloading (FSO) unit.

The control system needed upgrading due to obsolescence of flow computers, in addition to the client having a technical issue relating to the proving capability of the system. Alderley’s scope of work included the manufacture, test, installation and commissioning of the upgraded control system, designed using the latest technology to ensure it continues to remain reliable, secure and auditable.

Enhanced designThe enhanced design ensured the system was programmed to work with the client’s new corporate IT systems. It addressed the technical issue of proving capability by providing each flow computer with a dedicated prover board to offer full proving redundancy, along with two metering supervisory systems to ensure higher availability.

Services supplied:

• Enhanced control system design• Temporary metering set-up using existing flow computers• Decommissioning and removal of existing control panel• Full Factory Acceptance Testing in the UK before dispatched to Nigeria• New control bay assembled in situ• Reconnection of all existing field terminals into new control panel• Full hot and cold loop checks• Site Acceptance Testing• Commissioning• Operator training delivered onsite

No production disruptionIt was vital during decommissioning of the existing control panel that the offloading of the produced crude oil was not interrupted in anyway. To meet this challenge, Alderley’s commissioning engineers provided temporary metering functionality; this entailed diverting the crude through just one of the streams while the other two were locked out. Once this was in place and the flow totals continued to be recorded on the open stream, Alderley’s engineers supervised the installation, rewiring and connection of the new control panel.

All the necessary pre-commissioning works such as ‘cold’ and ‘hot’ loops were conducted during production shutdown to avoid any production problems. Communication tests with external systems were conducted and the new metering computers were successfully tested. All of this was completed on time with no interruption or production upset.

As part of Alderley’s services offering, a service engineer returned to the site to provide operator training for the prover. This ensures a high level of knowledge at an operational level and consquently efficiency in operation.

Original Equipment

Upgraded Equipment

• 3 x S500 flow computers • 1 x S500 prover/ancillary flow computer• 1 x metering supervisory computer (DMS) • 2 x Jiskoot InSpec sample controllers

• 3 x S600+ flow computers • 1 x OPC server • 2 x flow metering supervisory computers (FMS)• SCADA/HMI with data archiving and reporting • 2 x existing Jiskoot InSpec sample controllers fully integrated into the system