Seplat Petroleum Development Company (Oil & Gas, Nigeria)

An Opportunity for Greater Business​​​​​​​​​​​​​​
Conditions crystalized for Nigeria’s Seplat Petroleum Development Company to fill a growing demand for gas to power via the nation’s power grid. Design, fabrication, shipping, installation, and commissioning a new 150MMscfd gas plant – complete with preparations for three additional trains to be added as ‘plug and play’ – was completed in 18 months. A final shutdown of ten days enabled the new and the existing plants to be integrated to form a single plant.
In that short week and a half, many activities had to be accomplished, including tie in, test, and commission of more than 700 I/O for both the distributed control system (DCS) and the safety instrumented system (SIS). All went smoothly and Seplat could set production at maximum from day one.

Seasonal Flooding Delays Construction
Seplat knew well that the rainy season leads to high ground water which limits the ability to construct buried services such as cables, typical to a traditionally designed plant. To avoid that issue in the future, Seplat chose Emerson’s DeltaV™ DCS, Electronic Marshalling with CHARMs technology, and its field I/O solution, which eliminates long “home run” multicore cables. In this solution, short runs of multicore cables from field devices are connected to CHARMs housed in field-mounted junction boxes. Fiber optic cable connects the junction boxes to the control room. The project team replaced 265 multicore cables with four fiber optic cables.
Placing junction boxes — preconfigured and certified for zones 1 and 2— mounted in the field meant that Seplat no longer needed to construct a field auxiliary building that would typically house and protect the I/O system hardware. Expected footprint requirements, labor costs, documentation, and cabinet design time evaporated to produce a savings of $1.4M, but more critical to Seplat were the enormous savings on schedule and construction risk.

Accommodating Change and an On-Time Finish
Another advance made possible by Electronic Marshalling with CHARMs technology is the flexibility to leave I/O undefined until closer to DCS start-up. By separating the I/O subsystem design from the control strategy design, the CHARMs I/O Card allows the field instrumentation design to begin long before the control strategy is finalized. Because CHARMs enabled the project team to accommodate design changes late in the project, I/O signals could be modified without expensive change orders and negative schedule impact. The plant was commissioned in less than ten days and has been running for over twelve months with no major issues. The on-time finish and great project cost savings testifies to the certain success of this project and contributions of DeltaV and CHARMs.