The scalability and flexibility of the PlantPAx DCS from Rockwell Automation provided the Italian system integrator with the capability to successfully implement process control with Foundation Fieldbus Technology
DELIN Elettronica is a system integrator headquartered in Modena, Italy, offering system integration capabilities in both automation and process control applications.
The company had used equipment from Rockwell Automation for an installation providing gas dehydration, glycol regeneration and low-temperature separation within an extraction facility in Otumara, Nigeria. The collaboration intensified when faced with significant standardisation imposed by the end-customer, which therefore required a relevant evolution in the control system architecture.
The PlantPAx distributed control system from Rockwell Automation was recommended due to its modernity, scalability and flexibility, combined with the opportunity of providing process and safety management in a hazardous area.
Upon extraction, the raw natural gas is saturated with water vapour and needs to be dehydrated. Most of this water must be removed prior to the gas compression and shipment in liquid form to the storage tanks through dedicated pipelines.
The dehydration process takes place at the extraction site and in most cases, is achieved using glycol. In this specific case, triethylene glycol (TEG) is deployed, because it is regenerated at a higher purity level, accepting that, during the process, the glycol has a loss at a lower vapour level with respect to other diols. Such achievable high purity level and lower losses during the dehydration process increase efficiency and reduces process costs.
Although the equipment used for the dehydration process is generally the same, there may be relevant changes in its installation, depending on the type of sub-systems used.
For this specific project three customised packages were deployed: one for dehydration, one for glycol regeneration and another for separation at low temperatures. The units were installed as an integral part of the Otumara Node Project, with the aim of commercialising hydrocarbons that were previously burnt off.
The packages are engineered and conceived for outdoor use in hazardous areas, and were installed on a complex steel structure mounted on supports and located on one of the branches of the Niger delta.
DELIN Elettronica was involved in the early stages of the project, wanting to provide an installation based on minimal automatic control, therefore requiring standard process equipment. Including a Rockwell Automation system with controllers and operator workstations (OWS).
The PlantPAx system, engineered on a standard multi-disciplinary control architecture, allowed the strong integration between the different subsystems and components as requested by the project. The possibility to use the Rockwell Automation Library of Process Objects allowed easy implementation of an accurate and fine control and diagnostic of all process variables as well as field instruments, devices, motors and valve actuators with HART and Foundation Fieldbus too.
The flexibility and the openness of the Library of Process Objects allowed DELIN to develop specific and customised Function Blocks and Faceplates to fulfil project specific requirements. The DELIN Elettronica technical staff have always been supported by global product specialists from Rockwell Automation.
The use of Foundation Fieldbus Technology in PlantPAx enabled DELIN Elettronica to manage multiple integrated interfaces during software development, using tools that are fully integrated in the system.
Upon integration, it will generate relevant information concerning equipment diagnostics, while providing predictive-assessment capabilities for maintenance. All with a positive outcome for both the total cost of ownership (TCO) and optimisation of asset utilisation.