In this work, we present a Model Predictive Control (MPC) strategy to provide setpoints for the regulatory control layer of a gas compression system of an offshore platform, aiming to avoid excessive energy consumption, decrease the plant variability, and guarantee a stable and safe operation against load disturbances. The proposed method is tested in a digital twin of a typical industrial unit using a Dead-Time Compensator Generalized Predictive Controller (DTC-GPC).
The complete work is available in:
Model predictive control with dead-time compensation applied to a gas compression system
The gas compression system considered in this work is a digital twin based on a typical industrial unit validated with some real data obtained from the Petrobras oil company and employed phenomenological models of the gas compression system.
A two-level control structure was applied to a gas compression system of an offshore platform:
- Different PID regulatory controllers are implemented in the gas compression system to maintain plant stability and control the pressure in the sections.
- An MPC as an advanced control layer over the gas compressor unit’s regulatory control system.
A gas compression system is an important part of an offshore oil production unit. The most important type of equipment used in a gas compression system is the centrifugal compressor. A compressor failure may cause a complete production unit shut down. That is an undesired condition because restarting the compressor may take about an hour. On the other hand, when the compressor is operated at a rotation speed below its nominal value, it will have high energy consumption to get the compressor back to the operational point when the gas inlet flow rate increases
The advanced control MPC showed the potential to be used as a supervisory controller in the gas compression system of an offshore platform. Important benefits can be obtained; such as the plant reliability and safety by guaranteeing that key variables remain into desired operating regions and to reduce operating cost by reducing the energy consumption. In this work, a comparison between a system with MPC and without MPC was presented which showed that the advanced controller is more suitable to maintain the behavior of the compression system around a stable operating region.
A summary of the work can be seen in the following video in Spanish:
Or in the following video in Portuguese: