Adaptive Process Control and Dynamic Optimization: A Real Application on an Upstream Giant Brown Oilfield
Authors: Ghetti Martino , Cadei Luca , Gerardi Rocco , Vaccari Davide , Rossi Gianmarco , Bitetti Michele , Forte Marilena , Collura Laura , D'Ottavio Valentina , Bottani Cristina , Ricci Antonio , La Placa Vittoria 
Published: October 2022

The current oil and gas production scenario is characterized by high market volatility, increasing Energy Efficiency targets and subsequent requirements in operation excellence. This leads to an ever-increasing attention towards more efficient asset management. This paper illustrates the application of Advanced Process Control techniques to beyond-standard targets of process parameters and product specifications, supporting carbon footprint reduction process.

The Oil & Gas treatment facility is made of 4 oil and 5 gas process trains with an overall gross production of more than 100 KBOED. An advanced Adaptive Process Control application has been first tested on a Digital Twin and then implemented on one single GOSP (Gas Oil Separation) section. This application has then been extended to all the process trains, including the Gas treatment section. A fully integrated Adaptive Process Control Orchestrator and Dynamic Optimizer has been deployed across the entire site to grant an efficient load management between trains, maximizing hydrocarbon production and the energy efficiency of the asset maintaining every equipment within the proper operating windows.

APC deployment on a brownfield upstream facility demonstrated to improve asset efficiency by optimizing performance within design capabilities. Energy consumptions were significantly reduced by product specification prediction and early identification of potential process upsets. A sensible production capacity increase has also been recorded thanks to process stabilization. Results eventually show that in an industry where process optimization by design changes is not always feasible or cost-effective, a well-tuned APC controller can increase asset performance with a minimum investment. Moreover, project delivering didn't require disruption in normal operation nor design changes in existing equipment. Significant results have been obtained in terms of alarms reduction through a standardization of the control philosophy and also in terms of energy/CO2 reduction with an average −15% specific energy and CO2 reduction achieved just in GOSP section. Moreover, APC has demonstrated a critical support to operators during equipment upsets through the "auto-pilot" control of the process trains not affected by the transient.

Advanced Process Control is a multiple input – multiple output (MIMO) digital tool that nowadays has never been systematically implemented in upstream facilities. Main reasons are the high volatility of reservoir fluids flowrates and product overspecification that assures safe operations and production continuity. APC changes significantly control-room operator working routine of an upstream production plant. Without APC, operator's experience relies on 1-to-1 relationships between one manipulated variable (MV) and one controlled variable (CV) even if more than one CV is affected by one MV move. Optimization runs are carried out with a frequency lower than a minute and within every run, a move could be assigned to any manipulated variable. APC operator can focus on CV limits assignments, being relieved of smoothing PID loops moves.