Unified Gas Injection and Gas Export Management via Process Automation

Abstract

For oilfield with high associated gas production or non-associated gas (NAG) wells, gas injection is typically being given as priority, and only the resulting gas flow not taken by injection wells is exported as sales gas. With the unstable price of oil and the shift towards gas as cleaner energy source thus creating higher gas demand, the produced gas maybe prioritized for sales rather than for injection. This paper demonstrates the new approach of managing the gas export and gas injection including the flexibility in prioritizing either utilization options, and managing the impact of changes in injection gas supply accordingly via process analytics and automation. The paper described the concept and key design consideration in integrating the gas injection and gas export process analytics and control in oil and gas fields for improved hydrocarbon recovery application and flexibility of operation modes. It also described step-by-step approach for the technology development and adoption, which is a commendable to be replicated for other production system. Based on a case study, current operation gaps, limitation and opportunity are identified from system review, followed by development of automation strategy, mainly focusing at utilizing the current instrumentations available at the field to manage the gas export and injection accordingly based on desired prioritized mode. With the automation exercise, the operator can now control the system by changing the priority mode and set points at DCS rather than manually adjusting the choke valves opening to regulate the gas injection and gas export flow.