Enhanced Oil Recovery Surveillance and Operation Optimization through Digital Oilfield
Authors: Mehran Fatemeh , Turiman Hayati , Mohd Jamil Nur Farhana , A Aziz Khairul Mustaqim 
Published: March 2021

S Field field started enhancement planning and redevelopment recently by using an innovation EOR program called GASWAG, Gravity Assisted Simultaneous Water and Gas, in the selective oil-bearing sands. The initial program includes 6 infill producers, 2 water injectors, 3 gas injector wells and approximately 15 potential well reactivations to increase recovery by 7%. Since GASWAG is a new program in this region, it requires well and reservoir monitoring system to be implemented to have better understanding of complex behavior of water and gas injection and its effect on EOR performance. The main objective of the EOR Integrated Operation (IO) workflows solution, is to determine as quickly as possible if EOR performance is deviating from plan. This will be accomplished by earlier detection of EOR performance exceptions (compared to process without IO functionality), so that corrective action cycle time can be reduced, thereby reducing production deferment.

Well Surveillance & Operational: a workflow to monitor, analyse and manage EOR wells production/ injection performance using real-time and in-time data together with updated well model. This Workflow focus on well and zones monitoring by using the well model and existing measurement. In addition, the existing IO workflows are integrated with EOR-Operational and feeding online data to this WF which is consistent with operational safety limit and KPOs. All operational data required for reservoir and production engineering were extracted either from well model, measurement or other workflows to the same well interface. Additionally, production and injection well surveillance and alarming system is implemented to benchmark the current operational condition deviated from plan or operational limit. Updated dynamic model and optimizer tool are used to define the optimum choke size of each reservoir layer for injecting or producing wells.

This workflow was built and implemented successfully. It is designed based on very comprehensive technical aspects and KPIs from reservoir management, production engineering, facility constraint, well integrity to operational optimization. A single interactive visualization interface via web-based is implemented which cover all necessary production and reservoir data needed for collaborative decision making.

The EOR well surveillance IO workflows will assist in automating computation of injection and production well health and performance. This solution benefits the asset team by allowing early detection of underperforming injection and production wells. Main challenges in S Field was, it is divided by several jackets thus require movement via vessel for manual data gathering. Unpredictable and adverse weather heavily challenge this activity. By having IO would help to improve data hygiene and collective data on daily monitoring.

Additional functionality of the well surveillance workflow includes the monitoring of zonal rate and pressure, which are considered as main reservoir performance parameters. Operations, production, and reservoir engineers, as well as technical & business owners benefit from these workflows to steer the EOR operation.