Cost-Efficient Offshore Reservoir Management and Monitoring with Tracer Technology
The first co-implementation of inflow and inter-well tracers in offshore Abu Dhabi
A significant proportion of the world's oil reserves are found in multi-layered reservoirs which have complex structures. The operator was looking for recovery improvement through new EOR methods for monitoring a complex multi-layered reservoir with early-stage water injection.
Multi-layered reservoirs are complex to understand, and they have significant variations in different layers, which makes them difficult to monitor. They are characterized by multiple geological formations stacked on top of each other, heterogeneity, fluid saturation variations and compartmentalization. In these wells, accurate reservoir characterization is extremely difficult, making efficient reservoir management and maximizing recovery challenging in these wells.
We integrated two surveillance technologies, inflow & inter-well tracers, for the first time to monitor a multi-layered well. We collected fluid samples and analyzed them to detect the unique tracers in the production wells. Inflow tracers were designed to account for high temperatures and highly acidic stimulation fluids, and they provided qualitative and quantitative estimates of the zonal flow and helped to identify the source of water breakthrough. Inter-well tracers introduced in the injection wells allowed us to identify the primary flow paths and rate of movement of the injected fluid, allowing us to improve water flood conformance plans to maximize sweep efficiency.
Quantification models were used to quantify the zonal influx while accounting for the expected crossflow. The execution plan considers the optimum production and injection rates, equipment and lab test requirements, and an optimized field sampling schedule for transient and steady-state flow campaigns. Implementation of two tracer technologies in conjunction in the early stage of waterflood development offered a unique opportunity for effective reservoir monitoring as a less complex and more cost-efficient solution compared to wireline interventions.
Tracer technology offers several benefits for offshore reservoir management and monitoring, providing valuable insights into fluid movement, reservoir behavior and the effectiveness of various recovery processes. It allows for precise tracking of fluids and identification of production challenges that help with the optimization of injection strategies, early detection of reservoir challenges and verification of reservoir simulation models. Tracers offer a unique advantage for multi-layered reservoirs as they can penetrate different layers in the reservoir and allow for non-electric wireless monitoring of the reservoir for many years while reducing cost and increasing operational efficiency.