Understanding the fluid flow in the reservoir is one of the main factors affecting the success of waterflood projects. The level of reservoir heterogeneity and complexity of the structure are the main challenge factors to understand the fluid movement. Interwell water tracers is a significant approach especially in reservoirs that have high level of complexity to have better understanding of the injected water flow directions, flow units and reservoir geology.
Raudhatain-Mauddud reservoir is highly heterogeneous layered reservoir, bearing different oil qualities. The waterflood started in year 2000 and within a short period the oil rate has increased significantly but with rapid increase in the water cut. The management of Mauddud waterflood project became more complex with increasing the number of injectors and establishing injection in all layers. Interwell Tracers have been utilized to understand the complex injected water movement in the reservoir to improve waterflood management process.
Different conservative water tracers have been injected to track the injected water movement between the wells. Tracer breakthrough has been detected in many producers with wide range of tracer's residence time between the wells. Performance of tracer concentration in the stream of each well versus time has proven the flow through different flow units. The Tracer information has been utilized qualitatively and quantitatively to understand the fluid movement laterally and vertically between the flow units and provided invaluable information that has been used for optimizing Mauddud reservoir waterflood, calculating the swept volume and to optimize wells production.
This paper presents a detailed review of case history for utilizing the Interwell Water Tracer information to understand the fluid flow in the reservoir and the approach to manage Waterflood operations and optimizing wells` production.