High-quality reservoir characterization, improved reservoir dynamics, optimized water flooding and better understanding of fluid movements are some key factors for successful reservoir management. Interwell tracer test (IWTT) technology has been recognized as an efficient tool to determine fluid pathways between wells and evaluate areal water breakthrough between injectors and producers, along with estimating the velocities at which the injected water is breaking through, and these can be integrated in the geological and reservoir models of the field to reduce uncertainties attributed to fluid flow mechanism and interwell communication.
This paper presents a case study of IWTT technology application in a heterogeneous reservoir in a Saudi Arabian oil field and shows how this characterization tool was utilized to investigate the reservoir flow mechanism; and how the derived information facilitated a better reservoir management through improved reservoir monitoring and enhanced understanding of reservoir fluid dynamics. The project commenced in November 2007 through injecting unique chemical tracers into a set of injectors to effectively monitor injected fluid movement in the reservoir, after which tracers were continuously monitored through yearly sampling programs by collecting samples from adjacent oil producers.
The results of the project will be showcased on how it has provided valuable insights through identifying interwell pathways, estimating velocities at which tracers are traveling and optimizing water injection volumes. These findings were translated in optimized reservoir management, resulting in a tangible impact of the offset wells’ productivity and sustainability.