Front-tracking and monitoring of pattern water-flooding are crucial reservoir management activities in the Mauddud (MA) carbonate reservoir. This depletion drive reservoir has been on water flooding since 2000. To help understand the complex water movement that has been observed following implementation of the water floods, it is essential that water tracers be employed in MA injection wells. The use of tracer technology is becoming increasingly important to the petroleum industry and it has proven to be an efficient tool to investigate reservoir flow performance and reservoir properties that are controlling fluid displacement processes. Inter-well tracer has proven to be successful in identifying direct communication between the injection and production wells, flow patterns within the reservoir, thief zones, swept pore volume, reservoir layering, and flood performance. Tracer studies have also been used to complement the information provided by other reservoir characterization methods such as pulse and interference testing.
Water tracers were employed in MA since 2007 at a pilot level, which is gradually expanding to full-scale implementation. Monitoring tracer breakthough information have provided invaluable information concerning the influence of faulting and stratigraphy on fluid migration within the reservoir which has been used to guide calibration/updating MA model and planning more tracer projects. The tracer data have been used to reduce the uncertainty attributed to well-to-well communications, and vertical and horizontal flow barriers.
The study presented in this paper includes two injection wells which have been on waterflood since 2000. Different water tracers were injected in this field since 2007. Produced water samples were collected for tracer detection. This paper includes discussions on the implementation of tracers in a carbonate reservoir presenting detailed analysis and interpretation of the results.