Integrated Multiwell Formation Evaluation for Diagnosing Reservoir Dynamics

Abstract

In this paper, a multiwell data integration approach for improved formation evaluation is presented to describe: (1) Mixing between injected fresh water and saline formation water, (2) Water salinity variation vertically across reservoir intervals, and (3) Injected water movement in the reservoir. Data used included static and dynamic time lapse well data as well as a crosswell electromagnetic (CWEM) survey. With this integrated approach, we can answer critical formation evaluation and reservoir management questions, such as why the formation tester (FT) water sample salinity can be very different from the produced water salinity, and why a well located farthest from the injectors can produce water several years earlier than a well located nearest the injectors. Gaining a complete knowledge of water salinity, distribution, both vertically and areally, and water movement in-situ allows better assessment of reservoir saturation changes with time, thereby improving reservoir management.