Understanding and quantifying relative connections among injectors and producers is a key to improving reservoir performance under waterflood. Inter-well tracers were used to assess injector-producer connections in early days of development. A data-driven approach is a valuable process for estimating injector/producer connectivity as more wells are drilled. It offers a viable alternative to costly and challenging tracer operations in offshore environments such as the North Sea.
BP’s Field of the Future Technology Flagship has developed an innovative approach for waterflood performance, Top-Down Waterflood (TDWF) Diagnostics and Optimization. This novel approach combines the Capacitance Resistivity Model (CRM) and BP’s proprietary event detection and association technology to quantify the connections between the injectors and the producers.
This paper compares the use of inter-well tracer and streamline model with TDWF in a BP operated field (North Sea), using the value of injection water (VoiW) as the outcome of connectivity. Initially, the paper demonstrates evaluating the sensitivity of various CRM parameters, as well as selecting periods in a field’s history for comparison with tracer breakthrough data and streamline model results. The comparison to streamline and tracer results is made based on TDWF VoiW with no prior information on connectivity. For selected periods, CRM results mostly agree on connectivity with tracer and streamline results. Using injector events and producer responses (rate, pressure), we provide prior information to CRM which enhances the confidence in TDWF VoiW estimates and results in better consistency with tracer/streamline interpretations.
The best strategy for enhancing waterflood performance management is the integration of the TDWF methodology with existing workflows, such as tracer and streamlines modelling. As a direct result of this study, TDWF will be used as a "virtual" inter-well tracer. The efficiency of the newest injector in the field then can be understood better without the need to conduct a tracer program.