Abstract
This paper describes a dynamic modelling and optimization study to investigate the viability of deploying intelligent completions for well management in a mature oilfield in order to mitigate the challenges of increasing water cut and rapid diminishing of surface locations for new wells across the Greater Burgan field. Reservoir simulation is used to assess the potential benefits of installing Flow Control Valves (FCVs) in a candidate well, to control production from multiple reservoir zones.
A representative sector model is defined around the candidate well, to include surrounding wells that could influence its flow behaviour. Reservoir properties are extracted from a fine-scale geological realization and updated using current well logs. Sensitivity studies are performed to determine the appropriate size and grid design for simulation. The well is planned to be completed across six producing reservoir zones with a single tubing and an Electrical Submersible Pump (ESP). In the optimization strategy, the FCV aperture openings are adjusted over the lifetime of the well, to maximize the Net Present Value, while meeting operational and strategic constraints.
The robustness of the forecast outcomes are highly dependent on the quality of reservoir characterization. A sector model large enough to represent the effects of reservoir heterogeneities and interference from other wells, was used. The efficient optimization workflows used here can be generalized for similar analyses of other wells and other fields.
The optimized results demonstrate that installation of FCVs can help to meet the simultaneous objectives of boosting oil production while reducing water production. This is achieved by choking back the deeper high-water production zones to accelerate oil production from the upper high oil saturation zones, while also targeting offtake to induce the shallower low-pressure zone to deliver more. The large initial capital outlay, comprising the equipment and service cost of the FCV installation is fully offset within the first year of production, post installation.
This study highlights the significant upside benefits for the management of complex brown fields such as the Greater Burgan by adopting smart well completion strategy. Improving well production performance, and supporting multi-zone completions, should also enable reduction of well counts for fields with existing high well density and lack of surface space to accommodate many new dispersed wells.
