Enhanced Waterflooding in Multi-Stage Fractured Horizontal Wells - An Integrated Design Workflow and Unique Application of Active Injection Control Devices
Authors: Gurses Sule , Kozin Anton 
Published: November 2018

The waterflooding is a recovery method applied in the fields developed with multi-stage fracturing (MSF) wells to increase reservoir pressure and therefore improve producers’ performance. However, operators utilizing this method have been continually working on improving uneven injection, poor sweep efficiency and producers watering due to short-circuiting with injectors. Active injection control devices (ICD) application with an integrated design workflow offers the solution to address these challenges effectively. This paper gives an overview of the application method and design workflow.

Active ICD allows the wellbore segmentation with packers, injection control with nozzles and reclosing valve flexibility for shutting of the specific segment and opening the secondary valve to optimize injection further. The technology features a slim diameter to fit into restricted completions with erosion resistance, interchangeable and open/close position nozzles. An integrated discipline and software technology workflow is developed by involving distributed temperature sensing (DTS) for estimation of fractures injection contribution, integrated with well centric dynamic modeling for representative design base and ICDs technology design methodology for optimized nozzle sizes.

Active ICD features a re-closable multi-position valve with tungsten carbide nozzle inserts, which can be operated by a slim shifting tool deployed on coiled tubing (CT). Either swellable or hydraulically set packers could achieve zonal isolation. The system can be installed either in existing or newly drilled wellbores. During the initial injection period of the well, followed by a shut-in, DTS data steady state analysis provides an injection profile along the wellbore identifying fracture heterogeneity. The process uses a thermal model which accounts for radial conductive heat lost as a function of injection rate. Integration of thermal modeling results with well centric dynamic modeling enables representative flow profile along the wellbore from each hydraulic fracture and hence the ICD design methodology for efficient water injection equalization along the wellbore. Dynamic modeling workflow considers all the details of completion to optimize the nozzles selected to choke back high permeable zones when promoting even injection into low permeable zones and provides completion design for technology implementation to meet the expectations. Proposed workflow and the technology has been successfully implemented in numerous low permeability formations with positive field results leading to a significantly increased oil production in the offset wells.

This new and unique technology application and design workflow approach is the innovative way to help operators to improve injection efficiency in MSF wells therefore ultimately maximizing sweep efficiency. There’s a significant potential for this type of ICD technology implementation in many low permeability oil reservoirs developed by MSF’s to increase the recovery factors.