Proposing an Adaptable Subsurface Data Assessment Workflow for Identifying Fluid Pathways in Fractured Carbonate Reservoirs

Abstract

Abstract The understanding of reservoir fluid pathways and their dynamic behaviour through time is essential for a successful development of a fractured carbonate reservoir. This work aims to propose an adaptable data analysis workflow to optimize the characterization of the reservoir throughout its life cycle. Accounting for different maturity stages and geological scenarios, the proposed evaluation sequence supports an optimum assessment of the reservoir architecture and the understanding of its production behaviour and evolving performance. The methodology involves the dynamic evaluation and integration of geo-parameters, such as fault damage zones, fracture corridors and connected vuggy layers. The corresponding workflow enables a flexible data assessment of flow-dominating permeability zones and the degree of their spatial connectivity between wells and areas of undrained reservoir potential. The interpretation of image logs, regional field work and outcrops, seismic-scale faults, karstic sections, fractures and sub-seismic damage zones are combined to characterize flow zones and their corresponding hydraulic hierarchy expressed in the dynamic behaviour at well-scale. The results integrate all information extracted and interpreted from available data sets, determining the preferential networks for fluid movement and how these can be linked to current field development strategies and reservoir management initiatives. The utilized flexible workflow accommodates both parallel and sequential tasks and is adaptive to each given geological case, supporting a streamlined data analysis towards an optimized understanding of reservoir dynamics. The reservoir assessment based on this methodology allows to establish conceptual flow scenarios and their potential impact on field performance. This analysis does also help identifying favourable areas for well placement, including refinements of optimum well design, strategic packer placement and production mitigations aimed towards a stable and sustained field life. This paper is a contribution to the continuous learning process in field development optimization of heterogeneous fractured carbonate reservoirs. By implementing a flexible data analysis workflow, adaptive to complex geological and variable data scenarios, this work identifies the dynamic range of potential hydrocarbon and water pathways that will determine reservoir performance and helping to optimize the strategy for its development.