Classification of residual recoverable and non-recoverable oil reserves by the reservoir complexity index (RCI)

The paper considers a new engineering analytical tool for express oil reserves assessment. Proposed method is based on classifying oil reserves by complexity – reservoir complexity index (RCI). It allows to optimize the development system and form a well interventions program.
The method is suggested to use three main parameters for development complexity estimation: reservoir permeability, start watercut (which contains the parameters of the curve of relative permeability, saturation and viscosity) and geological heterogeneity (pattern efficiency).
An economic estimation of the well profitability is carried out by calculating PV UDC indicator (unit development cost, CAPEX / total oil production). The advantages of this indicator is that it allows to determine the economic attractiveness and does not require macro parameters and costs for the building well pads
Due to the economic assessment and well ranking, it is possible to obtain profitable well pads and select candidates for sidetracking.
The novelty of the work lies in the use of an updated methodology for the reservoir complexity index estimation for the remaining recoverable reserves classification.
As a result, high-quality tool is created that integrates RCI and economic model. It is aimed for solving reservoir engineering problems and increasing the project cost
The proposed method can be applied to other fields with minor modifications.

reservoir engineering, reservoir complexity index (RCI), permeability, start watercut, pattern efficiency, oil recovery factor, well interventions, unit development cost (UDC)

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