PetroVisor Package
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      AutoDCA Package

      This package creates DCA (decline curve analysis) objects for all entities in a given context using an external activity.

      Usage

      Add the auto DCA activity to a workflow and create and run schedules according to the need of the project.

      Details

      Activity Arguments

      • Production Signal: a signal holding the production rate data for the entities (e.g. oil production rate, gas production rate). The generated decline curves are fitted to the data stored on this signal.
      • Cumulative Signal: a signal holding the cumulated production data for the entities (e.g. cumulative oil production, cumulative gas production). The cumulatives are used to calculate the estimated ultimate recovery (EUR).
      • Tag Entries [optional]: if filters are specified, tag entries matching the filter criteria will be used to limit the range in which curves are fitted to the data. Using tag entries can speed up the calculations.
      • Tag Entries Option: defines how the given tag entries are applied to the data. Valid options are:
        • Use Start Date: only data where the date is greater or equal than the tag entry start date will be used to create a fit.
        • Use End Date: only data where the date is greater than the tag entry end date will be used to create a fit.
        • Define Fit Range: only data where the date is greater or equal than the tag entry start date and smaller than the tag entry end date will be used to create a fit.
        • Peak In Range: only data where the date is greater or equal to the date of the peak value inside the tag range and smaller than the tag entry end date will be used to create a fit.
        • Peak In Rankge +: only data where the date is greater or equal to the date of the peak value inside the tag range will be used to create a fit.
      • Force History Decline: if this flag is set to True, the generated fits will always take the entire scope of the given context as fit range. This means, that the entire production history within the scope will be used to create the fit, disregarding well events like interventions or workovers which may result in a unsteady production.
      • Fit Types: defines which fit types are used during curve fitting. Valid options are:
        • Arps and Linear: this option will fit linear, exponential, hyperbolic and harmonic curves.
        • Arps Only: this option will fit exponential, hyperbolic and harmonic curves only.
        • Linear Only: this option will fit linear curves only.
      • DCA Name: the string entered here will be used to generate the name of the DCA object in PetroVisor, following the format: Entity Name: DCA Name.
      • Economic Limit: this limit may be used to limit the EUR returned by the DCA. The forecast will stop as soon as the forecasted rate drops below the given economic limit.
      • Terminal Decline: if a terminal decline rate is specified and the best fit determined by the activity is a hyperbolic curve, a second segment will be added to the DCA representing an exponential decline with the given decline rate. The second segment's start date is the time step at which the first segment's decline rate drops below the given decline rate.
      • Preprocessing Script: the name of the script used for data preprocessing. See Preprocessing for more details.
      • Review Needed Threshold: fits with an R² smaller than the threshold given here will be marked with the flag review needed.
      • Minimum Slope: the minimum slope for the fitted curve.
      • Maximum Slope: the maximum slope for the fitted curve.
      • Minimum Constant: the minimum hyperbolic constant for the fitted curve.
      • Maximum Constant: the maximum hyperbolic constant for the fitted curve.

      Preprocessing

      The auto DCA activity uses a script to retrieve the data the fits are based on. This offers the possibility to customize the preprocessing. The script is called by the activity directly. No additional workflow or schedule is needed.

      The auto DCA activity expects the following items to be present in the preprocessing script:

      • A table named Input containing at least the columns Input Production and Input Cumulative
      • A table named Preprocessed containing at least the column Production Preprocessed. This column has to contain the preprocessed data the fits should be based on.

      Furthermore the preprocessing script has to use the entity set Single Entity Parameter.

      Data Requirements

      The following data is required:

      rate signal
      corresponding cumulative signal