ComboCurve: Import Forecast Parameter

ComboCurve: Import Forecast Parameter

Import Forecast Parameters 

In this article we outline the steps necessary to import a csv of forecast parameters into a ComboCurve forecast.
ComboCurve uses a specific format for forecast csv import. To better understand this format, we recommend creating a dummy forecast and export the forecast parameters. This can be done, by going to forecast options >> export forecast parameters (CSV). 
Note: Currently, the software only allows to import forecast through parameters and not volumes.

Before moving to create the import file, you’ll need to import the well themselves (header + production data) to the current project. Then you’ll need to create a forecast containing the wells.

Once the download is completed, you can refer to the csv as a template to add your own forecast parameters. However, not all the columns are needed for import. The required columns are listed below for a modified Arps segment:

INPT ID à unique identifier assigned when a well is imported in ComboCurve.

Last prod Date Monthly (or Daily) --> choose accordingly to the production data resolution (either monthly or daily) if you have monthly production you won’t need to fill out the daily column.

Phase --> Oil, Gas, Water. Not all three phases are required.

Monthly CUM (or Daily) --> cumulative production up to the last production date. Choose according to the production data resolution.

EUR (MBBL, MMCF) --> the total production which includes production volumes (CUMs) + forecast volumes.

Segment --> the number associated with the forecast segment, if only one segment, then it will be just 1.

Type --> the type of forecast you importing Rate or Ratio.

Segment Type --> the type of forecast model used, fore modified Arps this would be “arps_modified”.

Start Date --> start of the forecast.

End Date --> end of the forecast.

q start --> the peak rate (qi) of your modified Arps segment.

b factor --> b factor of your modified Arps segment.

Realized D Sw-Eff-Sec (%) --> effective secant decline (% over 1 year) at which the b=0 and the decline become exponential.

 

Note: With the above parameters, the software will back-calculate the effective and nominal initial Declines. In alternative, you can input the effective declines in place of the EUR and CUMs values.

Once the forecast parameter csv is completed, you can navigate to forecast options >> import forecast >> select the appropriate prod data resolution >> select the file >> import



Additional Notes

  1. When importing forecast parameters or a linear segment, the D_eff must be linearized as follows:

  1. D_eff (for all segment types) is calculated using the Secant method. To convert a Tangent decline to a secant decline you can use the following formula: