Sparse data option

When using sparse data, the hybrid model uses coarse timesteps for calculations, and each coarse timestep contains n points.

Note:    We recommend using sparse production data when running automatic parameter estimation (APE).

After you enter a value for n in the Use Sparse Production Data dialog box (opens when you click the Use Sparse Data icon (Use Sparse Data icon) on the Hybrid Model pane's toolbar), the history plot displays a new sparse set of production data to be used for calculations:

To ensure that the sparse dataset represents the actual production history, adjust the value for n, as required.

Click the Synthesize icon (Synthesize icon) to run the model. Note that the calculated results correspond to coarse timesteps.

If you run APE, each calculation runs using coarse timesteps based on your n value.

Note:    Your weighting and point selection are honored when running APE using sparse data.

While calculation results are slightly less accurate, the calculations run faster. After APE finds a match using sparse data, you can run one calculation using the entire production dataset (n = 1) to ensure that the match is still good.

History match

How sparse datasets are calculated

For Use Rate mode: Drawdowns are divided in coarse timesteps. Coarse timesteps contain n points, and the rate for each timestep is calculated as "total volume produced over the timestep" / "duration of the timestep". For buildups, all of the production data is used.

For Use Pressure mode: Drawdowns are divided in coarse timesteps. Coarse timesteps contain n points, and the pressure for each timestep is calculated as "last-measured pressure of the timestep". For buildups, all of the production data is used.

Tip:    You can select a rate or pressure in the Calculation Method section.

IHS Harmony Enterpriseā„¢ 2018.1 | Last revised: March 20, 2018

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