WellTest Wizard: Production / Injection before the test

It is essential to capture production that occurred before the test because it affects the analysis. For example, it significantly affects the superposition time functions used to calculate the Derivative, which is used to identify flow regimes.

In many cases, prior production data may be imported and brought into the Production Editor. It is common for prior production and test production data to come from different ASCII files. In this scenario, you may import both files separately, merge them, and then bring the merged dataset into the Production Editor. See Loading Data into the Production Editor for additional information.

When prior production data is not available in a format that is easy to import, you can enter it into the Production Editor manually, or specify an effective producing time.

Using an effective production time will provide reliable analysis results, if production / injection periods are not interrupted by significant shut-in periods, or major rate fluctuations. Otherwise, the production / injection should be entered in sufficient detail to provide a good representation of the rate history.