Test Design (Analytical Models)
Click to see Subtopics:Test design uses the same tab as forecasting, but its purpose is different. Test design is usually performed for green fields without any production data, and is used to:
- get an estimate of expected production volumes
- see the effect of various reservoir and completion parameters
Note: See the video tutorial: Test Design (requires Flash and opens in a new window) for additional information. Note that this video was produced in 2011, so some references to the user interface are slightly different.
To start test design:
1. Create a new well (see Adding an Entity for additional information).
2. (Optional) Rename the well (see Renaming Entities for additional information).
3. Fill in all the required properties in the Properties Editor.
Estimating Expected Production Volumes (using one model)
To estimate expected production volumes:
1. Launch the well for analysis (see Launching an Entity for Analysis for additional information).
2. Create an analytical model and populate the model parameters based on available information.
3. Once model parameters are populated, click the Forecast and Test Design tab, and set the forecast duration, # of steps, and forecast control. Change other forecast options if you wish. (See Forecasting for additional information).
The forecast is calculated and displayed on the Results plot. Expected ultimate recovery (EUR) is displayed in the Forecast Results section.
If you need to copy the forecast to MS Excel (or other software), right-click the Results plot and select Copy Plot. Or, you can click the Tables tab and copy data from there. The advantage of copying from the Tables tab is that you can convert data to your desired units before copying. To do so, right-click the unit you want to change, and select your preferred units.
Evaluating the Effect of Various Parameters
To have a better idea of possible outputs (e.g., expected production volume estimates), you may want to see how results will differ when you change some of the model parameters. This can be best illustrated with an example.
Test Design Example
Assume you have one model with a horizontal multifrac completion with a test design, and you want to see the effect of changing the number of fractures (nf).
1. Create one more model of the same type.
2. Copy all the parameters from the existing model to the new one by clicking the Defaults icon (
), and then change the number of fractures (nf) for the new model.
3. Fill in all the Test Design parameters in the same way as the original model.
4. Rename both analyses so they are easily identified.
5. Compare forecasts for both models using the Comparison plot.
Or, create a Rate Vs. Time worksheet, and select the checkboxes to compare both models on a plot. (See Performing a Decline Analysis for additional information.)
The plot below compares forecasts for models with 10 and 12 fractures. This plot illustrates that the model with 12 fractures has higher initial production, but later the rate for the model with 10 fractures becomes higher. Expected ultimate recoveries (EURs) are shown as well.
Following the same procedure, you can add more models to compare the effect of various parameters.
If you have many models, and want to compare the summary parameters (i.e., EURs, or recovery factors), use the Results Viewer tab.
Note: You can perform a more elaborate analysis on the effect of various model parameters by Creating a Probabilistic Analysis, or by Creating a Sensitivity Analysis. For the theory behind these analyses, see Probabilistic & Sensitivity reference materials.