2. Metodologías de la investigación
2.3 Genealogía de las mujeres
2.3.2 Genealogía feminista
This lesson demonstrates the capability of combining all three types of solutions you have learned to forecast oil production on a well that has a brief production history.
Combining Three Types of Solutions
1. Select BLUE_1:Ge_6 from the well list.
The (Empirical) forecast may display. Notice that with only a few data points, a visual trend may be unreliable. Assuming that you know the reservoir model and have formation parameters available, you could start the forecast from a different approach.
2. From the Properties pane select Empirical solution.
3. Change the Fit Type to Hyperbolic method.
4. Locate the b Value properties. Set the Method to User and enter User value of 0.6.
NOTE: During this lesson, you will probably encounter
“Type Curve match failure”
messages. It is due to either incorrect parameter specifications or the algorithm not converging.
Remember that you can specify your own Matching Settings. If needed, change the matching criteria (i.e.
match on cumulative rate instead of production rate, increase number of iterations/tolerance). Always keep in mind that anything that you change may affect the validity of your results.
Schlumberger Public 5. Select Edit > Scenario. The Current Scenario dialog
displays.
6. Select the Forecast tab and specify the following:
7. Click OK and the graph shows. You need to set limits to obtain a meaningful decline. Review the sections on Setting Limits and Digitizing Points as a guide.
Schlumberger Public 8. Save the forecast.
9. Select Edit > Scenario.
10. Select the Forecast tab and add Schedule #2.
11. For this schedule, use Analytical Transient Solution method and specify the following on the Forecast tab.
12. Enter these values on the Parameters tab:
13. Click OK.
Schlumberger Public 14. Select Tools > Typecurve Match.
15. Save the forecast.
16. Select the Forecast tab in the output window and find the section for Schedule #2.
17. Select Edit >Scenario.
18. Change Schedule #2 to Empirical.
19. Click OK. The graph displays (both working and saved forecasts).
20. Select Edit > Scenario.
21. Add Schedule #3.
22. On this schedule, use Fetkovich Type Curve.
23. Specify the following on the Forecast tab:
• Start Time – Months from End = 0
• Start Rate – Previous
NOTE: Pay attention to the saved forecast (in Cyan), you can distinguish the two portions of the curve, with different hyperbolic b values.
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• Decline Rate – User Defined = 0.03 24. Click OK.
25. Select Tools > Typecurve Match.
26. Save the forecast.
27. Click on the Forecast tab output window to view the result.
28. Switch back to Empirical to see the saved forecast.
Exercise 20 Performing a Forecast
Pick a well that does not have good production history (or one that does not have production at all) and do the forecast.
1. Close the Forecast window.
2. Clear the filter and return to the Basemap.
Review Questions
• Why would you use Analytical Transient Solution instead of Fetkovich Type Curve Analysis?
• Why is it necessary to set limits when you run a forecast analysis?
Summary
In this module you:
• set up base forecast case
• combined all three solutions.
In the next module, you will learn how to retrieve results from your forecast analysis in OFM.
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NOTES
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NOTES
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Module 6 Retrieving Forecast Results
Forecast information (reserves, rates, etc.) can be retrieved via calculated variables and displayed/used in other modules such as report, plot. In this module, you will create variables to return rates on group and individual wells. You will then create variables to return remaining reserves and estimated ultimate recoverables.
Use the forecast results saved in Case1.
Prerequisites
Knowledge of calculated variables, plotting, and reporting is a prerequisite in this lesson. If you have any problems, refer to the Online Help (or any training material that applies).
Learning Objectives
In this section, you will successfully learn how to perform the following procedures within this workflow:
• create variables to return remaining reserves
• estimate ultimate recoverables
• use forecast result.
Lesson 15 Calculated Variables
In this lesson you will create calculated variables to return remaining reserves.
Creating Calculated Variables
1. Create a calculated variable named FCST.OilonGroup to retrieve forecast oil rates on a group of wells. The definition of this variable is FCST.OilonGroup = @Forecast( date,
"oil", "Case1", "group" ).
2. Assign units to the variable accordingly.
3. Create a calculated variable named FCST.GroupofOil. This variable adds individual forecasts (oil rates) together for a group of wells. The definition of this variable is
FCST.GroupofOil = @Forecast( date, “oil”,
“Case1”, “sum” ).
Schlumberger Public entity (group/well) based on the specified case. The definition
is FCST.RemRes = @DcaResults( "oil RES",
"Case1", 1 ).
6. Assign units and a multiplier to the variable.
7. Create a calculated variable named FCST.EUR. This variable retrieves (oil) Ultimate Recoverables for the selected entity based on the specified case. The definition is FCST.EUR =
@DcaResults( "oil EUR", "Case1", 1 ).
8. Assign units and a multiplier to the variable.
9. Use these variables on the report first.
10. From the Forecasts pane, expand the Case1 node and locate the name of the Group forecast you created earlier in the Setting Up A Forecast Scenario section. Right-click on the group name and select Load. OFM loads the saved group forecast.
11. Select Analysis > Report to open a report window.
12. Select Edit > Report Parameters. The Edit Report dialog displays.
13. In the Select section of the Edit Report dialog enter Date, Monthlyprod.Oil, FCST.OilonGroup.
14. Click OK. The report displays.
Schlumberger Public 15. Select Edit > Report Parameters. The Edit Report window
displays. Add the FCST.GroupofOil variable to the report.
16. Click OK.
17. Use the Next and Previous buttons to navigate through all the wells. As you can see, for individual wells the group and the sum options are the same. Thus for individual wells, you can even omit this last argument in the variable definition, i.e.,
@Forecast( Date, “Oil”, “Case1” ).
18. Add the other two variables (FCST.RemRes and FCST.EUR) to the report.
19. Group the data to recover the group forecast results.
Constant values of Reserves and Recoverables are reported.
These values are the results of your forecast on the group, not the sums of individual reserves and recoverables.
Exercise 21 Verifying Report Results
Open a Forecast window and verify the results (by comparing the retrieved values on the report and the saved values on the
forecast).
1. Create a variable named FCST.OilRate. The definition is FCST.OilRate = @Forecast( Date, "Oil",
"Case1").
2. Associate the unit properly to the above variable.
Schlumberger Public 3. Add FCST.OilRate to the report as shown below.
4. Click OK.
5. Scroll down to see the results.
Notice that if you omit the last argument, the @Forecast() function takes the group option. (In other words, group is the default option). If the variable has been created this way (without the last argument), and you want to retrieve the summed values, you can specify an OFM option from the Tools > Settings menu.
6. Select Tools > Settings > Group. The Settings dialog displays.
Schlumberger Public 7. Check the option to Sum individual well forecasts when
grouping wells.
8. Click OK. Regroup the wells and the report displays.
9. Verify the result. Reverse the operation (by clearing that group option).
Exercise 22 Creating Variables to Retrieve Data
1. Select a few wells and perform a forecast on gas phase.
2. Save them to another case.
3. Create variables to retrieve forecast gas rates, reserves, and recoverables.
4. Select Analysis > Plot. The Edit Plot dialog displays.
Schlumberger Public 5. Add the following variables: Plot Oil.CalDay,
FCST.OilonGroup, and FCST.GroupofOil versus Date. Your plot should look similar to the one pictured below.
6. Navigate through all the wells in the list and see their plots. On individual wells, the two forecast variables are the same. You should expect to see the forecast portion consistent (in trend) to the historical portion. An example is shown below.
Exercise 23 Creating Bubble and Grid Maps
Create bubble map and grid map of oil RES and EUR.
NOTE: The @Forecast() system function can only retrieve rates.
The @DcaResults() system function retrieves constants (i.e., forecast parameters).
If you perform forecasts using ratios or cuts and want to retrieve those variables, use the @DcaCalc() system function.
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Review Questions
• What is the purpose of each of the following calculated variables?
o FCST.OilonGroup o FCST.GroupofOil o FCST.RemRes o FCST.EUR
• Are the reported constant values of Reserves and
Recoverables the result of your forecast on the group, or the sums of individual reserves and recoverables?
Summary
In this module you:
• set up base forecast case
• combined all three solutions.
You have completed the OilField Manager – Forecast Analysis training. Use what you have learned to successfully work within OFM 2007.
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