08 Reservoir and volume calculations

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Last updated: Sept 11, 2012Version comment
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Reservoir models

In order to calculate HCPV (i.e. hydrocarbon pore volume) for the reservoir there has to be a reservoir model. This is a folder with reservoir horizons in layer model and folders with petrophysical parameter grids.

The parameter grids are connected to the zone between two horizons and the zones in the layer model start with the first horizon. There are seven horizons and six zones; therefore the last horizon will have no petrophysical parameter grids associated.

Petrophysical parameter grids

The petrophysical parameter grids in the volumetric model are random generated between 0.1 and 0.6 approximately. That corresponds to realistic value domains. In real cases the petrophysical parameter grids are gridded from well data, f.inst. using the gridding panel Simple points and lines gridding.

The parameter grids should be organized as shown in the folder 09_Petrophysical parameters.


Layer model and cross sections


Folders showing the layer model and petrophysical folder with parameter grids

Exercise

Calculate hydrocarbon pore volume within a license.

  1. Right click on Depth data > Grids interpretation and activate Volume layer model calculation.
  2. Set Type of volume to be calculated to Between plane1 and plane2.
  3. Check in 1: contact and write in the level value 2700 (suitable for this project). Also called top contact.
  4. Check in 2: contact and write in the level value 3800 (suitable for this project). Also called bottom contact.
    • If there is only one contact plane you just check in 1: contact.
    • There are two types of calculation:
    1. From top reservoir to Top contact.
    2. Between Top contact and Bottom contact.
  5. Check in Apply folder or single area grid or outline for licenses or sub areas.
  6. Browse in 01_Cultural Licenses > License 07-18.
  7. Go to page Parameters.
  8. Check in boxes for petrophysical parameters and browse in the corresponding folders.
  9. Check in Expansion oil and set the value to 1.2.
  10. Check in Recovery factor oil and set the value to 0.4.
  11. Click Execute to start calculation.
  12. Go to Result page.
  13. Click on Volume report.
    • Goes default to your home area on disk and is placed in folder. The names are made of parameters set and a time stamp.
    • The folder has a typical name: Volumetric reports_Grids Interpretation_Wed Nov 16 2011.
    • The report has a typical name: VR_Grids Interpretation_2700_3800_Licens 07-18_b_p_n_w_Wed Nov 16 08_55_46 2011.
  14. Take the volume report into a editor and read it.
Volumetric report
Project: Course B1
Volumetric report for horizons in folder: Grids Interpretation.
Calculated and saved at: Wed Nov 16 08_55_46 2011

Parameters present and used:
Type of volume to be calculated: Between plane1 and plane2
First horizon used: 02BasePliocene
Last horizon used: 07Silurian

Contact plane 1: 2700
Contact plane 2: 3800

License or sub area: License 07-18

Porosity folder: Porosity
Net to Gross folder: Net to Gross
Water saturation folder: Water Saturation

Expansion value oil: 1.2
Recovery factor oil: 0.4

Units used in report table: Cubic km (10^9)

 Zone                 Bulk           Pore           HCPV           InPlace        Recoverable    
 02BasePliocene       57.859400      33.751980      10.205310      12.246370      4.898550       
 03UpperCretaceous    446.479170     174.687160     41.260900      49.513080      19.805230      
 04LowerCretacUCo     794.343640     384.093490     79.636180      95.563410      38.225360      
 05BaseJurassic       4603.565830    1667.313830    563.336510     676.003810     270.401530     
 06BaseTriassic       1299.398520    542.952390     85.428700      102.514440     41.005780      
 Total                7201.646570    2802.798850    779.867600     935.841120     374.336450

As one can see the names are generated by a simple system created by parameters used and a time stamp. For the folder name, the time stamp follows the day, while for the report itself, the time stamp is the actual day time down to seconds so the name will be unique. The b_p_n_w stands for _bulk porosity nettogross watersaturation to show that these parameters were present in the calculation.

Display features

Exercise

Display recoverable hydrocarbon volume within a license.

  1. Click on Display to display volumetric results.
  2. Select zone 4.
  3. Set option to As single volume.
  4. Click Display volume or contact area.
  5. Study the display and explain the map.
Exercise

Display hydrocarbon volume and cross sections.

  1. Click on Display to display volumetric results.
  2. Select zone 3.
  3. Set option to On bottom of horizon.
  4. Click Display volume or contact area.
  5. Make a cursor position with the y key.
  6. Click Get cursor values.
  7. Click X direction.
  8. Click Perform cross section from position values.
  9. Study the display and explain the map.


Base Jurassic recoverable volume as single volume grid


Base Jurassic draped on Base Triassic and cross sections

Exercise

Display hydrocarbon volume and fence diagram.

  1. Click on Display to display volumetric results.
  2. Select zone 4.
  3. Set option to On top of horizon.
  4. Click Display volume or contact area.
  5. Click Fence diagram cross sections.
  6. Study the display to and explain the map.
Exercise

Display recoverable hydrocarbon volume within a license.

  1. Click on Display to display volumetric results.
  2. Select zone 4.
  3. Set option to On top of horizon.
  4. Check in Display contact area (on zone top only).
  5. Click Display volume or contact area.
  6. Check off Erase screen.
  7. Select zone 5.
  8. Click Display volume or contact area.
  9. Go to the Volume page and display the contact planes.
  10. Study the display to and explain the map.


Volume draped on Base Jurassic and fence diagram


Base Triassic and Silurian and contact planes

Advanced display of volumetric results

Here is a viewport presentation of all volume grids draped on the top horizon for the zones. Try to reproduce it by following the steps.

Exercise

Display the volume grids for all zones in the layer model.

  1. Click on the viewport icon on the toolbar and open the viewport menu.
  2. Check in Connect all viewports.
  3. Create 2 x 3 viewports. You now have 6 connected viewports.
  4. Click on viewport at upper left to get that viewport frame in red.
  5. Set all parameters correct in the volume menu and Execute it.
  6. Go to the Display page.
  7. Select zone 1. Select On top of horizon. (All selections will do, and one must be consequent).
  8. Click Display volume or contact area.
  9. Go to the shell and type the text: tx2 .7 lle col bla txt "Base Pliocene". (2D text at lower left; see the ref. manual).
  10. Click on the next viewport.
  11. Select zone 2 and repeat the previous steps for zone 2.
  12. Repeat the steps for zone 3, 4 and 5.
  13. Put the viewports in 2D mode to see it from above.
  14. To display the lower right viewport (it is number 2) in 3D mode do as follows:
  15. Go to the command shell and type: vie 2 con off.
  16. Check in Display contact area (on zone top horizon only).
  17. Select zone 5.
  18. Click Display volume or contact area.
  19. Make a proper size of the screen and apply generic folder >New > Screenshot to save the picture.

Viewport display of volume maps draped on the top horizon for each zone.

Volume display for all zones in the training project Course B1

The procedure for making the viewport display is described as many interactive steps. It is however possible to set up a workflow to do it all in one action.

The documentation for volumetric calculation is located at Volumetric Calculations. Near the end of the chapter is a larger version of the viewport display.