petrel static modeling

PETREL

STATIC MODELING

PETREL MANUAL FOR FIELD DEVELOPMENT PROJECT

Petrel Manual for Field Development Project

P a g e | 2

Contents

1. MAKE SURFACE FROM BITMAP/IMAGE ............................................................................................... 3

2. MAKE SIMPLE GRID ............................................................................................................................ 22

3. IMPORT EXPLORATION WELLS ........................................................................................................... 24

4. IMPORT WELL LOGS ........................................................................................................................... 26

5. IMPORT WELL TOPS ........................................................................................................................... 29

6. MAKE ZONES: CREATE ISOCHORES ..................................................................................................... 31

7. MAKE ZONES ...................................................................................................................................... 36

8. MAKE LAYERING ................................................................................................................................ 39

9. PROPERTY MODELING ........................................................................................................................ 40

9.1 SCALE-UP WELL LOGS ............................................................................................................................... 40

9.2 PETROPHYSICAL MODELING ....................................................................................................................... 43

9.2.1 Deterministic modeling ............................................................................................................... 43

9.2.2 Stochastic modeling .................................................................................................................... 44

9.3 SCALE UP PROPERTIES .............................................................................................................................. 46

9.3.1 Scale up Properties process ......................................................................................................... 46

9.4 GEOMETRICAL MODELING ......................................................................................................................... 47

9.4.1 Create a bulk volume property.................................................................................................... 47

9.4.2 Create a cell angle property ........................................................................................................ 48

9.4.3 SW calculations: Create Above Contact Property ....................................................................... 49

9.4.4 Property Calculator ..................................................................................................................... 50

10. MAKE CONTACTS ............................................................................................................................. 54

10.1 MAKE CONTACTS GOC AND OWC ........................................................................................................ 54

10.2 VISUALIZE CONTACTS AS PROPERTIES IN 3D ................................................................................................ 55

11. VOLUME CALCULATION (PRACTICE MANUAL) .................................................................................. 56

12. UNCERTAINTY AND OPTIMIZATION.................................................................................................. 64

13. MAKE FLUID MODEL ......................................................................................................................... 66

13.1 IMPORT FLUID MODEL INTO PETREL ........................................................................................................... 66

14. MAKE ROCK PHYSICS FUNCTIONS .................................................................................................... 67

14.1 MAKE A SATURATION FUNCTION ............................................................................................................... 67

14.2 MAKE A ROCK COMPACTION FUNCTION ..................................................................................................... 68

15. INITIALIZATION ................................................................................................................................ 70

15.1 MAKE SATNUM REGIONS FOR PERMEABILITY ............................................................................................ 72


P a g e | 3

1. Make surface from Bitmap/image

1 - Import bitmap file

1. Right click on the Input pane > Import (on tree..)

2. Browse the image file

3. Change File of type to Bitmap image

4. The image item appear in Input pane


P a g e | 4

2 Setting the bitmap image

1. Right click the image item on input pane > Setting

2. In the Setting window > Setting tab

3. Select Continue spatially unaware when prompted


P a g e | 5

3 Set the coordinate

1. Choose on Located in world

2. Select the origin

3. Select Independent edges

4. Give a coordinate for x, y and z


P a g e | 6

4 View image in 3D window


P a g e | 7

5 Make surface

1. From the utilities pane, select Make/edit surface

2. Make surface window, drop bitmap image to main input

3. Name the surface

4. Geometry tab click on Get limits from selected

5. Select the grid increment

3

5

4

2


P a g e | 8

6 Select method

1. Algorithm tab > select Method

2. For simplicity, select Surface resampling

3. Click Apply & OK

4. You can see the surface created in the Input pane


P a g e | 9

7 Adjust colour scale

1. Created surface can be viewed on 3D window

2. Click on Adjust colour icon to better view the surface


P a g e | 10

8 - Exaggerate surface in Z-direction

This process is to specify the surface elevation depth as given in data provided.

1. Right click the surface in Input pane > Setting

2. Operation tab > Arithmetic operations > Z=Z*Constant

3. Give a constant value

4. Run

5. Click OK for changing the contour line spacing

1

2 2

3

4

5


P a g e | 11

9 View created surface

1. Surface can be viewed using 3D window

2. Repeat step 7 to adjust the colour scale


P a g e | 12

10 Smoothen the surface

1. Right click the surface in Input pane > Setting

2. Operation tab > Surface operations > Smooth

3. Run

4. Further adjustment can be done by changing Iterations and Filter width input

value

2

3

4


P a g e | 13

11 Before and after

Top Before

Bottom - After


P a g e | 14

12 Adjust Z elevation for surface

Surfaces Z elevation can be adjusted

1. On the Operations tab > Arithmetic operations > Z=Z+constant

2. Give the new elevation. ve value indicate below from the reference position

3. You may check the output operations in Statistics tab.

1

2


P a g e | 15

Make more surfaces

1. This method can be repeated to create several surfaces.

2. Make another 3 surfaces of Base Cretaceous, Top Tarbert and Top Etive.

3. These surfaces are different from the previous Seabed. They will be used to

make a simple grid.

Base Cretaceous

1. Import the bitmap file of Base Cretaceous

2. Follow the same procedure of the previous steps on how to create a surface.


P a g e | 16

3. Insert the coordinates.

4. When you view the image of the Base Cretaceous in a 3D Window, you will see

the surface of Base Cretaceous is bounded by outer white surface area. This

white surface area is captured along together from the bitmap, thus we need to

eliminate it out.

5. To accomplish this, a polygon needs to be made first.

6. Follow the next steps to make a polygon.


P a g e | 17

Make polygon

1. Open a 2D Window and view the image.

2. Expand the Utilities under the Processes pane and click on Make/edit polygons

once.

3. Click Add new points at the toolbar.

4. Make the polygon around the surface. Once you done until the end, click Close

selected polygon(s) to close the polygon.


P a g e | 18

Make surface Base Cretaceous

1. Open the Make/edit surface in Utilities pane.

2. Drop the surface into Input data.

3. Drop the Polygons from the Input pane into the Boundary.

4. Name the surface to Base Cretaceous.

5. Click Get limits from selected.

6. Select the grid increment of 40 in both X and Y.

7. In Algorithm tab, select Surface resampling

8. Click Apply and OK.


P a g e | 19

9. View the Base Cretaceous surface in a 3D Window. The outer part surface area

has now already been eliminated.

10. Adjust the colour scale.


P a g e | 20

Exaggerate Z direction

1. Open the settings of Base Cretaceous and view the Statistics tab.

2. The elevation depth of the surface is as stated above. The real delta of the

surface is to be 333.

3. Open Operation tab > Arithmetic operations > Z=Z*Constant

4. Enter the Constant value to match the real delta.

5. Click Run.

Smoothen the surface

1. Smoothen the surface. Operation tab > Surface operations > Smooth.

2. Specify the number of iteration to use.

3. Click Run and view the surface changes.


P a g e | 21

Adjust Z elevation

1. View the Statistics again.

2. Compare the current minimum elevation and the correct minimum elevation of

Base Cretaceous.

3. On the Operations tab > Arithmetic operations > Z=Z+Constant

4. Give the new elevation. ve value indicate below from the reference position.

5. Check the statistics again and check to make sure the Base Cretaceous is at the

correct elevation.

6. Make the surfaces for Top Tarbert, Top Ness and Top Etive using the same

previous steps.


P a g e | 22

2. Make simple grid

1. Open the Make simple grid process located under Utilities in the Processes

pane.

2. Select a name for the new grid, for example 3D Grid.

3. On the input data tab, select the Insert surface option.

4. Drop in the surfaces Base Cretaceous, Top Tarbert, Top Ness and Top Etive from

the Surfaces folder on the Input pane by clicking the Append item in the table

button .


P a g e | 23

5. Select the Geometry tab, and click the Get limits from selected button.

6. Select a Grid increment of 40 m in both the X and Y direction. Click OK.

7. Your grid is now stored in the Models pane. Select to view the skeleton grid in a

3D window.


P a g e | 24

3. Import Exploration Wells

1. Create a well folder. (Insert > New well folder)

2. A new wells folder is created at the Input pane. Right click on the wells folder

and select Import (on selection..)

3. Open the Well Dev folder (Wells>Well Dev). Change the files of type to Well

path/deviation (ASCII) (*.*)

4. Select A10 file. The File must be in type of DEV file. Click Open.


P a g e | 25

1 2 3 5 4

5. A match filename and well will pop out. In well trace, select Create new well.

Click OK.

6. In the Import multiple well paths dialog box that opens, select X, Y, TVD as

Column input data.

7. Look at the file capture at the bottom of the import dialog and type in the

correct column number for X, Y, and TVD. Click OK.


P a g e | 26

4. Import Well Logs

1. Again, Right click on the wells folder and select Import (on selection..)

2. Open the Well Logs folder (Wells>Well Logs). Change the files of type to Well

logs (LAS) (*.las)

3. Select A10 file. The type of file must be a LAS File. Click OPEN.

4. In Match files and wells, match wells by using Well name and well name based

on LAS header.

5. Click OK.

6. In Import well logs, select Automatic matching and click OK.

7. Expand the A10 well in Input pane, and expand the well logs. Try to display the

imported logs.


P a g e | 27

Import Other Wells

Import more exploration wells by repeating the same steps previously.

All the exploration wells are with name of:

A10

A15

A16

B8

B9

C2

C3

C4

C5

C6

#TIPS: You can select multiple of well files to import at once. Define the settings and

click OK for all.


P a g e | 28

Change the Facies and Fluvial Facies template

1. Go to the Templates pane.

2. Expand Discrete property templates.

3. Double click on Facies to open the settings.

4. Go to the Colors tab and give each facies codes a name and a color according to

the figure below.


6. Now double click on the fluvial facies. Open the color tab and fill in the codes

again according to the figure below.


P a g e | 29

5. Import well tops

1. Create a well tops folder. (Insert > New well tops)

2. A new well tops folder is created at the Input pane. Right click on the wells

folder and select Import (on selection..)

3. Open the Well tops folder. Change the files of type to Petrel well tops (ASCII)

(*.*).


P a g e | 30

4. Select Well tops file. Click Open.

5. In the Import petrel well tops, click OK for all.

6. Click OK for all for the Coordinate reference system selection.


P a g e | 31

6. Make Zones: Create Isochores

1. Go to the Well Tops folder in the Input pane and highlight the Top Tarbert well

top in the Stratigraphy folder. The well top becomes bold. Now right-click

directly on the Base Cretaceous well top and select Convert to Isochore Points.

2. Click NO on the Petrel message log.

3. A new point data set is generated at the bottom of the Input pane and named

Base Cretaceous Top Tarbert.

4. Expand this new point set; and expand a folder called Attributes. Look at the

attributes that are generated.


P a g e | 32

5. Display the point set in a 3D window. You may want to adjust the size of the

points so you can see them better. Show the axis in the 3D window using the

Show/Hide Axis icon in the Tool bar.

Notice in the Input pane, under the Attributes folder for the point set, Z

attribute is purple. This means that the Z values (or depth values) are being

used to position the points in the 3D window. To position the points in the 3D

window using the Thickness values instead, toggle on the thickness attribute

then right-click on it and select Use as visual vertical position. You will see the

points shift to the correct position above zero since all thicknesses should be

positive.


P a g e | 33

6. Double-click on the Z and the Thickness attributes and view the Statistics tabs for

both.

7. It is a good quality check step to see the Elevation and Thickness deltas. If the

thickness values are all negative, right-click on the Thickness attribute and select

Convert to Points. A new point data set is created called Base Cretaceous Top

Tarbert (Thickness). Go to the Calculations tab in the settings for this point data

and press the Assign: Z=-Z (not necessary here as it should be positive thickness

already).

8. Now make a surface (thickness map) of the point data; Double-click on the

Make/Edit Surface process.


P a g e | 34

9. Highlight the isochore points and drop them into the Main Input field using the

blue arrow. Change the attribute; select the Thickness attribute instead of the Z

attribute, using the drop-down menu from the Attribute field. Select the Name

field and type in Isochore BC-TT.

10. Press the Suggest settings from input button and select the Isochore

points/residuals option. Petrel will suggest the Convergent Interpolation

method in the Algorithm tab.


P a g e | 35

11. Go to the Geometry tab and select Automatic (from input data/boundary). Select

the checkbox in Boundary and select zero cell extension.

12. Click OK. A new surface with a thickness template is generated in the Input pane.

Display this surface in the 3D window together with the original isochore points.

If these are not easily visible, go to Style settings of the isochore points and

increase the Symbol size to 100.


P a g e | 36

7. Make Zones

This is the process of inserting geological zones in the stratigraphic intervals above, in-

between and below the horizons that were created in your 3D Grid model. The zones

are typically created based on isochore grids, constant values or built proportionally

from existing horizons. Well tops can be used for well adjustment of the horizons that

will be created.

1. Make sure your 3D Grid is active.

2. Double-click on the Make Zones process step in the Processes pane > Corner

point gridding. A dialog window will pop up.

3. Select the Stratigraphic interval to be worked first. This interval will be

completed (parameters specified) and the Apply button must be pressed before

moving to the next interval.

4. For Top Tarbert Top Ness interval there are three isochores (therefore 3

zones). For the Top Ness Top Etive interval there are two isochores (2 zones).

There will be no zonation for the other stratigraphic intervals listed.

5. For each stratigraphic interval:

a. Use either the Append item in the table icon or the Set number of

items in table icon selected near the top of the dialog to insert

rows, representing zones and their corresponding horizons, into the

table. Create as many zones as you have isochores to insert.

b. Note that for the Set number of items; a separate pop-up dialog appears,

making it easier for you to specify number of zones, type of zone, etc.


P a g e | 37

c. In the Input pane, select the Isochores from the Isochores folder and the

subfolder that corresponds with the stratigraphic interval that you

working on.

d. Insert the isochores by clicking on the blue arrow next to the input field

called Input.

e. Insert well tops between the isochores by going to Well

Tops>Stratigraphy. Select the Well Tops that correspond the

Stratigraphic interval you are working on.

f. The horizon name defaults to Horizon unless well tops are used, and

then it will adopt that name. The isochore name defaults to Zone

unless a 2D Isochore Grid is selected and then it adopts that name. The

names can be edited at any time.

g. Select Build from base

horizon and distribute the

volume correction as

proportional correction

among the various sub

intervals.

h. Select to build along True

Vertical Thickness (TVT).


P a g e | 38

g. In the Well Adjustment tab, set well adjustment Inside segment only (see

figure below).

h. Press Apply to generate the intermediate horizons and zone

6. Repeat the procedure for the next Stratigraphic interval (Top Ness Top Etive).

Press Apply and see the updates in the 3D Window.


P a g e | 39

8. Make Layering

1. Open the Layering process.

2. Select to build along the pillars.

3. Select to use minimum cell of 3.

4. Under the zone division, select numbers of layers to 10 for all the zones.



P a g e | 40

9. Property modeling

9.1 Scale-up well logs

The Scale up well logs process averages the values to the cells in the 3D grid that are

penetrated by the wells and gives the cell one single value per upscaled log. These cells

are later used as a starting point for Property modeling.

1. Activate the 3D grid in Models pane.

2. Double-click the Scale up well logs

icon in the Processes pane to open

the process dialog.

3. In the Scale up well logs tab, select

the Create new property option.

4. Select the wells to be included in the

process (use all wells for this model),

and select input from: Well Logs.

5. Select the Fluvial facies log to be

upscaled from the drop-down menu.

6. Define the Scale Up settings. Use the

defaults (Most of, As lines and

Neighbor cells), and press Apply. The

new property is stored is stored in the

Properties folder of the active 3D grid.

Display it in a 3D window.


P a g e | 41

7. Reselect Create new property and choose Porosity as the log to be

upscaled.

8. Define the Scale Up Settings. Use the defaults (Arithmetic as average

Method, treat the log As lines and use Neighbor cell as Method). You can

click on Use Bias and select the Fluvial facies [U] property.

9. Press Apply to create the upscaled property. Now press the Show result

in Well Section button in the upper right-hand corner, which turned

active after you generated the Porosity model.

10. A Well Section window will open and automatically display the original log

and the upscaled log. This is a great way to quality check the upscaling

process parameters and settings. If you want to make changes and recreate

the upscaled logs, set up two tracks; one for the raw log and one for the

upscaled log. In this way its easier to edit the result.


P a g e | 42

11. Use the Create/edit curve fill tool from the function bar to fill the original

porosity log. Click on the Well Tops for visualization in the Well section.

Statistical check of the scaled up well logs

1. Open the Settings dialog for one of the upscaled logs in the Properties folder by

double-clicking on the selected property. Select the Statistics tab.

2. Observe the various statistical parameters. Note that statistics are given both for

the raw log and the scaled up cells of the property.

3. Select the Histogram tab to view the histogram of the raw log and the scaled up

well log. This is done by clicking the Raw log and Upscale log buttons.


P a g e | 43

9.2 Petrophysical modeling

9.2.1 Deterministic modeling

When the well logs have been scaled up to the resolution of the cells in the 3D grid, the

values for each cell along the well trajectory can be interpolated between the wells in

the 3D grid. The result is a grid with property values for each cell.

There are several deterministic methods available in Petrel: examples are Kriging and

Moving Average. The deterministic methods will produce smooth results. The Kriging

method can include information about the variogram, hence producing an anisotropic

model that has captured the geostatical dependencies between points in the 3D model.

The deterministic approaches will not however, produce local variation; if you run 100

realizations the outputs will be identical for each run.

1. In your working project, activate the 3D grid model in Models pane.

2. Open the Petrophysical Modeling process.

3. Make a copy of your upscaled Porosity (U) and rename it Porosity_model.

4. Select Use Existing Property and select the Porosity_model as the property

to be modeled from the drop down menu.

5. Click Zones and select Same settings for all zones. Click on the Leave Zone

Unchanged icon to create a realization.

6. Select the Moving average as the Method; leave all other setting as default.

7. Click OK to create the property model and display the model in the 3D

Window.

8. Double click on the Porosity property in the Properties folder and check the

statistics in the Statistics tab.


P a g e | 44

9.2.2 Stochastic modeling

1. Creating first model:

a. Activate 3D grid model.

b. Open the Petrophysical Modeling process. Go to Existing Property and select

Porosity_model from the drop-down list.

c. Select Sequential Gaussian Simulation as the method for all zones.

d. In the Variogram tab, select Exponential Variogram type, 3500 as Major

Range, 1500 as Minor Range, 10 as Vertical Range and 25 degrees as

Azimuth.

e. Click OK to create the property model.

f. View the porosity model in 3D window.


P a g e | 45

2. Viewing the result:

a. Bring up a Histogram window from the Windows menu and select Tile

Vertical.

b. Use the Zone Filter to display the 3D property model and the Histogram

distribution for the well logs , the up-scaled cells and the whole

property for zone Top Ness Ness 1.

3. Changing the model:

a. Click on the 3D window to make it active and click on the Open Dialog for

Active Process icon in the Function bar.

b. Go to the Distribution tab in the Petrophysical Modeling process window. In

Output data range click on Estimate (this will estimate the porosity range

from the up-scaled cells within the zone).

c. Click Apply and observe the changes in the model. Lock the Top Ness Ness

1 zone.


P a g e | 46

9.3 Scale up Properties

9.3.1 Scale up Properties process

1. In the models pane, you should now have a new 3D Model of the Gulfaks field

(Upscaled_3D Grid). This new grid has a different number of grid cells if compared to the

fine 3D grid model (initial model).

2. The next step is to make the scale up properties. First click once on the Upscaeld_3D

Grid model to make it activated. Open the Scale up properties process in Upscaling.

3. Now you have to drop in the properties of the fine grid (the initial 3D Grid model) into

the inputs. Expand the properties folder in the fine grid and select Porosity_model and

Permeability_model. Drop the both properties into the inputs by clicking on the blue

arrow.

4. Now click on the Permeability model. Select Directional averaging in Algorithm.

5. Click Apply to run the scale up properties.

6. View the porosity and permeability properties in 3D Window. Compare the result with

the fine grid model. You may find the permeability of the upscaled up grid has been

created in the directions of I, J and K.

REPEAT STEP: Make a new simple grid of Gulfaks, name it with Upscaled_3D Grid

and set the grid increment of 100 in X and Y direction. Run the same procedures

of Make zones and Layering. Then follow the next steps to run the scale-up

properties.


P a g e | 47

9.4 Geometrical modeling

9.4.1 Create a bulk volume property

1. Activate the 3D Grid model.

2. Double-click on the Geometrical modeling under the Property modeling

process.

3. Select Create new property.

4. Select Cell Volume as Method.

5. Use Bulk Volume as Property Template and click Apply to generate it.

6. The Bulk Volume property is now stored in the properties folder within the

active 3D grid. View the Bulk Volume property in a 3D window. Also, check the

Statistics for the Bulk Volume property by opening the Settings dialog and go to

the Statistics tab.


P a g e | 48

9.4.2 Create a cell angle property

1. In Geometrical modeling, select Create new Property. From the drop-down

menu, choose the Cell angle method. Accept the default property template. The

cell angle property gives the deviation, from 90 degrees, of the angles in each

cell.

2. Display the Cell angle property in a 3D window.

3. Create a value filter. Right-click the Cell angle property and select Create 1D

filter.

4. Under the definition tab, specify the angles that should be filtered. Use a

minimum value of 20. Remember that values above 20 can be bad for simulation.


P a g e | 49

5. The filter is created once you click OK. It is stored in the Filters folder in the Input

pane. Turn the filter on and off and visualize the results.

9.4.3 SW calculations: Create Above Contact Property

1. In the Geometrical Modeling dialog, reselect Create new property.

2. Select Above Contact as Method. Set the Contact Level to a constant value

(O/W contact) with a negative sign.

3. Select the method to be By center of the part of the cell above contact.

4. Click OK to generate the Above Contact property.

5. In the Models pane, expand the Properties folder and display the properties Bulk

volume and Above Contact. Click the Show/Hide Auto Legend in the Tool

bar.


P a g e | 50

9.4.4 Property Calculator

1. Creating a new property:

a. Right-click on the Properties folder in the Gulfaks (3D model) and select

Calculator from the pull-down menu.

b. Change the Properties template to Net/Gross and type into the white

formula field NG=0.8 (creates a constant Net to Gross property).

c. Make sure the Use filter option is not toggled on to ensure calculation on the

entire grid.

d. Press ENTER.


P a g e | 51

e. Type in NetVol= and then select the Bulk volume property from within the

calculator and multiply it by the NG property selected from within the

calculator.

f. Display the new NetVol property in a 3D Window.


P a g e | 52

2. Calculating values:

a. The Calculator may be used as a normal calculator or for returns of single

values using properties and/or logs.

b. First create a new Pore Volume property, using the NetVol multiplied by

Porosity_model(1). Click Enter and click no on the pop up message to not

employ the calculator to all realizations of the porosity in your properties

folder.


P a g e | 53

c. The new PoreVolume property is stored in the properties folder and in the

field in the Calculator.

d. Now do a simple operation using the Functions feature in the calculator to

calculate the Sum of all the data for the PoreVolume property.

e. Select the PoreVolume property from within the calculator to put it into the

equation area. Remove an equal sign that appears after the property name.

Click the Functions button in the calculator. Choose .Sum from the

Functions pop up selector.

f. By pressing ENTER Petrel will output the pore volume in the Calculator field.

g. The value given is in the project units set for the Petrel project. If you are

uncertain; go to Project Settings in Menu bar Unit and coordinates tab.


P a g e | 54

10. Make contacts

After having built the 3D grid and prior to running the volume calculation, the various

contacts should be defined in the Make Contacts process.

Several sets of contacts can be defined and each Contact Set can contain a number of

different contact types. All Contact Sets will be stored in a folder named Fluid Contacts

in the Models pane.

The Contact Set can be created based on a constant depth value or a surface. If a

surface is used as an input for the contact, it has to exist in the Input pane. Any type of

surface can be used as an input.

10.1 Make Contacts GOC and OWC

1. Double click on the Make Contacts process in the Processes pane > Corner

point gridding.

2. Create a Gas Oil Contact by selecting it in the Make Contacts dialog box so that it

is highlighted in blue. In the field below the column All Segments, type the GOC

depth.

3. Create an Oil Water Contact by selecting it in the Make Contacts dialog box so

that it is highlighted in blue. In the field below the column All Segments, type the

OWC depth.

4. Click OK and the Fluid Contacts folder with the new set of contacts will appear in

the Models pane below the segment filter.


P a g e | 55

10.2 Visualize contacts as properties in 3D

This operation allows you to create a property where the cells are given a facies code

according to their position related to the hydrocarbon contacts.

1. Right-click on one Contact Set and select Settings.

2. In the settings window, view the Operation tab.

3. Select Gas Zone as the Code above the highest contact.

4. In the column Facies value below contact, specify: Oil Zone below the Gas Oil

Contact, and Water Zone below the Oil Water Contact.


P a g e | 56

11. Volume calculation (Practice manual)

The Volume calculation process accurately calculates the volumes in a 3D grid (bulk,

pore and fluid). These figures will often be used as a first indication of the economic

viability of the field, and together with an uncertainty analysis, can determine where

efforts in reservoir evaluation should be concentrated.

1. Open the Utilities > Volume calculation process. Select Create new, define the

name for the new case (for example, Case_1)

2. Select the 3D Grid.

3. In the Properties > Fluid zones tab, select both Oil and Gas hydrocarbon interval

4. Insert the Oil water contact and Gas oil contact by selecting it from 3D Grid.


P a g e | 57

5. In the General Properties tab, you can specify the Net/Gross. Put a constant of

0.8 for example. For the porosity, deselect the constant property. This may

enable you to select the Porosity property from the drop-down.

6. Now in the Oil properties tab, this is where you can define the value of fluid

saturations. For practice, keep the Constant property option selected and use a

constant 0.3 for Sw. Use a constant Formation Volume Factor of Oil (Bo) of 1.21.

7. Same steps apply to the Gas properties tab. Put the Constant property for Sw of

0.3 and So of 0.4. Type in a constant Formation Volume Factor of Gas (Bg) of

0.0009.


P a g e | 58

8. Now go to the Settings tab (at the same level as the Properties tab). Turn on the

properties as shown in the figure below. All the properties you select here will be

created and stored in the Properties folder of your 3D grid in the Models pane.

9. Go to the Facies tab and select the Fluvial facies object property created

earlier. This option makes it possible to locate in which facies type the

properties you create are located (make sure to output in the Report).


P a g e | 59

10. If you want to output a report at the same time as you run the case, then

press the Report Settings in the Results/Output tab. This will open a new

dialog window for setting up a report. Set it up as below, then click OK (do

not click Make Report).


P a g e | 60

11. Make sure the Make spreadsheet report is selected in the Output tab, and

then click Apply on the main dialog. Apply only save the settings but still not

run the Volumetrics. See both the Results pane and the Cases pane:

12. Now press the Run button . A report will be created and properties

will be stored in the Models pane. Inspect both.

Now repeat the volume calculation steps using your

own model inputs (Properties, Constant, Contacts)


P a g e | 61

Create a STOIIP Map

A hydrocarbon column height map is the sum of all values in the same X, Y position. For

instance, a STOIIP map will show the sum of STOIIP for every X, Y position in the entire

grid. Therefore, it will show you where to expect the highest concentration of oil.

1. Close the report window.

2. Open the Volume Calculation process again. Use the same settings as defined

previously, but click on STOIIP in the Make volume height map section in Output

tab.

3. You can select the option Overwrite existing properties (in the lower left part of

the window) to not create all the same properties over again.

4. Leave the map post-processing section default, the Apply and Run.


P a g e | 62

5. After running the process, the map will be placed in a folder in the bottom of the

Input pane.

6. Display the map in a 3D window. You will probably have to click on the View All

icon and the view from Above icon to be able to see it. Then click on

the map name in the Input pane and refresh the color scale using the Adjust

Color Table on Selected icon.

Draping the STOIIP map on a depth surface

1. Open the settings for the Top Tarbert horizon, found in the Horizons folder in 3D

Grid model. Open the operations tab and press the Make surface button. The

generated software will be stored in the Input pane.

2. Right click on the STOIIP (Case) map in the Volume Maps folder and select Copy

as surface attribute.

3. Right click on the Top Tarbert surface in the Input pane and select Paste as

surface attribute.


P a g e | 63

4. Display the Top Tarbet depth surface with the STOIIP map draped over it.

5. Toggle on the Top Tarbert surface with the STOIIP attribute.

6. Go to the Templates pane and under the Volume templates folder, toggle on the

STOIIP attribute.


P a g e | 64

12. Uncertainty and Optimization

Contacts uncertainty

1. Open the Uncertainty and optimization under the Utilities process. Select

Create new case and enter a name, (Ex: Contacts_uncertainty). Select the

Uncertainty task.

2. In the Base case tab, insert the case by selecting the volume calculation case

from the Cases pane by clicking the blue arrow button. Read the Petrel warning

and click Yes. In the process dialog, all processes involved in the 3D grid building

and volume calculation will appear.

3. In the Uncertainty and optimization process > Base case tab, double-click on the

Make contact processes for the Contact set properties. Change the value of Gas

oil contact to $GOC and Oil water contact to $OWC.


P a g e | 65

4. After the uncertain variables are defined, they will appear in the workflow

window along with the process where it has been declared, as shown in the

figure below.

5. Open the Variables tab. Remain the type of both contacts with Uncertain. Your

model GOC and OWC are automatically shown in the base value. For exercise,

lets try to use normal distribution for $GOC and uniform distribution for $OWC.

For normal distribution arguments, stick the mean value to be same as

the base value, and put the standard deviation as 5.

For uniform distribution arguments, put the minimum and maximum

value with 5 difference of the base value.

6. In the Uncertainty tab, define the No. of samples as 20, and select the Monte-

Carlo sampler. Click in the Apply and Test. If the status shows Test OK, click the

Run buttons.

7. Go to the Cases pane, a new folder is generated called Contacts_uncertainty. In

this folder, there are 20 contacts uncertainty cases from the uncertainty analysis.

8. Right-click on the Uncertainty folder and select the option Show variables

spreadsheet. In this new window, you can see the variable values and results for

each case. Click the Show volumetrics button and select STOIIP; it will be added

to the table.

9. Click the STOIIP column in the spreadsheet to highlight it (gray) then click the

%Percent ranks button to rank the cases.

The case closest to P50 is highlighted in green. The smallest value does not correspond

to 50% because the computation assumes a distribution, not just discrete set.


P a g e | 66

13. Make fluid model

ECLIPSE PVTi helps you generate PVT data from the laboratory analysis of oil and gas

samples. The output can be used as input data for Petrel. Use the PVTi tutorial for

guidance.

All the information needed can be referred in Reservoir Fluid Study Report (DST #1).

13.1 Import fluid model into Petrel

1. Right click on the input pane and select Import (on tree..).

2. In the Import File, change the Files of type to ECLIPSE fluid model (Keywords)

(*.*).

3. Select the fluid model saved file. (.pvo format)

4. Click Open. A new Fluid model is now imported into the input pane.

5. Open new function window and view the fluid study data.

13.1.1 Create initial condition

1. Open Make fluid model process in the input pane.

2. The imported Eclipse fluid model is in Edit existing. In General tab, select all the

phases of gas, oil and water. Define the reference pressure.

3. Next go into the Water tab. Fill in all the water properties. (can be taken from

exported water properties from PVTi)

4. Open the Initial conditions tab. Select to Use contact set. Drop in the Contact set

from the 3D grid model and select Fill table from contact. Click OK.


P a g e | 67

14. Make rock physics functions

The Exercise Workflow:

Make a saturation function

Make a rock compaction function

14.1 Make a saturation function

1. Insert new rock physics folder. (Insert > New rock physics folder)

2. Right click on the Rock physics folder and select Insert saturation function.

3. A new saturation function is created under the folder. Right click on the

saturation function and select Spreadsheet.

4. Fill up the spreadsheet by using the information contains in the Reservoir SCAL

Report.

5. View the saturation function in the function window.


P a g e | 68

14.2 Make a rock compaction function

1. Open the Make rock physics functions (Processes pane > Simulation > Make

rock physics) dialog and go to the Compaction tab.

2. Select Create new function to create new function.

3. Click Use presets and select a preset from the drop-down menu.

4. Click OK in the Make rock physics functions process dialog box.

5. The new rock compaction function is stored in the Rock physics functions folder

in the Input pane.


P a g e | 69

8. You can also make a rock compaction function based on constant

compressibility.

9. Open the Make rock physics functions dialog again.

10. Open the Compaction tab.

11. Select Create new and give the new function a name.

12. Select the number of table entries.

13. From the Correlation drop-down menu, leave User defined selected.

14. Enter the Compressibility.

15. Click OK.


P a g e | 70

15. Initialization

We will initialize the 3D model with fluid and rock physics functions.

1. In the Processes pane, expand the Simulation folder and open the Define

simulation case process.

2. Select Create new and name the new case Initialization.

3. Make sure the Simulator is set to ECLIPSE 100, and the Grid is set to the grid you

have in the Models pane.

4. In the Grid tab, use the blue arrows under input to drop Permeability and

Porosity properties by following the respective keywords.


P a g e | 71

5. Go to the Functions tab.

6. Select the Drainage relative permeabilities in the left panel by left-clicking it and

select the Region index property. Select SATNUM from the drop-down. (To

create a region, follow steps in 15.1 Make SATNUM Regions for Permeability)

7. Drop in the saturation function from the Input pane (by selecting it) and clicking

the blue arrow in the dialog, accordingly to the region specified.

8. Still in the Functions tab, select the Black oil fluid model from the list in the left

panel.

9. Select to use the initial condition.

10. Drop in the Black oil fluid model initial condition (contact set). For simplicity of

the exercise, we assume that all 7 regions in our model have the same PVT fluid.

11. Select the Rock compaction function from the list in the left panel. Once again,

select to use the Region index property. Drop in the Rock compaction to the

region specified accordingly.

12. The Strategies tab should be left empty as you are only initializing.

13. Click Apply to save the case. The case is saved to the Cases pane.

14. Click Run. ECLIPSE 100 is launched. Wait for the initialization of the case to finish.

15. Once the run is finished, go to the Cases pane, right-click on the simulation case

(ECLIPSE 100) and select Show print file. This will open the print file in your

default text editor.


P a g e | 72

15.1 Make SATNUM regions for Permeability

1. Open the settings of your permeability model and view the histogram tab to

analyze the permeability data.

2. Discuss and divide the permeability into three regions.

3. Now right-click on Properties folder in 3D Grid model and select Calculator.

4. In Attach new to template, choose to use Region.

5. Put in the SATNUM expression according to your permeability region.

6. Expression (example):

7. SATNUM = If ( ( Permeability_model_I > value And Permeability_model_J > value And

Permeability_model_K > value ), region_number , If (( Permeability_model_I > value And

Permeability_model_I value And

Permeability_model_J value And

Permeability_model_K

petrel static modeling

Documents