Attachments Overview Converting pre-Petrel2007.1 seismic projects Merge navigation and SEG-Y data Seismic server Use faults as constraint when autotracking Modify autotrack parameters Edit fault segments Horizon operation example Surface operation example Artificial light Generate surface from attribute maps Generate variograms from attribute maps Complete structural model Create velocity model using a seismic velocity cube Create velocity model using stacking velocities

Converting pre-Petrel 2007.1 seismic projects In Petrel 2007.1, select Open project from the File Menu Select the pre-P2007.1 project and open it Observe any warning and information boxes, as well as the Petrel message log that pops up 1 3 Pre-Petrel2007.1 conversion Due to the fact that the hierarchy of seismic data has changed in the latest version of Petrel, a conversion of pre-Petrel2007.1 projects needs to take place to reorganize seismic data into the seismic main folder. This conversion is automatic upon opening the project in Petrel 2007.1 for the first time. 2

Merge navigation and SEG-Y data From the Tool menu, select Launch SEGY Utility Select the UKOOA Navigation file Not finished 3 1 2

Connect to a seismic server From the View menu, select Panes and Seismic Server explorer In the Seismic Server explorer window, click on Connect and give in the needed parameters Available seismic volumes and interpretations can be copied and pasted locally as links to seismic server data 1 2 3 Projects can mix local and seismic server data. All data that resides on the seismic server is tagged with a small S on top of the icon. Volume attributes generation, autotracking of huge volumes etc. will then run in parallel on the server. Realizing a seismic volume to the local Petrel project makes a physical version that follows the workstation. 2 3

Using faults as constraint when autotracking Settings -> Tracking tab of an interpretation and set ’Stop at visible faults’ as Lateral constraints Interpreted faults are used to stop the autotracking 1 The fault compartment must be completely surrounded by faults (closed compartment). Any gap between faults may result in interpretation leaking through the hole. Where events are dipping, interpretation may leak over the top or under the base of faults. 2 Both interpreted faults and faults from a model (in combination) may be used to limit the 3D autotracking tool.

Modify autotrack parameters The ”best practice” is to use a polygon to limit the autotracking to an area of interest.Open a 2D Window and display seismic and interpretation data in that window Activate the Make/Edit Polygons process found under Utilities Use Add New Points and digitize a closed polygon around the area of interest. Close the polygon with Close Selected Polygon(s) 1 3 2

Modify autotrack parameters - basics Seed value confidence (minimum value tracked as % of seed point) Max vertical delta (maximum vertical position change from one trace to next) Toggle on Wavelet tracking and specify parameters Expansion quality (distance out checked against seed point) Hover cursor over questionmark for information on parameters Boundary polygon (closed polygon that autotracking is not permitted to expand beyond) Seismic volume (3D volume to use if more than one cube) Seeds (Visible -all points in display window / Selected -only selected points in display window / Satisfying filter-filter criteria) Override/Locking (Overrides or locks already tracked points) Track Now! (initiates tracking) 1 2 Things to think about when autotracking: • Limit autotracking, start conservatively and expand. • Use Seeded or Guided autotracking where reflector is continuous. • Add infill manually in poor data areas or areas of structural complexity • Use interpreted faults when available Things to think about regarding seed points: • Start at well-seismic ties. • Carry interpretation to intersecting inlines and crosslines. • Manually interpret around fault tips and transfer zones. • Different seeds in different fault blocks. 3 4 9 6 5 7 8

Edit fault segment Open the Interpretation Window used previously Make a copy of the fault (click on the fault in Input tab, Ctrl+C – Ctrl+V). Make the copy active Activate the Select and Edit/Add Points tool . Click on a point and move it To add points, activate the Interpret Faults tool . Left click to add interpretation The same procedure can be followed in a 3D Window, but is somewhat more cumbersome as the points may be moved out of the seismic plane 1 5 3 4 2

Edit Fault segment Continue using the open 3D Window, make sure the fault is active and shown Select the Cut Segment tool. Click on the line between two points to be cut To join two line segments, activate Set Select/Pick Mode . Hold Ctrl and click on the two line segments to be joined. Observe that all points on the segments turn yellow Click on the Join Points in Segment icon The same procedure can be followed in an Interpretation window 1 3 2 5 4

Surface operations – thickness map Display the two surfaces in a 3D Window Right click on the surface on top of the interval, open Settings -> Operations tab Under Calculations, Make Thickness map. Use the deeper surface as Base Surface. Make both TST and TVT maps and note the differences QC using the 3D window 5 1 4 2 Remember Petrel works in negative values. 3

Artificial light - edit Display a surface in a 3D window. Turn off Contours lines under Style tab on Settings Right click the Light sources icon on Windows pane. Insert new light source. Open Settings for new light source Example light source is Spot light Default light source is Headlight 1 2 3 colour Source settings Applying artificial lighting to an object enhances structural features that are not visible in other ways. The light and shadow effect can be optimized to view separate structural trends by setting the light from different directions. 4 To edit light source using the mouse: Right click light source and click on the view all on the tool bar

Generate surface from attribute maps Right click one attribute of an attribute map Use Convert to separate Surface A new surface is found at the bottom of the Input tab Display it in a 3D window 1 4 New surface Attribute map Original attribute map 1 3 2

Generate Variogram map from attribute maps Right click on the generated attribute of an attribute map Use Convert to Points A new object is found at the bottom of the Input pane. Display it in a 3D window Go to Settings -> Variogram tab. Use Variogram map, choose Type and Execute Display the resulting sample variogram in a Map window 1 2 4 3 converted points A Variogram map displays the separation distance in X-direction and Y-directions, not ordinary XY coordinates. This means that the variance map must be displayed in a map window since the center of the map is 0 (zero) X- and Y separation with increasing separation in X- and Y-directions respectively. 5

Generate Sample variogram from attribute maps Use an Attribute map converted to points (as previous slide) Go to Settings and the Variogram tab. Use Sample variogram, choose Type Under the Orientation Tab select Isotropic (toggled on) or Anisotropic (toggled off). Enter in correct Orientation and XY range, and Execute Display the resulting sample variogram in a Function window 1 2 4 3 The combined variogram information derived from the attribute map can be used in facies or petrophysical modeling. If a relationship exists between the attribute map and distributions of facies or any petrophysical parameter, the sample variogram can be used to establish a modeled variogram that can be used as input.

Complete Structural model – Fault interpretation continuation Activate the Fault Modeling process under Structural Modeling Convert any Interpreted Faults in the Input pane to Modeled Faults Set extra height on the Modeled Faults if needed Observe the faults in the fault model. If there are faults missing, go back to fault interpretation 1 3 2 4 Extra height above given Min Point and below given Max Point increases the height of the resulting Modeled Fault (in %) compared to the Interpreted Fault. A 3D view of the Fault Model against a back-drop of seismic data is a very useful tool to identify not only wrongly interpreted, but also missing faults. A combination of conventional seismic data, attribut maps, dip maps, attribute volumes enhancing discontinuities, isochron maps etc. gives the interpreter a perfect environment to create a consistent and trustworthy model.

Complete Structural model – Fault interpretation continuation Use the Fault Modeling tools to edit and build a consistent Fault model with smooth, connected and quality checked faults You can further use the Pillar Gridding to: Make Horizons/Zones and Layering processes to create a 3D grid based on all the seismic and geological data available 1 2 The completing of the structural model as well as the full 3D Grid is not covered in this course. An introduction to the entire workflow is given in the Introduction course. These topics are also covered in the Complex Structural Modeling course, which adds in more complexity to the process of building a Fault Model.

Additional slides Import velocity data – SEG-Y cube Velocity modeling – converting velocity cubes Velocity model using a seismic velocity cube Import velocity data – Stacking velocities Velocity model using a stacking velocities Velocity model using check shots and stacking velocities

Import velocity data – SEG-Y cube From the Menu bar, go to Insert and New Seismic Survey Folder Under Setting, Info tab, rename the folder to Velocity. Right click and use Import (on Selection) Open the file with File of type: SEG-Y Seismic data.In the Import box change Template to Velocity Display an Inline and Crossline from the velocity cube 2 1 3 No notes. 4

Velocity modeling - converting velocity cubes From the Input pane, expand the velocity cube object and display an inline and crossline. Right click on the velocity volume and open ’Volume attributes’. From Attribute library, select Depth conversion method from the drop down menu. Select Velocity cube (Depth type attribute). Toggle on Set output name and type in Average velocity. Use default parameters and click OK. 1 2 4 3 The next example shows how to use velocity data as a SEG-Y velocity cube in the modeling process. A velocity cube must be of type Average velocity (i.e. each point contains the velocity from MSL to that point). The input volume is converted to have the correct type of data for velocity modeling. 5 6

Velocity modeling using a seismic velocity cube Re-open the Make velocity model process Toggle on Create new velocity model Change correction to Well tops and drop in the corresponding tops from the Input pane Change Velocity model input to Velocity cube for the 5 last entries Drop in the Average velocity volume just created using the drop in arrows 2 3 1 4 5 This example is different from the previous one since well data is not used to make the velocity model, but Well tops are used for correcting the final model.

Import velocity data – Stacking velocities From the Menu bar, go to Insert and New Folder. Click on folder name (’New folder’), press F2, and change name - for example ’Stacking Velocities. With right-mouse-button: Select Import (on Selection). Open correct file. Use File of type Petrel Points with Attributes (ASCII). Match the import parameters with input file. Keep Z-value to feet for now. Click OK. 2 4 1 3

Import velocity data – Stacking velocities Right click on stacking velocity dataset and open Settings for the object Go to the Info tab and change Template to Elevation Time Expand the stacking velocity object and the Attributes sub-folder. Open Settings for Attribute Vstack Change Template to Stacking Velocity Display the point dataset in a 3D window 5 9 7 8 6

Velocity modeling using stacking velocities, Dix conversion In the Input tab, open the Vstack folder, the xytv-data (VL_D.txt) and the Attributes folder Right click on the point data, open Settings and go to Operations tab. Open Seismic Operations and use Dix conversion Drop in the data points with the drop in arrow . Click on Execute Interval velocity, average velocity and other attributes are generated 1 2 2 4 The next example shows how to use Stacking velocity data points to model velocities. 3

Velocity modeling using stacking velocities, upscaling Make sure the correct 3D Grid under the Models tab is active From the Process tab, open the Scale up well logs process Use Create new property Select Point attributes and drop in the point data using drop in arrow and select Average velocity After upscaling the point attributes,the Average velocity [U] property is generated for a 3D Grid 1 3 5 2 4

Velocity modeling with stacking velocities, populate 3D Grid From the Process tab, open the Petrophysical Modeling process Use existing property and select Average velocity [U] Unlock the first zone using the lock icon Select Moving Average (Interpolation) as Method for Zone Under Output data range, change Min/Max to Relative (%). Apply to populate the first zone 2 3 1 4 5

Velocity modeling using stacking velocities, 3D Grid With the first zone unlocked and all parameters set, click Copy settings from the selected zone Click on Paste settings to all zones . Under Output data range, change Min/Max to Relative (%) and Apply View the result in a 3D window 1 2 4 Using Relative (%) for Min/Max sets the output to be relative to the input in %.¨An alternative exists where Absolute is used. The data range needs to be estimated by clicking the Estimate button. All zones must be unlocked and output data range estimated for each. 3

Velocity modeling using stacking velocities From the Process tab, open the Make Velocity Model Use Create new velocity model (do not overwrite the previous generated model) Change Velocity Model input to Property for all intervals Drop in the corresponding Average velocity property using the arrows Make sure Correction is set to Well Tops, alternatively, drop in the corresponding tops from the Input tab 2 1 3 4 5

Velocity modeling using check shots and stacking velocities Right click on the check shot object, select Insert new attribute. Make a continous attribute with attached to the Average velocity. In the check shot spreadsheet, copy and past the calculated average velocity column into the created column Upscal the Average velocity points into a 3D grid 1 3 4 2 4

Velocity modeling using check shots and stacking velocities Open Petrophysical modeling, use the Average velocity (check shots) and open Zone 1. Select Method (Kriging by Gslib) and set variogram parameters. Do colocated Co-kriging with the Average velocity derived from Vstack as secondary variable Use the same setup for all zones to populate the checkshots derived average velocity 5 Use the new Average velocity property as input into the velocity modeling process 8 6 7 9

Seismic data sampled into a 3D grid Activate a 3D Grid in the models pane. Click on an Inline and Crossline for the volume to use Open the Petrophysical modeling process found under Property modeling in the Process pane Use correct Property template. Select zone to model and unlock it Use Assign values as Method for zone/facies. Click on the seismic volume to be sampled once and drop it into the Seismic drop in area using the blue arrow. Select Quality and Average method if necessary. Display the property in a 3D window 1 3 4 2 6 5

Scale up well logs Activate a 3D Grid in the models tab Open the Scale up well logs process found under Property modeling in the Process pane Click on Create new property. Make sure Select input from is Well logs Change to correct log in the Select log drop down menu Leave the parameters to default Display the upscaled property in a 3D window 1 3 4 2 5 6

Seismic attribute as property in Petrophysical modeling Activate a 3D Grid in the models tab Open the Petrophysical modeling process found under Property modeling in the Process pane Use existing property (here select PHIT [U]) Unlock Zone 1, as Method for zone/facies use Sequential Gaussian simulation. Leave the default setting, but toggle on Property as Secondary Variable under the Co-kriging tab. (Here select Frequency) Copy this setup to the rest of the zones. Apply and observe the result in a 3D window 3 1 5 2 4 6

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