RMS Petrophysical Modelling Training Manual PDF

A Training Exercise Introduction to RMS Petrophysical Modelling Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 B Contents 1 INTERPOLATION ...................................................................................... 3 2 STOCHASTIC MODELLING .........

A Training Exercise Introduction to RMS Petrophysical Modelling Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 B Contents 1 INTERPOLATION ...................................................................................... 3 2 STOCHASTIC MODELLING ..................................................................... 5 2.1 Data analysis ................................................................................................... 5 2.2 Stochastic Modelling of porosity & permeability ............................................... 8 3 WATER SATURATION MODELLING ..................................................... 17 3.1 Create fluid contact surfaces ......................................................................... 17 3.2 Model SW using a Look-up Function ............................................................. 19 3.2.1 Water Saturation Modelling ................................................................................... 19 3.2.2 SW modelling using variable OWC ....................................................................... 21 4 VOLUMETRICS CALCULATIONS .......................................................... 24 4.1 Define export units ......................................................................................... 24 4.2 Volumetrics .................................................................................................... 25 4.3 Volumetrics Results ....................................................................................... 28 5 WORKFLOW MANAGEMENT ................................................................ 32 5.1 Model Update ................................................................................................ 32 5.2 Multiple Realisations ...................................................................................... 36 Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 3 1 INTERPOLATION Objective Interpolate porosity values between the blocked wells to populate the 3D grid  Open the project: Intro_Petrophys_2013.pro  Open the Interpolation panel  Geomodel  MB1 on Grid in the Geomodel from the Task pane select Parameter interpolation from under Property modelling  Rename the job to interp_poro  Select the Poro log to interpolate  Select 'Separate interpolation in each zone' and select all zones.  In the Algorithms tab, specify the output parameter name: interp_Poro  Specify for each zone in turn the following information for the influence radius and orientation (leave the other input as default): Zone X Y Z Orientation (anti-clockwise from East) Below_TopC (Zone 1) 4000 2200 20 900 (long axis of reefs aligned N-S) Below_TopB (Zone 2) 2500 2500 20 00 (no orientation identified) 4 Note that influence orientation is defined anticlockwise from East, and it should be decided according to the conceptual model  Run the job  Double-click job to the end of the Workflow and save the project  Visualise the results in the 3D View. Also turn on the wells to see the source of the interpolated data. Use the frame player to play through layers. Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 5 2 STOCHASTIC MODELLING Objective Produce simulated porosity and permeability distributions. The 2 variables will be cosimulated, meaning that the relationship between them will be established from the blocked well data and this relationship used in the 3D distribution. 2.1 Data analysis Task Analyse the well data (blocked wells) using scatterplots to search for vertical and spatial trends.  Create a new chart view, type Scatterplot  Drag and drop the BW data object from the data tree onto the X-axis and from the pop up dialog select Poro  Drag and drop the same BW data object from the data tree onto the Y-axis and from the pop up dialog select TVD (s) by clicking on the source data and filtering button  Drag and drop the BW (Y-axis) data folder into the Colouring data drop site  Select Facies_disc, Apply Notice the scatterplot updates with the Facies colour coding.  Change the colour legend which can be done from the BW Facies_disc object in the data tree  MB3 on BW Facies_disc Visual settings,  Select Facies_disc from the dropdown list and select the ‘<Lib>Facies’ colour table. Turn on Colour range. Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 6 Task Look for a compactional trend in the main_reef and patch_reef facies and calculate trend lines which will be used to condition the stochastic porosity distribution.  In the Source data and filter dialog go to the discrete filters tab Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 7  Select Facies_disc from the drop-down menu in the discrete log options  Toggle off all facies and select main_reef only. Apply  Select a trendline from the drop-down menu in the scatterplot toolbar  Hover over the trend line in the scatterplot to reveal the line equation  MB3 on the trend line and select ‘Copy to Trends folder’. Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 8  Change the discrete filter in the source data and filter dialog to view the trend line for the patch_reef facies. Copy it to the trends folder as before. Note that these trend lines show decreasing porosity with increasing depth – what geological process does this indicate? These trends will be added in the petrophysical modelling job in the next chapter.  You can repeat the above and create scatterplots of BW Poro for the other spatial variables (X-value (s); Y-value (s); and Simbox depth (s)) to see if other trends exist. 2.2 Stochastic Modelling of porosity & permeability Objective Produce simulated porosity and permeability distributions. The 2 variables will be cosimulated, meaning that the relationship between them will be established from the blocked well data and this relationship used in the 3D distribution. The compactional trends derived in the previous exercise will also be used to condition the simulation, as well as the facies model.  Open the Petrophysical modelling panel:  Grid models  Geomodel  Grid  MB1 on Grid in the Geomodel from the Task pane select Petrophysical modelling.  Rename the job to ‘Poroperm’  Input the following settings in the general tab: Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 9  In the Distribution tab, change the user mode to Advanced.  Select zone: Below_TopC, facies: main_reef, parameter: Poro  Untoggle Automated Transformation sequence and toggle on to Show Distribution residuals  Select ”Geological trends” -> “Compactional depth trend” and append it to the transformation sequence by clicking the blue arrow Notice how the Distribution residuals histogram changes. The algorithm expects the input data to be a Gaussian distribution with a mean around zero, so by adding trends to the list you are removing them from the input data used in the calculation. These trends will be added to the result before the job is finished. Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 10  Select facies patch_reef from the list  Untoggle Automated Transformation sequence and toggle on to Show Distribution residuals  Select ”Geological trends” -> “Compactional depth trend” and append it to the transformation sequence.  Leave the rest at default  In the Correlations tab, Select each facies in turn, and estimate the correlations between Poro and Perm by pressing the estimate button.  Repeat for Below_TopB (Zone 2) Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 11  In the variogram tab, Open the Previewer at the bottom of the panel  Change the Variogram model from Texture to Standard -> Spherical  Select Copy and Paste to all. Now all will be set up with Spherical variogram  Change the variogram lengths and Azimuth for main reef and patch reef (numbers in bold): Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 12 Zone Facies Variogram model Standard Spherical Below_TopC Standard Main reef (Zone1) Spherical Standard Patch reef Spherical Standard Background Spherical Below_TopB Standard Clean_sand (Zone2) Spherical Standard Shaly_sand Spherical Background Parallel Azimuth to azimuth Normal to azimuth Vertical 0 1000 1000 10 60 1500 700 10 60 500 100 10 0 1000 1000 10 0 1000 1000 10 0 1000 1000 10 Note how the Variogram viewer changes as you type in new numbers. The interactive variogram plot/previewer can be used to get an idea of how the variogram settings will affect the parameter distribution. If the lower panel of the variogram viewer seems empty use MB1 in much the same way as in the 3D view to zoom in to a suitable scale (approx 103) Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 13  Run the job and add the job to the workflow  View the results in the 3D View. These are found under the Geomodel data object as Poroperm_Poro and Poroperm_Perm  Open the visual settings panel and calculate the range -> OK  Compare the results with the Facies distribution in both zones. To compare, open the view called “Compare3DParameters” and visualize the parameter in the left view  To play through the layers of the model, drag the view called “Player” out of the main frame and resize to a small view. Click on the visualized grid to produce the player.  Change the modus to Layer mode, by clicking the L-button. Play through the layers.  Check the results distribution and values. Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 14 Notice that the correlation length pattern of main reef and patch reef is according to the specified values in the variogram tab. Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 15  Observe that the facies distribution directly influences the porosity distribution as desired.  Create a histogram chart comparing the porosity of the BW object (Poro) to the simulated grid object stoch_1stpass_Poro.  Open Source data and filter and add two series. Rename them BW and Grid accordingly.    Check that the input distribution as indicated by the well data is captured also in the global 3D grid distribution of porosity. Important values are mean and standard deviation.  Change filter options to only compare main_reef under the Discrete filters tab.  For BW select Facies_disc from the Discrete log drop down list, and select main_reef only.  For Grid select Facies and main_reef only. Apply. Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 16    Save the project Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 17 3 WATER SATURATION MODELLING Objective Distribute water saturation values in the 3D grid using 2 methods 1. Using a pre-defined ‘look-up’ function to condition the distribution according to height above FWL (free water level) across the whole reservoir 2. Using a simple J-function, and varying the OWC (oil-water contact) within the reservoir fault blocks. 3.1 Create fluid contact surfaces Task Generate a constant oil-water contact (OWC) surface located at 1705 and a constant gas-oil contact (GOC) surface located at 1625. These will be used to represent the FWL for the height function.  Create a Fluid contacts folder in the Clipboard:  MB1 on clipboard  From the task pane select Create Folder  Name it ‘Fluid contacts’  Drag and drop any of the Depth surfaces from the Horizon folder (either TopC or BaseA) into this new folder.  Rename the Depth surface to OWC:  MB3 on the Depth surface icon in the clipboard Rename Rename it ‘OWC’  Then modify the z value of the OWC object, so it is at constant depth 1705m:  MB1 on OWC  From the task pane go to Operations  Scalar  Rename the job ‘OWC’  Type in the value 1705 to define the constant a  Click the Z=a button  Run the job and then drag and drop the job icon to the end of the Workflow Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 18  Change the visual settings of this OWC object to the appropriate colour and apply some transparency to enable you to view it with Depth horizons:  OWC  MB3  Visual settings  Apply Transparency 0.53  Duplicate this OWC surface:  MB1 on OWC  from the task pane go to OWC and select Duplicate  Rename the new surface to ‘GOC’  Repeat the steps you applied to OWC: Assign a constant depth value of 1625m  Change its colour accordingly (normally red)  Visualize the created fluid contacts with your TopC and BaseA horizons or Depth Surfaces.  Save the project Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 19 3.2 Model SW using a Look-up Function Task Import a pre-defined ‘look-up’ function, which is a function of one variable against another, in this case SW vs height above OWC. This will be used to distribute SW in the 3D grid.  Import the function into the Trends folder  Trends  MB1 on Functions from the task pane select Import Roxar text…  Select sw_lookup.f from ImportTrends directory  Give function the name Sw_lookup. Click ok  View the function  MB1 on Sw_Height icon  from the task pane select Show/edit values… Note that you can modify, remove and add points to the function 3.2.1 Water Saturation Modelling Task Use the imported function to distribute SW.  Open the Water Saturation Modelling dialog  Grid models  Geomodel MB1 on Grid from the task pane go to property modelling and select Water saturation modelling: Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 20  Rename the job Sw_lookup  In the General tab, name output Sw_lookup  Toggle on “Separate on zone” and Select All zones, leave the rest as default  In the variables folder, leave the Type as ‘Look-up function’ and set each variable as follows:  FWL (free water level, which will be represented by your OWC contact)  Tick ‘Use parameter/surface/trend’ and drag and drop the OWC contact into the All zone field  Click on the SWirr variable and set the value to 0.1 Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 21  Click on variable SWmax and set that to 1  Click on variable a and set that to 1  Click on lookup and toggle on ‘Use parameter/surface/trend’ and drag and drop the Sw_lookup from the Trends/Functions container  Run the job  Place the job into the workflow In the Geomodel, 2 new parameters have been created: Sw_lookup, which shows the SW in each cell, and Sw_lookup_H, which shows the height above the contact in each cell  Visualise the results in a 3D view. Display the colour legend and change the colour table for the Sw_lookup parameter to <Lib> Physics, which will show the water zone as blue (use parameter visual settings to do this)  Play through the layers using the frame player  Save the project 3.2.2 SW modelling using variable OWC Task Use different OWC values in different reservoir regions, and combine these with a J-function to distribute SW.  Open the Water saturation modelling task again and create a new job called ‘Sw_varOWC’  In the General folder, name the Output Sw_varOWC Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 22  Zones – Toggle on ‘separate on zone’ and select All  Region – FaultSegments- select All  Facies – none  Property classifier – none  In the Variables folder, select Functions J-function (Simplified)  Define the FWL variable separately for each segment: Segment 1 2 3 4 5 6 FWL 0 0 1705 1705 1725 0 Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 23  The other variables are defined using the same value for each segment, so set the ‘Define values for’ to ‘All zones, regions and facies’ to set the following:  SWirr = 0.1  SWmax = 1  Perm = Poroperm_Perm parameter  Poro = Poroperm_Poro parameter  a = 50  b = -2.9  Run the job, add it to the workflow and view the parameters Sw_varOWC and Sw_varOWC_H as before, using the 3D view and frame player  Save the project Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 24 4 VOLUMETRICS CALCULATIONS Objective Initial in place volumes will be derived from the geological model. These will be output in the format of 3D parameters, tabulated results by license boundary, reservoir zone and fault block, and average volume maps. 4.1 Define export units Task Change the default import/export metric units to export oil volumes in barrels.  Open the Unit set selector dialog  Main RMS menu  Tools Units  Define a new unit set based on the current metric set  Select Metric  Click on Show/edit details  Press the icon Copy to new.  Name the new unit set ‘volumes’ and select it from the ‘Details for unit set’ list  In the Volume section, change the reservoir volume and surface liquid volume to million barrels and million st. Barrels  Select this volumes unit set for the import/export set Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 25  Click OK and Continue for the warning message 4.2 Volumetrics Task Use the volumetrics dialog to calculate volumes by zone, segment and license boundary.  Open the Volumetrics dialog  Geomodel  MB1 on Grid  select Volumetrics from the task pane  Rename the job ‘Volumes_1stpass’  Set the General tab as below: Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 26  Set the Calculations tab as shown below. (Drag and drop the TopC Depth Surface into the Map layout drop site) Set the Variables tab as follows: Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 27  Highlight the Variable Water saturation (fraction), select ‘Use parameter’ and drag and drop the Sw_lookup parameter from the Geomodel  Select the Formation variables, and highlight the porosity. Toggle on the option to use a parameter, then drag and drop with MB1 the Poroperm_Poro parameter created previously in the Geomodel grid.  Leave the Net/Gross at value 1. Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 28  Set up the Report tab as follows:  Run the job, then drag and drop it to the end of the workflow 4.3 Volumetrics Results Task Inspect the volumetrics results as 3D parameters, 2D average maps and in tabulated format. Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 29 The following items have been created as the result of the Volumetrics job:  Five new parameters in the Gird:  A table object in the Tabulated results folder:  And a clipboard folder,  Visualise the 5 parameters in a 3D view. Click on a cell to see its parameter value Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 30  Open the parameter’s Information panel (MB3 on parameter Information) to reveal Sum statistics for the whole volume.  Display the Clipboard maps in a Map view:  View the tabulated volumetrics results  Volumetrics_1stpass  select Volumetrics table viewer from the task pane  Select HCPVOil as the variable and all Zones, Segments & boundaries: Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 31  The Raw data tab shows results by the variables selected. Export these to Excel using copy & paste (click the top left cell to highlight all cells)  Volumetrics_1stpass  select Volumetrics table viewer from the task pane Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 32 5 WORKFLOW MANAGEMENT Objective To learn how to use the Workflow Manager to update a model (in this case when new well data becomes available) and to create multiple realisations for the porosity and permeability distributions, which will generate a range of volumetric outcomes. 5.1 Model Update Objective You will use the workflow that you have been building during the facies and petrophysical modelling, to update the model with new well data. One well, Well_H, will be added to the model. Data analysis will be re-done to see if facies proportions have changed, then the facies, porosity/permeability, Sw and volumetrics jobs re-run in the workflow, and volumetrics results compared. Task Import a new well into the project, re-run the workflow and compare volumetrics results.  Import a new well, Well_H  MB1 on Wells folder  Import task group  Well data...  Select RMS Well as the input format  Select the file name – Well_H.txt in folder DataIO/ImportNewWell  In the Wellhead tab, set the Top MD value to 1691.55  Save the job – use ‘Save as’ and name it Well_H  Run the job and check that it appears in the wells folder Task Re-run the blocked wells job, including the new Well_H.  From the workflow, open the job Blocked wells: with_facies_bias  Check that Well_H has automatically been added to the list  Run the job  Open the Statistics for the Blocked wells Select the Zone Below_TopC. Click Update table. Do the same for Zone Below_Top B. You should now have the following facies percentages: Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 33 Below_TopC Below_TopB Task Update the facies model, using the new facies percentages as volume fractions.  From the workflow, open the job ‘Facies:Composite: Zone1_trend’  In the volume fractions tab, change the fractions for Zone 1 (Below_TopC) to main_reef : 0.41 patch_reef : 0.18  Update the Geometry tab to reflect the changes in the height geometries for the patch_reef facies that resulted from the new well data:  Save the job, but done run it Task Update the facies model for Zone 2, using the new facies percentages as volume fractions.  Open the job ‘Indicator simulation: Zone2_clastic’  In the Trends tab, change the volume fractions according to those reported in the new blocked well statistics: background : 0.17 clean_sand : 0.70 shaley_sand : 0.13  Click on the report consistency button to check the sum of the new volume fractions is equal to 1.  In the variogram tab, Estimate the variance again for each facies in turn.  Save and close the job Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 34 Task Change the output name for the Volumetrics job, so it is possible to compare the results.  Open the job ‘Volumes_1stpass’ from the workflow  In the General tab, type the prefix of output parameters and maps: ‘_updated’  In the Report file tab, add the suffix ‘_updated’ at the end of the Report file name and the Report table name  Save and close the job Task Run the workflow, from Facies modelling to volumetrics, to create the updated parameters, then compare the updated parameters (with Well_H) to the original ones  The workflow, from Blocked wells to Volumetrics, should look like the workflow below  To show the input and output objects, click View in the main RMS Menu and toggle on Workflow input objects and Workflow output objects  Slide the Start button using MB1 from the top of the workflow to Job 23 (Composite: Below_TopC(Zone1)  Observe the output parameters. When you run the workflow, all the parameters will be over written, except for the volumetrics parameters, which will be created anew. This will allow you to compare new with old.  Execute the workflow by clicking on the green play button Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 35  Once done, compare the old volumetrics results with the updated ones. Compare the report tables, average maps and 3D parameters  Save the project Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 36 5.2 Multiple Realisations Objective To learn how to use the Workflow Manager to update a model (in this case when new well data becomes available) and to create multiple realisations for the porosity and permeability distributions, which will generate a range of volumetric outcomes. Task Create multiple realisations for the project, in this case 11.  Click on the ‘Define realisation’ icon in the RMS main toolbar. Currently, you see only 1 realisation, which contains all the work in your project.  Change the Number of realisations to 11  The project data is either Shared (only one realisation for that data item) or not Shared, in which case you can elect to keep all 11 realisations, or just some of them.  Set all the data items to shared, except the stochastic petrophysical parameters, Sw parameters and the volumetric parameters. Click OK Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 37  Notice the change to the parameters in the data tree. Those that are not shared are now pre-fixed with a #  Change the project realisation number in the main menu to 2 and notice that shared items are still present, but no realisations are yet created for the non-shred items Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 38 Task Run porosity/permeability, SW & Volumetrics jobs for realisation 2-11  Set the Start and End points of the workflow to include the jobs from ‘Petrophysics:FirstPass’ to ‘Volumetric: Volumes_1stpass’  Creating the realisations automatically creates a realisation loop to the right of the workflow. Set the start of the loop to the ‘Petrophysics:FirstPass’ job  Click on the ‘Real...’ button on the loop and type in realisations 2-11. This will mean that the workflow will run only on these realisations. Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 39  Run the workflow and observe the realisation number changing as the workflow cycles through each one. If you display one of the parameters in a 3D view, you will also see that update briefly before RMS moves to the next realisation.  Once the workflow is finished, toggle through the realisations, displaying the ‘1st_pass_updated_Oil_HCPV’ parameter in the 3D view. Task Visualise the range of volumetrics results as a histogram.  Tabulated results  Volumetrics  Volumetrics _1stpass_updated  MB1  Select Histogram from the Task Pane  In the pop up menu select HCPVOil  Open the Source data and filter and colour the histogram by Zone Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1 40 Task View tabulated results and p10, p50 & p90 statistics.  View the results in the Table viewer Tabulated results  Volumetrics  Volumetrics _1stpass_updated  MB1  Select Volumetrics table viewer from the Task Pane  Select HCPVOil as the variable  In the Statistics tab, observe the results and check which are the closest realisations to P10, P50, P90...  In the Raw data tab, all realisations are shown. Click on the top left cell to highlight all cells to copy/paste them to an excel spread sheet.  Save the project. Exercise : RMS Petrophysical Modelling : Emerald. January 2015. RMS version 2013.1