Rubis (NUM) Tutorial #1

Transcription

1 Rubis (NUM) Tutorial #1 1. Introduction This example is an introduction to the basic features of Rubis. The exercise is by no means intended to reproduce a realistic scenario. It is assumed that the user has installed the Kappa Generation5 Workstation to follow this tutorial. An isothermal three-phase model, comprising a water injector and a producer, will be built and simulated. Before starting this session, the user is expected to have installed KAPPA-Workstation and started the NUM (Rubis) module. The tutorial will use the five files (below, left) located in the Examples folder in the Installation directory. Intermediate saved files are also available in the same location, allowing the user to start from a specific point in the tutorial. They are named NUMEX01_chapter_xx.kr5, where xx refers to the tutorial chapter from which the user may start using the file. Rubis starts (below, center) and brings the user to the File page. The active option is New and recent and a Blank icon can be seen towards the top left of the screen (below, right). 2. Creating a new document and PVT definition Click on the Blank icon. This starts a wizard that will take the user through two steps to initialize a new document and its first run. - Step 1: initialization of the main document options: reference time and location, general information, units and general comments. Keep everything as default and click. - Step 2: Define PVT for the first run and control the level of complexity in the numerical model. Since Rubis numerical models are always NL, Use real PVT is always checked (below, right) and PVT definition is required. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-1/22

2 To define PVT for the first run, click on and define the fluid type as Saturated oil and Water. Keep the other PVT parameters as default (below). Click on to accept the PVT definition, and then click on. The document and its first analysis are now initialized and the main Rubis window appears. The active tab is Map, showing the default numerical model contour. The ribbon at the top offer various options to construct the numerical model. Some of the main options are also available in the control panel on the left. The document is only in the active computer memory and it is named Untitled1. Save it and call it NUM Tutorial 1 using the Ctrl+S shortcut or select Save in the File menu. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-2/22

3 3. Reservoir model definition and construction 3.1. Reservoir geometry definition: Contour and Faults Click on the Image,, icon on the top ribbon to load NUMEX01_FieldMap.jpg which is a 2D representation of the reservoir. The next step is to define the map reference and scale. It is recommended this be done before importing any spatial data. To redefine the reference point (0,0), click on the Local X/Y,, icon in the ribbon at the top. Make sure that the radio button Change reference point is activated in the consequent dialog (below, left). Click on the black cross in the image to define this point as reference, which triggers an update of the X and Y values displayed in the dialog. Validate the changes by clicking on OK. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-3/22

4 Before setting the field scale, using the Zoom in option in the map tool bar, zoom in on the region of the loaded image with the scale. To scale the field, access the same dialog again using the icon and enable the Scale field radio button (below, left). On the map, hold and drag the left mouse click to draw a line spanning the length of the scale (below, right, top). As the line is drawn, the length of the line is shown (and updated) in the Length field on the dialog. Change the Length to 3000 ft (below, right, bottom) and validate the changes with Apply. Close the dialog by clicking on OK. Next, click on the Contour,, icon in the ribbon at the top. Starting anywhere on the contour indicated by the field image, proceed around the reservoir by moving the cursor and clicking until the polygon of the overlaid trace is complete. Finish with a double-click. The sealing faults in the image are to be created next. Click on the Fault,, icon in the map ribbon, and draw the two inner sealing faults symbolized by thick black lines on the reservoir bitmap. To connect a fault node to a contour node, move the cursor close to the contour node till it turns green. A left click in this state connects the fault node to the green contour node. Similar to the contour, finish with a double-click. At this stage the image can be hidden. To do so, click on the Show,, icon, and untick the Images node in the Display settings dialog (below, left) before validating with OK. We will display the image later when creating wells. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-4/22

5 The final geometry should look similar to the one shown below, right Reservoir geometry definition: defining Layers The file NUMEX01_chapter_3.2.kr5 may be used as a starting point for this chapter. To complete the definition of the reservoir geometry, the number of layers as well as the individual layer horizon and thickness needs to be defined. Click on the Geometry,, icon (in the control panel on the left or in the ribbon at the top) to open the Geometry definition dialog. In this dialog, set the number of layers to 3 and rename (by double clicking on the cell displaying the layer name) Layer #1 to Sand, Layer #2 to Shale and the bottom layer (Layer #3) to Bottom as illustrated below. To see a quick preview of the resulting grid, click on. Different ways to define the layer geometry are offered in the Geometry input drop down list. The default, 1-top + n-thickness will be used for this session. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-5/22

6 Change the top horizon type from constant to data set. This action automatically opens the spatial data dialog. In this dialog, create a new dataset by clicking on and rename it to Top Horizon. Click on and in the consequent dialog, click on the icon to load NUMEX01_TopHorizon.txt from the examples directory. This file contains tabulated data for the top horizon of the reservoir in a {x,y, top_depth} format, in ft. Make sure that the columns format type and the units are defined correctly (below, left). Click on to finish the loading process. After the data is loaded, they are displayed in the Spatial data dialog as a table and spatial distribution of the points displayed on the Map (above, right). Click on to validate and return to the Geometry definition dialog. Next, set the Sand layer thickness definition to dataset. Instead of loading the data from a file, thickness points will be interactively defined on the map. Enter a value of 50ft in the New value: field in the dialog, click on and click in a few locations in the south-west corner of the map to assign a thickness of 50ft there. Repeat the process to define a thickness of 40ft in the north-east and a maximum thickness of 70ft in the center, as displayed below. Call the dataset Sand Thickness. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-6/22

7 Click on to accept the changes and return to the Geometry definition dialog. The new dataset is of type thickness' and can also be assigned to any other layer. Finally, change the shale layer thickness to 1 ft before validating all changes with OK: Note that the numbers being displayed in the Value column of the table for datasets are a simple arithmetic average of all points in the dataset. As a result, the same numbers for the Sand top and Shale thickness should result as shown in the image above, whereas the value for the Sand-thickness will depend on the number of points picked to define the thickness. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-7/22

8 3.3. Reservoir properties: Petrophysical properties The file NUMEX01_chapter_3.3.kr5 may be used as a starting point for this chapter. To define/edit the Reservoir properties, click on the Properties,, icon in the top ribbon or the control panel on the left. By default, the entire reservoir carries the same petrophysical properties, initial state and KrPc curves, as illustrated by a unique property set called Default. The panels on the right define the properties/parameters/relationship curves for each property set. A property set is a combination of petrophysical properties (k, phi, NTG etc.), KrPc curves, Initial state, Unconsolidation relationship and Desorption isotherm. It is possible to define different property sets to different layers or regions in the reservoir. In this tutorial, specific petrophysical properties for each layer will be defined, but the KrPc curves and initial state will be unique to the reservoir. To achieve this, first change the reservoir topology to Layered : Right click on the cell labelled Default for the Shale layer and select New from the list (inset below). In the Property set definition panel on the right, change the name of the newly created property set from PS #1 to Shale rock. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-8/22

9 Similarly, create a specific property set for the Bottom layer and rename it Sand rock. To edit the default property set, select it in the list on the left. In the Property set definition panel on the right, change the type for Permeability from Constant to Data Set. In the spatial data dialog, load NUMEX01_DefaultPermeability.txt, located in the Examples directory. Call this dataset Default k. Repeat this operation for porosity in the default property set - its values are stored in NUMEX01_DefaultPorosity.txt and call the dataset Default phi (bottom, left). To finish, select the Shale rock property set and change its permeability to md, its porosity to 0.05 and its lower leakage factor (modeling a reduction of the layer to layer connection) to 0.01 (above, right). Keep the parameters values for the Sand rock property set at default. Specific petrophysical properties have been defined for the Sand and Shale layers. The next step is to input a unique description of the initial state and KrPc curves for the whole reservoir, although these properties could be defined for each property set. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-9/22

10 3.4. Reservoir properties: Initial State & KrPc To edit the unique initial state, select the Default property set in the list on the left and click on in the Property set definition panel. In the following dialog, set a reference pressure of 5000 psia at 6000 ft, change the Gas-oil mixture definition type to Gas-oil contact and set the GOC at 5500 ft and a FWL at 6080 ft as shown below, left. Click to accept the changes and close the Initial state dialog. As a result of the initial state definition, the bubble point pressure is modified, for same family of Black oil curves, to ensure Pb = P at GOC. Finally, click on to access the relative permeability curves and capillary pressures. It is possible to define KrPc curves using in-built correlations or load the points from an external file using the Load button at the bottom left. For this session, we will use the default curves. Just check No extrapolation at the bottom left of the dialog (shown in the image above, right) and validate the definition with OK. Confirm the reservoir property setup with OK. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-10/22

11 4. Defining the Wells The file NUMEX01_chapter_4.kr5 may be used as a starting point for this chapter Defining the P01 Producer Display the reservoir image from the Display manager (This step may not be necessary if the saved file is loaded). Click on the Well,, icon and click on the location on the map marked P01 in the image. The well info dialog pops up. The dialog shows the well name, type and geometry parameters in the Settings panel on the left and the Top or Cross section view in the View panel on the right. By default, the well is fully penetrating the three layers. Activate the Edit perforation option by clicking on the icon above the cross-section view, then click on the perforation nodes and shift them manually in order to make the well penetrating through the top layer only (to snap the perforation interval to the top and the bottom of the layer right-click on the perforation while the Edit mode is active). Change the well name to P01 (below, left). To define a well intake model for P01, check the Define intake checkbox at the bottom-left corner of the Well info dialog. A well intake definition dialog pops up (above, right). It is possible to define the intake using a range of in-built empirical and mechanistic flow correlations or to load external lift curves in Eclipse format. A time dependent intake may also be set up to model changing wellbore conditions with time for example. For this session, keep the default setup and validate with OK. The Intake conversion parameters section appears at the end of the Well parameters table on the left. Set the intake use to only above reservoir in the drop-down list: KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-11/22

12 The next and last stage consists of defining the production schedule for the well P01. Switch to the Schedule tab. To create a new schedule step, click on the button. The new schedule step appears in the well P01 schedule dialog. Keep the mode as Production and define a surface pressure target of 200 psia with a total bottomhole rate constraint of 10,000 B/D. (shown below). In practice, this setup implies that P01 will be produced at a constant surface pressure of 200 psia unless the total bottomhole rate goes above B/D, in which case the production will switch to a constant rate production fixed at the latter value (of B/D). Multiple production (or injection) sequences can be defined using the New button in the Editing schedule steps dialog. The drop down list at the bottom can be used to toggle through these sequences. For this session, a single sequence would suffice. Click on to finish the schedule step editing. Conditional constraints may be defined for the well based on Water Cut or GOR. This will not be done for this session. Click on to accept the changes and close the well P01 dialog. The producer well, P01, is now defined. The injector well, I02, will be created next Defining the I02 Injector Click again on Well,, icon and to interactively create the I02 well at the location displayed in the image. In the following Well info dialog rename the well as I02. Interactively edit the unique perforation by clicking on the icon and restricting the perforation length to the lower zone only, as shown below: KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-12/22

13 No well intake model will be defined for this well. To define a unique water injection control, move to the Schedule tab and click on. Change the mode to Injection and keep the default starting time. Define the target as a bottomhole water rate of B/D with a maximum bottomhole pressure constraint of 10,000 psia (shown below): Validate the setup to complete the creation for well I02. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-13/22

14 Two wells have been added to the model and are displayed on the 2DMap as illustrated below: 4.3. Loading a Well Sketch for P01 Move to the Reference logs tab. It is possible to load well schematics as well as open hole logs for each well. They then appear in the production logs plots (explained later in the tutorial), along with the simulated production logs. Select the well P01 in the Well list at the top and click on the Completion,, icon to open the Well schematic dialog. Click on and load the well sketch contained in the NUMEX01.wellsketch file, located in the Examples directory: KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-14/22

15 The loaded well completion diagram can be observed in the well schematic preview panel. Click on to accept the changes. Switch to the Map Tab. 5. Grid preview The file NUMEX01_chapter_5.kr5 may be used as a starting point for this chapter. After all the geometrical elements and input parameters have been defined in the model, it is possible to preview the grid by clicking on the Grid,, icon in the top ribbon and change the grid settings if needed. For this session, keep the default grid settings and exit the dialog with OK. The 3D plot Display settings on the right on the dialog will be explained later in the tutorial. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-15/22

16 6. Initialize & Simulate Click on the Initialize, steps:, icon in the control panel on the left. The initialization process consists of two - Step 1: Define model start time, outputs and numerical settings. This step consists of an Output tab with three pages on the left. These allow the user to select the well gauge, production logs and global results to output. Each output category has its own dedicated plot showing the simulation results. The frequency of the output gauges and results fields can be defined either as a number or explicitly as dates on which the output is required. In the Numerical Settings tab, numerical solver and its settings may be defined. For this session, in addition to the default parameters, export production logs calculated at P01. Click on to proceed. - Step 2: Define model time stepping, handling of targets and number of restarts. The times of restarts are automatically calculated based on the total simulation duration and number of restarts specified by the user. Set up the model to run for 25 years. Leave the rest as default and click on. Once model initialization is complete, the 3D plot, well results plot and production logs plot are created. Click on Simulate,, in the control panel to start the simulation. As the simulation proceeds, progress is summarized in the activity log, which can be hidden/shown using the icon in the Run ribbon at the top. The verbosity of the activity log can be set in the application settings (accessed through located at the top right of the Rubis window). Although several processes are parallelized in KAPPA-Workstation, the simulation itself is still run on a single thread. The well results, production logs and 3D plots are updated as the simulation progresses. Once the simulation is complete, the global results plot is created. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-16/22

17 7. Looking at Results The file NUMEX01_chapter_7.kr5 may be used as a starting point for this chapter Simulation results A run summary and some primary results (reserves, total cumulative production at the wells, etc...) can be obtained by double-clicking on the Simulation status window or the Results, Run Tab:, icon at the top under the When the simulation is complete, all results are displayed in the various plots created by default. Several instances of those plots can be created using the New plot icon in the ribbon at the top under the Run Tab. This will be skipped for the purpose of the tutorial. Some of the plot options, however, are illustrated in the following sections Well result plot Maximize the well results plot by double clicking on the plot title bar to see the simulated rates and pressure channels. The well for which we visualize the output gauges can be chosen from the list on the top ribbon ( ). KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-17/22

18 Click on the Show,, icon and uncheck all channels; keep only the GOR and the Water cut display: Double-click on the plot header to restore the plot Production logs plot Maximize the Production logs plot to visualize the inflow along the wellbore. For a better display, zoom in on the perforated section using the zoom on depth scale option ( ) in the plot toolbar: As the user navigates through different time steps, using the options in the Navigation panel at the top, the corresponding curves are highlighted in the tracks. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-18/22

19 7.4. Global Results Plot Maximize the Global Results plot, and bring up the Show,, options as for the well results plot. To take a closer look at the evolution of the remaining oil reserves as a function of time, layer by layer, make the selections as shown in the image below: D plot This section illustrates a few of the new display options added to the 3D plot. Maximize this plot, and increase the vertical gain by using the sliding bar at the bottom left of the plot. Superpose the background scale grid by selecting it in the plot menu (accessed by a right-click in the 3D plot preview): Open the Reservoir grid panel of the display settings, and select to display water saturation (Sw) (below, left). Next, open the data filtering panel and enable filtering on Sw, keeping only cells containing more than 25% of water (below, right). KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-19/22

20 The 3D scene should look something like shown below: The water saturation fields can be played back step by step by clicking on or in one go using to track the time at which the water front reaches the producer. Even though it is only qualitative, this result is consistent with the evolution of the water cut observed at this well in 7.2. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-20/22

21 8. Creating a template An important improvement in G5 is the ability to create interpretation templates. This may be done at any time by using the Save as template option in the File menu (below left). Once a template is created, it is made available in the file menu (below right). The template stores the setting of the document and the active run PVT and numerical settings at the time it was saved. The next time the user wants to create a new document, they will just have to select the template. Notice that the wizard, which takes the user through the two initialization steps, has the settings of the current analysis. This can be checked with the numerical settings (below left) and PVT definition (below right) in Step 2 of initializing the first run. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-21/22

22 9. What s next? This tutorial is over. You may save the results and exit Rubis. However, you may also want at this stage, to explore the capabilities of Rubis a little further. In the session above we had just created a simple model with some data sets and fairly simple PVT and reservoir description. You may initialize the reservoir description from a GRDECL file, define complex EOS PVT, define complex well geometries and schedules, use deviation survey to initialize well trajectory, define different initial states or KrPc curves in different regions of the reservoir, etc. KAPPA-Workstation also has a comprehensive contextual online help, including How to topics, Examples and FAQs, to assist the users whilst using the software. Users are encouraged to consult these. KW v Doc v KAPPA NUM Tutorial #1 NUMEX01-22/22