Reservoir AVO Modeling 2013.1 UserManual

Reservoir AVO Modeling

Version 2013.1

User Guide

Copyright 2013 WesternGeco. All rights reserved.This document is copyright protected. No part of this document may be reproduced, stored in a retrieval system, or transcribed in any form or by any means, electronic or mechanical, including photocopying and recording, without the permission of Schlumberger. Further, the document contains information proprietary to Schlumberger and should not be disclosed or distributed to third parties without the permission of Schlumberger. To the extent that documents are provided in electronic format, Schlumberger grants permission for the document to be stored electronically. All other restrictions set forth above regarding the documents use or distribution shall apply.

Schlumberger Trademarks and Service MarksSchlumberger, the Schlumberger logotype, WesternGeco, the WesternGeco logotype, and other words or symbols used to identify the products and services described herein are either trademarks, trade names, or service marks of Schlumberger and its licensors, or are the property of their respective owners. These marks may not be copied, imitated or used, in whole or in part, without the express prior written permission of Schlumberger. In addition, covers, page headers, custom graphics, buttons, and other design elements may be service marks, trademarks, and/or trade dress of Schlumberger, and may not be copied, imitated, or used, in whole or in part, without the express prior written permission of Schlumberger. Other company, product, and service names are the properties of their respective owners.

An asterisk (*) is used throughout this document to designate a mark of Schlumberger.User Guide iii

Schlumberger Private - Customer Use

iv Reservoir AVO Modeling 2013.1


Contents

1 Reservoir AVO Modeling 2013.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

System Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Certified Hardware Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Software Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Operating Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Licensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Licensing Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Purchasing a License on the Ocean Store . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Plug-in Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Before You Install . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Installing Reservoir AVO Modeling 2013.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

2 Reservoir AVO Modeling and Petrel 2013 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Reservoir AVO Modeling Integration with Petrel 2013 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Volume attributes Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Make wedge model Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

ToolTip Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

Help and Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

3 Using Reservoir AVO Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Using Reservoir AVO Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Performing Isotropic Synthetic Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Using the Spectrally shaped random noise Volume Attribute . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

Realizing Pre-existing Volume Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12

Creating a Wedge Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17

Wedge Model Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17

Generating a Wedge Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19

Generating a Synthetic Seismic Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24

4 Workflow Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Workflow Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

Contents v


Volume attributes in the Workflow editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Wedge modeling in the Workflow editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4vi Reservoir AVO Modeling 2013.1


1 Reservoir AVO Modeling 2013.1

In this Chapter

Overview .................................................................................................. 1-2

System Requirements ................................................................................ 1-3

Certified Hardware Solutions ................................................................ 1-3

Operating Systems .............................................................................. 1-4

Software Compatibility ......................................................................... 1-3

Licensing .................................................................................................. 1-5

Licensing Support ................................................................................ 1-5

Purchasing a License on the Ocean Store .............................................. 1-5

Plug-in Installation .................................................................................... 1-6

Before You Install ................................................................................ 1-6

Installing Reservoir AVO Modeling 2013.1 ............................................. 1-6

Technical Support ...................................................................................... 1-7

Training .................................................................................................... 1-8

Conventions .............................................................................................. 1-9User Guide 1-1


OverviewOverview

The Reservoir AVO (amplitude versus offset) Modeling for Petrel 2013 delivers components for modeling the synthetic seismic response of earth models.

Reservoir AVO Modeling integrates with Petrel as a process available from the Petrel Processes pane, and as worksteps available in the Workflow editor that can be incorporated into larger and more complex integrated workflows. In either case, you have the same dialog box to set up the synthetic modeling jobs.

The main components are:

Isotropic seismic modeling in the Volume attribute dialog box and a workstep. Includes both 2D and 3D seismic data.

Spectrally shaped random noise in the Volume attribute dialog box and a workstep

Make wedge model process and workstep. Optional output of either poststack or prestack seismic response.1-2 Reservoir AVO Modeling 2013.1


System RequirementsSystem Requirements

The following table lists the minimum and preferred system requirements for Reservoir AVO Modeling 2013.1.

Table 1-1 System Requirements

This section contains the following topics:

Certified Hardware Solutions

Operating Systems

Software Compatibility

Certified Hardware Solutions

WesternGeco tests hardware from different vendors. System Requirements lists the hardware used in the 2013.1 commercialization cycle. These hardware units are tested, not certified. WesternGeco cannot foresee all issues related to the hardware we test. Problems outside WesternGeco control such as driver and BIOS bugs and operating system limitations could affect the user experience. For detailed information, please visit the respective vendor sites.

Software Compatibility

Reservoir AVO Modeling 2013.1 is compatible with Petrel 2013.x (64-bit).

Minimum System Requirements

Workstations Configuration

Recommended Hardware Dell T7500

Operating System Microsoft Windows 7 Professional (64-bit)

Processor 8 core CPU

Memory 12 GB DDR3 SDRAM

Graphics NVIDIA Quadro 2000M

Preferred System Requirements

Workstations Configuration

Recommended Hardware Dell T7500

Operating System Microsoft Windows 7 Professional (64-bit)

Processor 8 core CPU

Memory Minimum GB SDRAMGraphics NVIDIA Quadro FX 2000User Guide 1-3


System RequirementsOperating Systems Reservoir AVO Modeling 2013.1 is only supported on Microsoft Windows 7 Professional (64-bit).

Warning: If you attempt to run this software using a 32-bit processor or

operating system, an error message appears and the software terminates.1-4 Reservoir AVO Modeling 2013.1


LicensingLicensing

You will need a valid license for Reservoir AVO Modeling 2013.1. This license can be purchased

On the Ocean Store at http://www.ocean.slb.com

Through your WesternGeco software sales representative

You will also need a FLEXnet network license manager to use Reservoir AVO Modeling on a network. The license manager is run on a server configured by your system administrator or configured locally on your system.

Please refer to Petrel documentation for more information.

When you order Reservoir AVO Modeling 2013.1 from the Ocean Store, full instructions for installing and activating the plug-in license are included in the e-mail that you will receive.

You can also find the information on the Ocean Store at http://www.ocean.slb.com. Select Contact Us and then select Ocean plug-in license orders.


Licensing Support

Purchasing a License on the Ocean Store

Licensing Support For licensing support, e-mail [email protected] or contact your local WesternGeco software sales representative.

Purchasing a License on the Ocean Store

To purchase a Reservoir AVO Modeling 2013.1 plug-in license on the Ocean Store, you will need

Your Ocean user name and password

A dongle ID

For directions, refer to http://www.ocean.slb.com/Pages/oceanstore-help.aspx#2. User Guide 1-5


Plug-in InstallationPlug-in Installation


Before You Install

Installing Reservoir AVO Modeling 2013.1

Before You Install Before you begin to install Reservoir AVO Modeling 2013.1:

Review all System Requirements.

Check that the specifications of the computer are sufficient to ensure the highest-quality user experience with the application.

Ensure that Petrel 2013 is installed and configured on your system. To do this, click Start; then select All Programs. Scroll down to the Petrel listing and verify the name and version number.

Installing Reservoir AVO Modeling 2013.1

To install the Reservoir AVO Modeling 2013.1 plug-in for Petrel 2013, follow the instructions provided in the Reservoir AVO Modeling 2013.1 Installation Guide.

Note: If you purchased Reservoir AVO Modeling from your WesternGeco Sales

representative, the installer will be on the installation DVD. The DVD also contains on-screen installation instructions. 1-6 Reservoir AVO Modeling 2013.1


Technical SupportTechnical Support

If you have any questions, please consult the Support Portal at https://support.slb.com.

Log in with your user name and password (provided with your purchase).

Select Product/Discipline and then select Non-Seismic Methods.User Guide 1-7


TrainingTraining

If you would like to schedule customized WesternGeco plug-in training for your company, contact your local WesternGeco software sales representative.

For Petrel public training courses, please visit www.slb.com/services/software/services/training.aspx.1-8 Reservoir AVO Modeling 2013.1


ConventionsConventions

Instructions for the procedures in this guide are written using the following conventions.

Note: Some of the conventions used in this manual indicate the information to

enter, but are not part of that information. For example, quotation marks and information between brackets indicate the information you should enter. Do not include the quotation marks or brackets when you type your information.

Character Convention Description

Typed in Bold Represents references to dialog box names and application areas or commands to be performed.

For example, Open the Open Asset Model dialog box.

Denotes keyboard commands.

For example, Type a name and press Enter.Inside triangle brackets Indicates values the user must supply, such as

and .

Typed in italics Represents file names or directories, such as ... edit the file sample.dat and...

Identifies first use of important terms or concepts.For example, compositional simulation or safe mode is used when...

Typed in fixed-width Represents code, data, and other literal text the user sees or types.For example, enter 0.7323.User Guide 1-9


Conventions1-10 Reservoir AVO Modeling 2013.1


2 Reservoir AVO Modeling and Petrel 2013

In this Chapter

Reservoir AVO Modeling Integration with Petrel 2013 ................................... 2-2

Process Integration .............................................................................. 2-2

Volume attributes Functionality ............................................................ 2-3

Make wedge model Process .................................................................. 2-7

ToolTip Help .............................................................................................. 2-8

Help and Support ...................................................................................... 2-9User Guide 2-1


Reservoir AVO Modeling Integration with Petrel 2013Reservoir AVO Modeling Integration with Petrel 2013

Reservoir AVO Modeling 2013.1 integrates with Petrel as an additional category in the Volume attributes process dialog box, a process available from the Processes pane, and worksteps available from the Workflow editor.

When Petrel has launched, open the Processes pane and expand the Geophysics branch. The Volume attributes and Make wedge model processes appear as shown:

Fig. 2-1 Geophysics Group with Volume attributes and Make wedge model Processes

In common with all Petrel processes, only one instance of the Volume attributes or Make wedge model process dialog can be open. Thus, there are limitations on setting up multiple synthetic modeling jobs using the process dialog boxes, but more flexibility is possible using the Workflow editor as described in the Workflow Integration chapter.


Volume attributes Functionality

Make wedge model Process2-2 Reservoir AVO Modeling 2013.1


Reservoir AVO Modeling Integration with Petrel 2013Volume attributes Functionality

In the Processes pane, double-click Volume attributes to open the process dialog. The Volume attributes dialog box has the Category option Reservoir AVO modeling.

Fig. 2-2 Volume attributes Process Selection*User Guide 2-3


Reservoir AVO Modeling Integration with Petrel 2013You can also open the data tree, select a pre-existing seismic volume, and right-click to open the context menu:

Fig. 2-3 Volume attributes Selection on a Context Menu from a Pre-existing Volume2-4 Reservoir AVO Modeling 2013.1


Reservoir AVO Modeling Integration with Petrel 2013From the Category menu, select Reservoir AVO modeling and then from the Attribute list, select Isotropic synthetic.

Fig. 2-4 Isotropic synthetic Response Parameters Dialog Box

The Spectrally shaped random noise volume attribute can also be found under the Reservoir AVO modeling category in the Volume attributes process. The User Guide 2-5


Reservoir AVO Modeling Integration with Petrel 2013noise-contaminated data can be used to test the seismic visibility of thin beds under realistic noise conditions.

Fig. 2-5 Spectrally shaped random noise Volume attribute Dialog Box 2-6 Reservoir AVO Modeling 2013.1


Reservoir AVO Modeling Integration with Petrel 2013Make wedge model Process

Double-click Make wedge model in the Geophysics branch of the Processes pane.

Fig. 2-6 Make wedge model Dialog BoxUser Guide 2-7


ToolTip HelpToolTipHelpExtensive ToolTip help is available throughout the system wherever you see the question mark button. View the associated help by hovering the cursor over the button; a tooltip will pop up as follows:

Fig. 2-7 ToolTip Help for Wavelet Selection

Click the button to pin the ToolTip on-screen; otherwise, it will disappear as soon as the question mark button loses focus. 2-8 Reservoir AVO Modeling 2013.1


Help and SupportHelp and Support

Online help and support for Petrel are available from the Help item on the Petrelmenu bar. Click Petrel help for help with Petrel. Click Plug-in help and then Reservoir AVO Modeling to open the online help for this plug-in.

Fig. 2-8 Online Help MenuUser Guide 2-9


Help and Support2-10 Reservoir AVO Modeling 2013.1


3 Using Reservoir AVO Modeling

In this Chapter

Using Reservoir AVO Modeling .................................................................... 3-2

Performing Isotropic Synthetic Modeling ...................................................... 3-3

Using the Spectrally shaped random noise Volume Attribute ........................3-10

Realizing Pre-existing Volume Attributes .....................................................3-12

Creating a Wedge Model ..........................................................................3-17

Wedge Model Resolution .....................................................................3-17

Generating a Wedge Model .................................................................3-19User Guide 3-1


Using Reservoir AVO ModelingUsing Reservoir AVO Modeling

The main components of Reservoir AVO Modeling are:

Isotropic synthetic category in the Volume attribute dialog box and a workstep

Spectrally shaped random noise category in the Volume attribute dialog box and a workstep

MakewedgemodelprocessandworkstepThe following sections describe how to use the Volume attribute and the Make wedge model processes. Workflow Integration describes how to use the worksteps in the Workflow editor. 3-2 Reservoir AVO Modeling 2013.1


Performing Isotropic Synthetic ModelingPerforming Isotropic Synthetic Modeling

Using Isotropic synthetic, you can generate either a 2D synthetic angle line or a 3D synthetic angle cube from an elastic property model defined in one of two ways:

From inverted elastic properties.

A hybrid model where a pillar grid is effectively embedded in a volume. The input line or volume provides the over/underburden properties required to mitigate edge effects at the top and base of the pillar grid.

To launch the Volume attributes process, click Volume attributes in the Processes pane, under the Geophysics branch.

Fig. 3-1 Isotropic synthetic Volume attributes Dialog Box for 2D InputUser Guide 3-3


Performing Isotropic Synthetic ModelingFig. 3-2 Isotropic synthetic Volume attributes Dialog Box for 3D Input

To generate a synthetic seismic cube or a synthetic seismic 2D line,

1 On the Volume attributes dialog box, select Reservoir AVO Modeling as the Category and Isotropic synthetic as the Attribute.

2 On the Input/Output tab, select as Input one to three pre-existing 2D seismic lines or 3D seismic volumes to represent inverted elastic properties, such as Acoustic impedance, Vp/Vs ratio, and Density.

Note: All input data, 2D seismic lines, or 3D seismic volumes must be in the time

domain. No depth domain objects should be entered.3-4 Reservoir AVO Modeling 2013.1


Performing Isotropic Synthetic Modeling Note: If the algorithm specified in the Parameters tab is Post stack, normal

incidence -acoustic impedance, then only one input is required. In this case, you will still need to provide the same acoustic impedance input to all three input fields (Input 1, Input 2, Input 3). The Fatti or the Verm & Hilterman methods require only two inputs. In those cases, either of the properties can be repeated for the third input. This requirement is due to a limitation of the Volume attributes process.

3 Define the Output for the isotropic synthetic 2D line or 3D cube attribute that will be created.

4 Click the Parameters tab.User Guide 3-5


Performing Isotropic Synthetic ModelingFig. 3-3 Parameters Tab in Isotropic synthetic Volume attributes Dialog Box

5 Select a modeling algorithm appropriate for the input seismic volumes (in this example, Aki & Richards). Select the inputs from the dropdown lists.

6 Select a wavelet from the data tree and click the blue arrow to input it. The wavelet can be a synthetic one, an imported one, or one derived from the Seismic well tie process.3-6 Reservoir AVO Modeling 2013.1


Performing Isotropic Synthetic Modeling7 Define angles as Average angles for most algorithms. For all Zoeppritz algorithms, define angles as Incident angles.

8 Specify an angle range for modeling. The effective angle is reported in a read-only field.

9 You can select a pillar grid and up to three elastic properties representing the same property types as those chosen for the input seismic volumes.TheseInputelasticpropertiesareautomaticallypreselectedbutyoucanselectdifferentonesfromthelists.

Note: The pillar grid and its properties must all be in the time domain. No depth

domain objects should be entered.

10 Click Apply to output the volume attribute and display the seismic response in the standard viewers.

11 You can change the parameters in this dialog box, press Enter (or click Apply), and immediately see the updated output in the viewers.

12 The parameterizations used for the volume attribute computation are retained in the synthetic seismic 2D line or 3D volume, and can be viewed from the Settings available from the context menu that appears when you right-click the volume in the data tree.User Guide 3-7


Performing Isotropic Synthetic ModelingFig. 3-4 Parameters for Isotropic Synthetic Seismic Volume3-8 Reservoir AVO Modeling 2013.1


Performing Isotropic Synthetic Modeling13 When you are satisfied with the synthetic volume, you can realize the volume by selecting the Realize checkbox at the upper right of the Volume attributes dialog box.

Fig. 3-5 Realize Checkbox in Volume attributes Dialog BoxUser Guide 3-9


Using the Spectrally shaped random noise Volume AttributeUsing the Spectrally shaped random noise Volume Attribute

You can add spectrally shaped Gaussian white noise to an existing seismic volume. This process works by first generating a Gaussian white noise at every sample in the seismic volume and then filtering the noise to give it the desired spectrum. The filtering step is optional, in which case the output is Gaussian white noise with a broadband spectrum.

1 In the Volume attributes dialog box, select Reservoir AVO Modeling as the Category and Spectrally shaped random noise as the Attribute.

Fig. 3-6 Spectrally shaped random noise Dialog Box

3-10 Reservoir AVO Modeling 2013.1


Using the Spectrally shaped random noise Volume Attribute2 Select an input seismic amplitude volume to contaminate with random noise and create a spectrally shaped random noise volume attribute. The input seismic amplitude volume can represent real data or a synthetic seismic volume created with Reservoir AVO Modeling.

3 Control the noise spectrum by specifying a noise wavelet, which could be the output of a separate signal/noise estimation signal processing algorithm.

Note: The creation of such a noise wavelet is not within the scope of the

Reservoir AVO Modeling plug-in.

4 You can set the root mean square (RMS) level of the signal and the noise. Click on either signal or noise fields to see the implied signal/noise value in Db.

Alternatively, you can specify the signal value and the S/N value and click in either the signal or noise fields to see the implied RMS noise level.

5 Select whether to let the random number seed be generated automatically or not.

If you select this checkbox, the random number seed will be generated automatically and a unique noise realization will be produced every time you click Apply or OK.

If you do not select this checkbox, you can enter a particular seed number for the random number seed used to generate the noise, thus producing a repeatable noise realization.

6 Select the Combine random noise with input data checkbox or deselect it to have only the random noise generated.

7 Click Apply to create or update the volume attribute and see the seismic response displayed in the standard viewers.

8 You can change the parameters in this dialog box, press Enter (or click Apply), and immediately see the updated output in the viewers.

9 When the noise characterization is satisfactory, you can select the Realize checkbox to realize the volume. User Guide 3-11


Realizing Pre-existing Volume AttributesRealizing Pre-existing Volume Attributes

You can realize any pre-existing volume attribute by following these steps:

1 Locate the pre-existing volume attribute in the data tree and right-click to view the context menu:

Fig. 3-7 Realize Output Synthetic Volume Option on Context Menu3-12 Reservoir AVO Modeling 2013.1


Realizing Pre-existing Volume Attributes2 Select Realize from the menu. The Settings dialog will display.

Fig. 3-8 Synthetic Seismic Volume Settings Histogram before ScanUser Guide 3-13


Realizing Pre-existing Volume Attributes Note: The source amplitude range is set to default values, which are defined by

the volume attribute, in this case -1512.9 to +1409.6. However, values will vary depending on the volume attribute parameter settings. These default source amplitude range values are usually a good approximation to the actual range of sample values in the volume and can normally be used to guide the realization process. The true range of sample values only becomes available when the volume has been scanned. However, the process of scanning the volume can be time consuming.

Also notice that the histogram view, which normally shows the distribution of amplitudes in the volume, only becomes visible after it has been scanned. Again, the process of scanning the volume can be time consuming.3-14 Reservoir AVO Modeling 2013.1


Realizing Pre-existing Volume Attributes3 Click Scan to update the source amplitude range and histogram.

Fig. 3-9 Synthetic Seismic Volume Settings Histogram after Scan

4 Select the desired Realization quality. User Guide 3-15


Realizing Pre-existing Volume Attributes Note: The default value for Realization quality is Integer 8 bit; if you select

this option, it is strongly recommended that you check whether this level of quantization is sufficient to capture the variations of amplitude.

5 Click Realize.

Note: In this example, the realization process could be time consuming because

the entire volume must be calculated. Check that the Parameter settings are correct and that the realization settings are appropriate before clicking Realize, to save time.

When the realization process is complete, a new volume appears in the data tree.3-16 Reservoir AVO Modeling 2013.1


Creating a Wedge Model Creating a Wedge Model

You can create a wedge model based on an input well and markers. The wedge model is represented as a standard pillar-grid model. The wedge model can be input to other processes (such as the isotropic seismic modeling or the synthetic seismic modeling).


Wedge Model Resolution

Generating a Wedge Model

Generating a Synthetic Seismic Volume

Wedge Model Resolution

The wedge model geometry and resolution is illustrated in the next two figures:

Fig. 3-10 Wedge Geometry and Resolution Thickness DefinitionUser Guide 3-17


Creating a Wedge Model Fig. 3-11 Resolution Thickness Definition when Well at Location 1

Use these figures as an aid in selecting grid size and position parameters.3-18 Reservoir AVO Modeling 2013.1


Creating a Wedge Model Generating a Wedge Model

To generate a wedge model, follow the following steps:

1 Double-click Make wedge model in the Geophysics branch of the Processes pane.

Fig. 3-12 Make wedge model Dialog Box

2 In the Define wedge model tab, select and input a Well and a well tops folder, which defines a stratigraphic column that will be used to create the zones of the wedge model.

The definition of the well tops and stratigraphic column is performed using standard Petrel functionality the well tops can be imported from a file or User Guide 3-19


Creating a Wedge Model interactively edited using the well section window and the Make/edit well tops process.

Fig. 3-13 Zones and horizons (left) and Well Tops in the Well section window (right)

3 Select one of the zones to act as a wedge zone, which has a thickness defined by the chosen zone thickness at the well location. It progressively thins to zero thickness at I = 1 and thickens at the same rate towards I = NI. See also the figures Wedge Geometry and Resolution Thickness Definition and Resolution Thickness Definition when Well at Location 1.

Note: A flat model without a wedge can be generated if no zone is specified. To

remove the default zone value, highlight it and click Delete on your keyboard.1.If no zone is specified, then the default behavior is to create a flat model without any wedge. The location of the well is from the wellhead coordinates. If the well is deviated, it will not intersect the model grid, and the model will not be displayed in the Well section window.2.For a wedge model using zone information, the well location is based on the grid at the top of the wedge. Even for the deviated well case, the model can be displayed in the Well section window.3-20 Reservoir AVO Modeling 2013.1


Creating a Wedge Model 4 Set the Grid size and position. Type the number of grid cells that will be in the output wedge model, specified in the I and J directions.

5 Type the I,J reference grid node location for the well in the wedge model. The default location is the centre of the model grid.

6 Type the grid increment in X and Y in the wedge model.

7 Click the Elastic properties tab.

Fig. 3-14 Elastic properties Tab in Make wedge model Dialog Box

8 Select the log to be used to define the layering in the wedge model. It is recommended to use a blocked log to define this fine layering. Using unblocked User Guide 3-21


Creating a Wedge Model logs to define the layering could result in a huge number of thin layers and long runtimes when applying the model.

Note: a. When blocked logs are used to define the layering, the median value,

over each block, of any unblocked log is used to build the model.

b. When unblocked logs are used to define the layering when other logs are blocked, then each cell of the fine layered model gets the same blocked property value.

To block logs using the Petrel Log editor:

a. Make a copy of all the logs you want to block using the Petrel Copy/Paste buttons.

b. Display the original and copied logs in Well section windows.

c. Right-click in the data tree on a log to be blocked and select Log editor.

d. Select Block, change the default setting to minimum thickness = 10 m or something small, and set the maximum contrast, for example, to = 0.01.

e. Click Run to show the effect in the Well section window.

f. You can tweak the parameters to decrease the number of blocks.

g. You can further constrain the wedge model layer thickness by specifying a minimum layer thickness in milliseconds.

9 Specify the Minimum layer thickness in ms. If you input an unblocked log to define the layering in the zones, a layer will be created at each log sample. To prevent this very fine layering, which might be well below the seismic resolution, from occurring, a minimum layer thickness can be entered. This value effectively blocks the log to a constant block interval. The default Minimum layer thickness is 1 msec.

10 Select and input the elastic logs to use to populate the wedge model. Blocked or unblocked Vp, Vs, and/or density logs can be selected. In all cases, the median log value from each layer will be used. Ifyouusedunblockedlogstodefinethefinelayering,youcancontroltheminimumlayerthicknesstoavoidgeneratingtoomanythinlayers.3-22 Reservoir AVO Modeling 2013.1


Creating a Wedge Model 11 Click Apply or OK. A wedge model is created in the Models tree.

Fig. 3-15 Wedge Model in the Models treeUser Guide 3-23


Creating a Wedge Model You can view the wedge model in a 3D window.

Fig. 3-16 Wedge model in 3D Viewer

The wedge model is a standard pillar-grid model that can be visualized and used in Petrel processes. For example, you can use Petrels property calculator to generate new properties, or you could use the wedge model in the standard Petrel Layering process.

Generating a Synthetic Seismic Volume

You can generate a synthetic seismic volume using the Synthetic seismic modeling tab.

1 Click the Synthetic seismic modeling tab.

2 Click Apply or Create new synthetic seismic to start this process.

You can display the wedge model and/or the synthetic seismic response in the standard viewers. 3-24 Reservoir AVO Modeling 2013.1


Creating a Wedge Model Two output seismic types can be selected:

The Post-stack Cube option creates a seismic cube with the same extent as the wedge model grid, with one trace at each cells corner.

The Pre-Stack Gathers option creates prestack seismic gathers with the same extent as the wedge model grid, with one gather at each cells corner.

Spectrally shaped random noise can only be added to the poststack wedge synthetic.

Fig. 3-17 Make wedge model Synthetic seismic modeling Tab Poststack Output

The following tips will help you use the synthetic seismic modeling function in Make wedge model. User Guide 3-25


Creating a Wedge Model Define angles as Average angles for most algorithms. For all Zoeppritz algorithms, define angles as Incident angles.

If you click Apply, a new wedge model will always be created, even if it is identical to the previous model and has no parameter changes.

After a model has been created, then a new synthetic seismic can be created or the current synthetic can be recalculated using this model with new parameters. If Automatically calculate new synthetic seismic on Apply/OK is selected, then the Create new synthetic seismic and Recalculate synthetic seismic buttons will not be available until the parameters are changed.

For poststack output, the angle and wavelet parameters may be updated and the synthetic seismic recomputed interactively via the Recalculate synthetic seismic button. For prestack output, the wavelet parameters may be updated and the synthetic seismic recomputed in the same way.

If you select Pre-Stack Gathers, each gather has one trace per angle defined in the Angle range parameters. These traces can be displayed in the 3D viewer or 3-26 Reservoir AVO Modeling 2013.1


Creating a Wedge Model the specific prestack viewer provided by the Prestack Seismic Interpretation plug-in.

Fig. 3-18 Make wedge model Synthetic seismic modeling tab Prestack OutputUser Guide 3-27


Creating a Wedge Model Fig.319SyntheticseismicgatherinPrestackwindowfromthePrestackSeismicInterpretationplugin,andcorrespondingwedgemodelintheWellsection*window3-28 Reservoir AVO Modeling 2013.1


Creating a Wedge Model Some example wedge model views are shown below. When the synthetic response of a wedge model has been computed, then it can be displayed in Petrel in conjunction with the wedge model as shown below:

Fig. 3-20 Wedge Model Superimposed on the Synthetic Seismic VolumeUser Guide 3-29


Creating a Wedge Model Fig. 3-21 Wedge Model Superimposed on the Prestack Synthetic Gathers3-30 Reservoir AVO Modeling 2013.1


4 Workflow Integration

In this Chapter

Workflow Integration ................................................................................. 4-2

Volume attributes in the Workflow editor ..................................................... 4-3

Wedge modeling in the Workflow editor ...................................................... 4-4User Guide 4-1


Workflow IntegrationWorkflow Integration

Use the Petrel Workflow editor to incorporate Reservoir AVO Modeling components into larger and more complex integrated workflows. These workflows can also incorporate any of the other standard Petrel workflow functionality to streamline your seismic-to-simulation workflows. The workflow can be saved as part of the Petrel project in the standard way.

The workflow approach allows you to configure multiple volume attribute or make wedge model jobs without the limitations associated with the process dialog. The Volume attributes workflow dialog allows you to create attributes from the Reservoir AVO modeling category and edit their parameters. You can also run a saved workflow from the command line (refer to the Petrel documentation for details) if batch processing is required.

Note: Objects created in the Workflow editor include more detailed history

information than objects created directly in the process do.4-2 Reservoir AVO Modeling 2013.1


Volume attributes in the Workflow editorVolume attributes in the Workflow editor

In the Workflow editor, the Volume attributes workstep is used to create synthetic seismic modeling and spectrally shaped random noise volume attributes. The Volume attributes workstep is available from the Geophysics branch under the Processes pane. Multiple Volume attribute instances, each with its own set of independently editable parameters, can be added to a workflow as shown below. Double-click any of the worksteps to open a dialog for that instance.

Fig. 4-1 Volume attributes in Workflow editorUser Guide 4-3


Wedge modeling in the Workflow editorWedge modeling in the Workflow editor

The Make wedge model workflow dialog allows you to create and edit wedge models. In the Workflow editor, the Make wedge model workstep is available from the Geophysics branch under the Processes pane.

Individual Make wedge model instances, each with its own set of independently editable parameters, can be added to a workflow as shown below. Double-click any of the Make wedge model worksteps to open the dialog for that instance.

Fig. 4-2 Make wedge model in Workflow editor4-4 Reservoir AVO Modeling 2013.1


Contents1 Reservoir AVO Modeling 2013.1OverviewSystem RequirementsCertified Hardware SolutionsSoftware CompatibilityOperating Systems

LicensingLicensing SupportPurchasing a License on the Ocean Store

Plug-in InstallationBefore You InstallInstalling Reservoir AVO Modeling 2013.1

Technical SupportTrainingConventions

2 Reservoir AVO Modeling and Petrel 2013Reservoir AVO Modeling Integration with Petrel 2013Volume attributes FunctionalityMake wedge model Process

ToolTip HelpHelp and Support

3 Using Reservoir AVO ModelingUsing Reservoir AVO ModelingPerforming Isotropic Synthetic ModelingUsing the Spectrally shaped random noise Volume AttributeRealizing Pre-existing Volume AttributesCreating a Wedge ModelWedge Model ResolutionGenerating a Wedge ModelGenerating a Synthetic Seismic Volume

4 Workflow IntegrationWorkflow IntegrationVolume attributes in the Workflow editorWedge modeling in the Workflow editor

Reservoir AVO Modeling 2013.1 UserManual

Documents

Transcript of Reservoir AVO Modeling 2013.1 UserManual