7/25/2019 M5 Log Upscaling
1/16
Module 5
Property Modeling
7/25/2019 M5 Log Upscaling
2/16
Petrel Workflow Tools
3D Grid
Construction
Structural Gridding
Stratigraphic
Modeling
Pillar Gridding
Well Log
Upscale
Facies &
Petrophysical
Modeling
Make contacts &
Volume Calculation
IntrotoPetrel
Interface
Workflow
Editor
Property Modeling
Make HorizonsZones & Layering
3D Grid Construction: Structural Modeling
Studio
3D Grid
Construction
Structural
Framework
Fault Modeling
Introduction Surfaces and
Data edit
7/25/2019 M5 Log Upscaling
3/16
Upscaling of Well Logs
Objectives
Gain an understanding of the concept and process
Understand and use discrete logs Averaging methods Facies weighting.
Understand and use continuous logs Averaging methods Biasing to a discrete log.
Look at different Scale-up settings
Treat log as lines or points Method of which penetrated cells to use.
QC of upscaled logs: Using well section window.
7/25/2019 M5 Log Upscaling
4/16
Overview
Cells exist along the well path.
Values assigned to cells based on
well log values along the well path.
Upscaled logs used to fill in the 3D grid.
The Scale-up well logs process averages the values to the cells in the 3D grid
that are penetrated by the wells. Each cell gets one value per upscaled log.
These cells are later used as a starting point for Property modeling.
Note: An upscaled property will have a [U]following its name in the Propertyfolder in the Modelspane.
7/25/2019 M5 Log Upscaling
5/16
Scale-Up Well Logs
Note: Upscaled logs will be part of the 3D property at the well
positions. The Property modeling processes will NOT overwrite
upscaled cell values!
1. Create a new property.
3. Choose a logfrom the drop-down list (captured
from Inputpane > Global well logsfolder)
4. Set the best scale-up Settings, depending on
the type of log (continuous or discrete).
2. Select Input from Well logs.
5. Click Applyor OK.
1
2
3
4
5
7/25/2019 M5 Log Upscaling
6/16
Commonly used Averaging Methods
Averaging
method
Description
Most of Used together with discrete logs, it selects the discrete value that is most represented in
the log for each particular cell.
Arithmetic mean Typically used for additive properties, such as porosity, saturation, and net/gross.
Harmonic mean Gives the effective vertical permeability if the reservoir is layered with constant
permeability in each layer. It works well with lognormal distributions and is sensitive to
lower values.
Geometric mean Normally a good estimate for permeability if it has no spatial correlation and is lognormally
distributed. It is sensitive to lower values.
7/25/2019 M5 Log Upscaling
7/16
Averaging Discrete Logs
Discrete logs, such as facies, have only
integer values (0,1,2, etc.).
2. The Average method is normally Most of, whichuses the value most represented in the cell.
3. In some situations, it may be necessary
to use the Weighting option. Click Use
weightingand fill in the Weighted tab.
1. Choose an input from a Facies well log to create a
new property.
2
3
13
7/25/2019 M5 Log Upscaling
8/16
Averaging Continuous Logs
Continuous logs, such as porosity, have realnumber values (decimals).
4. Specify that there should be a Minimum number of
well log samples in a cell for it to be included in the
upscaling.
2. Set the Average method (here Arithmetic for porosity).
3. It is possible to bias to an already upscaled facies log.
1. Choose an input from a continuous Well log to create
a new property (here, porosity).
1
2
3
4
7/25/2019 M5 Log Upscaling
9/16
Biasing to a Discrete Log
Raw porosityUpscaled facies Upscaled porosityRaw facies
Sand
Shale
7/25/2019 M5 Log Upscaling
10/16
Settings: Treat Log as Lines or Points
Treat log Description
As points All sample values within each cell are used for averaging.
As Lines If the midpoint of a line between two sample points is inside a cell the point outside the cell
will be used in the calculation.
7/25/2019 M5 Log Upscaling
11/16
Settings: Method of Which Penetrated Cells to Use
Method Description
Simple All cells penetrated by the well
trajectory are included.
Through cell The well trajectory must penetrate two
opposite cell walls.
Neighbor cell All penetrated cells are used but cellsin the same cell layer are averaged.
7/25/2019 M5 Log Upscaling
12/16
Quality Checking Upscaled Logs
When upscaling is done, it is a good practice
to QC the upscaled cells with the original log
in a Well section window.
1. Click the Show result in well sectionbutton in
the Scale up well logs dialog.
2. Display the upscaled log in the same track.Right-click on the upscaled log (Modelspane>
Propertiesfolder) and click Add to template in
the existing raw log track.
Alternatively, set up a Well section display on
your own. Choose raw logs (Global well logs
folder > Inputpane), right-click, and select Add
to template in a new track.
1
2
Averaged values for
each cell in the model
on top of the original
log
7/25/2019 M5 Log Upscaling
13/16
EXERCISE
7/25/2019 M5 Log Upscaling
14/16
Upscaling of Well Logs: QC of Upscaled Logs
Synthetic logs resemble the properties (Upscaled logs) but are stored as physicallogs under Global Well Logs.
1. Click the Make logstab of settings for Wells.
2. Choose the property from which the log will be made.
3. Click the Make logs button. The log is stored in the Global
Well Logs folder and can be toggled on from there.
7/25/2019 M5 Log Upscaling
15/16
Averaging Methods for Discrete Logs
Averaging method Description
Most of Will select the discrete value which is most represented in the log for each particular cell
Median Will sort the input values and select the center value.
Minimun/Maximum Samples the min/max value of the well log for the cell.
Mid Point Pick Will pick the log value where the well is halfway through the cell.
Random Pick Picks a log point at random from anywhere within the cell.
7/25/2019 M5 Log Upscaling
16/16
Averaging Methods for Continuous Logs
Averaging method Description
Arithmetic mean Typically used for additive properties such as porosity, saturation, and net/gross.
Harmonic mean Gives the effective vertical permeability if the reservoir is layered with constant
permeability in each layer. It works well with log normal distributions. It is sensitive to
lower values.
Geometric mean Normally a good estimate for permeability if it has no spatial correlation and the is lognormally distributed. It is sensitive to lower values.
Median Sorts the input values and select the center value.
RMS (Root Mean
Squared)
Provides a strong bias towards high values.
Minimun/Maximum Samples the min/max value of the well log for the cell.
Mid Point Pick Picks the log value where the well is halfway through the cell.
Random Pick Picks a log point at random from anywhere within the cell.
Top Related