Well Correlation

Petrel Workflow Tools5 Day Introduction Course

FaultModeling

FaciesModeling

Well DesignVolume Calculation

Plotting

PillarGridding

Depth Conversion

PetrophysicalModeling

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Seismic

Petrophysical ModelingObjectives

Discuss Different Petrophysical Modeling Techniques– Deterministic techniques– Stochastic techniques Learn How to Use Common Settings– Setting filters– Using many realizations Learn How to Use Zone Settings – Define zones Use The Different Algorithms– Sequential Gaussian Simulation– QC results Property Calculator

Overview

Interpolation with smooth effectKriging, Moving average

Regenerate local variationSequential Gaussian Simulation SGS

Petrophysical

Deterministic

Stochastic

• If well logs are up-scaled, they can be used in Deterministic and Stochastic modeling • If no logs are available, deterministic methods cannot be used, only unconditional stochastic

methods.

Common Settings

Two main buttons are available:• Common• Zone Settings

Define Common settings for all zones:• Use filter• Ensure that all cells get a value• Number of realizations

Zone Settings

1. Define Zone settings for each zone:A. Press the Zones button.B. Select zone of interest from the drop-

down menu.

1A1B

2. Select proper modeling technique:A. Press the padlock button to open the

settings for the selected zoneB. Select a method from the drop-down

menu for the zone

2A

2B

Sequential Gaussian Simulation (SGS) – Set Up

1. Property and zone selectionA. Make sure to pick the correct upscaled

property ([U] as suffix). B. Select SGS as method for the zone. 1B

1A

2. Variogram tab:A. Specify Range, Nugget and TypeB. or get a variogram from Data Analysis

2A

2B

3. Distribution tab:• Select Standard and From Upscaled logs

From distribution function

Used if no/few upscaled logs

Used if upscaled logs

3

Sequential Gaussian Simulation (SGS) – Results

SGS is a krig-based stochastic method• Needs a variogram.• Will honor the distribution

of the input data (upscaled logs).

• Petrel will automatically do a Normal score transformation before the simulation, and will back-transform the data.

• The output is distributed in a blurry manner.

QC Results

Filter:4) Use Zone filter5) Filter on other property values by

pressing the filter button and go to Property filter in Settings for the Properties folder.

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QC results in a histogram:• Go to the Settings for the Property

and select Histogram tab• Check that the Histogram follows

the distribution from: 1) Raw logs

2) Upscaled cells

3) 3D grid

1-3

Property Calculator – SW Property Example

1) Type in a simple expression. This requires:• Above Contact property from Geometrical modeling.• Function (imported or made in Petrel (SW vs. height)).

SW is a function of height above fluid contact,permeability and porosity. Two main options:

x

=

2) Load a more advanced expression (.mac/.txt file):• Toggle From file, browse and Run.

More Petrophysical Modeling in Petrel

Property Modeling course (3 days)

• Data analysis and basics of geostatistics• Data preparation, including well correlation• Facies Modeling; sequential indicator simulation, facies transition simulation, object facies modeling (adaptive channel), interactive facies modeling• Petrophysical modeling; data analysis, porosity modeling, permeability modeling• Modeling based on seismic attributes

EXERCISE Petrophysical Modeling