Download the Getting Started Guide

Pre-Stack Pro
Getting started guide
Version 4.4
Contents
• New Features
- Synthetic modelling
- 1D Model Builder
- Processing algorithms
 Dip Filter
 Tau-P Deconvolution
 Velocity Converter
- New Attributes
- Cultural Data and Coordinate Reference System
- Multi-azimuth data support
- Utilities
• Improvements of existing features
- Well Log Viewer
- Wavelet Tool
- Data Comparator
- 2D SEG-Y loading
2
Sharp Reflections 2015
File Number
SYNTHETIC MODELLING
3
Sharp Reflections 2015
File Number
1D synthetic modelling
Interpretation-Processing > Generate synthetic gather ...
Define logs and wavelet
for synthetic
Define geometry for output.
Can be copied from an
existing dataset in the
volume pool.
4
Sharp Reflections 2015
File Number
1D synthetic modelling
Zoeppritz, Aki-Richards, etc
Modelling options
Can make synthetic with no NMO
correction for offset synthetics (but not
for angle synthetics)
If a T-D table exists in the well it can
be used. In that case the Fit Accuracy
parameter controls how closely the TD table is honoured.
If there is no T-D table or it is not
desired to use it, a single time-depth
pair can be entered manually and the
T-D curve is obtained from that point
and the integrated sonic log.
A simple overburden model can be typed in to define
what happens above the start of the logs. This is
important when creating offset synthetics, as it
affects the angle-to-offset relationship considerably.
5
Sharp Reflections 2015
File Number
1D synthetic modelling
Logs can be de-spiked and
blocked if desired.
Log preconditioning
Spikes are identified by looking for
deviation from a moving window
average (the min amplitude) and a
maximum width (in depth). They are
replaced by interpolated values.
Blocking is based on identifying jumps
in the logs by comparing moving
window statistics. A block boundary is
defined if a jump exceeds a fraction of
the local value.
The maximum block thickness is also
specified to ensure that detail is not
lost in the blocking process.
6
Sharp Reflections 2015
File Number
1D MODEL BUILDER
7
Sharp Reflections 2015
File Number
Introduction
• New feature in version 4.4: 1D Model Builder
• Creates 3 synthetic logs at any well, Vp, Vs and density
( logs called .SynthModel_Vp, _Vs and _Rho )
• These logs are made from at least 3 user defined layers.
( Top, Target and Bottom layers + any added inbetween)
• The Target layer has a fixed top MD, from which the model is built
• All the layers have a thickness to define their top / base from this
• Layer properties can be defined as follows •
: Vp, Vs, Rho by manual entry of values,
•
•
•
•
:
Vs, Rho by Castagna and Gardner equations
: Vp, Vs, Rho by well facies or zone, averages
: Vp, Vs, Rho by «Reservoir» Castagna fluid substitution
: Vp, Vs, Rho by «Reservoir» Gassmann fluid substitution
• A Synthetic gather is created using ‘Start Synthetic Gather Algo..’
• Any model input log update, forces a redraw of this synthetic
8
Sharp Reflections 2015
File Number
Introduction
• Interpretation Processing  1D Model Builder
• New feature in version 4.4:
• Creates 3 synthetic logs at any
well - Density, Vp and Vs
9
Sharp Reflections 2015
File Number
Model setup
Select Well for log use/save
Enter Target layer top depth ( MD )
( 2000 = model reference datum )
Choose which layers will be
‘reservoir’ and have fluid
substitution options
Enter layer thickness in m
10
Sharp Reflections 2015
File Number
Layer properties definition
• Vs, Density coefficient selection
Shale coeffs
Select Preset
lithology or enter
values into
coefficient boxes
Sandstone coeffs
11
Sharp Reflections 2015
File Number
Layer properties definition
• Vp, Vs, Density facies/zone averages 1
Zones created in Well Log
Viewer, can be used to
calculate an average Vp,
Vs, Rho - in this case for
Shale
Shale zone Vp, Vs Rho
averages
12
Sharp Reflections 2015
File Number
Layer properties definition
• Vp, Vs, Density facies/zone averages 2
Shale zone Vp, Vs Rho
averages
13
Sharp Reflections 2015
File Number
Layer properties definition
• Vp, Vs, Rho, from fluid substitution – reservoir layers only
Castagna equation – consolidated sands
Gassmann equation – soft sands
14
Sharp Reflections 2015
File Number
Final 5 layer model
• Example from Fred Hilterman’s 2001 SEG DISC book :
Seismic amplitude interpretation - 9000ft GOM AVO
Shale Vp = 2600 m/s, Sst (Brine) Vp = 3000 m/s, Vs & Rho from equations
Brine filled Sand
Gas filled Sand
Calculated by Gassmann
fluid sub,  = 25%
15
Sharp Reflections 2015
File Number
Calculate synthetic gather
• Angle gather -
with bpass wavelet 5-15-45-55
Click on «Start Synthetic Gather
algo» takes the model logs and
creates a gather synthetic.
The wavelet applied comes from
the project wavelet list.
Use the «Tie log depth» modelling
option to ensure the synthetic
Target layer top is at the right
TWT.
( MD = TVDss = 2000m = 2.0secs )
16
Sharp Reflections 2015
File Number
View results in Data Comparator
Data Comparator allows wiggle
trace display
Also amplitude extractions can
be made for the brine and gas
cases and visually compared in
the plots above the gathers.
( blue = brine, red = gas )
The first gather is with a 50m
gas reservoir thickness
The 2nd with only 10m
Brine Sand
Gas Sand
The thinning of the layer has
dimmed the AVO response but
it stays opposite in polarity
17
Sharp Reflections 2015
File Number
PROCESSING
18
Sharp Reflections 2015
File Number
Dip Filter
• Processing  Dip Filter
• Attenuate given dips on pre-stack volume in the
offset class domain or post-stack
Section size and overlap. Recommends large section and overlap
of 50% in all axis
Definition of dip to remove
19
Sharp Reflections 2015
File Number
Tau-P deconvolution
• Processing  Tau-P deconvolution
• Predictive gaped deconvolution in Tau-P domain.
Targets short period multiples. Input is non NMO
corrected gathers
20
Sharp Reflections 2015
File Number
Tau-P deconvolution
Definition of both design and application windows
Graphical gap design. Shift + Mouse left button
to move the line.
Tau-P transform parameters and operator length parameters.
NB: Operator length correspond to the active part of the operator.
21
Sharp Reflections 2015
File Number
Velocity converter
• Processing  Velocity converter
• Input a velocity volume and convert to Interval/RMS
on the fly.
22
Sharp Reflections 2015
File Number
NEW ATTRIBUTES
23
Sharp Reflections 2015
File Number
Dip-Steered Semblance
Stack with dipping events and its inline slope attribute
24
Sharp Reflections 2015
File Number
Dip-Steered Semblance
• Go to Attributes -> Dip-steered semblance
• The algorithm takes as input a seismic volume and its
inline and crossline slopes computed per offset classes.
• Semblance is a measure of the coherence of seismic
data and is equal to the energy of a stacked trace
divided by the energy of all the traces that make up the
stack. The stencil within which the semblance is
computed will use the inline and crossline slopes to
follow dipping events, resulting in a better estimation of
the signal coherency for structures with large dips than
with conventional vertical moving windows.
25
Sharp Reflections 2015
File Number
Dip-Steered Semblance
• Slopes can be calculated
with Attributes ->
Structural Dip
• For time domain data the
slopes will be measured in
slowness along the inline
and crossline direction
• This attributes are derived
from the second-moment
matrix of the seismic that
involves the computation
of the gradient in a stencil
Dipping event
26
Sharp Reflections 2015
File Number
Dip-Steered Semblance
• The user has to specify 2
parameters for slope
calculation
• Noise scale: defines the
resolution of the filter.
• Integration scale: gives a
trade of between edgeenhancing diffusion and
coherency enhancing
diffusion behavior
Positive slope
associated to the
dipping event
27
Sharp Reflections 2015
File Number
Signal to Noise Ratio
Signal to Noise Ratio extracted at top reservoir
28
Sharp Reflections 2015
File Number
Signal to Noise Ratio
• Go to Attributes -> Signal to Noise Ratio
• S2N is defined as the ratio between the signal power to
the noise power. Two methods have been implemented
to estimate this measure. A correlation method based
on the assumption that the form and phase of the signal
is consistent across neighbor traces and that the noise
is spatially incoherent and uncorrelated to the signal.
The stack method makes the assumption that the
seismic wavelet is stable in a given spatial window and
that the noise is white.
29
Sharp Reflections 2015
File Number
Signal to Noise Ratio
• Correlation method
• The user specifies the
size of the stencil (in
space and time) and the
maximum time shift which
corresponds to the halflength of the correlation
window
• Xc = average correlation
coefficient between
central and neighbors
traces
• Ac = auto-correlation
coefficient of the central
trace
• S2N = Xc/(Ac-Xc)
Region with high signal
to noise ratio
30
Sharp Reflections 2015
File Number
Signal to Noise Ratio
Region with low signal to
noise ratio
31
Sharp Reflections 2015
• Stack method
• The user specifies the
size of the stencil (in
space and time)
• Since the noise is
assumed to be white its
spatial average value
inside the stencil is zero
• Therefore the energy of
the signal is the spatial
some of the square of the
stacked trace and the
energy of the noise is the
total energy minus the
energy of the signal
File Number
Geometric Properties
• Go to Attributes -> Geometric Properties
• Input has to be an horizon or a stack volume (in this
case the computation will be done for every time slices)
• Curvature attributes are calculated by locally fitting (in a
least-square sense) a second order 2D polynomial to
the input horizon
• Outputs will be the maximum and minimum curvature as
well as the maximum dip angle and azimuth
32
Sharp Reflections 2015
File Number
Geometric Properties
Horizontal dip (0 degree) at the top of the anticline
Maximum dip angle computed on a synthetic checkerboard
33
Sharp Reflections 2015
File Number
Examples
34
Sharp Reflections 2015
File Number
Examples
35
Sharp Reflections 2015
File Number
Example
36
Sharp Reflections 2015
File Number
Examples
37
Sharp Reflections 2015
File Number
38
Sharp Reflections 2015
File Number
COORDINATE REFERENCE
SYSTEMS (CRS) AND
CULTURAL DATA
39
Sharp Reflections 2015
File Number
Project Coordinate Reference System (CRS)
• Project CRS is defined in Project->Edit Project
Geometry in the tab Project CRS
Name of CRS
Blue: Cursor marked CRS
Green: Currently chosen Project CRS
Complete definition of Project CRS –
in Well-Known Text (WKT) format
Number in the IOGP’s EPSG Geodetic Parameter
Dataset. IOGP : International Association of Oil &
Gas Producers. EPSG : European Petroleum
Survey Group. www.epsg.org
40
Sharp Reflections 2015
File Number
Choosing a new CRS
• Open Project CRS tab in Project->Edit Project
Geometry
• Choose a new CRS from the predefined list
• Double click on the new CRS (turns green), and Save
Filter used to reduce the number of
possible CRS’s. Only CRS’s that fit
the filter will be visible. Use wildcard *
between text strings.
After double clicking on a given CRS,
it will be chosen as the Project CRS.
Notice that whenever the user marks a CRS by
clicking on it, it will turn blue. When choosing a new
CRS by double clicking on it, the new CRS will look
blue. If the user moves the cursor to another CRS and
marks it by clicking once – this CRS will turn blue,
while the chosen Project CRS will be visible as green.
The CRS Definition will be updated
when choosing a new Project CRS.
Save the new Project CRS
41
Sharp Reflections 2015
File Number
Cultural data - import
• Project  Import  Import Cultural Data...
• Input a file or directory with cultural data in
shapefile format.
Shapefile format
42
Sharp Reflections 2015
File Number
Cultural data – in File Manager
Imported cultural data visible in File Manager
43
Sharp Reflections 2015
File Number
Cultural data – in Map Viewer
Example from the Norwegian
Continental Shelf: Block data
and discoveries.
Turn visualization on/off, and change color.
44
Sharp Reflections 2015
File Number
Cultural data and coordinate reference system
• The shapefile contains information about the UTM
zone for the imported cultural data.
• PSPRO will convert or transform the imported cultural
data to the project defined coordinate reference
system.
• There is no coordinate conversion or transformation
for project data (seismic, horizons, well locations etc.).
• It is still the user’s responsibility to import project data
in a consistent way, i e. that the coordinates for all
project data are imported with the same UTM zone.
45
Sharp Reflections 2015
File Number
UTILITIES
46
Sharp Reflections 2015
File Number
Unit conversion
• Utilities  Unit
converter
In any viewer, click on the read out value to change
the units.
47
Sharp Reflections 2015
File Number
Trace header interpolation
• Utilities  Trace header interpolation
• Workflow for interpolating a stack and using the
header for SEG-Y output
- Interpolate the stack volume
- Interpolate the original headers to the same geometry
- In SEG-Y output, used the interpolated header to copy the
X/Y locations
Same grid as the volume you want to output
48
Sharp Reflections 2015
Tick off to create a new header
File Number
SUPPORT OF MULTI AZIMUTH
DATA
49
Sharp Reflections 2015
File Number
Import of Irregular files
• Pre-Stack Pro currently do not handle the
import of 5D irregular SEGY files.
• For this you will need the tool Seismic Data
Certification developed by Fraunhofer ITWM.
• Please contact directly Dr. Norman Ettrich to
request the binary and user manual:
[email protected]
50
Sharp Reflections 2015
File Number
2D Viewers
Switch between the first fold axis and the second fold axis
Browse through first/second fold classes
COV gathers displayed in the prestack viewer
51
Sharp Reflections 2015
File Number
2D Viewers
• Supported input data are:
- COV (common offset vectors)
- COCA (common offset common azimuth)
- CICA (common incidence angle common azimuth)
COCA/CICA gather = polar binning
52
-
Sharp Reflections 2015
COV gather= Cartesian binning
File Number
2D Viewers
Look at your COCA/CICA gather along the offset/angle direction for constant azimuth
sectors
Look at your COCA/CICA gather along azimuth direction for constant offset/angle slices
Look at your COV gather along the Offset X direction
Look at your COV gather along the Offset Y direction
53
Sharp Reflections 2015
File Number
Algorithms
• Most algorithms have been extended to handle
5D data.
• However, the following ones can’t currently have
multi-azimuth gathers as input:
- EPS 3D
- Structural Dip
- Q Models & Filters
- Multi Well Scalar
- Tau-p decon
- AVO Scaling
- Semblance Optimization
- RMO
- Continuous Velocity Analysis – Offset Interpolation
- Dip Filter
- PCube
54
Sharp Reflections 2015
File Number
Algorithms
• In addition, some algorithms will only allow
COCA or CICA gathers (mostly for Geophysical
reasons):
- Offset to Angle (and reciprocal)
- Radon
- 2D ECED
- AVA attributes
55
Sharp Reflections 2015
File Number
Algorithms
Create a 5D mute (one mute per
azimuth sector) by right clicking
on a control point
Change the preview for different
second fold (azimuth/Offset Y)
values
Gather displayed along
the first fold
(offset/angle/offset X)
Linear Radon muting on COCA gathers
56
Sharp Reflections 2015
File Number
5D Horizon Tracking
5D gathers
3D horizon
Parameters for 5D extension are
the same as for the classic 4D
extension.
57
Sharp Reflections 2015
File Number
5D Horizon Tracking
Horizon extend along the offset direction
Extend your horizons to prestack both in the offset and azimuth
direction
58
Sharp Reflections 2015
File Number
5D Horizon Tracking
Horizon extend along the azimuth direction
Extend your horizons to prestack both in the offset and azimuth
direction
59
Sharp Reflections 2015
File Number
COCA Sectorization
Select the desired number
of azimuth sectors
Choose an appropriate number of
Offsets
Stack together all the traces falling in
the same bin or select the trace that is
the closest to its center
Rebin your data from COV (Cartesian) to COCA (polar)
60
Sharp Reflections 2015
File Number
WELL LOG VIEWER
61
Sharp Reflections 2015
File Number
Well Log Editor  Custom edits
1. Create a temporary copy for editing
62
Sharp Reflections 2015
File Number
Well Log Editor  Custom edits
2. Combine logs and choose
Custom merge
63
Sharp Reflections 2015
File Number
Well Log Editor  Custom edits
3. Choose 2nd log and use Custom
Equation to create a new log.
In this example we are creating a Vp/Vs ratio
64
Sharp Reflections 2015
File Number
Manage Wells  T/D Tables
Several T/D tables can be associated to one well
One must be active and applied to the wellpath for the stretch
65
Sharp Reflections 2015
File Number
Well Log Set
1. Manage Log Set
2. Create a set and move logs to it.
Log set can then be manipulated as a group
of objects.
66
Sharp Reflections 2015
File Number
WAVELET TOOL
67
Sharp Reflections 2015
File Number
New Features
•
•
•
•
•
68
Setting the default sample interval
Reorganised menus
Automatic zero-phasing on load
Creating spectra from well logs
Coloured inversion workflow
Sharp Reflections 2015
File Number
Set the default sample interval
• This value is used as the default sample interval for any new wavelets
created in the wavelet tool.
• Wavelets loaded from the project keep their original sample interval.
• If it is changed during a session, any wavelets already in the tool are
not resampled, they keep their original sample interval. Any wavelets
created after the change will have the new default sample interval.
• This is just the default value for the sample interval. The individual
GUIs for adding wavelets still allow you to change the sample interval
for individual wavelets.
69
Sharp Reflections 2015
File Number
Reorganised function menus
• The tabs have been
replaced by a dropdown menu list.
• There is an item for
coloured inversion
to clarify the
workflow.
70
Sharp Reflections 2015
File Number
Zero-phasing on load from project
• Since the first step in many workflows is to zero-phase
the extracted spectra, an option has been added to
“Load from project” to perform this automatically.
• It is On by default, so don’t forget to switch it off if you
need the phase information too.
71
Sharp Reflections 2015
File Number
Creating spectra from well logs
Choose a t-d table
from drop-down list
Start and end depths (in MD) for the spectral
analysis can be typed in or defined by tops.
72
Sharp Reflections 2015
File Number
Coloured inversion
• The key steps in the
coloured inversion
workflow are collected in
the CI Function group to
clarify the workflow.
• The tools have been
modified to include
spectral smoothing,
tapering, and filtering
where necessary instead
of having to use
separate functions.
73
Sharp Reflections 2015
File Number
DATA COMPARATOR NEW
FEATURES
74
Sharp Reflections 2015
File Number
Attributes computation
1. Select input volume
2. Select attribute
75
Sharp Reflections 2015
File Number
Amplitude extraction
3. The amplitude extraction is done
on all visible panels
1. Right click and select
«Extract amplitude on all panels»
2. Parameters window opens
76
Sharp Reflections 2015
File Number
Use of points set
Points Set are Seed points put a different locations.
It allows you to cycle through all locations on all panels.
1. Activate it by clicking on the flag icon
2. Choose the SeedPoints set and go trough each
location.
77
Sharp Reflections 2015
File Number
New icons and other features
1
2
• 1. Set the width of all panels
• 2. Toggle on/off the read
out extraction for all panels
• A horizon that has been snapped on one panel can be
used for Amplitude Extraction on another panel, when
dragging the horizon on the panel there is now a small
pop-up that asks whether the horizon should just be
displayed on the panel or used for an extraction.
• The Datapanels can now be reordered using Drag &
Drop in the tree and resized manually via the context
menu or all at once via a toolbar button.
• The y− axes of the amplitude plots are now
synchronized by default if the Data panel display data
from the same domain. This can be disabled in the
Control Tab.
78
Sharp Reflections 2015
File Number
2D SEG-Y LINES
79
Sharp Reflections 2015
File Number
2D SEG-Y lines import
Necessary keys are:
- Line number
- CDP number
- World X and Y coordinates
- Fold
80
Sharp Reflections 2015
File Number
2D SEG-Y lines import
A path representing the line position will be created
81
Sharp Reflections 2015
File Number
2D SEG-Y lines import
• It is possible to import several lines as a batch
• The lines position can be displayed on a map using
the corresponding arbitrary paths
82
Sharp Reflections 2015
File Number