NAME
stratslab - Extract a stratigraphic slab of data bracketing
a picked horizon or formation. stratslab [ -Nfile_in ] [
-Ofile_out ] [ -tmaxtmax ] [ -tdatumtdatum ] [ -ttaperttaper
] [ -uhuh ] [ -lhlh ] [ -uwuw ] [ -lwlw ] [ -nonHorzTra-
ceValuenhtVal ] [ -DeadTraceValuedeadVal ] [ -startrecstar-
trec [ -endrecendrec [ -starttracestarttrace [ -endtra-
ceendtrace [ -nonHorzTraceLive ] [ -L ] [ -U ] [ -V ] [ -VT
] [ -? ]
DESCRIPTION
stratslab extract an irregular window (slab) of seismic data
about a picked stratigraphic horizon or formation from a 3D
data cube.
stratslab gets all its parameters from command line argu-
ments. These arguments specify the input file name and hor-
izon header words, as well as the output horizon file name
and windowing directives.
-N file_in
Enter the input file name immediately after typing -N.
This input file should include the complete path name
if the file resides in a different directory. Example
-N/export/data2/san_juan/time_stack tells the program
to look for file 'time_stack' in directory
'/export/data2/san_juan'. Missing data should be pad-
ded in with dead traces flagged by the dead trace
header flag 'StaCor'=30000. The absence of the -N
option indicates the data are read in via standard
input (such as a pipe).
-O file_out
A Enter the output filtered data set name or file
immediately after typing -O. This output file name is
not required when piping the output to another process.
-uh uh
Enter the trace header word name (posibilities include
Horz01, Horz02,..., Horz08) of the upper horizon to be
used in flattening. (Default: uh=Horz01).
-lh lh
Enter the trace header word name (posibilities include
Horz01, Horz02,..., Horz08) of the lower horizon to be
used in flattening. Horizons that do not exist at a
given trace (such as caused by erosion or faulting)
should be indicated with a trace header value of
-30000. These headers are most often filled in upon
export from an interpretive workstation, using a pro-
gram such as lm3dhrztosis (Default: lh = uh).
-nonHorzTraceValue nhtVal
Enter the value that should be given to traces that do
not have the horizon(s) of interest defined (trace
header for horiz = HrzNul). The default value is 0.
-DeadTraceValue deadVal
Enter the value to be given to dead traces (default =
0).
-uw uw
Enter the beginning window of the data to be extracted,
measured relative to the upper horizon, uh (Default
uh=-48 ms).
-lw lw
Enter the beginning window of the data to be extracted,
measured relative to the lower horizon, lh (Default
lh=+48 ms).
-tmax tmax
Enter the length in ms (m, ft) of the output, flattened
slab of seismic data. (Default tmax=200 ms)
-tdatum tdatum
Enter the output datum time in ms (m,ft). The upper
horizon will be mapped to tdatum if -U is specified,
while the lower horizon will be mapped to tdatum if -L
is specified. In the absence of -U or -L, the center of
the extracted slab/formation will be mapped to tdatum.
Default tdatum=tmax/2..
-ttaper ttaper
Enter the length in ms (m, ft) of a taper to be applied
to the beginning and end of the output data slab
(Default: ttaper = 0 ms, or no tapering).
-startrec startrec
Enter the first output record to be generated (Default:
startrec=1, the first record of the data set).
-endrec endrec
Enter the last output record to be generated (Default:
endrec= the last record of the data set).
-starttrace starttrace
Enter the first output trace to be generated (Default:
starttrace=1, the first trace of the data set).
-endtrace endtrace
Enter the last output trace to be generated (Default:
endtrace= the last trace of the data set).
-nonHorzTraceLive
If present, do NOT mark traces in which the horizon(s)
of interest are not defined as dead. (Default is to
mark them dead)
-L If present, flatten on the lower horizon, lh (Default:
Flatten on the midpoint between uh and lh).
-L If present, flatten on the lower horizon, lh (Default:
Flatten on the midpoint between uh and lh).
-VT Enter the command line argument '-VT' to get printout
of current status of program. A message will be
printed to stderr every time a new record is encoun-
tered.
-V Enter the command line argument '-V' to get additional
printout.
-? Enter the command line argument '-?' to get onrec help.
The program terminates
after the help screen is printed.
EXAMPLE 1:
Export a slab of seismic amplitude data called 'amp01.3dv'
from a landmark project called 'baltim' bounding the
'eocene' horizon for use in routine princ3d. Pipe this file
back into the landmark.
#!/bin/sh -e
lm3dvtosis -project baltim -input amp01.3dv |
lm3dhrztosis -project baltim -Horz01 eocene |
stratslab -uhHorz01 -uw-40 -lw+40 -tmax 100 tdatum 50 -Ttaper 10 |
princ3d -lwin 80 |
sistolm3dv -project baltim -output princ01.3dv
EXAMPLE 2:
Export a slab of seismic amplitude data called 'amp01.3dv'
from a landmark project called 'baltim' bounding the
'eocene' horizon for use in routine semb3d. Bring both the
intermediate solid angle dip/azimuth as well as coherence
file back into the into the landmark. In this code, we only
need to calculate the slab at 50 ms (the time flattened in
the previous, stratslab step).
#!/bin/sh -e
lm3dvtosis -project baltim -input amp01.3dv |
lm3dhrztosis -project baltim -Horz01 eocene |
stratslab -uhHorz01 -uw-40 -lw+40 -tmax 100 -tdatum 50 -ttaper 10 |
semb3d -smax 0.25 -rad 30 -tstart 50 -tend 50 -S semblance -omega dip_azimuth
#
sistolm3dv -project baltim -input semblance -output semb01.3dv
sistolm3dv -project baltim -input dip_azimuth -output omega01.3dv
EXAMPLE 3:
Export a slab of seismic amplitude data called 'rwflt.3dv'
from a landmark project called 'baltim' bounding the
'eocene' horizon for use in routine samps. Bring the result-
ing frequency traces to Landmark as a "3dv" file which can
be used for subsequent frequency slices.
#!/bin/sh -e
lm3dvtosis -project baltim -input rwflt.3dv |
lm3dhrztosis -project baltim -Horz01 eocene |
stratslab -uhHorz01 -uw-50 -lw+50 -tmax 100 -tdatum 50 -ttaper 10 |
samps -f270 -fi1 -Oout.samps
utop -Nout.samps -dt1 |
sistolm3dv -project baltim -output nsfr01.3dv
REFERENCES:
BUGS
No bugs known at present.
SEE ALSO
flatten, rest, lm3dvtosis, sistolm3dv, lm3dhrztosis
CONTRACT AGREEMENT
This product is brought to you by Development Agreement D-
95-2548 (the Seismic Coherency Cube). Thank you for your
support.
AUTHOR
Kurt J. Marfurt, EPTG (1995).
COPYRIGHT
copyright 2001, Amoco Production Company
All Rights Reserved
an affiliate of BP America Inc.
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