NAME
velin - create USP velocity data set (or rnmo data set).
SYNOPSIS
velin [ -Nntap ] [ -Ootap ] [ -Pptap ] [ -vvtap ] [ -rnmo ]
[ -xsd ] [ -flat ] [ -tdfn ] [ -hmig ] [ -tensor ] [ -disco
] [ -hwiwd ] [ -shot ] [ -receiver ] [ -cdp ] [ -pri ] [
-sinsin ] [ -soutsout ] [ -vinvin ] [ -voutvout ] [ -ilis ]
[ -sisi ] [ -osiosi ] [ -dxdx ] [ -dydy ] [ -dzdz ] [
-safisaf ] [ -svv0 ] [ -dvdv0 ] [ -psiipsi ] [ -force ] [ -S
] [ -R ] [ -V ] [ -? ]
DESCRIPTION
velin allows the user to create either a USP format velo-
city (or rnmo) dataset from an input velocity (or rnmo)
function set. This function set may be supplied in one of
several formats as discussed below. The output dataset con-
sists of a number of single trace velocity records, one for
every associated record on the control [-N] seismic dataset.
The input velocity function set may contain interval, aver-
age or rms velocity data sampled in time or depth. Any com-
bination of velocity type and sample reference may be chosen
for output. An optional velocity pick file may be generated
to contain the output velocity function set for overlay on
velocity spectra using XSD . The velocity dataset output
from velin may be used as input to other USP routines such
as anmo, bdnmo and taupnmo.
In the case of rnmo functions the concepts of interval, etc
have no meaning and so no such conversions can be done. The
function is merely checked to see that the end time of the
functions are equal to the trace length.
MINIMUM ACCEPTABLE QUALITY CONTROL
Plot the output velocity dataset and verify that velocities
have been correctly interpolated between control points.
Velocity busts are extremely obvious here.
Examine the velocity dataset RecNum trace header values [
using program scan ] to verify that the indexing is correct
between your input velocity function control and your con-
trol seismic dataset. The -np command line entry of pro-
gram scan should be used to examine the actual velocity
sample values on the output dataset.
Use the velin command line entry -V to generate a com-
plete listing of the input and output velocity functions
which should be examined for correctness. This is especially
true if units conversion is being undertaken. This listing
is written to the velin printfile.
Command line arguments
-N ntap [Default: stdin] [may be a pipe]
Enter the fully qualified path name to the file con-
taining your control seismic dataset.
-O otap [Default: stdout] [may be a pipe]
Enter the fully qualified path name to the file to con-
tain your output USP velocity dataset.
-P ptap [Default: not used]
Enter the fully qualified path name for the dataset to
contain your output XSD velocity pick file. If you
use this option then trace offset and increment values
used must correspond to the dataset that you wish to
overlay the velocities on. Also you should attach the
desired display dataset to -N above so that the
correct number of traces per record and samples per
trace get put into the pick file header. For instance
if you have a velspec dataset that you wish to over-
lay some picks on then the -sv and -dv entries on
the command line should correspond to the -vmin and
velocity increment (look in Velspec printout file)
used in the velspec run.
-v vtap [Default: none]
The input velocity function file may be in any of the
formats controlled by the command line flags discussed
below. If the first and last indices in the velocity
file do not correspond to the control data velin will
extrapolate using the closest function. Linear inter-
polation is done between functions. The presence of
the -S flag will result in only the first function
being used.
-rnmo
Used if input functions are RNMO times (not veloci-
ties). This results in an RNMO seismic format file
suitable for input to rnmo.
-xsd Used if input velocity function set is in XSD pick
file format.
-flat
Used if input velocity function set is in USP flat
file format.
-tdfn
Used if input velocity function set is in TDFN card
image format.
-hmig
Used if input velocity function set is in SATTLEGGER
hmig99 print file format.
-tensor
Used if input velocity function set is in Tensor for-
mat.
-disco
Used if input velocity function set is in DISCO
handvel card image format.
[default]
If none of the above format flags are present it is
assumed that the input velocity function set is a USP
velocity dataset.
-hw iwd [Default: RecNum ]
Enter the USP trace header mnemonic corresponding to
velocity function set index [eg, -hw SGRDat ]. A
nonblank entry will obviate the flags below...
-shot
Used if the input velocity function set is referenced
to SrcLoc
-receiver
Used if the input velocity function set is referenced
to RecInd
-cdp Used if the input velocity function set is referenced
to DphInd
-pri Used if the input velocity function set is referenced
to PrRcNm
-sin sin [Default: T]
Enter the type of the input velocity function set sam-
ple units
T --> time
D --> depth
-sout sout [Default: T]
Enter the type of the output velocity dataset sample
units
T --> time
D --> depth
-vin vin [Default: R]
Enter the velocity type of the input velocity function
set
I --> interval velocity
R --> rms velocity
A --> average velocity
-vout vout [Default: R]
Enter the velocity type of the output velocity dataset
I --> interval velocity
R --> rms velocity
A --> average velocity
-ilis [Default: not used]
If present, the fifth order polynomial approximation
used by the ILIS System will be used to sample your
input velocity function set. This approximation is in
time only no smoothing [other than linear interpola-
tion] is done between input velocity function loca-
tions.
-si si [Default: SmpInt from -N dataset line header]
override the -N dataset sample interval when reading
the velocity function set from a USP velocity
dataset. Useful if the control seismic dataset is in
depth and the input velocity model is a velocity tape
in time. The value of si is used to control the scale
of the input only. The output sample interval is not
affected by this parameter.
-osi osi [Default: SmpInt from -N dataset line header]
override the -N dataset sample interval when creating
a USP velocity dataset. Useful if the control
dataset is in depth and the input velocity model is a
velocity tape in time. The value of osi is used to
control the scale of the output only. The input sample
interval is not affected by this parameter.
-dx dx [Default: 0]
Enter horizontal trace spacing (ft, m). This value
multiplied by 1000 is written into the line header of
the output USP velocity dataset in a slot used by the
MBS migration codes.
-dy dy [Default: 0]
Enter horizontal record spacing (ft, m). This value
multiplied by 1000 is written into the line header of
the output USP velocity dataset in a slot used by the
MBS migration codes.
-dz dz [Default: 0]
Enter vertical depth interval (ft, m). This value mul-
tiplied by 1000 is written into the line header of the
output USP velocity dataset in a slot used by the MBS
migration codes.
otherwise]
-saf saf [Default: 1 percent for -
voutI else 0.1 percent
When the input velocity function set is a USP velo-
city dataset and a velocity type conversion is
required, the slope adjustment factor is used to glean
the input velocity function set. The smaller the
number, the greater the number of samples in the output
function. Useful in varying the spatial smoothness of
the output velocity dataset.
-sv v0 [Default: not used]
if the -xsd option is chosen, a velocity starting
value for the picked spectrum may be provided which
will define the velocity to use at trace one on the
input pick file.
-dv dv0 [Default: not used]
if the -xsd option is chosen, a velocity increment
for the picked spectrum may be provided which will
define the velocity increment to use between traces on
the input pick file.
-psi psi [Default: SmpInt from -
N dataset line header]
if the -xsd option is chosen, a sample increment
override for the picked spectrum may be provided which
will define the sample increment to use on the input
pick file.
-force
If present when an RMS velocity inversion is detected
during a conversion to interval velocity, instead of
killing the process, velin will use the interval
velocity last calculated until the inversion is passed.
-S If present a single velocity function is assumed to
exist in the input velocity function set and a single
output trace only will be generated.
-R If present regular data numbering is assumed. The
appropriate header value is read from the first trace
of the control seismic dataset and all subsequent
indices are determined by incrementing this value by 1
for each additional input record. This saves on data
I/O when working with large regularly numbered
datasets.
-V Verbose printout mode. Recommended for quality control
of velin operation.
WARNING: Printfile can become very large when a USP
dataset is input as the velocity function set. In this
case make a partial run to be certain indexing and
velocity conversion is correct then run the job to
completion without the -V flag.
-? or -h
Query mode. With this flag velin will execute its'
internal help subroutine yielding information concern-
ing its' command line arguments then exit.
DISCUSSION
-xsd
Units 1.000000 55.000000 4.000000 0
0 1500 Offset 999.000000 1445.000000 0.000000
Count
Segment = 1 color = 0
1000.000000 1500.000000 4.000000
1000.000000 1500.000000 1480.000000
1000.000000 2168.771973 2336.000000
1000.000000 3124.576172 2896.000000
1000.000000 5498.824219 3264.000000
1000.000000 4384.036133 3440.000000
1000.000000 9866.474609 3624.000000
1000.000000 5233.472656 4192.000000
1000.000000 10882.781250 4320.000000
1000.000000 5432.408203 5136.000000
1000.000000 6266.374512 5880.000000
Segment = 2 color = 0
1001.000000 1500.000000 4.000000
1001.000000 1500.000000 1480.000000
1001.000000 2168.771973 2336.000000
1001.000000 3124.576172 2896.000000
1001.000000 5498.824219 3264.000000
1001.000000 4384.036133 3440.000000
1001.000000 9866.474609 3624.000000
1001.000000 5233.472656 4192.000000
1001.000000 10882.781250 4320.000000
1001.000000 5432.408203 5136.000000
1001.000000 6266.374512 5880.000000
NOTE: Columns are ( index, velocity, time )
-flat
0, 1500, 1000
1480, 1500, 1000
2336, 2169, 1000
2896, 3125, 1000
3264, 5499, 1000
3440, 4384, 1000
3624, 9866, 1000
4192, 5233, 1000
4320, 10883, 1000
5136, 5432, 1000
5880, 6266, 1000
-1, 0, 1000
0, 1500, 1001
1480, 1500, 1001
2336, 2169, 1001
2896, 3125, 1001
3264, 5499, 1001
3440, 4384, 1001
3624, 9866, 1001
4192, 5233, 1001
4320, 10883, 1001
5136, 5432, 1001
5880, 6266, 1001
-1, 0, 1001
NOTE: Columns are ( time, velocity, index )
-tdfn
1TDFN 4 15001480 15002336 21692896 31253264 54993440
43843624 9866 1000
9TDFN4192 52334320108835136 54325880 6266
1000
1TDFN 4 15001480 15002336 21692896 31253264 54993440
43843624 9866 1001
9TDFN4192 52334320108835136 54325880 6266
1001
NOTE: As many TDFN cards as desired may be used per func-
tion location. The last card in the function must begin
with 9TDFN.
-hmig
19-JUL-91, 11:27:30 HMIG99, RELEASE 8.3
Sattlegger GmbH phone 05931 18069
________________ fax 05931 13923
with country code 0049 5931 .....
PROSPECT: TRC MODE
(NOPODS AND BEAUFORT MODELS)
LINE: NOPODS
UNIT OF LENGTH: METERS
SWITCH IGRASW: STACKED SECTION (MIGRATION)
DATUM LEVEL: 0. M
PRINT CONTROL: 0
----- H M I G 9 9 ------------------------ LINE NOPODS
-----------------
OPTION NO. 16 OF HMIG99 MAIN MENU SELECTED
INTERVAL VELOCITY FROM VELOCITY FUNCTIONS
=========================================
INTERVAL VELOCITIES AT LOCATION S = 0. M
SHOTP.= 1
NO. INTERFC. SEGM. T Z VI
1 2 1 0.233 350. 3000.
2 4 1 0.333 550. 4000.
3 6 1 0.513 1000. 5000.
4 8 1 0.638 1500. 8000.
5 10 1 0.838 2500. 10000.
6 12 1 0.915 3000. 13000.
7 14 1 1.182 5000. 15000.
INTERVAL VELOCITIES AT LOCATION S = 22000. M
SHOTP.= 41
NO. INTERFC. SEGM. T Z VI
1 2 1 0.233 350. 3000.
2 4 1 0.333 550. 4000.
3 6 1 0.513 1000. 5000.
4 8 1 0.638 1500. 8000.
5 10 1 0.738 2000. 10000.
6 12 1 0.815 2500. 13000.
7 14 1 1.149 5000. 15000.
----- H M I G 9 9 ------------------------ LINE NOPODS
-----------------
********* E N D H M I G 9 9 *********
JOB RUN TIME: 44 SEC.
-tensor
LINE NUMBER = nopods
SHOT POINT = 1
TIME VSTAK
0. 3000.
234. 4000.
336. 5000.
514. 8000.
636. 10000.
835. 13000.
913. 15000. END 0 0
LINE NUMBER = nopods
SHOT POINT = 41
TIME VSTAK
0. 3000.
240. 4000.
335. 5312.
516. 8989.
641. 10000.
740. 13000.
817. 15000. END 0 0
-disco
HANDVEL 1000
4.0 1500.0 1480.0 1500.0 2336.0 1775.0
2896.0 2105.0
3264.0 2710.0 3440.0 2820.0 3624.0 3535.0
4192.0 3810.0
4320.0 4195.0 5136.0 4415.0 5880.0 4690.0
6000.0 4727.0
HANDVEL 1001
4.0 1500.0 1480.0 1500.0 2336.0 1775.0
2896.0 2105.0
3264.0 2710.0 3440.0 2820.0 3624.0 3535.0
4192.0 3810.0
4320.0 4195.0 5136.0 4415.0 5880.0 4690.0
6000.0 4727.0
NOTE: velin reads these cards in free format so that
right or left justification is not a problem.
BUGS
Should your input rms velocity function have velocity inver-
sions and you have either asked for a velocity type conver-
sion, or do not have an entry in your input velocity func-
tion set at the maximum time of your input data velin will
fail. The velocity type conversion using the Dix equation
is done in both of these instances. In the latter to calcu-
late an appropriate rms velocity to use at the max time of
your datset. An rms velocity inversion will cause a nega-
tive square root in the conversion expression. As this is
an imaginary situation velin cannot handle it and the pro-
gram will terminate. An error message will be printed to
the printout file listing the location and time that the
violation occurred. To get around this either supply inter-
val velocity as the input or if rms is desired install a
velocity pick at the maximum time [or depth] of your control
seismic dataset.
SEE ALSO
anmo(1), bdnmo(1), taupnmo(1), tvdin(1)
AUTHOR
R. B. Herrmann, Saint Louis University, (1986)
Mods by P.G.A. Garossino TRC (1991)
COPYRIGHT
copyright 2001, Amoco Production Company
All Rights Reserved
an affiliate of BP America Inc.
Man(1) output converted with
man2html