Guidelines to using the suresstat command in SU
Abdullatif Al-Shuhail (KFUPM – Saudi Arabia)
September 5, 2007
The following 3 steps must be followed:
1. Sort NMO-corrected data into shot gathers using the susort command.
2. Use suresstat command to calculate the residual statics associated with
every source and receiver.
3. Use the sustatic command to apply the calculated source and receiver
statics to the data.
Example
o I have the NMO-corrected dataset sorted in CDP in a file called: data-tm-
flt-dec-bal-cdp-nmo.su (
Figure 1).
o I sort it into shot gathers using the command:
susort < data-tm-flt-dec-bal-cdp-nmo.su > data-tm-flt-dec-bal-cdp-nmo-fldr.su fldr
offset
o The sorted data is shown in Figure 2.
o I calculate the source and receiver statics using the command:
suresstat < data-tm-flt-dec-bal-cdp-nmo-fldr.su ssol=sstats rsol=rstats
ntraces=594 ntpick=50 niter=5 nshot=19 nr=33 nc=594 sfold=33 rfold=18
cfold=18
o Note the following:
¾ The ntraces parameter must be equal to the number of prestack
traces in the line (594 traces).
¾ The ntpick parameter sets the maximum allowable shift desired (in
samples NOT time).
¾ The niter parameter sets the number of iterations desired.
¾ The nshot parameter must be equal to the maximum fldr number in
the data. Note that this number might be different from the actual
number of shot records in the data (i.e., the maximum ep number).
For getting the correct maximum fldr number, you may use the
surange command.
¾ The nr parameter must be equal to the largest number of receivers
per shot in the whole data.
¾ The nc parameter must be equal to the number of prestack traces in
the data.
¾ The sfold parameter must be equal to the nr parameter.
¾ The rfold parameter must be equal to the maximum ep number.
¾ The cfold parameter must be equal to the maximum CDP fold,
which is equal to the maximum number under the cdpt entry in the
output of the surange command.
o This command should produce the 2 files named sstats and rstats
containing the source and receiver statics, respectively.
o I apply the statics using the command:
sustatic < data-tm-flt-dec-bal-cdp-nmo.su > data-tm-flt-dec-bal-cdp-nmostat.su
hdrs=3 sou_file=sstats rec_file=rstats ns=19 nr=65
o Note the following:
¾ We apply the statics to the CDP-sorted file (NOT the shot-sorted
file).
