NAME

     presgraph2den - Compute Density field using Presgraph  tech-
     nique or Gardner technique -- which ever is better.

SYNOPSIS

     presgraph2den [-VELntap] [-DENotap] [-nsns] [-nene] [-rsirs]
     [-reire]   [-wvwatvel]  [-wdwatden]  [-ascale]  [-bexpo]  [-
     svsaltvel] [-sdsaltden]  [-phi0phi0]  [-obcobc]  [-rhomrhom]
     [-rhorho] [-carbcarbvelmin] [-eng] [-met] [-V] [-?]  [-h]

DESCRIPTION

     Given a some parameters, this program will compute a density
     field  and given a velocity field, this program will compute
     an alternative density field.  It will determine which  den-
     sity  field  is  best  and output the better of the two on a
     point by point basis.

     presgraph2den gets its dataset names and its parameters from
     command  line  arguments.   This  program expects the header
     value "Dz1000" to be present in the line header.  The  input
     and output datasets are USP formatted.

  Command line arguments
     -VELntap
          Enter the name of the input density field after  typing
          -DEN.  This input file should include the complete path
          name if the file  resides  in  a  different  directory.
          Example  -L/b/vsp/dummy  tells  the program to look for
          file 'dummy' in directory 'vsp' stored on the 'b' disk.
          The  density  dataset should be in grams/cubic centime-
          ter.

     -DENotap
          Enter the name of the output overburden gradient  field
          after typing -OBG.  This dataset also requires the full
          pathname (see above).

     -nsns
          Enter the trace number of the first  trace  to  process
          after  typing  -ns.   The  default  is to use the first
          trace of the record.

     -nene
          Enter the trace number of the  last  trace  to  process
          after typing -ne.  The default is to use the last trace
          of the record.

     -rsirs
          Enter the record number of the first record to  process
          after  typing  -rs.   The  default  is to use the first
          record of the dataset.

     -reire
          Enter the record number of the last record  to  process
          after  typing  -re.   The  default  is  to use the last
          record of the dataset.

     -wvwatvel
          Enter the water velocity.  The default is 5000 ft/sec.

     -wdwatden
          Enter the water density.  The default is 1.026.

     -svsaltvel
          Enter the salt velocity.  The default is 14850 ft/sec.

     -sdsaltden
          Enter the salt density.  The default is 2.16 ft/sec.

     -ascale
          Enter the Gardner scale constant The default is .23.

     -bexpo
          Enter the Gardner exponent.  The default is .25.

     -phi0phi0
          Enter the seafloor porosity.  The default is .41.

     -obcobc
          Enter the overburden gradient.  The default is 5200.

     -rhomrhom
          Enter the density of the matrix.  The default is 2.65.

     -rhofrhof
          Enter the density of the fluid.  The default is 1.02.

     -carbcarbvelmin
          Enter the carbonate velocity which will allow Gardner's
          method  to  override  presgraph method.  The default is
          7000 ft/sec.

     -V   Enter the command line argument '-V' to get  additional
          printout.  The default is 5000 ft/sec.

     -?   Enter this (or '-?' if you are running in  c-shell)  to
          get  online  help.   The  program  will terminate after
          printing this.

     -h   Enter this option to get online help.  The program will
          terminate after printing this.

SEE ALSO

     den2obg, vel2den, ppvtrn, pptrnehz, ppetn.

BUGS

     None known.

AUTHOR

     Gary Murphy

COPYRIGHT

     copyright 2001, Amoco Production Company
               All Rights Reserved
          an affiliate of BP America Inc.