GENVSP

This is a Vertical Seismic Profile, VSP (down-hole) survey pattern generator. It is an interactive program that creates a NEZ file that can be used to assign geometry to a down-hole survey. Suitable for use with either Bison or SEG-2 file formats. The naming of the shot record files is used to determine the type of data. Bison file names are 8 character alpha numeric without a suffix, SEG-2 files are assumed to have names like 1000.DAT

The hole is assumed to be vertical, reference phone fixed. This code is hardwired for how the author acquires data. Note the initial Channel order switch assumption choice at the beginning of the program execution. See Michaels (1998).

Output files are:

*.nez (Northing Easting Elevation file) (10.1.8.1)
geom (calls topcon program, unites *nez survey data with the data file, producing an *.xyz header file) (10.1.8.2 )
geom2 (calls script go1 for each shot effort) (10.1.8.3)
go1 (calls BHED program to unite *.xyz header data with seismic data into BSEGY data formated files.) (10.1.8.4)

NOTE: change the permissions on geom, geom2, and go1 files to executable. For example: chmod +x geom

EXAMPLE RUN:

  Down-hole VSP  Pattern Generator 
  For Setting Geometry 
  Handles both Bison and SEG-2 File Formats 
  
  Set Channel Order Switch
   1=ascending  1,2,3=downhole 4,5,6=reference
  -1=descending 6,5,4=downhole 3,2,1=reference
   2=ascending  1,2,3=down 4,5,6=ref,7=load_cell
  -2=descending 7=load_cell,6,5,4=down 3,2,1=ref
  
1
  
 -----------BOREHOLE----------------------------
   Enter 6 char. name for nez file (ex. STP001)
STP001
   Enter 4 char. LINEID
0001
   Enter Z-Datum: Casing Elevation
849.
  
   BOREHOLE LOCATION:
   Borehole is origin of the local coordinate system
   Source and Reference phone locations are x,y 
   relative to borehole.
  
   Following entries will shift every x,y input to
   a final global coordinate system:
   Enter Global x-coord. of borehole
1000
   Enter Global y-coord. of borehole
1000
   Enter number of sources 
1
 FOR THIS SOURCE:
   Enter Shot Record Names 8char: First
STP30001
   Enter Shot Record Names 8char: Last
STP30100
     STP30001STP30100
   Enter Source: x, y, z_sub_CE (positive down)
0,-1,-.5
   Enter Source Polarization: azi, ver
0, 180
  
 -----------REFERENCE RECEIVER------------------
   Enter Reference: x, y, z_sub_CE (positive down)
0,+1,-.4
   Enter Reference Polarizations: R-azi, T-azi
0,270
  
 -----------BOREHOLE PHONES---------------------
   Enter Bulk Shift (Added To Geophone Depth ONLY)
.3
  For Shot: SP01  AZI=  0 VER=180

   Enter Station Spacing:  dz
.25
   Enter First Station Depth:  zmax
20
   Enter Last Station Depth:  zmin
0.5
  Number of receivers =    79
---------------------------------------------
  CHECK DATA TYPE 
                  
  Files like XXXX0001 detected, ID=BISON
  Is above ID Correct, or overide needed?
  1=YES correct    0=NO incorrect 
1

In the above example, the tool has 6 channels, so there will be 6 lines for each down-hole station. The first 3 lines are the down-hole components, 2 horizontal, 1 vertical. The next 3 lines are the reference phone (note the elevation column does not change for the reference phone since it is stationary).

Subsections