NAME xm_well - Well format for the xmap8 program SYNOPSIS xm_well - Input File Format DESCRIPTION Wells are simple lists of 3D lines in space. Actually "well" is a misnomer: you can plot any 3D line using this option of xmap8. I use this to plot 3D vectors. There is an extended format that allows you to also plot lithology and dip alon the well. Format: id = well ident # = number of points in well style = 0,1,2,3 see below default is 0 for simple well. color = color for plotting (1-20) lat = degrees lon = degrees positive east depth = km, positive downward id # flag color lat lon depth . . . example: 32-20 68 0 11 36.011303 -117.792274 -0.087500 36.011303 -117.792267 -0.027500 36.011303 -117.792259 0.052500 36.011295 -117.792259 0.082500 36.011292 -117.792259 0.132500 36.011292 -117.792259 0.162500 . . .etc.... Here is the extended format for the wells: lat lon depth dip strike length lithology For example: 23-17 107 3 2 36.022938 -117.795868 -0.127500 45.000000 20.000000 0.200000 2 36.022938 -117.795868 -0.087500 45.000000 20.000000 0.200000 2 36.022942 -117.795860 -0.037500 45.000000 20.000000 0.200000 2 36.022942 -117.795868 -0.017500 45.000000 20.000000 0.200000 2 36.022942 -117.795868 0.002500 45.000000 20.000000 0.200000 2 36.022942 -117.795876 0.052500 45.000000 20.000000 0.200000 2 36.022942 -117.795883 0.082500 45.000000 40.000000 0.200000 4 LAT LON Z AZIM (deg) DIP Length Lithology the first line includes: name #_of_points style color where, name= 8 character identifier #_of_points = total number of points for that well You may have numerous wells per file style = 0 = simple well (lat lon z) 1 = well with lithology (lat lon z lith) 2 = well with dip meter only (lat lon z strike dip length) 3 = well with dip and lith (lat lon z strike dip length lith) color = one of the 28 available colors from the palette. There are thus 4 styles one can use to insert well information at this point. I may expand this at a later date to include well log information plotted as a time series along the well. ---------------- 3D ARROWS ------------------ I have written a program to convert focal mechanism P-axes into little 3D arrows - which I then rotate using spin. All you have to do is make a "well" file which has the lat-lon-depth of the positions you want plotted as vectors. Here is an example arrow plotting a P-axis direction in Western Washington: (there are 3 "wells" here) paxis 5 0 5 47.186123 -122.539413 3.900000 47.172630 -122.550819 2.900000 47.179489 -122.543701 3.437500 47.180271 -122.545677 3.437500 47.172630 -122.550819 2.900000 paxis 5 0 6 47.186123 -122.486626 5.200000 47.172630 -122.475220 4.200000 47.180271 -122.480354 4.737500 47.179489 -122.482338 4.737500 47.172630 -122.475220 4.200000 paxis 5 0 7 47.217281 -122.460205 6.500000 47.217281 -122.437340 5.500000 47.218060 -122.449631 6.037500 47.216503 -122.449631 6.037500 47.217281 -122.437340 5.500000 The arrows consist of 5 points in this order: (tail, head, UP_point, DN_point, head) UP \ \ Tail-------------------------Head / / DN The points must be inthe correct order to plot so it looks like an arrow. You could make a simpler plot with just 2 lines or even just one line if you are not concerned with directionality. I create these arrows by first drawing them in 2D and then rotating them and translating them to their correct position and orientation. (that is the programming you may have to do. you can modify my program for plotting P-axes if you like) When running xmap8 you will see a well symbol plotted at the location of the first element in the well (the Tail) if you select "Project Wells" you will see the horizontal projections. When you make cross sections you will see the wells in 3D. Wells can be imported into the spin module, but if you have a ton of them, spnnning will be slow, of course. The spin module allows you to plot the wells in any 3D view angle. SEE ALSO xmap8 xm_color xm_hypo xm_map xm_menu xm_origin xm_points xm_raster xm_station xm_well xm_wire xm_xsec xm_ellipse
REFERENCES see article by J. M. Lees: Lees, J. M. (1995) Xmap8: Three-dimensional GIS for geology and geophysics, Seismological Research Letters: 66, 33-37.
Prof. Jonathan M. Lees Yale Geology Dept. P.O. Box 208109 New Haven, CT 06520-8109 (203)432-6947 lees@love.geology.yale.edu