7000.                           :x-coord. of top of well7000.  2000.                    :x,z  5000.  7000.                    :x,z1.   -999999.                   :end of well definitionNotes-----(1) When the upper surface is curved you may not know the elevationat the x-coordinate of the top of the  well. The program calculates this for you -hence you only provide the x-coordinate where the well meets the uppersurface.(2) The well should not be too curvy, and must be single valued in z (ie itcan't turn back towards the upper surface).