Identification of sandstone body types by computer method

Three sandstone body types—progradational (coarsening upward), aggradational (coarsening downward), and block—can be identified by computer using the least-squares method. The basic data are the digital gamma () ray and sonic log data. Other logs such as SP and resistivity (or conductivity) may also be used with minor changes in the computer program. A statistical program to compute the percent of each of these three types in a specified geologic unit was also written and run for several wells in the Beaufort Basin, Canada. An areal mapping of these calculated results shows the features of progradational sedimentation in this area. The percentage of progradational sandstones increases northward in a seaward direction. The amount of sandstones usually decreases in this direction.