A method of normalizing exploration functions for petroleum basins leads to an effective basis for comparing their exploration histories. In this study, an exploration function of a basin is a plot of cumulative footage drilled versus cumulative oil reserves discovered. However, 2 different basins may have the same amount of absolute drilling, but one basin may be much smaller and therefore more extensively explored. It is more meaningful to compare exploration functions independent of basin size. One way to do this is to plot the cumulative footage drilled per basin volume versus cumulative oil reserves discovered--i.e., normalizing the exploration functions according to basin size.

Exploration functions and their corresponding normalized functions based on historical data have been drawn for the Powder River, Denver, and Midland basins and their subdivisions. The subdivisions are horizontal depth zones, vertical well density zones, and the blocks formed by the intersections of those zones. The volume used for determining a normalized function corresponds to the volume of sedimentary rock within the basin, zone, or block under consideration.

Results show that normalizing exploration functions makes a difference in the apparent extent to which a basin has been explored. Furthermore, the rate of finding oil and the forecasted total amounts of oil can be determined. Of the 3 basins considered, Midland basin is the best choice for further oil exploration.

End_of_Article - Last_Page 483------------