A method for determining fluids in a formation. The method includes obtaining open hole measurements for a borehole in the formation; identifying points in the borehole from which to obtain pressure measurements using the open hole measurements; obtaining pressure measurements at the identified points in the borehole; applying an excess pressure technique to the pressure measurements to identify a plurality of pressure compartments in the borehole; characterizing fluid in each of the plurality of compartments; and developing a drilling plan based on characterization of fluids in each of the plurality of compartments.