sample chamber a container for holding the sample which is still at formation pressure is attached to the outlet of the chamber outlet valve 62 a source of compressed air is attached to the expulsion valve 60 upon opening the outlet valve 62 the internal pressure is released but the sample is still in the sample chamber the compressed air attached to the expulsion valve 60 pushes the baffle 72 toward the outlet valve 62 forcing the sample out of the sample chamber 56 the sample chamber may be cleaned by refilling with water or solvent through the outlet valve 62 and cycling the baffle 72 with compressed air via the expulsion valve 60 the fluid can then be analyzed for hydrocarbon number distribution bubble point pressure or other properties once the operator decides to adjust the drilling fluid density the method comprises the steps of measuring the hydrostatic pressure of the well bore at the target formation then the packers 24 26 are set so that an upper 32 a lower 34 and an intermediate annulus 33 are formed within the well bore next the well bore fluid is withdrawn from the intermediate annulus 33 as has been previously described and the pressure of the formation is measured within the intermediate annulus 32 the other embodiments of extendable elements may also be used to determine formation pressure the method further includes the steps of adjusting the density of the drilling fluid according.