A method of determining a formation pressure for a reservoir , the method comprising: receiving measurement data for a pretest of a formation of the reservoir from a data acquisition tool ; characterized by : the data acquisition tool being positioned in a wellbore associated with the reservoir ; wherein a pretest of the formation of the reservoir is performed by drawing a small volume of fluid from the formation with the data acquisition tool ; wherein the measurement data is collected with the data acquisition tool , the pretest including a small pressure drawdown and a resulting pressure buildup; analyzing, with at least one processor of a data processing system , the measurement data to determine a last-read event and a corresponding last-read pressure for the pretest; determining, with the at least one processor , derivative data for a flow regime identification based at least in part on the measurement data; analyzing, with the at least one processor , the derivative data to determine a pressure derivative response; and determining, with the at least one processor , the formation pressure for the formation based at least in part on the last-read event, the last-read pressure, and the pressure derivative response; wherein the step of analyzing the derivative data to determine the pressure derivative response further comprises: analyzing the derivative data to determine whether a spherical flow regime is exhibited during the pretest; and analyzing the derivative data to determine whether a radial flow regime is exhibited during the pretest, and wherein the formation pressure is determined based at least in part on whether the pretest exhibits the spherical flow regime , and the formation pressure is determined based at least in part on whether the pretest exhibits the radial flow regime . the data acquisition tool being positioned in a wellbore associated with the reservoir ; wherein a pretest of the formation of the reservoir is performed by drawing a small volume of fluid from the formation with the data acquisition tool ; wherein the measurement data is collected with the data acquisition tool , the pretest including a small pressure drawdown and a resulting pressure buildup; analyzing, with at least one processor of a data processing system , the measurement data to determine a last-read event and a corresponding last-read pressure for the pretest; determining, with the at least one processor , derivative data for a flow regime identification based at least in part on the measurement data; analyzing, with the at least one processor , the derivative data to determine a pressure derivative response; and determining, with the at least one processor , the formation pressure for the formation based at least in part on the last-read event, the last-read pressure, and the pressure derivative response; wherein the step of analyzing the derivative data to determine the pressure derivative response further comprises: analyzing the derivative data to determine whether a spherical flow regime is exhibited during the pretest; and analyzing the derivative data to determine whether a radial flow regime is exhibited during the pretest, and wherein the formation pressure is determined based at least in part on whether the pretest exhibits the spherical flow regime , and the formation pressure is determined based at least in part on whether the pretest exhibits the radial flow regime . analyzing the derivative data to determine whether a spherical flow regime is exhibited during the pretest; and analyzing the derivative data to determine whether a radial flow regime is exhibited during the pretest, and wherein the formation pressure is determined based at least in part on whether the pretest exhibits the spherical flow regime , and the formation pressure is determined based at least in part on whether the pretest exhibits the radial flow regime . <EOS>