P ressure build-up test is a transient pressure test technique in which the wellis produced at a constant production rate for a certain period of time (flow period),and then the well is closed (shut-in period) by closing the wellhead on the surface.The pressure build-up test can be carried out with the wellbore closed, and it isexpected that the wellbore will return to its original stable state. This test is carriedout according to the data requirements of reservoir properties and can be used as areference for the analysis of oil and gas field development. The data obtained fromthis test include well static pressure, average well pressure, rock permeability, skincoefficient, pressure drop due to skin, flow efficiency, and productivity index as anindicator of well production.In this final project, the author analyzes the results of the pressure test carriedout on the PR-1 well in the PR field using the Horner and Derivative Plot methods.PR-1 well is a well with carbonate reservoir rock type which has two porosities.Based on the results of the transient pressure test analysis that has been carried outusing petroleum software, it is known that this well has an initial reservoir pressureparameter value (Pi) of 813,987 psia; permeability of 11.4 mD; total formationdamage (skin) of -4.17; a decrease in skin pressure by -397,079 psi; and thecoefficient of wellbore storage is 0.0169 bbl/psi. In addition, from this analysis, itcan be seen several parameters of the dual-porosity reservoir such as omega whichis 0.673; lambda of 9.2E-7; and a fault distance of 172 ft.