A test tool attached to test string comprising a fluid conduit is deployed to a test position within a wellbore. The deployment includes hydraulically isolating a portion of the wellbore proximate the test tool to form an isolation zone containing the test position. A fluid inflow test is performed within the isolation zone and an initial formation property and a fluid property are determined based on the fluid inflow test. A fluid injection test is performed within the isolation zone including applying an injection fluid through the test string into the isolation zone, wherein the flow rate or pressure of the injection fluid application is determined based, at least in part, on the at least one of the formation property and fluid property.