A method for performing fluid influx tests in a wellbore comprises inserting a well test device into the wellbore such that it separates a well test section from other sections of the wellbore; performing a first fluid influx test during which fluid pressure in the test section is reduced, pore fluid is induced to flow into the test section and fluid influx into the test section is monitored; injecting a completion fluid into the test section, and inducing the completion fluid to flow into the formation; performing a second fluid influx test during which fluid pressure within the test section is reduced, completion and pore fluids are induced to flow into the test section, and fluid influx into the test section is monitored; comparing fluid influx monitoring data acquired during the fluid influx tests to determine any effects of the completion fluid on formation pore fluid influx into the test section.