A shroud assembly that is conveyable within a wellbore extending into a subterranean formation via a tubular member. The shroud assembly and at least a portion of the tubular member at least partially define an annular volume around the tubular member. The shroud assembly includes apertures permitting fluid flow between the wellbore and the annular volume. A fluid tracer positioned within the annular volume is carried by flow of the fluid from the annular volume into the wellbore or tubular member.