This paper outlines how developments in the placement software are able to predict the squeeze lifetime when using different overflush fluid types (hydrocarbon overflush vs. seawater overflush). The study present field data from two production wells, each treated with the same aqueous scale inhibitor. The initial squeeze treatment for each well used a diesel overflush to displace the chemical (low water cut wells). Subsequent squeeze treatments to these wells utilised the same inhibitor but with seawater displacement. It is clear from field returns data that the seawater rather than marine diesel improved chemical placement and extended treatment life. The theory behind this phenomenon is be outlined along with the changes to the placement software that can now predict this effect, so allowing more accurate treatment designs to be generated. © 2008 by NACE International.