The invention concerns a process for the production of middle distillates, comprising at least one step for the catalytic oligomerization of a feed comprising olefins containing 3 to 9 carbon atoms, in which the reaction section comprises at least two reactors which are positioned in series and which can be permutated, each containing at least one oligomerization catalyst for the oligomerization reactions, said catalysts being identical or different, and in which the reactor which is the furthest downstream in the direction of movement of said feed comprising olefins contains the catalyst with a period of service which is shorter than the period of service of the catalysts present in the other reactors and is operated at an average temperature (WABTn) which is lower than the average temperature (WABTn−1) of the reactor directly preceding it, the difference between said average temperatures being at least 10° C. (WABTn−1−WABTn≥10° C.).