If oil is changed regularly within the guidelines of the manufacturer and no mechanical problems exist then no the oil should not sludge. Does conventional oil leave deposits, sure, but this is really a non-issue today because oils are so much better than decades ago.
Three exceptions are engines that require synthetic but conventional is used instead, or engines that are known to have issues with sludging, or engines equipped with Turbo's where the oil is continually beaten up by excessive temperatures like at a track or super heavy aggressive driving all the time leading to extended period of times where the Turbo bearings are hot.