The fact that prices haven't increased noticeably sure seems like a sign that sanctions against Russia were largely toothless and their oil is making its way into the global supply all the same.

Russia is responsible for something like 12% of all global crude oil. If sanctions actually worked and global demand for oil went unchanged prices would have increased, likely quite a bit as the demand is very sticky and not likely to decrease quickly in response to prices.

Best I can tell, the temporary bump in prices in Europe were largely a factor of political plays making oil temporarily more scare while Russia and the oil industry adjusted. Prices are back down now because Russia and the oil industry found a new flow pattern to move Russian oil into the global supply.