A method of producing liquid fuels by providing an olefin feed containing at least one C2-C20 olefin, oligomerizing a part of the feed in the presence of a first catalyst to form a first product comprising oligomers of the at least one olefin, and oligomerizing a portion of the first product in the presence of a second catalyst to produce a second product. A system of producing liquid hydrocarbons, the system including a first reactor configured to provide a first product by oligomerizing, in the presence of a first catalyst, at least a portion of an olefin feed comprising at least one olefin, a separator configured to provide an unreacted olefin-reduced first product by separating unreacted olefin from the first product, and a second reactor configured to provide a second product by oligomerizing, in the presence of a second catalyst, at least a portion of the unreacted olefin-reduced first product.