A method for producing a blended jet boiling range composition stream may include: oligomerizing an ethylene stream to a C4+ olefin stream in a first olefin oligomerization unit, wherein the C4+ olefin stream contains no greater than 10 wt % of methane, ethylene, and ethane combined; wherein the ethylene stream contains at least 50 wt % ethylene, at least 2000 wppm ethane, no greater than 1000 wppm of methane, and no greater than 20 wppm each of carbon monoxide and hydrogen; oligomerizing the C4+ olefin stream and a propylene/C4+ olefin stream in a second oligomerization unit to produce an isoolefinic stream; subjecting at least a portion of the isoolefinic stream to a hydroprocessing process with hydrogen as treat gas to produce an isoparaffinic stream having no greater than 10 wt % olefin content; and using least a portion of the isoparaffinic stream to create the blended jet boiling range.