Oil smooths, fuels and soothes, so tradition reads it as ease, energy and things running without friction. Spilled oil in a dream can stand for something slippery or hard to clean up.
Does the traditional reading fit your dream, or did it mean something else to you?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.