If you're dealing with a small oil spill on your carpet, you can try to remove it with some paper towels. First, blot up as much of the oil as possible. Then, mix together one part dish soap with two parts warm water and apply it to the stain. Use a scrub brush to work the solution into the carpet, then blot again with clean paper towels until the stain is gone. If you're dealing with a larger spill, you may need to use a commercial carpet cleaner.