Blot up as much of the oil as possible from the wood as quickly as possible. Don't wipe because it can push the oil further into the wood.
Sprinkle a fine, unscented, cat litter or baking soda directly on the oil. Either of these will absorb excess oil and help dry out the surface.
Let the baking soda or litter sit on the stain for about 15 minutes and then brush it away with a dust brush or vacuum it up with a shop vacuum.
Mix a degreasing detergent, such as dishwashing liquid, in warm water. Use a soft-bristled brush to scrub any remaining oil out of the wood. Work slowly and use a circular motion over the stained area.
Rinse the area well with clean water and let dry. Repeat washing with soap and water if oil still remains.