Oil jack pumps in the Kern River oil field in Bakersfield, California.

A surge in oil hedges will spur drilling activity in the U.S., Wood Mackenzie said in a report released on Monday, likely keeping a supply response in place longer than expected even if spot prices fall sharply.

"Those hoping that recent oil-price weakness will prompt U.S. producers to pull back drilling activity and ease the glut of oil supply may need to keep waiting," said the consultancy.