Horizontal drilling

Because the pipe that drives oil drills is surprisingly flexible, a horizontal well can snake around to reach isolated pockets or follow a reservoir that meanders across the terrain.

Horizontal drilling has evolved over the past 25 years, and even though it remains more expensive than vertical drilling, greater productivity led to rapid acceptance. Between 3,000 and 4,000 wells are drilled annually with the technology. The record hole is a long-haul monster that wanders almost 7 miles, on the coast of southern England in the Wytch Farm oil field.