Horizontal drilling, also known as directional drilling, is one of the real technological advances behind oil and natural gas extraction. This technology, equal in importance to hydraulic fracturing, enables companies to extract millions of barrels of oil and trillions of cubic feet of natural gas from the various Shale formations.
Horizontal Drilling provides access to reservoirs of oil and natural gas thousands of feet beneath the surface that would otherwise not be available via vertical drilling, and also minimizes the above ground drilling, protecting acres of beautiful landscape. Horizontal drilling allows for the use of only one access road and one pipeline on land, instead of hundreds needed with vertical drilling. Additional benefits of horizontal drilling is the production of previously untapped resources is increasing the supply of crude oil and natural gas. Horizontal drilling has helped shaped the future of energy in the United States, helping keep fuel and utility costs low.
Horizontal Drilling and Directional Drilling-Natural Gas Wells: Geology.com
Directional Drilling Technology: EPA.gov