Horizontal and vertical drilling are two different drilling techniques used to explore and develop oil and natural gas properties. Horizontal drilling has gained market share over the last few years and is now the dominant form of drilling in the United States, according to Baker Hughes, which maintains industry data on rig counts.
Vertical drilling involves drilling a well straight down into the earth until the drill bit reaches the formation being developed. The well is then completed and starts producing oil or natural gas.
According to the Schulmberger Oilfield Glossary, horizontal drilling involves drilling a well to a predetermined depth based on seismic and other geological data and then turning the well horizontally to a set lateral length. The well is then completed and production of oil and natural gas begins. This is sometimes referred to as directional drilling.
As of April 2010, there were 749 horizontal rigs, 225 directional rigs and 502 vertical rigs drilling for oil and gas in the United States, according to Baker Hughes.
Vertical vs. Horizontal Drilling
Wells drilled horizontally are much more productive than vertical wells because of extended contact with the formation. This leads to greater reserves and production of oil and gas, reports S. D. Joshi of Joshi Technologies International, Inc.
Importance of Horizontal Drilling
Horizontal drilling has been around for many years, but the application of this type of drilling in combination with hydraulic fracturing of unconventional oil and gas formations has led to the development of large amounts of oil and natural gas in the United States.