Directional drilling is a non-vertical drilling process that involves drilling in any other direction besides directly vertical. This is especially useful for tapping into oil or gas reserves that are inaccessible from directly above. In other cases, the spot may be located under a small body of water, such as a lake or pond, where creating a floating oil rig would be both expensive and unnecessary. Directional drilling as a whole has a variety of advantages that makes it one of the most widely-used drilling processes.
This form of drilling has been an important part of the oil and gas industry since its introduction in the 1920s. This came about when oil companies realized that many oil wells were not necessarily vertical, resulting from numerous lawsuits involving drilling into oil reserves located on a different property. Vertical wells curve when they reach a certain depth, and as a result, a well would be drilled on one property, but tap into an oil reserve on another. Amidst all the related legal problems, oil companies realized that they could also drill in other directions.
Technology greatly improved over the years to the point where wells are drilled not only vertically, but at multiple angles. This not only allows for reaching an increased amount of oil and gas reserves, but also for minimizing drilling costs, as only one facility can drill into multiple reserves. This also effectively minimizes the environmental impact that an oil- or gas-drilling facility has on the environment, as placement of the facility is flexible. For example, if an oil or gas reserve was located directly beneath a body of water, vertical drilling would require an oil rig to be set up directly above it. With directional drilling, however, the rig can be set up on-shore, and, therefore, have less of an environmental impact.
Since its introduction, the technology involved in directional drilling has been adapted to greatly increase drilling accuracy, precision and efficiency. One of the most useful of these technologies would be global positioning systems (GPS), which provide for a pre-determined drilling direction. With that, an oil rig can drill with increased accuracy and precision, nearly guaranteeing tapping into a reserve at the best possible location. In many other cases, however, directional drilling does not use such complex technology; instead, the drill is pointed into the direction it needs to drill, and a mud motor drills through the earth until it reaches the reserve.