What is Exploration Drilling?

Mary McMahon
Mary McMahon

Exploration drilling is a procedure in which several test holes are drilled for the purpose of evaluating the contents of the ground in a particular area. It is conducted to find out whether or not materials of value are present, and to assess the quality of those materials. There are a number of industries which use exploration drilling in their work, sometimes with their own drilling crews, and sometimes through companies which provide for-hire drilling services.

Exploration drilling is often used to locate crude oil.
Exploration drilling is often used to locate crude oil.

One common reason for exploration drilling to be done is in mineral exploration. Once a potential site is identified, exploration drilling can be used to determine whether or not the site has materials of interest, ranging from metal ores to diamonds, and to assess the quality and quantity of those materials. This is done by sinking a drill bit which takes a core sample into the ground; the core sample is extracted and analyzed.

Crude oil, a common target of exploration drilling.
Crude oil, a common target of exploration drilling.

In the early stages of exploration drilling, several test holes can be dug for core samples which cover a broad area. Once the value of the site is confirmed, additional holes can be drilled and people can learn more about the quality of the site. The company must determine whether exploiting the site will generate profits which outweigh the costs of drilling and the ongoing costs of maintaining the site once it is active. A site with potentially poor yields could be too costly to invest in, leading the company to pull out.

The oil industry also utilizes exploration drilling to probe suspected petroleum deposits. Samples from the drill are analyzed to determine the quality of the crude oil, while geologists work on estimates of how much oil may be available at the site. People are sometimes surprised to learn that crude oil does in fact come in ranges of quality which dictate how much it can fetch on the open market, making analysis of oil deposits at a site critical.

Geologists may use exploration drilling to learn more about geologic strata, without the specific goal of exploiting mineral resources. Core samples can provide a great deal of information about a site's geological composition and history. These samples can also be taken from deposits of ice and mud to collect layers of deposited data which provides information about the climate; shifting pollen counts can indicate changing weather, for example, while rises in deposits of certain chemicals can sometimes be linked with geologic or human activity.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


Is there someone who knows about George Bernard Reynolds, the first oil well (1908) driller and geologist? I need his diaries and biography photos.


@highlighter- Offshore drilling has been a hot button issue for at least the last 40 years. Because of this, it may be hard to find purely objective information on the pros and cons of drilling in our nation's waters. You can find a number of scientific studies, impact statements, and risk analysis on the topic, but sometimes even these are biased. I would recommend searching for information about the offshore drilling debate. You will find all of the points of view you could ever want. If you examine the sources of information, you will be able to piece together reliable information on the advantages and disadvantages of drilling.

The government agency you might want to examine is the new Bureau of Ocean Energy Management, Regulation, and Enforcement. The Department of the Interior created this agency in 2010 to replace the Minerals Management Service, which was in the pocket of oil companies. It has received an extra $70 billion in funding and has greater regulatory authority so it can serve the best interests of the United States and not the oil companies.


What state or federal agency controls the rights for offshore drilling and exploration? How far offshore can a company drill before it is in international water? Is it even possible to drill for resources in international waters?

Offshore oil exploration seems like such a complex subject that it I cannot figure out if I like the idea or not. Politicians never give the full truth about anything that they say because there is always an agenda. I would like to learn a little more about this before I make a decision this election season. Can anyone point me in the direction of good resources that will outline the pros, cons, and regulations surrounding offshore oil exploration?


@aplenty- Your questions are actually a lot more complex than they seem. In the United States, land rights were originally fee simple ownership rights, meaning that the property owner controls the land below and the air above their property to a certain extent. Over time, the rights of the surface and substrate of a property have changed that multiple people may own different parts of a piece of property. There are also environmental and zoning considerations to account for.

It is often advisable to retain the services of an attorney, and possibly geologists when deciding to act on mineral rights on private property. Most people do not have the capital or the equipment to explore for mineral resources, so they will sell, lease, or partner their property with a mining company. Certain states like Texas, California and others are oil rich, so they make resources on oil and mineral drilling easily accessible. You would need to do some research on the particular scenario that you want information about.


Would one need a permit to perform exploratory drilling on his or her land? What are the requirements for exploratory drilling? Could I just hire a drilling company to do some exploratory drilling? These are just purely theoretical questions, but I would like to know what is involved in the process of exploring for minerals and oil.

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