Oil is one of the most important energy resources in the world, and because of that, experts have been working for decades to make the extraction of oil as efficient as possible. The process, while quite complex and risky, has been able to provide several billion barrels of oil for many years.

Research, Exploration, and Preparation

Before the drilling process can even get started, it’s important to first research, explore, and prepare the area that is going to get drilled for oil. The most common way geologists do this is through seismic surveys. These surveys require different techniques, depending on the area in which geologists are researching. On land, for example, seismic surveys are based on vibrations through the earth, requiring tools such as a vibrating pad under a large truck or small explosions. By conducting these surveys, these scientists can explore the geology below the surface of the earth, which allows them to study the area for potential drilling spots. Geologists also work in tandem with ecologists, who study the area of potential drilling spots to assess the safest ecological way to drill for oil without causing massive damage to the nearby ecosystems.

Once an area has been researched and explored by geologists and ecologists, the area must then be prepared for drilling. The preparations for drilling are incredibly thorough, as the workers are not only preparing for the drill itself, but for the space around the drill as well. While preparations include aspects such as drilling pads and designated access roads to get to the drill, they also include other aspects such as traffic plans and noise barriers. These aspects are all based on local and state laws, which may vary depending on the area in which oil is being drilled.

Drilling The Well and Pumping Oil

Once a location has been safely prepared for drilling, the next step is to install the drill rig and the drill that will be pumping the oil. These parts are brought in by several truckloads to the drilling location and set up on top of the drilling pad. Workers then drill what is known as a surface hole to a predetermined depth of around one hundred feet below the deepest aquifer in the area before cementing a steel casing in place. The purpose of the steel casing is to protect the aquifers from any potential pollution involved in the drilling process, as well as providing structural integrity to the hole and isolated areas of rock that may explode due to high pressure. Following the same rock bed that the surface hole was made, the hole’s directional pattern is changed to move horizontally and around 1,000 feet above where oil, as well as natural gas, is trapped. This horizontal hole is usually around one or two miles long and is a technological advancement that allows for more drills to be used on one drill pad, increasing productivity while minimizing its ecological impact.

Following the drilling of this hole, mud is added to the drill bit, now several miles underground. This mud, which is a combination of various chemicals, fluids, and solids, acts as a lubricant for the drill bit as well as for surrounding bits of broken rock to help them move. Once the hole has been completed, or in other words prepared for extraction by perforating the steel casing, the drill is tested rigorously to ensure the safety of its usage before it can begin to pump oil. To get the oil out, there is a process called fracking, which includes pumping fracking fluid (a combination of water, sand, and chemicals) into the hole at high pressures. By doing this, the pressure breaks thin cracks in the shale rock, allowing for substances such as oil and natural gas to pour out and into the hole that the drill bit.

Storage and Transportation

To pump crude oil out of the oil well, the pressure from underground pushes the substance up to the surface, where it is collected in barrels. If the area is more depleted of its oil supply, which causes the underground pressure to not be strong enough to push the oil up and out of the hole, then other tools such as pumpjacks are utilized to make the oil move. Once collected in barrels, various forms of transportation take the crude oil to be refined before it can be used for market demands. These forms of transportation vary wildly, from underground pipelines to overseas shipping to tanker trucks. Once the oil is refined, it is transported again to be utilized in various ways across the globe, such as for heating oil for homes and business in cold climates, gasoline or diesel for regions with high transportation needs, and many more.

After an oil well has met its economic limit, meaning that it has reached a point where the cost of production is more than what can be covered by the cost of the oil drilled, then the well is abandoned. However, to safely abandon the site, the well must be properly closed. To do this, the tubing used for the drill is removed, and cement is poured into the hole, keeping the hydrocarbon reservoirs separate from the underground water supply. The head of the pump is then also taken out, and a cap is welded in place before everything is buried. As complicated and dangerous as the drilling process is to set up as well as to take down, accidents are bound to happen, but the various technological advances over the decades of the oil industry’s maturation help mitigate the number of accidents and their severity.