Traditional methods of oil extraction are not able to extract as much oil as other methods, such as thermal enhanced oil recovery. When oil drillers are able to extract the maximum amount of oil, There are many ways in which oil drilling companies are able to extract oil from the ground, including technologies that already exist and technologies that are in development.

Steam

Steam is the most common material used to enhance oil recovery efforts. Hot water or hot gases can also be used, but they are not as effective as steam. The steam heats the oil to reduce viscosity. Some of the oil also vaporizes, making extraction easier. Decreased viscosity reduces surface tension, makes the oil more permeable and improves the reservoir seepage conditions. The oil is able to flow more freely through the reservoir. The steam is either introduced through cyclic steam stimulation or through steam flooding. After achieving the desired viscosity, the engineer stops heating the oil to allow the heat to become evenly distributed. 

Microwaves

Microwave heating is one technology in development that is designed to increase the amount of oil that can be recovered. The microwave is faster and is able to perform the same work while using less energy. One of the challenges is amplifying the wavelengths. While a wavelength cannot be amplified, this problem can be overcome by inserting an antennae into the downhole. A casing placed in the borehole can absorb the microwaves. The well bore needs to be made from plastic or porcelain so the microwaves can pass through the borehole. 

In-Situ Combustion

In-situ combustion can be used to refine and separate oil while it is in the ground. This is used when the oil in the reservoir is produced through combustion. Thermal cracking reactions happen at higher temperatures. The heavy oil that is put in place is cracked in light oil. The heavy metals and sulfur can be separated from the oil through this process and left in the ground.

Steam-Assisted Gravity Drainage

Oil drillers might be able to extract oil with the help of steam-assisted gravity drainage. While steam flooding is already used to extract oil, it has an inefficient recovery rate because bitumen is not exposed to steam for long enough. Steam-assisted gravity drainage uses two wells and has a recovery rate as high as 70%. This allows the bitumen to remain hot as it flows toward the production well.