Definition - What does Injection Well mean?
An Injection Well is a device which helps in placing fluids underground in porous rock formations like limestone and sandstone, or below in the shallow soil layer. The fluids could be wastewater, brine, water, or water mixed with chemicals. The deep injection wells are also known as class 2 underground injection wells. These wells are used to dispose of wastewater that contains high content of salt, chemicals, radioactive materials and heavy metals.
Petropedia explains Injection Well
The construction of an Injection Well depends upon the depth and type of fluid injected. It is constructed to offer multiple layers of protective cement and casing. The shallow wells, in contrast, usually have a simple construction. The well is used to enhance oil production, store carbon dioxide, dispose of water, prevent saltwater intrusion and is used in mining as well. There are two main types of injection – water and gas. The imported gas or separated gas from the production wells can be re-injected into the upper section of the reservoirs which contain gas. In water injection wells, treated and filtered seawater is injected into the lower section of the reservoirs bearing water. Water injection wells are usually in offshore sites.