What is hydraulic fracturing primarily used for?

Hydraulic fracturing, commonly referred to as fracking, is primarily utilized to extract oil or gas from underground formations. This technique involves injecting high-pressure fluid into the geological strata to create fractures in the rock, thereby enhancing the permeability of the reservoir. By increasing the flow of hydrocarbons, hydraulic fracturing allows for the efficient recovery of oil and natural gas that would otherwise be difficult to extract due to low permeability.

In the context of this question, the other options involve activities that do not align with the primary purpose of hydraulic fracturing. Extracting water from underground aquifers, while a crucial water management process, is not the goal of hydraulic fracturing. Similarly, creating water reservoirs or draining excess groundwater from soil serves different objectives related to water resource management and environmental control, rather than the extraction of hydrocarbons.