Definition - What does Borehole mean?
A Borehole, also known as a wellbore is a well that is drilled in the earth's surface in order to extract crude oil and natural gas. A borehole is not a complete oil well, but a pre-completion stage of an oil well. Once the hole has been drilled, it has to be cased, cemented, and perforations have to be made so that hydrocarbons can seep into the borehole.
Petropedia explains Borehole
A borehole can be drilled in either vertical or horizontal directions. Generally, it is a narrow shaft bored into the ground to the reservoir bed. A borehole is gradually converted into an oil or a gas well after performing various tasks such as casing, well cementing and perforating the cased well.
Boreholes are also drilled for various other purposes other than extracting oil and gas. A hole can be drilled to extract drinking water from an underground water aquifer, to investigate the rock geology and structure or to conduct any studies and decompose radioactive substances deep beneath the earth's surface.