Shale drilling – drilling to reach shale formations as a source of natural gas and natural gas liquids.
Vertical drilling – conventional wells drilled straight down to reach the formation being developed for oil or natural gas.
Horizontal drilling – sometimes referred to as directional drilling, wells are drilled to a predetermined depth based on seismic and geological data then turned horizontally to reach oil and gas formations.
Hydraulic fracturing – pumping a mixture of water, sand and other additives into a wellhead at high pressure, creating fractures in the rock bed for extraction.
Oil and gas associated wells – oil wells in which accompanying natural gas is used to add pressure to the well and improve extraction or extracting the natural gas along with oil if it exists in large enough quantities.
Workovers and completion – removing casings as part of extensive well overhauls.