Bakken Formation in the context of "Oil shale"

Billings is the most populous city in the U.S. state of Montana. The population was 117,116 at the 2020 census, while the Billings metropolitan area has an estimated 193,000 people. Located in the south-central portion of the state, it is the seat of Yellowstone County. Billings is the trade and distribution center for much of Montana east of the Continental Divide and has one of the largest trade areas in the United States. It is also the largest retail destination for much of the same area. The Billings Chamber of Commerce claims the area of commerce covers more than 125,000 square miles (320,000 km).

Billings was nicknamed the "Magic City" because of its rapid growth from its founding as a railroad town in March 1882. The nearby Crow and Cheyenne peoples call the city Ammalapáshkuua and É'êxováhtóva respectively, meaning 'where they cut wood', named as such because of a sawmill built in the area by early white settlers. The city has experienced rapid growth and maintains a strong economy. From 1969 to 2021, the Billings area population growth was 89%, compared to Montana's overall increase of 59%. With more hotel accommodations than any area within a five-state region, the city hosts a variety of conventions, concerts, sporting events, and other rallies. It provides services to the Bakken oil development 250 to 350 miles to the east, as well as the Heath Shale oil discovery north of Billings.

A drilling rig is an integrated system that drills wells, such as oil or water wells, or holes for piling and other construction purposes, into the earth's subsurface. Drilling rigs can be massive structures housing equipment used to drill water wells, oil wells, or natural gas extraction wells, or they can be small enough to be moved manually by one person and such are called augers. Drilling rigs can sample subsurface mineral deposits, test rock, soil and groundwater physical properties, and also can be used to install sub-surface fabrications, such as underground utilities, instrumentation, tunnels or wells. Drilling rigs can be mobile equipment mounted on trucks, tracks or trailers, or more permanent land or marine-based structures (such as oil platforms, commonly called 'offshore oil rigs' even if they don't contain a drilling rig). The term "rig" therefore generally refers to the complex equipment that is used to penetrate the surface of the Earth's crust.

Small to medium-sized drilling rigs are mobile, such as those used in mineral exploration drilling, blast-hole, water wells and environmental investigations. Larger rigs are capable of drilling through thousands of metres of the Earth's crust, using large "mud pumps" to circulate drilling fluid (slurry) through the bit and up the casing annulus, for cooling and removing the "cuttings" while a well is drilled. Hoists in the rig, a derrick, can lift hundreds of tons of pipe. Other equipment can force acid or sand into reservoirs to facilitate extraction of the oil or natural gas; and in remote locations there can be permanent living accommodation and catering for crews (which may be more than a hundred). Marine rigs may operate thousands of miles distant from the supply base with infrequent crew rotation or cycle.