A pumpjack is the overground drive for a reciprocating piston pump in an oil well.
It is used to mechanically lift liquid out of the well if there is not enough bottom hole pressure for the liquid to flow all the way to the surface. The arrangement is often used for onshore wells. Pumpjacks are common in oil-rich areas.
An oil well is a drillhole boring in Earth that is designed to bring petroleum oil hydrocarbons to the surface. Usually some natural gas is released as associated petroleum gas along with the oil. A well that is designed to produce only gas may be termed a gas well. Wells are created by drilling down into an oil or gas reserve and if necessary equipped with extraction devices such as pumpjacks. Creating the wells can be an expensive process, costing at least hundreds of thousands of dollars, and costing much more when in difficult-to-access locations, e.g., offshore. The process of modern drilling for wells first started in the 19th century but was made more efficient with advances to oil drilling rigs and technology during the 20th century.
Wells are frequently sold or exchanged between different oil and gas companies as an asset – in large part because during a drop in the price of oil and gas, a well may be unproductive, but if prices rise, even low-production wells may be economically valuable. Moreover, new methods, such as hydraulic fracturing (a process of injecting gas or liquid to force more oil or natural gas production) have made some wells viable. However, peak oil and climate policy surrounding fossil fuels have made fewer of these wells and costly techniques viable.
Petroleum is a fossil fuel that can be drawn from beneath the Earth's surface. Reservoirs of petroleum are formed through the mixture of plants, algae, and sediments in shallow seas under high pressure. Petroleum is mostly recovered from oil drilling. Seismic surveys and other methods are used to locate oil reservoirs. Oil rigs and oil platforms are used to drill long holes into the earth to create an oil well and extract petroleum. After extraction, oil is refined to make gasoline and other products such as tires and refrigerators. Extraction of petroleum can be dangerous and has led to oil spills.
A sucker rod is a steel rod, typically measuring between 7 and 9 metres (25 and 30 ft) in length, with threaded ends at both sides. It is used in the oil industry to connect the surface components with the downhole components of a reciprocating piston pump in an oil well. The pumpjack, which is the visible above-ground drive for the well pump, is linked to the downhole pump at the base of the well through a series of interconnected sucker rods. Sucker rods are also available in fiberglass, typically manufactured in lengths of 37 1/2 feet and diameters of 3/4, 7/8, 1, and 1 1/4 inch. These rods feature metallic threaded ends, female on one side and male on the other.
The surface unit transfers energy from the prime-mover to the sucker rod string to facilitate well pumping. It achieves this by converting the rotary motion of the prime-mover into the reciprocating motion required by the sucker rod and reducing the prime-mover's speed to a suitable pumping rate. Speed reduction is managed through a gear reducer, while the rotary motion of the crankshaft is transformed into oscillatory motion using a walking beam. The crank arm connects to the walking beam via a pitman arm. The walking beam is supported by a Samson post and saddle bearing. The horse head and bridle ensure vertical pull on the sucker rod string at all times, preventing bearing movement above the stuffing box. A combination of the polished rod and stuffing box is employed to maintain an effective liquid seal at the surface.