Oil Well

The Oil Well is a mid-to-late game building used to extract Crude Oil from an Oil Reservoir when supplied with Water. Any Water pumped into the reservoir is consumed permanently and cannot be recovered, so an Oil Well is a one-way conversion point in your resource chain. It also produces Natural Gas as a byproduct, making it a source of both fuel and oil once you have the infrastructure to support it.

Although the in-game database shows the Oil Well as a 4x4 structure, its functional footprint is 4x2, and the eight tiles above it can be occupied by other buildings. If those upper tiles contain natural terrain, the Oil Well is still considered buried. In practice, the building itself does not block construction; the Oil Reservoir does. Because the reservoir is made of Sedimentary Rock, it can be melted after the Oil Well is built, allowing other structures to be placed within the well’s 4x4 area afterward.

When supplied with Water, the Oil Well produces Crude Oil at a minimum temperature of 90°C, and hotter input Water produces hotter Crude Oil. It also generates Natural Gas at 300°C and stores up to 80 kg at full backpressure. The two outputs are produced in the bottom tiles: Natural Gas from the second tile from the left, and Crude Oil from the rightmost tile. Placing Tempshift Plates near these output tiles is useful for managing the heat.

The stored gas does not directly exchange heat with the Oil Well, but it can still warm the building indirectly through the gas or liquid surrounding it. Since both outputs are very hot, the Oil Well is best integrated into a heat-managed industrial area rather than left next to sensitive equipment.

When the internal pressure reaches the player-set backpressure release threshold, a Duplicant must operate the building to vent Natural Gas into the environment. This vented gas comes out at roughly 300°C, so the worker should wear an exosuit to avoid scalding and stress. Releasing pressure pauses oil extraction, and if done too slowly, Water inside the Oil Well can turn into Steam and contaminate the gas output, and potentially the liquid output as well. Because the Oil Well is not harmed by being submerged, a practical way to manage heat is to keep 1–2 tiles of Crude Oil around the lower part of the well so the oil can absorb heat and reduce the risk of vaporizing the internal Water.

• The base Natural Gas release rate is about 444 g/s.
• This rate is affected additively by the Duplicant’s Machinery skill and the lit workspace bonus.
• A Gas Pump can be used to remove vented Natural Gas automatically, and an Atmo Sensor can be used to control it. This is especially useful if the Oil Well is sealed in a compartment with tiles and mechanized airlocks.
• If the Oil Well is used to supply Natural Gas Generators, note that the generators’ output can easily become too hot if the gas is not cooled first. Mixing the well’s Natural Gas with cooler Crude Oil is one practical way to bring the temperature down for handling.
• Water sent into the reservoir is a complete loss, so Oil Well use should be planned with the broader oil and power chain in mind.