Enhanced oil recovery (EOR) is a process for recovering more oil than traditional primary and secondary recovery techniques can achieve. It involves various advanced techniques for offsetting reservoir decline and increasing production from existing oilfields. It is commonly used when other primary and secondary methods are no longer economically viable.

EOR can be divided into two main types: thermal and gas injection. Thermal recovery methods involve the injection of steam and/or hot water underground. This helps to lower the viscosity of the oil and make it easier to extract. Gas injection methods use gases such as nitrogen, carbon dioxide, and methane to push oil to the surface.

EOR is an important part of increasing the amount of oil that can be recovered, but it can also have negative environmental impacts. Traditional methods of extraction can lead to water pollution, soil contamination, and even climate change due to the release of CO2 when gas is injected into the reservoir. However, new innovations in the sector, such as low-emission EOR processes and development of alternative energy sources, may reduce these negative impacts in the future.

EOR can also be part of a larger effort for sustainability in the petroleum industry. This can involve developing more efficient systems for drilling, completing wells, and extracting oil in a cost-effective and environmentally-friendly way. This could lead to increased economic stability for the oil industry and reduce its overall environmental impact.

Overall, EOR has become an increasingly important part of the oil and gas industry and one that is likely to further develop in the future. It helps to offset decline in existing fields and increase production, providing economic benefits for oil companies and more stable energy supplies for consumers. While traditional EOR techniques have their drawbacks, new innovative solutions are being developed and implemented to reduce their environmental impact.