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Production of mature oil fields emits significant amount of CO 2 related to circulation and handling of large volumes of gas and water. This can be reduced either by (1) using a low-carbon energy source and/or (2) reducing the volumes of the non-hydrocarbon produced/injected fluids. This paper describes how improved oil recovery techniques can be designed to reduce CO 2 intensity (kgCO 2 /bbl oil) of oil production by efficient use of the injectants. It is shown that CO 2 emissions associated with injection of chemicals is strongly influenced by water cut at the start of the project, extent of the water cut reduction, and chemical utilization factor defined as the volume of produced oil per mass or volume of the injectant. As an example, for the oil field considered in this study, 3–8% reduction in water cut can result in 50–80% reduction in its CO 2 intensity. In addition to the incremental oil production with lower CO 2 intensity, the earlier implementation of enhanced oil recovery methods can extend the lifetime of the mature fields if carbon emission cut-offs are applied. In case of CO 2 enhanced oil recovery (EOR), the large storage potential for CO 2 can significantly reduce the overall CO 2 emissions of oil, albeit at a large energetic cost. For CO 2 EOR using CO 2 captured from gas power plants, improving the utilization factor from 2 bbl/tCO 2 to 4 bbl/tCO 2 can reduce the CO 2 intensity of the produced oil from 120 kgCO 2 /bbl to 80 kgCO 2 /bbl (33% reduction). [Display omitted] • Improved oil recovery methods can lead to cleaner production of oil. • Efficient utilization of injectants is key to reduce CO 2 emissions from operations. • CO 2 enhanced oil recovery reduces total CO 2 intensity of oil by 80%. • Cleaner production of hydrocarbon fields extends their lifetime. • Earlier implementation of EOR techniques lowers overall CO 2 footprint of fields. [ABSTRACT FROM AUTHOR]