Oxygen-reduced air injection is an effective technique for developing low-permeability oil reservoirs.Under reservoir conditions,oxygen-reduced air can undergo low-temperature oxidation reaction with crude oil,thereby enhancing oil recovery.Regarding the inade-quate understanding of the mechanism underlying the oxygen-reduced air flooding for enhanced oil recovery(EOR)in the Guo-8 block of the Yuguo oilfield,isothermal oxidation experiments and long-core displacement experiments were conducted to investigate the influences of oil oxidation process and generated substances on EOR.The results of the isothermal oxidation experiments indicate that sedimentary substances are generated during the low-temperature oxidation process of light oil.With the increase of temperature,the degree of oxidation significantly increases,with the sedimentation of heavy components reaching 1.25×10-3 g/g at 89℃,3.43×10-3 g/g at 100℃,and 5.02×10-3 g/g at 120℃.The results of the long-core displacement experiments demonstrate that the sedimentation of heavy components at different oxidation tem-peratures affects EOR.With temperature increasing,the timing of gas channeling delays,the sweeping effect improves,and the final recov-ery increases to 52.77%,58.89%,and 65.23%at temperatures of 89℃,100℃,and 120℃,respectively.
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