Addressing issues such as poor water injection capacity

substandard water quality and wax deposition of high pour point crude oil in low permeability reservoirs of Shuanghe Oilfield in Henan

an independently designed water-CO

2

reservoir injection capability evaluation device was utilized to conduct flowability experiments and CO

2

displacement tests. Combined with core scanning electron microscopy and other testing methods

the main mechanism of poor water injection capacity of Shuanghe low permeability reservoirs was clarified

and the mai

n mechanism of CO

2

improving the injection capacity of low permeability reservoirs was explored. The results show that the deposition of suspended particles in the produced water and wax crystals in the oil can lead to pore blockage

thereby reducing the water injection capacity of the reservoir. CO

2

has a significant dissolving effect on inorganic suspended particles in produced water and on alkaline minerals and carbonate minerals in rocks

which is the main mechanism for significantly enhancing the reservoir's water injection capacity. CO

2

can dissolve paraffin deposits on the rock surface

effectively improving the reservoir's water injection capability. At the same time

the effect of CO

2

flooding is obvious

the recovery rate is increased by 13.01% ~ 21.51%

and the subsequent water flooding is further increased by 5.40% ~ 6.04%. This study shows that CO

2

injection can significantly improve the injection capacity of low permeability reservoirs in Shuanghe Oilfield

and provides theoretical support for the field application of CO

2

injection and oil displacement technology.