In order to explore the feasibility of N2 huff and puff development in the heavy oil reservoirs in Bohai S Oilfield,the gas injection phase change experiment and long core N2 huff and puff physical simulation experiment were carried out,and the enhanced oil recovery by N2 huff and puff and its influencing factors were studied.The experimental results show that:1)The saturation pressure rises rapidly,and the expansion factor and density of crude oil are unchanged after injecting N2 into the heavy oil reservoir in Bohai S Oilfield;2)The oil recovery is increased by 24.42％,and most oil is produced in the first three huff and puff cycles after four cycles of huff and puff experiments with long core device;3)The lower the crude oil viscosity,the greater the reservoir permeability and the lower the production pressure,and the better the N2 huff and puff effect.Therefore,the huff and puff efficiency can be improved by improving the reservoir permeability and making a reasonable production pressure difference when N2 huff and puff is implemented.The understanding is of great significance to the development of gas injection huff and puff in offshore heavy oil fields.
关键词
渤海稠油/氮气吞吐/相态特征/采收率/吞吐效果
Key words
Bohai heavy oil/N2 huff and puff/phase characteristics/recovery factor/huff and puff effect
维普
万方数据