渗透率级差对空气泡沫驱油效果的影响

Effect of Permeability Ratio on Oil Displacement Efficiency of Air Foam Flooding

在华北油田文120区块油藏条件下(温度87℃、矿化度28291 mg/L),用不同目数的石英砂制成4组渗透率级差分别为2.8、6.8、8.9、10.7的填砂管物理模型,研究渗透率级差对空气泡沫驱油效果的影响。结果表明,随着渗透率级差的增大,高、低渗管及双管采收率增幅先增大后减小。渗透率级差由2.8增至8.9时,高渗管采收率增幅由15.13%增至18.56%,低渗管由19.45%增至29.81%,双管由17.24%增至23.43%,泡沫体系对高、低渗层的封堵调剖能力增强,驱油效果变好;渗透率级差为10.7时,高渗管、低渗管、双管采收率增幅分别为13.55%、9.00%、11.74%,泡沫体系对高、低渗层的封堵调剖能力降低,驱油效果变差。

Under the reservoir conditions of Wen 120 block in Huabei oilfield with 87℃ and 28291 mg/L salinity, the effect of permeability ratio on oil displacement efficiency of air foam flooding was researched with four groups of physical models which were made of different mesh number of quartz sand, whose permeability ratio was 2.8, 6.8, 8.9 and 10.7 respectively. The resultsshowed that the enhanced oil recovery rate of high permeable tube, low permeable tube and double tube increased first and then decreased with increasing permeability ratio. When the permeability ratio increased from 2.8 to 8.9, the enhanced oil recovery rate of high permeable tube increased from 15.13% to 18.56%, that of low permeable tube increased from 19.45% to 29.81%, and that of double tube increased from 17.24% to 23.43%. The foam system enhanced the ability of profile control and water plugging in high and low permeability layer, and the effect of oil displacement became better. When the permeability ratio reached 10.7, the enhanced oil recovery rate of high permeable tube, low permeable tube and double tube was 13.55%, 9.00% and 11.74% respectively. The ability of profile control and water plugging of foam system reduced in high and low permeability layer, and the effect of oil displacement became worse.