压力对泡沫驱封堵能力及气泡大小的影响

The Influence of Pressure on Plugging Capacity and Bubble Size of the Air Foaming

空气泡沫驱油工艺中,泡沫对孔喉的封堵能力主要受气泡尺寸大小的影响。通过室内驱替实验研究了压力对空气泡沫渗流过程中的封堵能力和气泡大小的影响。实验装置为自制可视化填砂管模型,实验用起泡剂为有效浓度为0.5%的ZY起泡体系。在不同压力下,用精密压力表测定填砂管首尾测压点(p1和p4)和填砂管中间的两个测压点(p2和p3)压力数值;p2和p3之间相距1m,距填砂管首尾两端距离都为0.5m。结果表明:①泡沫的封堵能力与压力成正比,压力越大,泡沫产生的阻力系数越大,封堵能力越强;压力为0.1MPa、5MPa和10MPa时,泡沫产生的阻力系数分别为48、58和70。②气泡的直径与压力成反比,常压(0.1MPa)时,气泡平均直径约为7.38μm;压力为5MPa时,气泡平均直径约为5.46μm。③压力为5MPa时,气泡与孔喉的匹配性比常压(0.1MPa)时更好。

Plugging capacity of the foam to pore-throat is influenced by the bubble size during the air foam oil displacement.The impact of the pressure on the plugging capacity and bubble size in the air foam perco- lation process is researched through the indoor flooding experiments.The experiment is done through man- made visualized sand packed model.Foaming agent applied in the experiment is ZY with 0.5% of the effec- tive mass fraction.Vernier gauge is applied to measuring the pressure at the top,center and bottom of the sand-packed pipe （P1,P2 and p3,p4）.The space between the point of P2 and P3 is lm,and the space between the point of p1 and P2 or P3 and P4 is 0.Sm.The results show that ：the plugging capacity of the foam is pro- portional to the pressure ,more pressure brings more resistance coefficient of the foam and stronger plugging capacity;the pressure is 0.1MPa, 5MPa and 10MPa,the resistance coefficient of the foam is 48,58 and 70 respectively.The diameter of the bubble is inversely proportional to the pressure.When the pressure is 0.1MPa,the average diameter of bubbles is nearly 7.38μm.When the pressure is 5MPa,the average diameter of bubbles is nearly 5.461xm.When the pressure is 5MPa,the size of the bubble is better match the pore than 0.1MPa.