振动-空气泡沫驱封堵性能评价与矿场试验研究

Plugging Performance Evaluation and Field Test of Vibration-Air Foam Flooding

为了解决鄂尔多斯盆地裂缝性低渗透油藏开发后期含水上升快、采收率低的问题,基于低频振动作用下空气泡沫驱的增效机理,利用自制波场模拟实验装置,探讨了低频振动对空气泡沫驱封堵性能以及提高采收率的影响。实验结果表明,相对于静态泡沫封堵,振动作用下的动态泡沫封堵性能有明显提升,且在振动频率为10 Hz、振动加速度为0.04g(g为重力加速度)时效果最优;随着水驱渗透率的增大,振动-空气泡沫驱对填砂管的封堵效果变好,采收率平均提高19.63%,渗透率级差由3.08增加到37.08时,采收率增幅由18.52%增加到38.69%。同时,在延长油田进行的振动-空气泡沫驱矿场试验显示调驱后注入流量降低约46.8%,泵注压力提高约135.1%,油井日产液相对降低9.5%,日产油相对增加12.2%,综合含水率降低了8.8%,生产状况有明显改善。

In order to solve the problems of the rapid water content increase and low recovery factor of fractured low-permeability reservoirs in Ordos Basin in the late stage of development,the influences of low frequency vibration on the plugging performance and the enhanced oil recovery of air foam flooding is studied using the self-made wave field simulation device based on the oil recovery enhancing mechanism of air foam flooding under the low-frequency vibration. The experimental results show that,compared with the static foam,the plugging performance of the dynamic foam under the vibration is greatly improved,and it is the best under the vibration frequency of 10 Hz and the vibration acceleration of 0. 04g（ g is the acceleration of gravity）. With the increase of the water flooding permeability of sand packs,the plugging effect of vibration-air foam flooding becomes good,and the oil recovery factor is enhanced averagely by19. 63%. The enhanced oil recovery is increased from 18. 52% to 38. 69% when the grade difference between the permeability of two sand-packs increases from 3. 08 to 37. 08. Meanwhile,the field tests of vibration-air foam flooding in Yanchang Oilfield show that,after the vibration-air foam flooding,the injection flow is increased by about 46. 8%,injection pressure is increased by about 135. 1%,the daily fluid production of oil wells is decreased by 9. 5%,the daily oil production of them is increased by 12. 2%,total water cut is decreased by 8. 8%,and the production of the oil wells is improved significantly. The economic benefit of the vibration-air foam flooding is better than that of air foam flooding.