特低渗透油藏水驱油特征实验研究

针对特低渗—超低渗油层渗流特点,选取西峰油田长8油层21块岩心,通过室内水驱油实验研究,分析了低渗透油层驱油效率与储层渗透率的关系,驱油效率与注水倍数的关系,以及驱油效率与驱替压力梯度的关系.研究结果表明,低渗透油层在渗透率较低的范围内,随渗透率的降低,驱油效率则急剧降低;随注水倍数的增加,各含水阶段驱油效率增加的幅度不同,消耗的注水量也不同;随着驱替压力梯度的提高,驱油效率均呈上升趋势.

Experimental study on the water-flooding characteristics in super-low permeability reservoirs

According to the laboratory water-flooding experiments of 21 cores from Chang 8 formation in Xifeng oilfield,the relationships between water oil displacement efficiency andreservoir permeability,water injection multiple and displacement pressure gradient are gained.The results show that,for low-permeability reservoirs,the oil displacement efficiency decreases quickly with the permeability decreasing in lower permeability range;it increases at different amplitudes in different water-cut stages with the water injection multiple increasing,and the water injection rate is also different in different water-cut stages;it presents rising tent with the displacement pressure gradient increasing.