致密砂岩油藏热水+表活剂驱提高采收率机理及其对产能贡献的定量评价

在室内实验的基础上,通过数值模拟定量评价了长庆油田致密砂岩稀油油藏热水+表活剂驱提高采收率的各种机理对产能的贡献.研究结果表明:致密砂岩油藏热水驱提高采收率的主要机理是原油的热膨胀和对相渗曲线的影响,在注入温度100℃情况下,20 a末的采收率由冷水驱的19.3%提高到22.8%,增加了3.5%,其中热膨胀和对相渗曲线影响的贡献各占42%;热水+表活剂驱提高采收率的主要机理是原油热膨胀、对相渗曲线的影响和对界面张力的影响,在注入温度100℃情况下,20 a末的采收率从冷水驱的19.3%提高到25.6%,提高了6.3%,其中热水驱贡献占55%,表活剂贡献占45%.

Enhanced oil recovery mechanisms of "hot water+surfactant" flooding and quantitative evaluation of their contribution to the productivity of tight sandstone reservoirs

Through the laboratory experiment and numerical simulation,enhanced oil recovery mechanisms of "hot water + surfactant" flooding in tight sandstone oil reservoirs of Changqing Oilfield are studied systematically.It is shown that the main enhanced oil recovery mechanisms of hot water flooding are the thermal expansion of crude oil and its effect on relative permeability curve.At the optimal injection temperature of 100 ℃,the recovery ratio will be increased to 22.8% at the end of 20 years from 19.3% of cold water flooding by hot water flooding,and it was increased by 3.5%,in which the contribution of thermal expansion and relative permeability curve change is both 42%.The main enhanced oil recovery mechanisms of "hot water + surfactant" flooding are thermal expansion,relative permeability curve change and effect of surfactant on interfacial tension.At the optimal injection temperature of 100 ℃,the recovery ratio will be increased to 25.6% at the end of 20 years from 19.3% of cold water flooding by "hot water + surfactant" flooding,and it is increased by 6.3%,in which the contribution of hot water flooding is 55%,and the contribution of surfactant flooding is 45%.