二元复合驱波及系数和驱油效率对采收率的影响

INFLUENCES OF THE SWEPT COEFFICIENT AND OIL DISPLACED EFFICIENCY ON EOR FOR THE BINARY COMBINED FLOODING

无碱二元复合驱是今后化学驱发展的主要方向。为认清二元复合驱提高采收率机理,通过室内三维物理模拟实验,研究了二元复合驱过程中非均质油藏波及系数与驱油效率的变化特征,并量化其对提高采收率的贡献程度。实验结果表明:在有隔层的条件下,中渗透层提高采收率幅度最高,低渗透层次之,高渗透层最低;二元驱高渗透层以提高驱油效率为主,低渗透层以提高波及系数为主,中渗透层同等提高波及系数和驱油效率;初步得出驱油效率对最终提高采收率的贡献率为40%,扩大波及系数的贡献率为60%,可有效指导二元驱配方组合设计思路。

Non-alkali binary combined flooding is the main development direction of chemical flooding from now on. In order to make clear of the mechanism of the binary flooding, the dynamic characteristics of the swept coeffi- cient and oil displaced efficiency is studied through 3 D physical simulating test, and moreover the contribution rate to enhance oil recovery is also quantified. The experimental results show that in the condition of the barriers, the EOR contribution for the medium-permeability oil reservoirs is the highest, the next is the low-permeability reser- voirs, but that of the high-permeability ones is the lowest ; the action of the binary flooding for the high-permeability reservoirs is dominantly improving the oil displaced efficiency, on the contrary, for the low-permeable reservoirs, to enhance the swept coefficient is key, and for the medium-permeability reservoirs, the two co-actions of the above is are realived at the same time; the contribution rate of the obtained efficiency to enhance the ultimate oil recovery is 40% , and that of the swept coefficient is 60%. All the achievements can guide the design thought of the formula combination of the binary complex flooding.