The Effect Of Wettability On Oil Recovery For Low Permeability Oil Layers

In view of the research about the effect of wettability on oil recovery for low permeability oil layers is not systematic,we did quantify analysis about the relationship of the wettability and the oil recovery by doing some experiments with the low permeable cores.We treated the cores with different chemical.The results show that:the rate of artificial cores contact angle is -57.18%～58.39%,the rate of natural cores NO.22 contact angle is -47.98%～29.85%,the rate of natural cores NO.5-3 contact angle is -53.02%～26.63%the rate of natural cores NO.22 contact angle is -55.18%～21.18%.About the effect of wettability on water drive recovery efficiency,the results show that:the range of artificial cores contact angle is 35.77°～133.35°,the range of water drive recovery efficiency is 30.43%～40.85%. The weakly water-wet core NO.25 witch contact angle is 67.17°have the highest water drive recovery efficiency.Its water drive recovery efficiency is 40.85%.The natural cores range of contact angle is 45.24°～122.43°,the range of water drive recovery efficiency is 13.02%～19.35%.The weakly water-wet core NO.22-5 witch contact angle is 69.77°have the highest water drive recovery efficiency.Its water drive recovery efficiency is 18.33%.The weakly water-wet core NO.5-3-5 witch contact angle is 71.64°have the highest water drive recovery efficiency.Its water drive recovery efficiency is 19.35%.The weakly water-wet core NO.6-5 witch contact angle is 72.60°have the highest water drive recovery efficiency.Its water drive recovery efficiency is 18.60%.About the effect of wettability on combination recovery efficiency,the results show that:the artificial cores range of contact angle is 35.77°～133.35°,the range of combination recovery efficiency is 4.23%～6.35%.The intermediate wettability core NO.22 witch contact angle is 100.78°have the highest combination recovery efficiency.Its combination recovery efficiency is 6.35%.The natural cores range of contact angle is 45.24°～122.43°,the range of combination recovery efficiency is 2.87%～5.74%. The intermediate wettability core witch contact angle range is 81.68°～85.48°have the highest combination recovery efficiency.The core NO.22-4 witch contact angle is 81.68°Its combination recovery efficiency is 5.74%.The core NO.5-3-4 witch contact angle is 82.16°Its combination recovery efficiency is 5.47%.The core NO.6-4 witch contact angle is 85.48°Its combination recovery efficiency is 5.39%.The effect of wettability on water flooding oil recovery is higher than the effect of wettability on combination flooding.The maximal value of artificial cores water flooding is 10.42%higher than the minimal.The maximal value is 2.12%higher than the minimal.The maximal value of natural cores water flooding is 5.94% higher than the minimal.The maximal value is 2.60%higher than the minimal.