【摘要】：我國的不少油田也相繼進入了開發(fā)的中后期,產水率增加,產油率快速下降,經過一次采油、二次采油和三次采油油藏中仍有仍有40%~60%左右的剩余油。可見,提高采收率的途徑需要尋找新的方法驅油。由于毛細管阻力等因素的作用,油藏中的殘余油不容易滲流通過巖石中很小的毛細管,這種流動體系使油相的相對滲透率較低,殘余油增加,導致原油采收率降低。如果我們能使地下的原油就地自發(fā)乳化,使原油變成粒徑小于多孔介質孔喉直徑的乳狀液,那么油相就非常容易地通過巖石中的毛細管,使殘余油飽度下降,從而提高原油采收率。針對勝利油藏地質條件,本文篩選優(yōu)化出一種自發(fā)乳化調驅體系,并對該體系進行了界面張力、油膜收縮性能、洗油砂性能、自滲吸性能等性能評價,同時開展了室內物模驅油試驗研究。研究結果表明:實驗溫度為80℃時,自乳化體系2000 mg/L Z1+2000mg/L A2在輕微外力作用下,不需要達到超低界面張力,即可與原油發(fā)生乳化,將油滴從油砂中清洗出來,形成的乳狀液滴平均粒徑為15μm,在顯微鏡下可觀察到明顯的液滴聚并和橋接現象。通過室內物模驅油試驗,得出:該體系在水驅至含水98%后,仍可大幅度提高采收率,采收率增值仍然大于20%。
[Abstract]:Many oilfields in our country have entered the middle and late stage of development one after another. The water production rate increases and the oil production rate decreases rapidly. After the first oil recovery, the secondary oil recovery and the tertiary oil recovery reservoir, there are still 40% or 60% of the remaining oil. Therefore, the way to improve oil recovery needs to find a new way to drive oil. Because of the effect of capillary resistance, the residual oil in the reservoir is not easily percolated through the small capillary in the rock. This flow system makes the relative permeability of the oil phase lower and the residual oil increase, resulting in the decrease of oil recovery. If we can make the underground crude oil spontaneously emulsify in situ and turn the crude oil into an emulsion with a diameter smaller than the diameter of the pore throat of the porous medium, then the oil phase will very easily pass through the capillary tube in the rock and reduce the saturation of the residual oil. In order to improve oil recovery. According to the geological conditions of Shengli reservoir, a spontaneous emulsification and flooding system was selected and optimized, and the interfacial tension, oil film shrinkage, oil sand washing and self-permeability were evaluated. At the same time, the laboratory model oil displacement test was carried out. The results show that when the experimental temperature is 80 鈩，

本文編號：2327017