非均质油藏三元复合驱后提高采收率实验研究

发布时间：2018-08-20 15:13

【摘要】：三元复合驱是油田开采后期为提高原油采收率而提出的一种三次采油技术,三元复合驱包括强碱三元复合驱和弱碱三元复合驱。由于三元复合驱存在对地层伤害较大、结垢严重等现象,因此,研究三元复合驱体系对采收率的影响,对油田进一步开采具有重要的指导意义。本文以大庆杏树岗油田为实验平台,采用黏度测试验方法研究了聚合物、聚表二元体系、三元复合体系、聚合物凝胶的黏度变化规律;在三管并联均质岩心条件下开展了强碱三元复合驱后弱碱三元复合驱、无碱二元复合驱、高浓度聚合物驱、“凝胶1+弱碱三元复合体系”、“凝胶2+体膨颗粒+弱碱三元复合体系”、“凝胶1+无碱二元复合体系”和“凝胶2+体膨颗粒+无碱二元复合体系”驱提高采收率方法增油效果实验研究,在“五点法”仿真物理模型条件下开展了强碱三元复合驱后高浓聚合物和“调剖剂+弱碱三元复合驱”提高采收率方法增油效果实验研究。结果表明:强碱三元复合驱过程中,调驱剂注入初期和中期高渗透层分流率降低,中低渗透层分流率升高。当注入到中后期时,中低渗透层分流率降低,高渗透层分流率升高,即出现所谓“剖面反转”现象;与调驱剂洗油能力相比较,其扩大波及体积能力对采收率贡献率较大。因此,强碱三元复合驱后注入调驱剂必须具有更强流度控制和洗油能力,只有这样才能较大幅度提高采收率;在五点仿真模型上,强碱三元复合体系后采用“恒压实验”方法注入高浓聚合物溶液和“凝胶2+体膨颗粒+弱碱三元体系”都能够进一步提高采收率,采收率增幅分别为11.5%和12.9%;在五点仿真模型上,强碱三元复合驱后剩余油主要在中渗层远离注入端地带和整个低渗层,高浓聚合物驱和“凝胶2+体膨颗粒+弱碱三元”驱驱替对象主要就是这部分剩余油;从经济效果方面考虑,强碱三元复合驱后推荐注入0.7 PV高浓聚合物溶液。从技术效果方面考虑,强碱三元复合驱后推荐注入“0.1 PV(凝胶2+体膨颗粒)+0.35 PV弱碱主段塞+0.15 PV弱碱副段塞+0.1 PV后续聚合物”组合。
[Abstract]:ASP flooding is a kind of tertiary oil recovery technology proposed to improve oil recovery in the later stage of oilfield production. ASP flooding includes strong alkali ASP flooding and weak alkali ASP flooding. Because the formation damage and scaling are serious in ASP flooding, it is very important to study the effect of ASP flooding system on oil recovery. On the platform of Daqing Xingshugang Oilfield, the viscosity change of polymer, ternary system and polymer gel was studied by viscosity test method in this paper. Under the condition of three parallel homogeneous cores, weak alkali ternary flooding, alkali free binary composite flooding, high concentration polymer flooding, "gel 1 weak alkali ternary compound system" were carried out after strong alkali ternary flooding. Experimental study on enhanced oil recovery effect of "weak alkali ternary compound system of gel 2 bulking particles", "gel 1 alkali-free binary composite system" and "gel 2 expansion particle no alkali binary composite system". Under the condition of "five-point method" simulation physical model, the experimental study on enhancing oil recovery effect of high concentration polymer and "profile control agent weak alkali ternary flooding" after strong alkali ternary flooding was carried out. The results show that in the process of strong alkali ASP flooding, the distributary rate of high permeability layer decreases in the early and middle period of the injection of adjusting flooding agent, and the distribution rate of low and middle permeability layer increases. At the middle and late stage of injection, the distributary rate of middle and low permeability layers decreases, and the distribution rate of high permeability layer increases, that is, the phenomenon of "profile inversion" occurs, and compared with the oil washing ability of flooding adjuster, its expanded sweep volume capacity contributes more to oil recovery. Therefore, the injection adjuster must have stronger mobility control and oil washing ability after strong alkali ASP flooding, only in this way can oil recovery be greatly improved. After the strong alkali ternary system was injected into the high concentration polymer solution and the gel two-body dilatation particle weak alkali ternary system by "constant pressure experiment", the recovery factor was further improved by 11.5% and 12.9% respectively, and in the five-point simulation model, the oil recovery was increased by 12.5% and 12.9%, respectively. The remaining oil after strong alkali ASP flooding is mainly located far away from the injection end zone and the whole low permeability zone in the middle permeable layer, and the remaining oil is the main displacement object of high concentration polymer flooding and weak alkali ternary flooding. Considering the economic effect, it is recommended that 0.7 PV high concentration polymer solution should be injected after strong alkali ASP flooding. Considering the technical effect, it is recommended to inject "0.1 PV (gel 2 bulking particle) 0.35 PV weak base slug 0.15 PV weak base secondary slug 0.1 PV follow-up polymer" after strong alkali ASP flooding.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE357.46

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