Abstract: Aiming at technical demand on relieving the reverse of imbibition profile, displacement effect of alternate injection of Cr3+ polymer gel and water was studied, taking reservoir of Bohai oilfield as simulation object, regarding injection pressure, water content and recovery efficiency as evaluation index. Results showed that as the displacement agent flowed into the medium and low permeability layer, on the one hand, the swept volume was magnified. On the other hand, seepage resistance and start up pressure of imbibition were increased, thus resulting in the reverse of the imbibition profile. Once the alternate injection of Cr3+ polymer gel and water was adopted, polymer solution could get priority to flow into the high permeable layer and block off it, then subsequent water flowed into medium and low permeability layers to displace the oil. Therefore the phenomenon of the reverse of imbibition profile was relieved or even eliminated. Once the alternate injection of C3+ polymer gel and water was conducted in A22 injection well in LD5-2 Oilfield, injection pressure get increased, which was good for enlarging sweep volume effect.

Key words: font-family: Calibri, font-variant: normal, vertical-align: baseline, text-transform: none, color: windowtext, mso-ascii-font-family: Calibri, mso-fareast-font-family: 宋体">Bohai oilfield, Polymer gel, Alternate injection, Displacement effect, Physical simulation, Mechanism analysis

摘要： 针对矿场减缓吸液剖面反转技术需求, 以渤海油藏储层为模拟对象, 以注入压力、 含水率和采收率为
评价指标, 开展了“ C r 3+聚合物凝胶+水” 交替注入调驱方式增油效果实验及矿场研究。结果表明, 调驱剂进入储层
中低渗透层, 一方面扩大了波及体积, 另一方面增加了渗流阻力和吸液启动压力, 引起吸液剖面反转。采用“ C r 3+ 聚
合物凝胶+水” 交替注入调驱方式, 不仅有利于增强C r 3+聚合物凝胶前置段塞对高渗透层的封堵作用, 还可进一步
发挥后续水段塞转向进入中低渗透层后的驱油作用, 从而减缓甚至消除调驱剂进入储层中低渗透层后引起的吸液
剖面反转现象。L D 5 - 2油田 A 2 2井实施“ C r 3+聚合物凝胶+水” 交替注入调驱工艺后, 压力明显提高, 有利于增强驱
替剂扩大波及体积效果。

关键词: 渤海油藏, 聚合物凝胶,  , 交替注入,  , 增油效果, 物理模拟, 机理分析