回注水中固体颗粒对储层伤害的实验研究

Experimental Study on Damage of Suspended Solid Particles to Reservoir Permeability During Water Injection

回注水中的悬浮固体颗粒进入储层导致储层渗透率降低,而较为严苛的水质要求会增加回注水处理的经济成本,研究不同渗透率储层回注水中悬浮固体颗粒的回注界限具有重要意义。以孤岛油田X区块中高渗油藏为例,基于采出液中悬浮固体颗粒质量浓度和粒径分析,通过岩心流动实验研究不同粒径、质量浓度的悬浮固体颗粒溶液通过渗透率不同的人造岩心时对岩心渗透率造成的损伤,并分析注入速度对上述结果的影响。结果表明:注入速度对悬浮固体颗粒溶液侵入岩心的伤害影响较小;悬浮固体颗粒对侵入储层的伤害程度随着岩心渗透率增大而降低;对于同一级别渗透率的岩心,固体颗粒质量浓度越高、粒径越大,对侵入储层的伤害程度越严重。最终通过最小曲率插值法对实验结果进行处理,得到了适用于孤岛X区块不同渗透率储层的悬浮固体颗粒溶液的注入界限,对提高油田注水效果有重要指导意义。

When the suspended solid particles in the reinjection water enter into the reservoir with different permeability, the reservoir will be damaged in different degrees. Taking the reservoir with high permeability in a block of Shengli Oilfield as an example, based on the analysis results of suspended solids content and particle size in the produced fluid, the damage of artificial core permeability was studied by injecting three different kinds of particle contents with different particle sizes. Different injection rates were studied as well. The results showed that the damage of the suspended solid particles to the reservoir increased with the increase of the injected pore volume and then reached to a stable value. The larger the core permeability, the smaller the permeability loss. For the core with same level of permeability, the larger the solid particle content and the larger the particle size, the more serious damage of the reservoir. The injection rate of the suspended solid particle had little effect on the damage of the core. Finally,through the interpolation of minimum curvature, the injection pattern of suspended solid particle solution in different permeability reservoirs was achieved, which had significantly important guiding significance for improving the effect of oilfield water injection.