纳米微球在岩石矿物表面的静态吸附规律

Static Adsorption of Nano-spheres on Mineral Surface in Liquid Phase

姜旭 陈军斌 张狄杰 曹毅 孙晨

JIANG Xu CHEN Junbin ZHANG Dijie CAO Yi SUN Chen

纳米微球调驱技术已被广泛应用于低渗透油藏开发过程。为开展纳米微球在岩石矿物表面的吸附作用机理研究，需定量表征矿物种类对微球在其表面吸附量的影响。首先，运用淀粉-碘化镉法标定纳米微球乳液的浓度，进而分别实现了微球在单组分矿物表面和多组分矿物表面吸附量的测定。随后，在所测单组分矿物表面的微球吸附量基础上按照岩石矿物的相对含量进行加权叠加，得到多组分矿物表面微球吸附量的预测值。结果表明，纳米微球在不同矿物表面的静态吸附量差异较大。黏土矿物对微球的吸附能力普遍强于非黏土矿物。对微球吸附能力最强的为高岭石，比吸附能力最弱的石英强14.75 倍。微球在钾长石表面的吸附量变化值分别是在 钠长石和石英表面的1.96 倍和8.42 倍。对于多组分矿物表面的微球吸附量，加权叠加方法预测值与实验测定值的相对误差在3%以内。基于纳米微球在孔隙通道运移时的固液界面吸附现象，分析认为孔隙壁面上的黏土矿物强化了微球的吸附作用，有利于改变孔隙半径，实现在不完全封堵条件下的部分液流转向。

Nanospheres have been widely used in low permeability reservoir development. In order to study the adsorption mechanism of nano-spheres on rock and mineral surfaces，it is necessary to quantitatively characterize the influence of mineral types on the adsorption capacity of nano-spheres on rock and mineral surfaces. Firstly，starch-cadmium iodide method was used to calibrate the concentration of emulsion，and then the adsorption capacity of microspheres on the surface of single component mineral and multi-component mineral was determined. Then，based on the measured microsphere adsorption capacity on the surface of single component mineral，the predicted value of microsphere adsorption capacity on the surface of multi-component mineral was obtained by weighted superposition according to the relative content of rock minerals. The results showed that the static adsorption capacity of nanospheres on different mineral surfaces varied greatly. The adsorption capacity of clay mineral to microspheres was generally stronger than that of non-clay mineral. Kaolinite had the strongest adsorption capacity for microspheres， which was 14.75 times stronger than quartz. The adsorption capacity of microspheres on the surface of potash feldspar was 1.96 times and 8.42 times stronger than that on the surface of albite and quartz，respectively. For the adsorption capacity of microspheres on the surface of multi-component mineral，the relative error between predicted value and measured value by weighted superposition method was within 3% . Based on the adsorption phenomenon at solid-liquid interface during the migration of nano-spheres in pore channels，the analysis showed that the clay mineral on the pore wall could strengthen the adsorption of nano-spheres，which was beneficial to change the pore radius and realized partial liquid flow direction under the condition of incomplete plugging.

10.19346/j.cnki.1000-4092.2022.02.016