关键词: 纳米SiO₂, 降压增注机理, 吸附法, 岩石孔隙, 流体流动, 滑移效应, 润湿性, 渗透率, 实验研究

Abstract:

The alternating mechanisms of flow resistance to porous wall and the mechanism of enhancing water injection by using nano-particle of SiO₂ were investigated with the nano-particle adsorption method. When the hydrophobic nano-particles were adsorbed on the surface of porous walls, a layer of nanometer particles was formed instead of hydrated layer. The wettability of porous wall then could be translated to strongly hydrophobicity from hydrophilicity, and the slip effects on the nano-particles layer happened. The flow resistance could be reduced obviously, and the fluid velocity was enlarged obviously. A series of experiments were made to validate the feasibility to form the slip effects on the porous wall by nano-particle adsorption method. The results of displacement experiment show that the water-phase effective permeability could increase about 47 percent averagely. The Lattice Boltzmann Method was used to simulate the slippage length on the porous wall induced by nano-particle adsorption method.

Key words: hydrophobic nano-particle of SiO₂, reducing pressure and enhancing water injection mechanism, nano-particle adsorption method, rock pore, fluid flow, slippage effect, wettability, permeability, experimental study