关键词: 结垢机理, 油层, 结垢油层伤害, 模拟实验, 砂岩微观孔隙模型, 注水开发油田

Abstract: By means of simulation experiments in sandstone micromodels,scaling mechanism and formation damage due to scaling of BaSO₄ and CaCO₃ are studied respectively. The results show:1)Formation scaling is formed in the repeated heterogeneous-phase nucleation and crystal growth. The crystal can grow both in pores and at throats. 2)The characteristics of scaling are different for different scales. BaSO₄ scaling develops intermittently in the alternate process of water mixing and scaling, the morphology of the scale crystals develops poorly and the crystals are fine.While CaCO₃ scaling develops continuously,the morpholgy of the scale crystals develops perfectly and the crystals are large. 3)The formation damage due to scaling is a complex problem,even if effects of temperature and multiphase flow are excluded,it is still affected by the amount of scale and formation permeability. In general,the larger the amount of scale is or the lower the permeability is, the severer the formation damage is. As the permeability of formation decreases, the difference of formation damage decreases due to different amount of scale. As the amount of scale increase, the difference of formation damage decreases in formations with different permeability.

Key words: scaling mechanism, formation, formation damage due to scaling, simulation experiment, sandstone micromodel, waterflooding oil field