关键词: 配伍性,    ,  地层系数法,    ,  孔喉结构,    ,  注入水,    , 悬浮固体,    ,  粒径分布

Abstract: The injected water suspended solids particle size index of Qikou 172 oilfield is mainly based on the industry standard, it is essential to carry out the study on compatibility between suspended solids particle size and pore throat on this basis. The distribution of principle waterinjection intake level for Qikou 172 oilfield is obtained via the statistics of the formation factor. Based on the capillary pressure curves from the main water injection reservoir, the microscopic pore structure was analyzed and the median primary fluid throat was obtained. In order to find out the compatibility ratio of suspended particle to the median primary fluid throat during waterflooding for the target oilfield, 24 pieces of cores, which its’ permeability are around 2 000 mD, are used to simulate waterflooding. According to Chinese standard SY/T 5329—94, the upper limit of particles concentration of the most strictest index at the target permeability is 5 mg/L. Considering that when the damage extent is over 25%, the relevant size distribution of the particles should be avoided and it’s lower limit is adopted for the working site. Experimental results show that the ratio of the lower limit to the median primary fluid throat is 1/8. The damage extent was over 20% when the concentration of the particles was 5 mg/L and the upper limit of the size distribution was 4 μm.Thus the concentration and the upper limit of the size distribution of the suspend particles should be controlled individually in 5 mg/L and 4 μm. 

Key words: Compatibility,    ,  Formation factor method,    ,  Microscopic pore structure,    ,  Injected water,    , Suspended particle,    ,  Size distribution