页岩气藏滑溜水压裂用降阻剂性能影响因素研究

Influencing factors of friction reducer in shale slickwater fracturing

关键词:  体积压裂  降阻剂  降阻性能  相对分子质量  线速度 

Key words:  volume fracturing  friction reducer  friction reducing performance  relative molecular mass  linear velocity

摘要:

“大排量、大液量”体积压裂日益成为页岩气藏开发的有效方式,降阻性能是体积压裂液体关键性能,直接决定了体积压裂的成败。研究了剪切速率、线速度、雷诺数、降阻剂相对分子质量、降阻剂质量分数与降阻性能的关系,水质对降阻性能的影响。结果 表明,模拟现场降阻性能时,采用剪切速率相似原则并不能完全有效地评价滑溜水降阻性能,建议依据线速度、雷诺数相似模拟；降阻剂结构相似,有效浓度一致时,相对分子质量越大降阻性能越好,但高相对分子质量降阻剂耐剪切、溶解等性能差；降阻剂质量分数提高,降阻性能提高,但质量分数增加到一定值时,降阻性能提高较小,降阻剂质量分数低于一定值时耐剪切性能差；水质对降阻剂性能有影响,矿化度高时,阳离子降阻剂降阻性能较好。

Abstract:

Large displacement and large amount of fluid volume fracturing is increasingly becoming an effective way of shale gas reservoir development. The friction reducer performance is the critical performance of volume fracturing which directly determines the success or failure of the volume fracturing. This paper studied the relationship among “shear velocity, linear velocity, the Reynolds number, relative molecular mass, concentration and water quality”with the friction reducer performance. The results showed that using shear rate similar principle could not effectively evaluate friction reducer performance of slickwater. The performance of friction reducing was recommended to be evaluated by the linear velocity and Reynolds similar principle. When the friction reducers had similar structure and consistent effective concentration, the bigger relative molecular mass, the friction reducing performance was better. But high relative molecular mass would cause the cut-resistant and dissolving performance poorly. The concentration of friction reducer increased, the friction reducing performance improved, but when the concentration increased to a certain value, the friction reducing performance increased smaller; when friction reducer concentration was lower than a certain value,the cut-resistant performance was poor. Water quality had an impact on friction reducer performance,namely higher the salinity, better the cationic friction reducer performance .