高性能纳米降滤失剂氧化石墨烯的研制与评价

以天然鳞片石墨为原料,通过改进的Hummers法制备了具有单层或多层平面薄膜结构的氧化石墨烯纳米材料降滤失剂,并借助红外光谱、X射线衍射、热重分析、透射电镜等手段进行了化学结构和微观形貌表征。通过API滤失实验研究了氧化石墨烯的降滤失性能,与目前现场常用的几种降滤失剂进行比较后的结果表明,氧化石墨烯由于其纳米尺度分散的特性在较低浓度下即具有较强的降滤失性能,优于传统的降滤失剂。通过氧化石墨烯与膨润土和羧甲基纤维素的复配实验发现,氧化石墨烯作为一种封堵类降滤失剂,无需膨润土的存在就可起到优异的效果;通过与增黏剂类处理剂的复配可以在节约成本的基础上进一步提高降滤失性能;通过粒度分析发现,氧化石墨烯的横向粒径越大,降滤失效果越好,而制备大横向尺度氧化石墨烯的关键在于选择低目数的鳞片石墨作为原料。

Preparation and evaluation of nano-graphene oxide as a high-performance fluid loss additive

Taking natural flake graphite as a raw material, nano-graphene oxide(GO) as a high performance fluid loss additive was prepared by means of the modified Hummers' method. The chemical structure and micro-topography of GO were characterized through a combination of FTIR, XRD, TG and TEM. The performance of GO on fluid loss control was evaluated via an API filtration tests and a comparison of GO with several commonly used fluid loss additives was made. The results shows that: GO performances much better in reducing fluid loss than other additives even at relatively low concentration due to its good aqueous dispersion of nano scales; it was found in a formulation experiment of GO with bentonite and carboxy methyl cellulose that GO is an outstanding plugging type fluid loss additive even in the absence of bentonite; in order to further improve the performance of reducing fluid loss at low cost, GO can be composited with some viscosifiers; the results of grain size analysis indicated that the bigger the transverse grain size, the better GO performances, therefore the key to prepare GO with large horizontal scale lies in taking low-mesh natural flake graphite as a raw material.