页岩稳定剂氧化石墨烯的研制与评价

Research and evaluation of graphene oxide as shale stabilizer

以石墨粉和硝酸钠为原料,采用氧化还原法,制备了氧化石墨烯(GO)。利用黏土线性膨胀实验、岩心自然渗吸实验、页岩抗压强度实验以及对纳微米孔隙的滤失控制实验,评价了GO对黏土膨胀的抑制效果和纳微米孔隙的封堵性能,以及对页岩强度的影响。与其他抑制和封堵剂相比,0.6%GO分散液的抑制黏土膨胀性能优于2.0%聚醚胺,0.1%GO降低液体向纳微米孔隙的侵入效果强于1.0%纳米SiO_(2),0.6%GO维持页岩抗压强度性能优于4.0%膨润土和3.0%SiO_(2),0.6%GO分散液中浸泡后的岩心抗压强度与原始干岩心相比仅有微弱下降。通过透射电镜分析发现,柔性的GO片层可以形成大面积的膜状物,这是氧化石墨烯能够高效封堵纳微米孔隙、保护页岩的重要原因。

In this paper,graphene oxide(GO)was prepared by the redox process method using graphite powder and sodium nitrate as raw materials.The inhibition effect of GO on clay swelling and plugging performance of nano-micron pores,as well as the effect on shale strength were evaluated using linear swelling experiment of clay,natural percolation experiment of core,compressive strength experiment of shale,and filter loss control experiment of nano-micron pores.Compared with other inhibition and plugging agents,0.6%GO inhibited clay swelling better than 2.0%polyetheramine,0.1%GO reduced liquid intrusion into nano-pores better than 1.0%nano-SiO_(2),0.6%GO maintained shale compressive strength better than 4%bentonite and 3.0%SiO_(2).Compared with that of original dry cores,the compressive strength of cores soaked in 0.6%GO dispersion liquid was only slightly decreased.By transmission electron microscopy analysis,it was found that the flexible GO lamellae could form a large area of membrane,which is an important reason for the efficient plugging of nano-micron pores to protect the shale.