Even 20 years ago (at the beginning of the XXI century), three-dimensional (diamond, graphite), one-dimensional (nanotubes) and zero-dimensional (fullerenes) allotropic forms of carbon were known. Scientists assumed the presence of a 2D modification, but could not detect it due to the thermodynamic instability of two-dimensional crystals. For a long time, attempts have been made to synthesize graphene using the chemical detachment method. Thanks to the improved micromechanical chipping technique, in 2004 physicists Andre Geim and Konstantin Novoselov were able to obtain graphene. Scientists have come up with a way to sequentially separate layers from crystalline graphite using ordinary adhesive tape. The appearance of graphene as a building material for other 2D carbon modifications is shown in the figure 2 [2].
FIG. 2. Graphene is a building material
for 2D carbon materials of all other dimensions
Graphene, the most popular and at the same time unique carbon material in the scientific world, is one of the most durable, and its resistance to mechanical influences is comparable to diamond.
Grouting cement is usually used for the construction and sealing of oil and gas wells. The use of only cement and water for the preparation of a grouting compound, as practical experience shows, entails a significant number of complications during well operation, usually associated with the quality of cement stone and its weak adhesive contact at the metal –cement–rock boundary. This affects the ever-increasing costs of major well repairs and increases the environmental burden on the environment.
Since one of the main problems that arise when fixing the casing in oil and gas wells is the low strength of cement stone, graphene additives in grouting compositions interested the authors [3] of the article Alkhamis M. and Imqam A. from the Missouri University of Science and Technology (USA). The study focuses on reducing the migration of gas fluid through the backwater space. The authors introduced graphene nanoplates as an additive to the grouting solution. Experimental tests were conducted to assess the effects of the introduction of these nanomaterials into the cement system. The results of the research showed that when graphene nanoplates in an amount from 0.3 to 0.9% by weight are added to grouting mixtures, an improvement in the mechanical properties of cement stone is observed: compressive and tensile strength increases by 10-30%. X-ray diffraction analysis has shown that the presence of graphene nanoplastics plays a key role in regulating the microstructure of hydration products. The authors of the work have experimentally proved that the quality of cementing oil wells can be significantly improved through the use of carbon nanomaterials.
If we assume that graphene is a rapidly rising star on the horizon of materials science and condensed matter physics, then its 3D allotropes – diamond and graphite – have long been studied as materials with the most amazing properties.
