In nature, pure carbon is most often found in the form of graphite. This soft black material has unique physical properties – fire resistance (up to 1500 ° C), the highest electrical and thermal conductivity among non-metals, refractoriness, chemical resistance, plasticity, high specific heat capacity, etc. Graphite is used in metallurgy, mechanical engineering, electrical engineering and the oil and gas industry.
To determine the effect of graphite on grouting solutions in a study the scientists from the University of Oklahoma (USA) Shawgi A., Chinedum P.E. и Saeed S. [5] used nanosynthetic graphite. The test results, including the determination of compressive strength, rheological parameters of the grouting solution and the rate of formation of cement stone, showed a number of positive properties of nanosynthetic graphite as an additive to cement-water paste. The introduction of only 0.5% nanosynthetic graphite by weight of cement proved to be sufficient to support the effective growth of minerals in the cement system, contributing to the early development of strength. It has been proven that the new grouting mixtures have excellent thermal and electrical conductivity. Rheological tests and experiments to determine the WOC have confirmed the satisfactory pumpability of the grouting solution.
To improve the physico-mechanical characteristics of cement stone in [6] the authors of the article Peyvandi A., Taleghani A.D., Soroushian P. and Cammarata R. used inexpensive graphite nanoplates to pan the grouting mixture. Graphite nanoplates have the same mechanical, physical and geometric characteristics as carbon nanotubes (CNTs), but at a much lower cost. Experimental results have revealed prospects for achieving the necessary properties of cement mortar by introducing graphite nanoplates.
The main purpose of the study by Tabatabaei M. (University of Pennsylvania, USA) [7] was studying influence of inexpensive graphite nanoplates for cementing well casings (Fig. 4). The authors proved that modified grouting mixtures have improved long-term insulation of the borehole and increased durability of cement stone.
FIG. 4. The appearance of graphite nanoplates under a microscope
