The research detailed in this thesis is an investigation of the chemistry, applications, and methods for the synthesis of graphene oxide (GO), GO derivatives, graphite derivatives, carbon black derivatives, and activated charcoal derivatives, with an emphasis on applications relevant to the oil and gas industry. More particularly, the research involves a method for the rapid purification of GO; the use of GO and GO derivatives in oil-drilling fluids; the use of activated charcoal and carbon black for asphaltene inhibition; and the synthesis of nanoplatelets from an H2SO4/SO3/SO5- graphite intercalation compound and their application as conductivity enhancers in oil-based drilling fluids. Although many applications for GO have been reported in the literature, development of these applications on an industrial scale is held back by the lack of scalable procedures for the purification of GO after synthesis. A scheme for scalable purification is presented in Chapter 1. Suspensions of the resulting GO were tested for rheology and radionuclide uptake. One of the many possible industrial applications of GO and GO-derived products are their use in oil-drilling formulations also known as “drilling muds”. In Chapter 2, the performance of GO and chemically converted graphene as fluid loss control (FLC) agents and rheological modifiers in water-based mud (WBM) is investigated. Large-flake GO was found to be the best FLC additive in fresh-water mud (FWM), and five times more efficient as a rheological modifier than materials used in current FWM formulations. When WBM cannot be used for drilling, and oil-based mud (OBM) needs to be used instead, the reduced performance of resistivity-based imaging tools is of concern. In order to improve their performance, the electrical permittivity of the oil-based medium needs to be improved without disrupting the chemical equilibrium of the drilling formulation. For this purpose, a new method for the synthesis of graphite-derived nanoplatelets was studied (Chapter 3), and their performance as conductivity enhancers in OBM was investigated (Chapter 4). As an additional application of carbonaceous nanoparticles to the oilfield, the use of carbon black and activated charcoal particles for the inhibition, prevention or remediation of asphaltene deposition was investigated (Chapter 5). It was found that these nanoparticles can help stabilize, or controllably precipitate, asphaltenes by virtue of their high surface area, and by being a thermodynamically preferable surface for asphaltene deposition. Early collaborative works with a significant contribution by the author are included in Chapter 6 and Chapter 7. The work included in Chapter 6 pertains to the background of Chapter 2, and the work included in Chapter 7 pertains to the background of Chapter 3.