Various techniques were used to compare the effectiveness of a commercially available wax inhibitor (WIA) to a newly developed wax inhibitor (WIEP) using a highly waxy Wyoming crude oilwhich causes plugging within wellbores and pipelines. The two additives were compared using centrifuge experiments, cold finger tests, and the precipitation and redissolution waxphaltene determinator (WD) method. Centrifuge tube experiments, and cold finger tests, showed that the newly developed WIEP additive was significantly more effective at reducing the amount of ambient temperature wax crystallites in the crude oil, as well as reducing the amount of wax deposited on a cold finger. WD analysis was performed on model compounds to differentiate between shorter and longer n-paraffins. Whole crude oils, ambient temperature waxes centrifuged from the oils, and waxes from cold finger deposits were also analyzed by the WD method. Taken together with high temperature gas chromatography, the WD profile of whole crude oils readily distinguishes shorter n-paraffins from the more problematic longer n-paraffins that are prone to crystallization at ambient temperature. For treated Elliott crude oil, the WD Analysis profile showed a consistent decrease in wax with WIA concentration to give a linear correlation; however, a less consistent change was observed with the WIEP additive. By applying the WD analysis to the additives themselves, it was elucidated that the WIEP additive contained components that were highly polar and/or more associated. This observation suggests that components in the WIEP additive may self-precipitate to a greater degree than becoming incorporated with the waxes during the WD separation. This effect caused the WIEP to appear as though it is not as effective as the WIA additive in the WD analysis.

As phenalene is an alternant hydrocarbon it is oxidized very easily to phenalenone, which condenses with various nitrogen nucleophiles in the presence of p‐toluenesulphonic acid. 2‐Methylindolylphenalene is obtained with 2‐ methylindole, together with other products. This product is a mixture of five tautomers in equilibrium, and these were analysed by homo‐ and heteronuclear two‐dimensional high‐field NMR (500 MHz) spectroscopy.

An immersed quartz crystal resonator (QCR) was employed to assess the effectiveness of a modified alkylphenol resin in reducing asphaltene deposition on metal surfaces under various temperature and pressure conditions. The QCR response to asphaltene flocculation was first monitored during isothermal n-heptane titration experiments of dead crude oils with different contents of the asphaltene inhibitor (AI). In addition, the effect of the AI presence on the morphology of asphaltene deposits was analyzed by atomic force microscopy (AFM). Then, constant mass expansion experiments were carried out to determine whether the presence of the AI influenced the asphaltene instability pressure and the deposition rate of asphaltenes in a dead oil + CH4 system with various CH4 contents. The results of all these investigations in the nanometer range shed new light on the AI technology and clearly demonstrate that the presence of the AI can reduce the asphaltene deposition rate and modify the viscoelastic properties of the asphaltene solution in oil production conditions.

The reaction of phenalenone with various sulphur‐derived nucleophiles gave 1‐hydroxy‐9‐alkyl‐ or ‐aryl‐thiophenalenes. The complexity of the aromatic 1H and 13C signals does not allow straightforward assignments. These were rendered possible by the use of two‐dimensional 1H‐detected heteronuclear one‐bond (HMQC) and multiple‐bond (HMBC) correlation techniques.

A physicochemical approach was taken to show wax-based and crude oil-based differences between three waxy crudes (Amenam, Norne, and Varandey), that had similar amounts of wax according to DSC crystallizable areas, that were responsible for very different responses to pour point depressant additive treatments. Varandey crude oil was the most difficult to treat, and the effectiveness of the additives decreased with time when the oil had been aged for 2 years prior to treating with the additives. Detailed compositional analysis of these three crude oils, and their waxes, showed that Varandey contains the highest concentration of longer n-paraffins, significantly more total n-paraffins, a higher wax appearance temperature, the highest amount of wax that can be centrifuged at ambient temperature, a bimodal distribution of crystallizable waxes by DSC, more saturates in the heavy ends by the Saturates, Aromatics, Resins-Asphaltene Determinator, a very high amount of Waxphaltene Determinator Waxy B (−24 °C methyl ethyl ketone precipitated waxes that do not dissolve in heptane at that temperature but melt at 60 °C in heptane) and very little asphaltenes that do not flocculate. These additional characterization methods, including the wax appearance temperature, show that the amount of wax by DSC is not discriminating for some crude oils. Microscopy of Varandey showed large fractal crystalline domains that were different from Amenam, which showed classic large macrocrystalline needle-like crystals, or Norne that had a gelled network with much smaller needle-like crystals. Norne is less responsive to additive treatment than Amenam despite having significantly less n-paraffins, Waxphaltene Determinator Waxy B waxes, and asphaltenes. Simulated distillation shows that Norne is the heaviest oil and has the highest amount of isomeric material in the C24−C34 range and a higher temperature wax appearance temperature. Furthermore, its asphaltenes flocculated with the addition of isooctane at 60 °C, whereas the asphaltenes did not flocculate in Amenam. The higher amount of isomeric material by GCMS and the much smaller needle-like crystallites suggest that Norne wax is more microcrystalline in nature. Centrifuging Varandey waxes and doping them into Amenam and Norne resulted in the doped crude oils having a bimodal DSC profile with a higher wax appearance temperature. The presence of Varandey wax caused the oils to be significantly less responsive to pour point additive treatments. Overall, for these relatively similar crude oils, it is shown that the nature of the highest carbon number waxes, the wax appearance temperature, and the amount of the least soluble waxes are significantly more important than the crude oil composition when treating with additives since they will dictate the temperature at which n-paraffins first self-associate leading to crystal nucleation.