Determination of the aromatics content in mineral oils by LF NMR

Molecular group composition analysis of mineral oils is helpful to predict the performance of a future lubricant and to assess the compatibility of plasticizer oil with rubbers. The method of pulsed low-frequency NMR relaxation was used to determine the molecular group composition of 11 mineral oil samples, and the ratio of aromatic and non-aromatic hydrocarbons in them was calculated. NMR measurements were performed on a Chromatec-Proton 20M NMR analyzer with a 1H resonance frequency of 20 MHz. The method used consists in recording free induction decay signals, reconstructing the total signal amplitude, estimating the relative signal amplitude per unit mass of the sample, and calculating the proportion of aromatic hydrocarbons in the sample. The results were compared with those obtained by the standard chromatographic method. A high degree of correlation (R2 = 0.99) was observed between the results

Induced thermal shocking by BiMTheCh technology as a new approach for enhanced oil recovery from tight reservoirs with heavy oil

This work is devoted to investigate the ability of thermal shocking to create fractures in rock samples and thermal cracking of heavy crude oil structure. In order to study the thermobaric characterizations of catalytic and thermal decomposition reaction of binary mixture (BM), a series of experiments was designed in high-temperature and high-pressure reactor (HTHP) and the time to reach the maximum temperature and pressure were monitored. Before and after the experiments, core samples were scanned by 4D tomography. In addition, SARA analysis was done to study the effect of thermal shocking on heavy oil composition. The results showed that using BiMTheCh, the temperature in the reaction zone was increased up to 273 °C during very short time (2 seconds) after activation of the reaction. Either, the pressure was increased up to 129 atm. As results showed, the simultaneous sudden increase in temperature and pressure creates a thermal shock which reduces breakdown pressure from 235 to 12 atm. Computed scanning tomography results confirmed formation of new fractures on the surface of core samples. Results of the SARA analysis also confirmed that the molecular structure of heavy oil due to the binary mixture's reaction was changed. Sharp increase in pressure and temperature induced transformation of heavy components of crude oil such as asphaltenes into lighter components such as saturates. Generally, the binary mixture technology can be used as a new high-efficient and eco-friendly technology for enhanced heavy oil recovery from tight heavy oil reservoirs