Kinetics Of Crude Oil Research Articles

Oxidation behavior and kinetics of shale oil under different oxygen concentrations

The oxidation behavior and kinetics of crude oil within tight shale differ from those of traditional light and heavy oils. In this study, the static oxidation tests on tight shale samples were conducted under different oxygen concentrations (11%, 16%, 21%, and 26%), followed by analysis of effluent gas and oxidized oil. Specifically, the compositional changes in shale oil at the molecular level were studied. Additionally, the self-ignition potential of shale oil under different oxygen concentrations was evaluated using accelerating rate calorimetry, and the corresponding kinetic parameters were determined. The results indicated that as the oxygen concentration increased from 16% to 26%, the relative abundance of O1 species decreased from 10.96% to 8.66%, whereas that of O3 species increased from 6.16% to 8.46%. Also, the relative abundance of chain saturated aliphatic acids and tricyclic naphthenic acids was observed to decrease and increase, respectively, in the shale oil oxidized at 26% oxygen concentration compared to the other shale oils oxidized at oxygen concentration lower than 26%. The shale oil displayed significant oxidation activity under different oxygen concentrations (16%, 21%, and 26%), and an increased oxygen partial pressure resulted in a shorter induction period of oxidation and higher combustion intensity. The kinetics results showed that the combustion activity of coke was enhanced while increasing oxygen concentration from 16% to 26%. The shale oil encountered fewer concentration-dependent oxidation reactions under higher oxygen concentration. Overall, this study provides valuable insights into the oxidation behavior of crude oil within tight shale.

An experimental investigation on hydrogen generation from in-situ gasification by pyrolysis

Hydrogen can be generated from crude oil by in situ gasification (ISG); pyrolysis gasification is one of the main methods used for hydrogen production. In this study, thermogravimetric analysis with mass spectrometry (TG-MS) was used to study hydrogen generation from crude oil through pyrolysis gasification and was combined with equivalent characteristic spectrum analysis (ECSA) to obtain the amount of hydrogen and hydrogen generation efficiency (HGE). The results of thermogravimetry (TG) and derivative thermogravimetry (DTG) from heavy oil (HO) and light oil (LO) can be divided into three stages: drying, pyrolysis, and coking. HO generated hydrogen in all stages, whereas LO produced hydrogen only during the pyrolysis and coking stages. The results of quantitative analysis indicated that hydrogen was mainly generated in pyrolysis stage, where temperature interval was 358–521 °C. The Friedman, Ozawa-Flynn-Wall (OFW), and Kissinger-Akahira-Sunose (KAS) methods were used to calculate the kinetic parameters. The results suggested a raising trend of activation energies with the temperature increase, and the range of activation energies of hydrogen generation from HO and LO are 80.40–258.84 kJ/mol and 130.35–285.16 kJ/mol, respectively. The hydrogen generation behavior and kinetics of crude oil by pyrolysis gasification can provide certain parameters for ISG technology and assist in understanding the hydrogen generation process, which can promote the development of hydrogen generation through in-situ gasification.

TGA and DSC investigation of different clay mineral effects on the combustion behavior and kinetics of crude oil from Kazan region, Russia

In this research, the effect of different clay minerals (bentonite, illite and kaolinite) on the combustion behavior and kinetics of crude oils from Kazan region (Russia) was studied using thermogravimetry (TGA) and differential scanning calorimeter (DSC). The ramped temperature experiments were performed at constant heating rates (10, 20 and 30 °C/min) under air atmosphere. In both TGA and DSC experiments, two reaction zones were identified known as low temperature oxidation (LTO) and high temperature oxidation (HTO). The reaction regions, burn-out temperatures, mass loss, heat of reaction and peak temperatures were determined. It was observed that the reaction intervals and the peak temperatures were also affected in the presence of different clay minerals. Kinetic parameters were calculated by Ozawa-Flynn-Wall (OFW), Kissenger-Akahira-Sunouse (KAS) kinetic methods. The addition of different clay minerals reduced the mass loss percentages of the crude oil samples due to the surface area effect. In addition, all clay samples show a good catalytic effect by a significant reduction in activation energy.

Experimental study on dynamic characteristics of low temperature oxidation for Bohai offshore light oil under reservoir conditions

Air flooding has shown to be a promising method for enhanced oil recovery (EOR). The air injection into reservoir causes complex oxidation reaction, resulting in the change of the properties and components of crude oil. Most studies on thermal behavior and kinetics of crude oil were not conducted under realistic reservoir conditions, bringing difficulties to understand the suitability of air flooding for a light oil reservoir. The objectives of this research were to investigate dynamic characteristics of low temperature oxidation (LTO) of Bohai offshore light oil under realistic reservoir conditions. Thermogravimetry experiments (TG), static and dynamic oxidation experiments were used to evaluate the oxidation reaction of Bohai light oil reservoir. Besides, the thermal behavior of the light oil and alteration of oil components during LTO were comprehensively measured. The results indicated that there were three stages for light oil in LTO stage, the first and second stages of LTO showed positive activation energy but the third stage showed negative activation energy, manifesting the LTO stage might include multiple mechanisms. The LTO of light oil was promoted by pressure, and the negative temperature coefficient (NTC) stage of LTO might be controlled by medium oil component (C7-C17). Additionally, oxygen consume rate of dynamic oxidation experiment was much higher than that of static oxidation experiment, which was closer to the realistic reservoir conditions. This study can provide insights to the LTO of light oil reservoir and explore the potential of air flooding based on EOR projects.

Effect of Pressure on Crude-Oil Kinetics During In Situ Combustion

We study the effects of pressure on crude-oil oxidation kinetics using ramped temperature oxidation for a large range of pressures and heating rates (1.5, 2.0, 5.0, 7.5, 8.0, 10.0, 15.0, 20.0, and ...

The impact of the oil character and quartz sands on the thermal behavior and kinetics of crude oil

Oxidation reaction plays an important role in air flooding. In this paper, three oxidation reaction stages of both light and heavy oils, as well as mixtures of oil and quartz sands are studied at four heating rates by conducting thermogravimetric experiments. Commonly used kinetic methods are modified to estimate kinetics parameters, and a more realistic range of conversion rates is used. The results demonstrate that low temperature oxidation (LTO) dominates for light oil but fuel deposition (FD) and high temperature oxidation (HTO) dominate for heavy oil. The region of transition intervals in both LTO & FD and FD & HTO should be avoided to get more accurate kinetics parameters. Quartz sands are used to provide a large surface area, which result in decreasing the estimated activation energy of LTO for light oil by 15%, whereas the FD and HTO of heavy oil are enhanced by 11.7% and 14.1%, resulting in enhancing oil recovery (EOR). These results improve the understanding of the oxidation of different crude oils over the whole range of temperatures and have broad applicability to improving the design of air injection based on EOR projects.

Wax deposition during production of waxy crude oil and its remediation

ABSTRACTIn the current paper, fundamental aspects of wax deposition problems in pipeline are defined, and characterization of paraffin and their solubility tendencies have been discussed. Wax deposition depends on flow rate, the temperature differential between crude and pipe surface, the cooling rate, and surface properties. The physico-chemical characterization of crude oil is determined. The experiments were carried out in “Cold Finger Apparatus.” Best pour point depressant for the selected crude oil has been found out as Lubrizol-6682 among different chemicals available that reduces the pour point from 36° to 12°. The deposition of paraffin wax, its dispersion, and inhibition were studied with available chemicals and by the optimization of suitable additives for particular well. Kinetics of crude oil in terms of time and differential temperature has also been studied and effective dispersion times are observed for particular oil. It is found that dispersion is effective within 30–60 min of starting. Kinetic study of oil with respect to differential temperature is done in two ways either by varying ambient/surface temperature or pumping/reservoir temperature. The tendencies of wax deposition on different sample with neat and treated crude are observed and ideal differential temperature for particular oil to flow is determined.

Sensitivity study on thermal behavior and kinetics of crude oil using thermal analysis techniques

ABSTRACTIn this study, the effect of heating rate, oil chemical composition, and clay mineral type on thermokinetic behaviors of oil oxidation was investigated by TG and DTA tests. The results show that temperature intervals of reactions are extended and peak and burnout temperatures are shifted to higher values when increasing the heating rate. Heavier oil with more heavy components exhibits faster reaction rate and higher energy requirement in the low-temperature oxidation stage, and releases more heat in the high-temperature oxidation stage. The catalytic properties and surface area effect of clays can positively influence the high-pressure air injection process through forming more carbonaceous deposits and lowering the activation energy of reactions.

Clay concentration and heating rate effect on crude oil combustion by thermogravimetry

In this research, the effect of heating rate and different clay concentrations on heavy oil combustion was investigated by thermogravimetry (TG–DTG). In TG–DTG experiments, two main distinct reaction regions were identified in all of the crude oil+limestone mixtures; known as low temperature oxidation (LTO) and high temperature oxidation (HTO) respectively. It was observed that addition of clay to porous matrix (limestone+heavy oil) significantly affected the thermal characteristics and kinetics of crude oil. It was also observed that heating rate affected the reaction region intervals, peak and burn-out temperatures. Kinetic analysis of the samples was determined and it was observed that activation energies generated for the high temperature oxidation region for crude oil and crude oil/clay mixtures are in the range of 48.5–151kJmol−1 at three different heating rates