A. V. Vakhin

Contribution of thermal analysis and kinetics of Siberian and Tatarstan regions crude oils for in situ combustion process

This research focused on the characterization and kinetics of Siberian and Tatarstan crude oils by gas chromatography, combustion calorimetry, and thermogravimetry (TG–DTG) techniques. Calorimetric experiments show that crude oil with higher saturate content and low resin fraction has higher heating value. TG–DTG curves indicates that the crude oils undergoes two major transitions when subjected to an oxidizing and constant rate environment known as low- and high-temperature oxidations at each heating rate studied. Kinetic analysis in the low- and high-temperature oxidation regions was performed using model-free methods knows as Ozawa–Flynn–Wall and Kissinger–Akahira–Sunose. Throughout the study, it was observed that the activation energy values of the crude oil samples are varied between 41–72 and 145–198xa0kJxa0mol−1 in low- and high-temperature oxidation regions, respectively.

Chemical evaluation and kinetics of Siberian, north regions of Russia and Republic of Tatarstan crude oils

ABSTRACT In this research, thermal characteristics and model free kinetics of five different °American Petroleum Institute gravity crude oil samples from different locations were studied using combustion calorimetry and thermogravimetry (TGA) techniques. Higher heating values of crude oils were determined from the combustion calorimetry experiments. It was shown that these values increase with an increase in saturate fraction and °API gravity of studied samples and decrease with an increase in viscosity, aromatics fraction, and resin fraction of crude oils. In thermogravimetry, experiments were performed at 10, 20, and 30°C/min heating rates under an air atmosphere. Thermal characteristics of the samples such as reaction intervals and corresponding peak temperatures, mass loss, and residue of the crude oil samples were also determined. Two different model free kinetic methods, known as Ozawa–Flynn–Wall (OFW) and Kissinger–Akahira–Sunose (KAS), were used in order to determine the activation energy values of the crude oil samples studied.

Transformations of hydrocarbons of Ashal’hinskoe heavy oil under catalytic aquathermolysis conditions

The influence of temperatures of 250, 300, and 350°C on the character of changes in the group and hydrocarbon compositions of heavy oil from the Ashal’chinskoe field in laboratory experiments on the simulation of oil aquathermolysis processes under reservoir conditions has been revealed. The experiments have been carried out in the presence of kaolin as a rock-forming mineral, using oil-soluble iron carboxylate and tetralin as a proton donor. It has been shown that temperature elevation to 300 and 350°C increases the amount of saturated fractions by factors of 1.5 and 1.75, respectively, and decreases the resin content almost by half in comparison with the initial oil. The proportion of n-alkanes and light alkylcyclohexane and trimethylalkylbenzene homologues in the saturated fractions increases as a result of cracking reactions involving the preferential degradation of high-molecular-weight resins. A noticeable increase in the amount of newly formed hydrocarbons and asphaltenes at the temperature of 350°C indicates that not only intensive cracking processes, but also condensation processes occur under these conditions. Changes in the quantitative and qualitative composition of the proton donor tetralin by its dehydrogenation to form naphthalene and hydrogenation to yield the cis- and trans-isomers of decalin have been revealed.

Mössbauer study of products of the thermocatalytic treatment of kerogen-containing rocks

To understand the mechanism of highly efficient catalyst formation from precursors, the active form of an iron-containing catalyst and kerogen samples from the Bazhen formation are studied by Mössbauer spectroscopy and X-ray diffraction analysis. It is established that as a result of phase changes, the multicomponent precursors are transformed into mixed transition metal oxides. It is found that the thermocatalytic effect on pyrite-containing kerogen leads to the formation of pyrrhotite FeS1 − x and mixed oxides of iron.

Influence of the Nature of Metals and Modifying Additives on Changes in the Structure of Heavy Oil in a Catalytic Aquathermolysis System

The direction of catalytic aquathermolysis processes involving high-molecular-weight components of heavy oil has been revealed in model experiments, depending on the metal nature and the conditions of the experiments carried out at 300°C in neutral and carbon dioxide media, using oil-soluble carboxylates of the transition metals nickel, iron, cobalt, and copper as a catalyst. The yield and quality of the products formed in the presence of individual metals and their compositions have been determined. Propanol and tetralin have been studied as modifying additives. The viscosity of heavy oil in a carbon dioxide medium has been significantly reduced by using an iron-, cobalt-, and copper-containing catalyst composition together with the propanol additive, as a result of an increase in the amount of saturated and aromatic hydrocarbons and a decrease in the resin content in its composition. An increase in the value of the C13–C17/C18–C22 index can serve as a parameter for monitoring the progress of catalytic aquathermolysis processes.

Aquathermolysis of heavy oil in reservoir conditions with the use of oil-soluble catalysts: part I – changes in composition of saturated hydrocarbons

Abstract This paper is devoted to the study of aquathermolysis processes of heavy oil produced by CSS technology on Boca de Jaruco oil field. Various catalysts based on cobalt, nickel, iron and copper were used for intensification of in-situ upgrading processes of heavy oil. The first paper in series is presented results of transformation of crude oil and its saturate fraction after thermal treatment with and without catalysts by SARA analysis, MALDI mass-spectrometry, FTIR-spectroscopy and gas chromatography. It is revealed, that catalysts provide more deep conversion of asphaltenes and resins into lighter hydrocarbons. Particularly, for the given heavy oil, catalysts based on iron and nickel organic salts are more effective to reduce the content of high molecular weight components (asphaltenes). Saturates fraction after thermal treatment in presence of the catalysts is enriched with lighter alkanes in comparison to the crude oil treated without catalysts. Obtained results show that crude oil recovered by catalytic aquathermolysis processes will be better quality than the original oil in the place.

Aquathermolysis of heavy oil in reservoir conditions with the use of oil-soluble catalysts: part III – changes in composition resins and asphaltenes

Abstract This paper discusses aquathermolysis process of heavy crude oil from Boca de Jaruco reservoir, which is developed by CSS method. The catalysts based on cobalt, nickel, iron and cupper are used to intensify the in-situ conversion processes. The active form of catalysts generates after steam injection. The third part of paper discusses conversion of resins and asphaltenes. The influence of thermo-catalytic conditions and composition of catalysts are also studied. The destruction of resins and asphaltenes are observed after thermocatalytic treatments. The changes in composition of resins and asphaltenes are revealed by IR-spectroscopy data.

The influence of transition metals – Fe, Co, Cu on transformation of organic matters from Domanic rocks in hydrothermal catalytic system

Abstract Character of conversion of organic matter from Domanic rocks of Pervomaiskoye field (Tatarstan) of Semiluki horizon of upper Devonian deposits in the hydrothermal-catalytic system at temperature of 300u2009°C in carbon dioxide medium was studied with the application of complex of oil-soluble precursors of catalysts containing Fe, Co, and Cu. In presence of catalysts complex, content of organic extract increases, in which content of hydrocarbon fractions, saturated and aromatic hydrocarbons, increases 1.5 times, while resins content decreases by two times. As result of kerogen destruction in products of experiments, the content of asphaltenes and carbonaceous substances such as carbenes and carboides increase.