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In-situ combustion (ISC) is a promising thermal enhanced oil recovery (EOR) method for heavy oils. However, its field application is still limited due to difficulty in ignition, low combustion efficiency, unstable combustion front, etc. To improve the success rate of ISC process, we investigated the effectiveness of copper-based oil soluble catalyst for catalyzing combustion and in-situ upgrading of heavy oils. High-pressure differential scanning calorimetry (HP-DSC) and TGA were used to investigate the effect of catalyst on the thermochemistry (onset temperature, temperature range of reaction interval, heat effect, etc.) and kinetic parameters of combustion process. A Porous medium thermo-effect cell (PMTEC) was designed to study the catalytic combustion of heavy oil in porous media under air flow. And, a visual combustion tube (VCT) was developed to study the catalytic effect of catalyst on the ISC process, including improving combustion front propagation, in-situ upgrading of heavy oils, and oil recovery. HP-DSC results showed that copper-based oil soluble catalyst significantly shifted the low-temperature oxidation (LTO), transition stage (FD), and high-temperature oxidation (HTO) into lower temperature ranges. Especially for HTO, the end temperature was decreased about 120 °C. It was finished at a narrower temperature region with a higher heat flow, which implies that the combustion efficiency of HTO was greatly improved. TG-DTG data also showed the combustion reaction was transferred into lower temperatures. In addition, from TG-DTG and kinetic data, it can be concluded that the catalyst significantly reduced the activation energy in FD and HTO stage, which thus decreases the reaction barriers between FD and HTO and increases the continuity of reactions between FD and HTO. PEMTC experiments also showed that the ignition temperature of heavy oil combustion in porous media in airflow was decreased about 46 °C by copper-based catalyst. VCT experiments indicated that in the presence of copper-based oil soluble catalyst, combustion front propagate faster, oil recovery was 10% higher than without catalyst, and a deep in-situ oil upgrading was achieved with a significant viscosity reduction (9 times lower) and increase of saturates content (especially alkanes with lower carbon number C11-C17). All these results showed that copper-based oil soluble catalyst has a great potential in improving the efficiency of ISC process and in-situ oil upgrading. Its application can help to improve the success rate and wide application of ISC process for heavy oil recovery, which will promote the highly efficient development of heavy oil resources.

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In this work method to improve the efficiency of the development of shallow deposits of extra-heavy oil using cyclic team stimulation (CSS) technology together with injection of catalyst for in-situ upgrading and solvent was proposed. Oil-soluble catalyst has been developed. Efficiency of catalyst was proved in laboratory. Volume and conditions of catalyst and solvent injection together with steam were determined based on simulation results. Pilot tests of technology were carried out on extra-heavy oilfield in Tatarstan, Russia. The screening of catalysts and solvents together with injection of steam was studied in high pressure reactors under reservoir conditions. Heavy oil displacement coefficients in basic scenario of steam injection and second scenario of steam injection together with catalyst and solvent were measured on self-designed experimental steam injection apparatus. The technology was simulated with tNavigator softwarre (Rock Fluid Dynamics) version 18.2, STARS. Pilot tests were carried out in several stages: preliminary short-term injection of steam to pre-heat the reservoir, injection of catalyst solution and solvent, the subsequent full-scale stage of steam injection, imbibition, and production. The results of field tests confirmed laboratory and simulation data. According to the analyzed samples after six months of field tests, the viscosity at the first stage decreases as a result of dilution with a solvent. The effect of the catalyst, which particles are adsorbed on the reservoir rocks, clearly demonstrated later. It is shown that the combined use of in-situ upgrading catalyst and a solvent in CSS method allows to increase oil recovery factor. At the same time, the produced oil has better properties. Significant degree of conversion of resins and asphaltenes to light fractions was established. Field tests on Ashal'cha oilfield have shown that this technology is effective for the development of shallow deposits of extra-heavy oil.

The design of highly efficient catalysts of cracking reactions for intensification of thermal enhanced oil recovery technologies is a relevant task. Moreover, the cost-effective industrial synthesis of such catalysts is very important. In this paper, we discuss the efficiency of bimetallic catalyst, which forms in-situ from the mixture of oil-soluble iron and cobalt precursors, on the processes of upgrading heavy oil in the reservoir of Tatarstan Republic (Russia). A simulation of aquathermolysis was carried out in a high-pressure reactor – autoclave at 150-250оС. The treatment time varied from 6 to 24 hours and the share of catalyst and hydrogen donor was 2 %wt. each. The phase composition of the active form of binary catalyst was estimated from the result of X-ray diffraction measurement. It is characterized by the presence of individual (Fe3O4 and Fe2O3) and mixed oxides with ideal stoichiometry – СоFe2O4. The formation of cobalt sulfide (CoS2) was observed, which indicates the destruction of C-S bonds in high-molecular components of oil. According to the results of SARA-analysis and rheology behavior, the catalyst intensifies destructive processes of resinous compounds (their content reduces more than 45%). This provides an increase in the content of saturated hydrocarbons by 16% and redistribution of aromatic fragments in hydrocarbons with hybrid structure. Thus, the reduction of dynamic viscosity by 32% was succeeded.

Increasing the efficiency of thermal recovery methods is an important and relevant task. This study is devoted to reducing heavy components (resins and asphaltenes) and quality improvement of heavy oil by catalytic hydrothermal treatment. The object of this study is a bituminous sandstone sample from the Ashal’cha reservoir. The catalytic (iron tallate) hydrothermal simulation was carried out under reservoir conditions (200°C, 30 bar). The composition and physicochemical characteristics of the products were studied using elemental and SARA analysis, MALDI, GC-MS, FT-IR. Moreover, the extracted rock is analyzed in XRD and DSA (Drop Shape Analyzer). The introduction of catalyst in combination with a hydrogen donor reduces the content of resins by 22.0%wt. with an increase in the share of saturated hydrocarbons by 27%wt. The destructive hydrogenation leads to a decrease in the sulfur content of upgrading products. This is crucial for the oil reservoirs of the Tatarstan Republic, as their crude oils are characterized by high sulfur content. According to the wettability data, the hydrophilicity of the rock surface increases due to inhibition of the coke formation after the introduction of the catalytic complex. Thus, the oil recovery factor can be increased due to the alteration of the oil-wetting properties of reservoir rocks.

Currently the super-viscous oil deposits are under active development in the Republic of Tatarstan. The general method of production is Steam-Assisted Gravity Drainage (SAGD). The problem of creation the complex of methods to monitor and control the reservoir processes caused by steam injection is of a great importance for increasing the development efficiency. Traditional control methods of shallow deposits development are normally based on seismic survey and whether insufficiently adatped for shallow deposits of super-viscous oil or very expensive. Thus, the special modifications of geophysical methods are required. The paper discusses general approaches used for creation of complex of methods for steam chamber monitoring the oil production from the shallow deposits of super-viscous oil by SAGD. The methods developed include seismic and geoelectric survey. In context of integrated monitoring technique creation the set of special core survey was conducted to define the possibility of detection of the steam chamber distribution by seismic methods. The distinguishing feature of the monitoring technology developed is the use of downhole monitoring tools to receive the seismic signal and to perform the geoelectrical field establishing. The article contains the description of the seismic data obtained processing methods and the results of the seismic data interpretation. The study was made with the financial support of Ministry of Education and Science of the Russian Federation (project № №02.G25.31.0170)