Volume 55, Nº 4 (2019)

Associated petroleum gas (APG) is of considerable interest and is one of the priority directions of development of the oil and gas industry. In this context, the problem of environmental safety of hydrocarbon gas extraction processes is being solved simultaneously. Burning of petroleum gas at the field in flaring stacks affects the ecosystem adversely and leads to economic losses. Special projects implemented by large oil and gas companies are aimed at reducing environmental and economic losses in the APG extraction process. This article discusses the mechanisms of economic and environmental assessment of the main modern trends of APG utilization. The measures that take account of the peculiarities of the chemical composition of APG when choosing the method of its utilization are presented. An integrated approach to assessment and determination of the effective methods of beneficial utilization of APG and production of high-value-added products is used to solve this problem.

Hydrothermal liquefaction of microalgae biomass at various temperatures was studied. The products were analyzed by thermogravimetry, elemental analysis, and gas-chromatography—mass-spectromeny. It was concluded that the temperature affected the product yield and composition. The quantitative contents of the major components in the gasoline fraction of the produced bio-oil were determined. The main components in the gasoline fraction were aromatic hydrocarbons, alkanes, and cycloalkanes. The hydrothermal processing products also contained significant quantities of phenols, organic sulfides, and nitrogenous organic compounds that prevented their direct use as fuel components.

Activities of HCeY vacuum gas-oil cracking catalysts based on the H-form of Fe-modified kaolinites from Kazakhstan deposits with and without zeolites are reported. The physicochemical properties of the catalysts were determined. The main cracking product of vacuum gas oil on Fe-modified H-kaolinites without zeolites was light gas oil, the yields of which was 65.3-67.3%. Adding zeolite increased the gasoline yield up to 22% with rather high feedstock conversion (up to 90.3%).

A zeolite-containing diesel-fuel dearomatization catalyst was prepared using synthesized tungsten-doped zirconia \( {\mathrm{WO}}_4^{2-} \)/ZrO₂ and an Ni—Mo complex. The catalyst was tested for diesel fuel dearomatization at 4.5 MPa, feedstock input volume flow rate 1.5 h^-1, H₂/feedstock volume ratio 1000 nm³/m³, and temperature range 270-330°C. The highest conversion (78.8%) of polycyclic aromatic hydrocarbons and greatest cetane number were attained at 290°C. Also, the cloud and pour points of the diesel fuel decreased by 23-25°C because of cracking at 310-330°C and extensive isomerization at 290°C. This was confirmed by the yields of target diesel fraction of 69.8-72.9 and 89.2 wt. %, respectively.

The properties of petroleum and synthetic oils used as bases for anti-corrosion materials are determined. The viscosity-temperature characteristics determine the feasibility of applying oil coatings. Regression equations allowing the thickness of the resulting protective film to be calculated as a function of the oil viscosity are obtained. Results from wettability assessments indicate that the oil surface is hydrophilic. The oil films are permeable to water; stimulants, and corrosion inhibitors. Films of the studied oils inhibit anodic dissolution of steel and accelerate slightly cathodic reduction of oxygen. The nature of the oil base has little effect on the protection effectiveness if anti-corrosion additives Emulgin or Mobiin-3 are added at concentrations wt. %.

The application of degassed oil instead of recombined oil model for a slim tube technique was investigated. It is found that the use of degassed oil is not recommended for modeling and studying of gas and oil miscibility under typical conditions of Western Siberia deposits. The previously estimated miscibility of light oil and associated gas was confirmed in case of application of recombined oil model or degassed oil at displacement from a slim tube. This occurs because of a gradual transition from the mode of immiscible displacement to the mode of limited-mixing displacement of oil and further to the mode of complete mixing as a result of the mass exchange of light oil and associated gas.

During more than 100 years of oil development, cementing technologies have been constantly improved. Depending on the well conditions, the technologies vary in number of stages, cementing mixture composition, and methods to provide leakage-proof and gas-tight cementing, etc. In this paper the authors analyzed the creep law application and its models for the salt-gypsum layer and performed the comparative adaptability evaluation of cementing methods in the salt-gypsum layer.

Single-well injection-production technology is an effective measure for stabilizing oil and water control of the high water cut oilfield. The rod pump injection-production system uses gravity to separate oil and water under the well; throught two sets of rod pumps, the water is injected back into the formation and the concentrate is lifted to the ground. Because of the particularity of pump structure and the complexity of its working environment, the calculation method of 1st pump efficiency is quite different from that of conventional pumps. Reasonable matching of the production pump and the infection pump is the key factor to reduce the water cut of the produced liquid. Based on the gas PVT theory and the principle of mass conservation, the gas volume equation of the down well was established in this paper, and the calculation method of pump efficiency of single well injection-production system was established, which was verified and corrected by 17 field test wells, with considering the influence of pump stroke loss and leakage. Combining the established mechanical model of the single-well injection-production system, aimed at the lowest water cut of the produced fluid, we use the enumeration method to design a reasonable matching of the production-injection pump and suction parameters, and formulated the selection template of production-injection pump type and the selection of the working system for the rod pump single-well injection-production system. It provides a basis for the process design of the single-well injection-production system and provides technical support for the field application of the fourth generation oil recovery technology.

Time-of-Flight (ToF) camera can collect the depth data of dynamic scene surface in real time, which has been applied to 3D reconstruction of refinery buildings. However; due to the limitations of sensor hardware, the resolution of the depth image obtained is very low, so it cannot meet the requirements of dense depth of scene in practical applications such as 3D reconstruction. Therefore, it is necessary to make a breakthrough in software and design a good algorithm to improve the resolution of depth image. We propose of an algorithm of depth image super-resolution by using fusion of multiple progressive convolution neural networks, which uses a context-based network fusion framework to fuse multiple different progressive networks, so as to improve individual network performance and efficiency while maintaining the simplicity of network training. Finally, we have carried out experiments on the public data set, and the experimental results show that the proposed algorithm has reached or even exceeded the most advanced algorithms at present.

Modern ideas about the aging process of road binders and the principles of restoring their properties and structure are given. Technology of production of standard restored road binders (bitumen and polymer modified bituminous materials) using devulcanized rubber crumb (RC) obtained by crushing spent tires, elemental sulfur, oil dispersing agents (asphalt from deasphalting tar and heavy gas oil catalytic cracking) and polymer-thermoplastic elastomer is proposed. In addition, this technology provides the skillful use of elemental sulfur, waste asphalt from the process of deasphalting tars, and straight-run tar that is in surplus at many refineries. The physical and chemical properties of the restored road binders were evaluated for compliance with the Russian and American standards.

At present, alkali-surfactant-polymer (ASP) flooding in Daqing oilfield entered into the industrial application stage and demonstrated good result in increasing oil production and decreasing water-cut. However, using the ASP system with strong base caused serious problems at some blocks and wells. The influence of alkali on the formation could complicate maintaining oil product and improving recovery. In this paper the authors investigated reactions between alkali and reservoir minerals and their effects on seepage characteristic. The research was carried out on typical core sample from Daqing oilfield. The sample were characterized by pore structure, elemental composition, resistance facto, and residual resistance factor as evaluation indices. The results showed that the reservoir rocks of typical blocks in Daqing oilfield contained alkali-sensitive mineral. The degree of alkali-sensitivity damage was evaluated as mid-weak. Compared with a weak base (NaCO₃), a strong base (NaOH) could cause higher damage to the reservoir. Moreover, alkali-sensitivity damage to reservoir minerals could lead to higher injection pressure.

The acknowledgement is missing. It reads

The study was financially supported by the Ministry of Science and Higher Education of the Russian Federation (unique project identifier RFMEFI57717X0252).