High-viscosity Oil Research Articles

Efficient solar-driven crude oil cleanup via graphene/cellulose aerogel with radial and centrosymmetric design

Frequent oil spills pose significant threats to ecosystems; therefore, strict requirements are needed for prompt remediation and reclamation of spilled oil. Influenced by the structure of coniferous trees and their water transport, this experiment used cellulose nanofiber (CNF), polyvinyl alcohol (PVA), and methyltrimethoxysilane (MTMS) to prepare radially centrosymmetric aerogels. By utilizing the in-situ polycondensation reaction of MTMS, CNF, and PVA were connected, and the hydrophobicity and mechanical properties of the aerogel were greatly enhanced. Furthermore, the introduction of graphene oxide (GO), enshrouded within the cross-linked network, engenders heightened photo-thermal effects. The resultant composite aerogel exhibits expeditious oil absorption under solar irradiation and radial layered channel architecture, significantly curtailing the crude oil absorption timeframe (achieving a maximum absorption capacity of 51.7 g/g). Moreover, it demonstrates superior performance in rapidly and repeatedly adsorbing highly viscous crude oil, surpassing existing literature. Notably, continuous absorption of high-viscosity crude oil is achieved by integrating the composite aerogel with a peristaltic pump. This study offers a novel approach to the absorption and retrieval of high-viscosity crude oil, broadening the potential application horizons of CNF-based aerogels within environmental remediation.

Surface-Functionalized Nano-Montmorillonite and Its Application as Crude Oil Flow Improver

In view of the problem of poor flowability in the production and transportation of high-wax crude oil and high-viscosity crude oil, crude oil flow improvers are commonly used to reduce their viscosity and pour point. Although polymer-based crude oil flow improvers are highly effective in improving crude oil flowability, there are still problems such as high cost and the need for a large amount of solvent dilution when used. In this work, highly dispersed organic modified nano-montmorillonite was prepared by using Na-based montmorillonite and quaternary ammonium salts, and the influencing factors on the viscosity of the crude oil were investigated. The most effective modified nano-montmorillonite (B@MMT) can reduce the viscosity by 96.7% (21 °C) and depress the pour point by 15 °C. Furthermore, it has shown a high improvement in flowability in the other four different sources of crude oil, with viscosity reduction rates of 52.2, 93.4, 79.1 and 67.4%, respectively. B@MMT was characterized by FTIR, SEM, zeta potential and contact angle. Based on DSC and wax crystal structure analysis, the mechanism of the influence of B@MMT on crude oil viscosity and pour point was explored. Finally, the cost of B@MMT was estimated, and the result shows that, compared with the crude oil flow improver in use, B@MMT has considerable commercial competitive advantages.

Mechanically durable, recyclable polyvinyl alcohol/lignin-based aerogel for efficient oil/water separation and solar-powered removal of high-viscosity oil

Marine oil spill pollution poses a significant environmental issue, and its swift cleanup remains a global challenge and intricate dilemma. To address this problem, a polyvinyl alcohol/lignin-based multifunctional aerogel adsorbents were successfully crafted using unidirectional freeze-drying and chemical vapor deposition with alkali lignin (AL), poly(vinyl alcohol) (PVA), multi-armed carbon nanotubes (CNTs), and methyltrimethoxysilane (MTMS). These aerogels excel in photothermal conversion, leveraging lignin and CNTs' synergistic heat transfer. Swiftly warmed by sunlight, they reach surface temperatures of 76.1 °C and 96.0 °C in 120 s under 100 mW cm−2 and 200 mW cm−2 intensities. With an adsorption capacity 36–86 times its weight, the aerogel is reusable, maintaining 90 % efficiency after 10 cycles. Furthermore, it maintains high oil absorption rates in acidic, alkaline, high-temperature, and high-salt environments. Hence, this aerogel is promising for marine oil spill responses. Additionally, this work introduces a novel method for synthesizing high-performance oil-absorbing agents from biological resources, realizing the concept of waste-to-treasure and enhancing the high-value utilization of lignin.

USAGE OF TECHNICAL MEANS FOR ANNULAR GAS EXTRACTION TO INCREASE OIL WELL PRODUCTION

In recent years, the technology of annular gas extraction from wells has become increasingly widespread in the fields in order to improve the working conditions of the submersible pump due to increasing its filling and supply coefficients, as well as increasing depression on the formation. Some types of compressor designs have been developed and put into production, allowing the annular gas extraction from wells and forced injection into the pressure line of the well. One of the most well-known types of compressors is a piston pair driven by a piston from a rocking machine balancer. They were used at oil production facilities in the Orenburg, Ulyanovsk Regions, the Republics of Tatarstan and Bashkortostan, Udmurtia and other regions of the Russian Federation.In the fields of Sheshmaoil LLC, a complex for pumping gas from the annulus of a well and pumping it into the COGS product collection system has found mass usage, allowing gas to be taken from a group of wells and reducing pressure in the annulus to values close to 0.1 MPa. Hydraulic piston compressors, in which gas compression occurs using a high-pressure pump that drives the piston group of the compressor, have been tested.One of the main disadvantages of the developed types of compressors is the insufficient volume and pressure of the compressed gas. The article provides an analysis of the technological parameters of the compressors. As a result of research possible solutions to the problem are worked out.To achieve the largest pumping volumes of separated annular gas, the maximum permissible diameter of the compressor cylinder should not exceed 0.07 m in order to prevent significant resistance exerted by the piston rod on the balancer of the pumping machine.The most suitable region for the effective use of suspended compressors is the Ural-Volga Region at fairly depleted oil fields with at least 60–65 % water cut, oil well flow rate of no more than 10–15 tons/day and a gas factor of no more than 15–20 m3/t . At the fields of Western Siberia, suspended compressors cannot be used due to high flow rates and gas factors. Exceptions may be wells with a water cut of at least 80 % and flow rates of no more than 20–25 tons/day.The KOGS compressor unit, developed and widely implemented at Sheshmaoil Management Company LLC, showed positive results, consisting of an increase in flow rate and additional oil production. For further use of the unit in fields, especially for high-viscosity oil production, as well as operation in winter conditions, it is necessary to increase the maximum gas injection pressure.

Assessment of nozzle performance in high-viscosity oil spray system for rectangular copper conductors

This article presents a detailed examination of the performance characteristics of a high-viscosity spray oil cooling system, utilizing various commercial nozzles. These include one spiral hollow cone nozzle, three full cone nozzles, and three flat fan nozzles, all of which were subjected to experimental investigation. Parameters such as temperature, temperature uniformity, injection pressure, spray coverage, spray patterns, spray angles, spray capacitance, heat transfer coefficient, and spray power consumption were assessed to gauge the system's effectiveness. To conduct these experiments, a dedicated test bench was constructed, and a range of commercial nozzles with different spray patterns (full cone, hollow cone, and flat fan) and spray angles (narrow, medium, and wide) were selected. Through a series of experiments, the influence of various nozzle input parameters was scrutinized, with a focus on heat transfer capabilities, temperature uniformity, and cooling efficiency. The results revealed that increasing the nozzle's inlet pressure significantly improves its performance. Moreover, nozzles with medium to wide spray angles demonstrated the best cooling performance, particularly flat fan nozzles in this category. Based on these findings, the article offers recommendations to enhance temperature regulation and cooling efficiency for improved overall system performance.

AN EXPERIMENTAL STUDY ON THE USE OF SEDIMENTATION COMPOSITIONS DURING STEAM INJECTION

At present time, many oil fields, especially in historically developed areas of The experience of developing deposits of high-viscosity oils (HVO) and natural bitumen has shown that thermal methods are the most promising technologies. Of the entire arsenal of thermal methods, areal steam injection and cyclic-steam stimulation have become the most widespread.When choosing an effective thermal impact technology, it is necessary to take into account the peculiarities of the geological and physical parameters of deposits and the factors involved in oil recovery. An effective technology should be based on the use of the main most important factors that increase oil recovery.One example of areal steam injection is the underground-surface method of developing the Yarega area of the Yaregskoef ield. With this technology, steam is pumped from the surface through vertical wells. Oil production is carried out in the underground galleries of the oil sheds.Twenty years of practice and geophysical studies of steam injection wells have revealed a number of factors that prevent uniform heating of the reservoir over the entire thickness and efficient use of coolant energy. It turned out that the injected steam is mainly concentrated in the bed zone of the formation. In this case, the formation does not warm up evenly in thickness. The heterogeneity of the reservoir (tectonic disturbances, cracks every 20-25 m) does not allow the creation of steam pressure up to 1,6 MPa along the contour of the developed areas in order to involve the inclined block. At design pressures, steam breaks into mine workings and gently descending production wells are observed.The experimental studies described in this work are aimed at finding alignment of the intake profile of steam injection wells and redistribution of coolant in a remote reservoir zone. The results of the application of sedimentation compositions in bulk reservoir models under various thermobaric conditions of steam injection are presented. As a result of injection of solutions of iron sulfate, sodium carbonate and calcium chloride, insoluble sediments were formed in the rock, which led to a decrease in permeability during water vapor filtration. The experimental study was performed on a bulk reservoir model using natural core grinding, as well as drilled and extracted core samples from wells of the Yaregskoe field. The use of sedimentation compositions in steam injection wells in the future may contribute to the involvement of rock sections in the development by redistributing the steam flow, which in turn will increase the oil recovery coefficient and reduce the steam-oil ratio.

Eco-friendly superhydrophobic sponges for efficient oil-water separation and resource recycling

Owing to the risk of oil spills in the water pollution and human health, it is urgent to exploit the efficient, simple and low-cost materials to treat oily wastewater. Inspired by the native super-wettability surface of lotus leaves, a green, multi-functionality, multi-response and recyclable superhydrophobic material has been established via an one-step dip-coating method based on waste polyurethane sponges (PU), which is expected to settle the treatment problem of oil/water mixture. And the coating system is mainly constituted by a mixture of silicon resin, nano-Fe3O4 and ultrafine expandable graphene (EG), which can act as lowing low surface energy and fabricating the hierarchical micro-/nano-scaled surface roughness. The water contact angle (WCA) of 156.2 ± 1.4° and water sliding angle (WSA) of 8.0 ± 0.5° have triggered a series of skills in water repellency, self-cleaning and anti-fouling. Most of all, the exceptional oil–water separation capabilities have been achieved that the sorption capacity, separation efficiency and flux for light oil can reach 33.2 g/g, 99.5 % and 31,611 L m-1h−1, respectively. Accorded with the intrinsic thermal harvesting ability of Fe3O4 and EG, the excellent photothermal conversion performance has been gained that the temperature of superhydrophobic sponges can reach 68.7 °C in 180 s when the irradiation intensity is 1.2 sunlight, endowing the potential sorption ability of high-viscosity crude oils. Most importantly, the various oil–water separation modes can be also realized that are composed of gravity-driven, magnetism-driven, vacuum-driven and photothermal-driven methods. Except that, the adequate flame retardancy, mechanical durability and chemical stability have been acquired that have raised the high-value-added utilization of modified sponges in fields of environment protection and functional materials.

Eco-friendly MXene/enteromorpha prolifera biomass aerogel with excellent photothermal conversion and flame retardant properties for efficient separation of viscous oil/seawater mixture

Traditional adsorbents are often ineffective in cleaning up high-viscosity oil spills that cause harm to the marine environment. An efficient, safe and eco-friendly solution is urgently needed. Here, we prepare a superhydrophobic MXene/gelatin-enteromorpha prolifera biomass aerogel (H-MXene/G-EP) with excellent photothermal conversion and flame retardancy for solar-driven remediation of high-viscosity oil spills. The short-range aligned multidomain lamellar structure constructed through unidirectional freeze casting endows H-MXene/G-EP with compressibility and an adsorption capacity (63.7 g/g). Due to the excellent light responsiveness and full-spectrum high absorption of H-MXene/G-EP, it can reach a surface temperature 71.6 °C under 1 Sun (1.0 kW/m2), and an in-situ adsorption rate 367.40 g/h for viscous crude oil. The efficiency of separating O/W emulsions is up to 99.1%, which greatly broadens the range of applications for oil/water separation technology. Furthermore, the H-MXene/G-EP exhibits excellent flame retardancy, reducing the heat release rate by 89.59% and the total smoke production rate by 47.83%, respectively. This effectively reduces the probability of secondary marine fires. Thus, this novel biomass-derived aerogel provides a feasible and environmentally friendly solution for effective remediation of marine oil spills.

Forecasting the efficiency of waterflooding, thermal and chemical enhanced oil recovery methods in Bobrikovian reservoirs

The development of reserves contained viscous and highly viscous oil poses one of the major challenges in modern reservoir engineering. The poor performance of conventional waterflooding prompts the application of enhanced oil recovery (EOR) methods, of which thermal and chemical EOR are considered the most efficient. Reservoir simulation is a powerful tool for evaluating EOR performance. Serial runs of a history-matched model of a Bobrikovian reservoir are used to evaluate the incremental oil production due to each EOR technique and formulate the efficiency limits of the process performance criteria. In contrast to previous studies that evaluated EOR applications using reservoir simulation modeling, an entirely new quality model is derived through automatic history matching performed by solving an inverse problem. Another novel feature is the automated selection of the optimum field development scenario given a user-defined objective function. Evaluating the performance of hot water injection in a Bobrikovian reservoir suggests that this technology yields positive effects when the injected water temperature ranges from 50 °C to 90 °C. The surfactant–polymer flooding method is also investigated. The largest incremental oil production with a constant surfactant concentration of 0.5% is observed for a polyacrylamide concentration of 0.25%, which can be attributed to a water cut reduction due to plugging the well-drained and flushed reservoir zones. The greatest incremental oil production is achieved when injecting 1.5% surfactant and 0.25% polyacrylamide. The highest efficiency per ton of injected chemicals is obtained when injecting 0.5% polyacrylamide and 0.10% surfactant. Keywords: High-viscosity oil; EOR; thermal methods; surfactant-polymer flooding; reservoir simulation; history matching; injection simulation scenario.

Prospects and current state of chemical EOR methods applied in Kazakhstan

At present, at almost all fields of the Republic of Kazakhstan the main technology of oil recovery enhancement is the traditional method of waterflooding of productive formations. Many oil and gas fields in Kazakhstan are at a late stage of development and are categorized as «mature» fields. In the global experience of mature field development, the key focus is on the application of enhanced oil recovery (EOR) techniques - chemical, thermal, gas and microbiological methods. This paper considers the application of chemical EOR at a number of Kazakh fields such as Zaburunye, North Buzachi, Kalamkas, East Moldabek. As the results of the pilot studies have shown, the most effective EOR here is the application of polymer flooding. It should also be noted that polymer flooding is successfully applied in Kazakhstan for high-viscosity oil fields such as North Buzachi (oil viscosity 316-417 mPa·s), East Moldabek (oil viscosity 246-377 mPa·s). In this case, water cut, smoothing of injectivity profile and, as a result, increase of oil production is achieved. Successful application of the technology largely depends on the parameters of physical and chemical impact at each stage - the volume of injection of gel-polymer composition, concentration of ingredients, the flow rate of filtered water, the presence and linear size of cracks, the permeability of pore channels and etc. Polymer flooding applied in Kazakhstan showed its technological and economic efficiency on the example of pilot tests, laboratory studies, which reduces water cut and increases oil production. Widespread use of EOR methods would allow increasing recoverable oil reserves by at least 5-10 %. Keywords: Enhanced Oil Recovery (EOR); gas Injection; hydrocarbon recovery methods; chemical EOR methods; thermal EOR methods; oil production; polymer flooding; oil recovery.

Prediction of emergency-free operation of production wells with a horizontal termination under conditions of high removal of mechanical impurities on the example of the Severo-Komsomolskoe field

Relevance. As readily available oil reserves are developed and production technologies develop, oil and gas companies are gradually moving to the development of previously unprofitable assets. Over the past five years, several oil-and-gas condensate fields with oil rims have been put into operation in Western Siberia. Their development is further complicated by oil high viscosity and poor cementation of the reservoir rocks. Low values of critical drawdown do not allow oil to be produced without destruction of the productive formation, and mechanical impurities entering the well lead to spillage of perforation intervals and downhole equipment failures. The use of mathematical modeling in relation to the operation of wells in the conditions of the removal of mechanical impurities will make it possible to control production and select the optimal well operation mode. Aim. Forecasting the trouble-free operation of a production well under conditions of high removal of mechanical impurities. Objects. Producing oil wells; the subject of the study is the movement of solid particles in the wellbore of a production well, the relationship and dependence of formation of sand plugs on the operating parameters of the well. Methods. Theoretical research methods – analysis (analysis of models for calculating the critical flow velocity in a horizontal pipe (calculation of the critical velocity in a single-phase flow; calculation of the critical velocity in a multi-phase flow; calculation of the critical velocity based on the balance of forces)) and modeling (simulation of work wells with the removal of mechanical impurities). The totality and combination of these methods are adequate to the goals and objectives, the object and subject of the study of this work. Results. The problem of sand production is typical not only for fields that are in the late stages of development, but also for fields that have recently been put into operation. Sand shows up are a complicating factor in the operation of wells at the Severo-Komsomolskoe high-viscosity oil field located in Western Siberia. The main object of development of the studied field is a weakly cemented sandy layer. Oil production in such difficult areas requires a very careful approach to the choice of development system, to the selection of methods to deal with complications, including the choice of the right method to limit sanding. However, regardless of the approach taken to solve the problem of sand production, some rock will still flow into the well. To prevent the formation of sand plugs, it is necessary to understand the nature of the movement of solid particles along the wellbore. It is possible to assess whether a well is capable of carrying out solid particles from a horizontal section using modeling in specialized software products. Modeling of the well operation, taking into account the influence of mechanical impurities, made it possible to solve the following problems: 1) determine the fluid to carry rock particles out of the horizontal section; 2) identify the areas in which there is a risk of sand plugs; 3) present the dependence for calculating the critical speed for high-viscosity oil with different water cut; 4) assess how the water cut and gas factor affect well operation in conditions of high removal of mechanical impurities; 5) calculate the time of formation of sand plugs.

Effect of jet ejector geometry on the supply of a pumping unit preventing wax-deposit

Relevance. Today oil production by installations of electric centrifugal pumps is one of the leading methods of mechanized oil production. The mechanized operation of hard-to-recover oil objects is complicated by the high viscosity of reservoir oil, the formation of wax-deposits in the wellbore. This leads to an increase in hydraulic resistances due to a decrease in the flow section of pipes and other pumping equipment components, a decrease in the productivity of wells and the efficiency of pumping production. In this regard, an urgent task is to develop and improve methods and devices for preventing deposits of wax-deposits in wells. Object. Downhole pumping unit for dosing reagent (inhibitor of wax-deposits) into the well, which is a combination of two technical devices – a pump dosing the reagent and a jet pump. Aim. To analyze the influence of the design parameters of the dosing unit on the efficiency of its operation (reagent consumption, liquid cavitation coefficient in the jet pump). Methods. Mathematical modeling of the operation of a downhole dosing unit for the supply of reagent, based on the application of the laws of conservation of mass and quantity of motion, as well as Bernoulli's law for a moving flow in a jet pump. Results. Based on the simulation results, the nature of the influence of the design parameters of the developed installation on the reagent consumption is established. It is established that the maximum flow rate of the reagent is achieved with a mixing chamber diameter of about 22 mm; an increase in diameter relative to the specified value leads to a decrease in the degree of local pressure reduction, a decrease in the diameter of the mixing chamber – a drop in flow due to an increase in the flow rate in the chamber and an increase in hydraulic resistance. It was found that an increase in the supply of electric centrifugal pumps in the considered range of 100–200 m3 per day has practically no effect on the reagent consumption when the mixing chamber diameter is more than 30 mm. It was found that at confuser length values exceeding 210 mm, the cavitation coefficient, regardless of the mixing chamber diameter, exceeds one, which indicates a smooth and uniform pressure reduction in the device body. In general, it is shown that by regulating the design parameters of a downhole metering unit, it is possible to ensure the required reagent consumption at a known electric centrifugal pump supply (well flow rate).

Solar-heating superhydrophobic sponge based on size-controllable polydopamine nanoparticles for fast crude oil recovery and photothermal deicing

In the wake of recurring oil spills causing devastating environmental and ecological damage, there is an urgent need for efficient oil spill remediation strategies. Conventional absorbents are often ineffective in harsh environments and struggle with the recovery of high-viscosity crude oil at room temperature. Although photothermal absorbents can greatly improve the fluidity of crude oil, their practical applications are still limited due to complicated preparation processes, hazardous fluorinated reagents, and secondary pollution. This study introduces a facile, one-step dip-coating method to develop a photothermal superhydrophobic melamine sponge (MS), incorporating a fluorine-free suspension of polydimethylsiloxane (PDMS), siloxane-containing acrylate copolymers (SAC), and polydopamine nanoparticles (PDA NPs). The resulting PDMS/SAC-PDA@MS shows an exceptional water contact angle (WCA) and significant self-cleaning abilities due to its superhydrophobicity. With superior mechanical and chemical durability, the sponge achieves remarkable oil absorption (up to 102.6 times its weight) and efficient oil/water separation. Crucially, under solar irradiation, the sponge’s surface temperature reaches 87.6 °C, effectively reducing oil viscosity and enabling rapid cleanup of oil spills and active deicing. This study presents a green, economical approach to synthesizing photothermal superhydrophobic adsorbents with potential applications in environmental cleanup and active deicing.

PREVENTION OF CRYSTALLISATION OF ASPHALT-RESIN-PARAFFIN DEPOSITS UNDER THE INFLUENCE OF A PERMANENT MAGNETIC FIELD

During the operation of oil production wells, significant losses occur due to asphalt-resin-paraffin deposits (ARPD) in the pores of reservoirs and lift pipes. Understanding the detection and technology for combating ARPD is an urgent scientific, technical, and practical task, as this factor affects the wells’ operability and ultimate productivity. Keywords: oil products pipeline transportation, high-viscosity oil, paraffin deposition, permanent magnetic field.

Intensyfikacja wydobycia i przygotowania ropy naftowej o wysokiej lepkości ze złoża Kokhanivka do produkcji bituminu

The existing problems of production, collection and preparation of high-viscosity oils need to be solved by further research and search for effective technologies. The oil of the Kokhanivske field is unique among the fields of Prykarpattia region, which is characterized by a high density of ≈1000 kg/m3, a significant content of asphaltenes, resins up to (45–60% by weight) and sulphur (7%), which is most suitable for the production of the highest quality bitumen. According to the physico-chemical characteristics and composition of the oil of the Kokhanivske field, an analysis of the conformity of this oil to the bituminous group according to the international classification was carried out. It is emphasized that this oil can be an analogue of the raw material from which high-quality bitumen of the Swedish company Nynas are produced. In connection with the above-mentioned physical and chemical properties of the oil from the Kokhanivske field (high density, viscosity asphaltene and resin content, etc.), significant complications arise during its collection and preparation. In order to solve the problem of preparing this type of oil, a technological solution for its preparation with a wave field of different intensity is proposed. In accordance with this technological solution, a laboratory setup was developed to study the effect of a wave field of different intensity on high-viscosity oil of the Kokhanivske field based on the Yutkin effect.

Performance of Motorcycle Fueled with Pertalite‒LDPE Pyrolytic Oil Blendings

Plastic use has expanded substantially, and its waste is primarily disposed of in landfills, which further harm ecosystems owing to inadequate waste management. Pyrolysis, which converts plastic waste into liquid fuel, is one of the potential chemical recycling alternatives for plastic. The purpose of this study is to determine the viability of using pyrolytic oil from an LDPE grocery bag as an alternative fuel for a four-stroke spark ignition motorcycle engine. The LDPE grocery bag was pyrolyzed at 500 oC at a heating rate of 3 oC/min, and the condensed pyrolytic vapor's characteristics were determined. Torque, power, and fuel consumption were investigated using a four-stroke spark ignition motorbike powered by pertalite‒LDPE pyrolytic oil blends. The results reveal that the properties of LDPE pyrolytic oil and pertalite were considerably different; hence, when the blending fuel was applied to the motorcycle, the engine torque and power decreased at low engine speed (2000‒3500 rpm), about equal at medium speed (3500‒5500 rpm), and increased at high engine speed (5500‒8500 rpm). Furthermore, the greater blending fuel greatly reduced fuel usage due to the high viscosity of the LDPE pyrolytic oil.

The Role of Amphiphilic Nanosilica Fluid in Reducing Viscosity in Heavy Oil

Heavy oil accounts for a considerable proportion of the world’s petroleum resources, and its exploitation helps to mitigate reliance on conventional oil resources and diversify energy supply. However, due to the high viscosity and high adhesion characteristics of heavy oil, conventional methods such as thermal recovery, emulsification, and dilution have significant limitations and cannot meet the growing demands for heavy oil production. In this study, 3-propyltrimethoxysilane (MPS) was used to modify and graft amphiphilic surfactants (AS) onto nanosilica to prepare a salt-resistant (total mineralization > 8000 mg/L, Ca2+ + Mg2+ > 1000 mg/L) and temperature-resistant (250 °C) nanosilicon viscosity reducer (NSD). This article compares amphiphilic surfactants (AS) as conventional viscosity-reducing agents with NSD. FTIR and TEM measurements indicated successful bonding of 3-propyltrimethoxysilane to the surface of silica. Experimental results show that at a concentration of 0.2 wt% and a mineralization of 8829 mg/L, the viscosity reduction rates of thick oil (LD-1) before and after aging were 85.29% and 81.36%, respectively, from an initial viscosity of 38,700 mPa·s. Contact angle experiments demonstrated that 0.2 wt% concentration of NSD could change the surface of reservoir rock from oil-wet to water-wet. Interfacial tension experiments showed that the interfacial tension between 0.2 wt% NSD and heavy oil was 0.076 mN/m. Additionally, when the liquid-to-solid ratio was 10:1, the dynamic and static adsorption amounts of 0.2 wt% NSD were 1.328 mg/g-sand and 0.745 mg/g-sand, respectively. Furthermore, one-dimensional displacement experiments verified the oil recovery performance of NSD at different concentrations (0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%) at 250 °C and compared the oil recovery efficiency of 0.2 wt% NSD with different types of demulsifiers. Experimental results indicate that the recovery rate increased with the increase in NSD concentration, and 0.2 wt% NSD could improve the recovery rate of heavy oil by 22.8% at 250 °C. The study of nano-demulsification oil recovery systems can effectively improve the development efficiency of heavy oil.

UiO-66-NH2/hydrothermal carbon nanocomposite assembled mesh membrane with photocatalytic self-cleaning and antibacterial properties for on-demand oily wastewater separation

The poor wettability, limited permeation flux and unsatisfactory anti-fouling property of oil/water separation membranes significantly hinder their practical application. This study developed a novel UiO-66-NH2/hydrothermal carbon@stainless steel mesh (UiO/HC@SSM) membrane, fabricated through a straightforward dip-coating strategy that offers membrane thickness control. The resulting membrane exhibited superhydrophilic/underwater superoleophobic property and high porosity, enabling gravity-driven separation of emulsified and stratified oil/water mixtures on-demand with high separation efficiency and superior flux. Specifically, UiO/HC@SSM-5 (dip-coating five times) showed ultrahigh permeate fluxes of 51428–56425 L m−2 h−1 for stratified oil/water mixtures separation, and UiO/HC@SSM-10 exhibited interface demulsification and gravity separation ability for emulsified oil/water mixtures with high fluxes of 4050–4504 L m−2 h−1. Notably, UiO/HC nanocomposite endowed the membrane with exceptional photocatalytic self-cleaning and antibacterial activities, effectively addressing both oil and microbial fouling. High-viscosity crude oil fouling can be light-induced decontaminated from the composite membrane surface with superior flux recovery ratio (FRR) up to 97 %. The as-prepared UiO/HC@SSM also exhibited near-complete bacterial inactivation activity after 10 min of visible light irradiation. Encouragingly, UiO/HC@SSM demonstrated superior separation and photocatalytic capabilities compared to UiO@SSM, attributed to the dual promoting role of cost-effective hydrothermal carbon in hydrophilicity and photoelectric properties. Moreover, UiO/HC modified SSM membrane displayed robust chemical and mechanical stability, coupled with superior harsh environments and oil pressure resistances. This membrane, boasting desirable wettability, high permeability, exceptional photocatalytic activity, and excellent stability, offers a reliable solution for treating complex oily wastewater. Additionally, the demulsification and photocatalysis mechanisms of UiO/HC@SSM membrane were examined in depth. This study holds significant potential in advancing the development of novel SSM membranes functionalized with MOF/carbon material, thereby enhancing their practical applications in purifying oily wastewater.

SELECTION OF AN EFFICIENT TRANSPORTATION PROCESS OF VERY HIGH VISCOSITY AND HEAVY OILS AND INVESTIGATION OF RESULTING COMPLICATIONS

The article discusses the investigation of the difficulties that arise during the transportation of very high viscosity crude oils and the features of the transportation process. Among high-viscosity oils in Azerbaijan, "Muradkhanli" oil can be mentioned. Special attention is paid to the rheologically complex behavior processes of such crude oils. In general, the storage and transportation of very high viscosity oils has been and remains a complex process for oil producing countries around the world. Heavy and highly viscous crudes are thick and sludgy, so they resist flow through pipelines during transport and are often transported by truck or rail, adding significant costs and potential hazards. Pipeline transportation of oils is also hampered by asphaltene and paraffin precipitation, formation water and salt content, and corrosion problems. Of course, each of these cases should be taken into account. There are various ways to improve this process (by heating, by adding depressants with different reagent composition, etc.). Keywords: high viscosity, heavy crude oil, depressant, railway-transportation, oil crystallization.

Solar-heated mono-domain-structured ferrimagnetic cellulosic sponge fabricated by using bidirectional freeze casting for energy-efficient liquid adsorption

Liquid adsorption has a wide range of industrial and environmental applications. In recent years, interest in liquid adsorption technology that leverages porous materials has surged, primarily driven by these materials’ substantial surface area and adjustable wettability. However, high tortuous structures of conventional porous materials impede the flow of liquids, limiting their applicability in situations requiring rapid liquid adsorption such as oil spill cleanups. This study proposed two strategies for rapid liquid adsorption. We introduced a polydimethylsiloxane (PDMS) wedge to control ice crystal growth by generating a dual temperature gradient. This led to a mono-domain lamellar structure composed of vertically aligned channels. Cubic iron oxide nanoparticles (CION) were also utilized to enhance solar heating, that enabled rapid adsorption, even of high-viscosity liquids, without an external power supply unit for heating sorbents. The application of a solar-heated ferrimagnetic cellulosic sponge with precisely controlled channels facilitates the rapid removal of high-viscosity oils, which have traditionally been challenging for large-scale oil spill cleanups in oceans.