Water-oil Ratio Research Articles

Effect of Sinapine on Microstructure and Anti-Digestion Properties of Dual-Protein-Based Hydrogels.

Sinapine is a natural polyphenol from the cruciferous plant family that has anti-aging effects but is low in bioavailability. To improve the bioavailability and therapeutic effect of sinapine, sinapine-crosslinked dual-protein-based hydrogels were prepared using soy protein isolate as a cross-linking agent. The preparation conditions were optimized by single-factor experiments, and the optimal ratios were obtained as follows: the concentration of sinapine was 300 μg/mL; the water-oil ratio was 1:3. The encapsulation rate was greater than 95%, and the drug loading capacity was 3.5 mg/g. In vitro, digestion experiments showed that the dual-protein-based hydrogels as a drug carrier stabilized the release of sinapine and improved the bioavailability of sinapine by 19.3%. The IC50 of DPPH antioxidants was 25 μg/mL as determined by in vitro digestion, and the antioxidant capacity of ABTS was about 20% higher than that of glutaraldehyde control. This is due to the addition of sinapine to enhance the antioxidant properties of the system. It can be seen that the developed hydrogels have potential applications in related fields, such as food nutrition fortification and drug delivery.

Enzymatic synthesis of ω-3 fatty acids-based structured phospholipids: A novel solvent-free preparation approach and its catalytic mechanism

ω-3 fatty acids-based phospholipids (ω-3-PLs) exhibit higher bioavailability within organisms and stability compared to polyunsaturated fatty acids in their neutral forms. In this study, ω-3 fatty acids enriched partial acylglycerols (ω-3-AGs) were produced from hydrolysis of algal oil firstly. The effects of hydrolysis processing parameters such as enzyme type, enzyme loading, oil-water ratio, reaction temperature, and time were evaluated. Subsequently, ω-3-PLs were prepared via interesterification of ω-3-AGs with PLs catalyzed by PLA1. When monoacylglycerols (MAGs) reached 60% in partial acylglycerols, the interesterification reaction showed a marked improvement, leading to the achievement of the optimal final ω-3-PLs content of 38.93%. Using molecular docking techniques to speculate on the catalytic mechanism, the results indicate that MAGs exhibit an affinity of up to −6.33 kcal/mol with PLA1, verifying their critical role in the interesterification process.

Emulsion formation and stability of surfactant–polymer flooding

Emulsification plays a pivotal role in the process of enhanced oil recovery, especially in chemical flooding. Surfactant–polymer flooding is a promising technique with significant potential for improving oil recovery in medium and high permeability oilfields in China. Emulsification has emerged as one of the key mechanisms facilitating oil recovery in surfactant–polymer flooding. This study aimed to assess the effects of surfactant structure and concentration, polymer, oil–water ratio, clay content, and injection rate on the formation of different emulsion types and their stabilities. The assessment was conducted based on the actual conditions of surfactant–polymer flooding in the Qizhong area of the Xinjiang oilfield. The findings revealed that KPS-1 (petroleum sulfonate) demonstrated superior emulsifying and solubilizing abilities for crude oil compared to BS-18 (betaine), whereas BS-18 exhibited better emulsifying stability. KPS, which was a combination system of KPS-1 and BS-18, displayed favorable emulsifying ability. However, the emulsifying stability of the three surfactants decreased in the presence of HPAM (hydrolyzed polyacrylamide). The oil–water ratio primarily influenced the morphology of the emulsion. When the oil–water ratio exceeded 6:4, a water-in-oil emulsion was formed, and the viscosity of the emulsion reached its maximum at an oil–water ratio of 7:3. Moreover, clay demonstrated a significantly high ability to emulsify, resulting in the formation of emulsions with increased viscosity and robust stability. Regarding the injection rate, effective emulsification occurred when the injection rate reached 1 m/d, while emulsions with high viscosity were observed at an injection rate of 7 m/d.

Realizing the Rapid Release of Drag Reducers via pH-Induced Oil Phase Transition of Inverse Emulsion.

As a key component of slickwater fracturing fluids, emulsion drag reducers play a vital role. The dissolving capacity of traditional emulsion drag reducers is improved by adding hydrophilic surfactants, which leads to poor stability of the emulsion drag reducer. In order to eliminate the contradiction between stability and release of the emulsion drag reducer, here, pH-responsive polymer emulsion was fabricated using the switching solvent (HA) and white oil as the continuous phase. Monomer emulsions exhibit obvious pH-responsive behavior. This is because the deprotonation of HA by pH stimulation leads to a change in the oil-water ratio of the emulsion, thereby facilitating the demulsification of emulsion. The remarkable stability of the monomer emulsion benefits the preparation of inverse emulsion polymers (P(AM-AA-AMPS)). The obtained P(AM-AA-AMPS) polymer emulsion features remarkable stability even after 15 days of storage. Importantly, the P(AM-AA-AMPS) polymer was released from the emulsion efficiently by pH stimulation instead of introducing an extra hydrophilic surfactant, which confirmed the improvement of polymer release by pH stimulation. The viscosity of the P(AM-AA-AMPS) polymer aqueous solution reaches a maximum value of 96 mPa s within 80 s at a pH value of 9.2. The release efficiency of P(AA-AM-AMPS) polymer emulsion is increased by 33% in comparison with that of traditional polymer emulsion (2 min). The P(AM-AA-AMPS) emulsion demonstrated remarkable drag-reduction performance by achieving a drag-reduction rate of 73% at a concentration of 0.05 wt %. P(AM-AA-AMPS) polymer emulsion with pH responsiveness eliminates the contradiction between the stability and release of emulsion drag reducers. Research based on pH-responsive P(AM-AA-AMPS) polymer emulsion provides other ideas for the development of quickly dissolving and long-term storage drag reducers, which is helpful for the development of low-permeability oil and gas resources.

Fabrication and characterization of edible Pickering emulsion stabilized by donkey myofibrillar protein

This study aims to investigate the properties of edible Pickering emulsions (PEs) stabilized by donkey myofibrillar protein (DMP). The DMP was characterized by an atomic force microscope and interfacial tensiometer. The PEs stabilized by DMP were characterized by a confocal laser scanning microscope, rheometer, and lumisizer stability analyzer. The results showed that the DMP particles were spherical nanoparticles with an average size of 143.97 nm. The DMP could reduce the oil-water interfacial tension very well. The emulsifying activity index was below 14.06 m2/g, and the emulsion stability index was up to 93.76% when the DMP concentration was above 10 mg/mL. Increasing the concentration of DMP (5 mg/mL to 25 mg/mL) could decrease the emulsion droplet sizes and fluidity of the PEs and increase the viscoelasticity of the PEs. The increase in the oil-water ratio (1:9 to 5:5) resulted in a larger average emulsion droplet size, reduced fluidity, and enhanced viscoelasticity. The increase in DMP concentration (from 5 mg/mL to 25 mg/mL) and oil-water ratio (from 1:9 to 4:6) improved the physical stability of the PEs. These results may expand the application of DMP and provide new insight into developing edible PEs suitable for the formulation of functional foods.

Fabrication of chitosan-encapsulated microcapsules containing wood wax oil for antibacterial self-healing wood coatings

Wood multifunctional smart coating is a new functional coating that combines smart material technology with traditional wood. In this study, wood wax oil based on thistle oil and flaxseed oil was used as the core material, and chitosan was used as the wall material to prepare self-repairing antibacterial microcapsules. The optimal preparation conditions were found to be an oil-water ratio (OWR) of 2:1, a core-to-wall ratio of 3:1, using OP-10 as the emulsifier at a concentration of 10.0 %, and a crosslinker concentration of 0.18 g/mL. The encapsulation efficiency of microcapsules was 73.7 % by spray drying, and the thermal stability was improved. The chitosan microcapsules exhibit the characteristics of water sensitivity and acid selective response, with rapid release at pH 7.0. Blending microcapsules at concentrations of 2.0 %, 5.0 %, and 8.0 % with UV topcoat and applying them to walnut plywood resulted in a multifunctional wood coating. Artificially simulated daily scratch damage was effectively repaired within 7 d. Furthermore, the 10.0 % microcapsules demonstrated antibacterial properties against Escherichia coli (E. coli) and Escherichia coli (E. coli), with an antibacterial E. coli and S. aureus rate of up to 75.82 % and 42.96 %. The IC50 of the wood coatings against E. coli was 5.667, while against S. aureus it was 15.45. The minimum inhibitory concentration (MIC) of the microcapsules against both E. coli and S. aureus was 10.0 %. The coating film containing 2.0 % microcapsules demonstrated superior overall performance. This research established a foundation for the development of self-healing antibacterial coatings for wood and addressed the gap in dual-functional self-healing antibacterial paint films for wood.

Multilayer 3D seismic attribute analysis and fault framework modeling of shallow extensional fault systems in the Delaware Basin

Shallow extensional fault systems within the southern Delaware Basin have gained the interest of Permian operators since published works noted them in 2019. These shallow extensional fault systems, referred to as “lineaments” by operators, are seismogenic hazards, pose significant hazards to drilling operations, and are associated with elevated water-oil ratios and H2S concentrations. Previous work using seismic attribute analysis has resulted in the successful mapping of extensional fault systems at the Ochoan/Guadalupian interface, whereas fault geometry, origin, and depth of penetration have remained elusive. First- and second-order ant tracking of the variance cube is rendered on multiple seismic horizons throughout an 856 km2 (approximately 330 mi2) depth-migrated 3D seismic reflection volume to expand the interpretation of the deformation zone at depth and guide a robust 3D fault model that forms the framework for the predictive model. A total of 60 previously undocumented features are identified in southwestern Reeves County — 56 penetrate the Ochoan/Guadalupian interface, 60 penetrate the middle Guadalupian, 29 penetrate the early Guadalupian, and 21 penetrate the early Leonardian. Structural modeling returns an average strike orientation of 318° north-northwest–south-southeast and an average dip of 84°. Spatial and temporal analysis of the model constrains the timing of extension to the Cenozoic. In contrast to previous studies, the improved depth of investigation of the 3D fault model allows for the correlation of documented drilling hazards with offset wastewater disposal wells along shared lineaments. Communication is indicated by H2S risking flags from mass spectrometry data along the vertical and horizontal sections of producing and injecting wells. Drilling data validates the seismic characterization and prediction of the 3D faulted architecture within the largest contiguous study of shallow extensional fault systems within the Delaware Basin and establishes a repeatable workflow for mitigating the negative impacts of shallow lineament geohazards on drilling operations and production profiles.

A natural protein-lipid co-assembly as efficient Pickering emulsifier from egg yolk sphere microgel prepared via high-pressure homogenization

Egg yolk sphere is a kind of natural colloidal histological structure formed by the co-assembly of a large number of proteins and lipids, which has the dual functions of hydrophilic and lipophilic for application in emulsion. In this study, egg yolk sphere microgels (EYSMs) were prepared by high pressure homogenization (HPH) technique at various pressures (0–90 MPa) and used as Pickering emulsifiers for emulsification to obtain oil-in-water emulsions with an oil-water ratio of 11:9. The microscopic morphology, structure, and physicochemical properties of EYSMs were analyzed. The results showed that EYSMs obtained at 60 MPa (60-EYSMs) exhibited superior emulsifying properties with an emulsifying activity index (EAI) of 2.8 m2/g and an emulsifying stability index (ESI) of 356.6 min, resulting in enhanced storage stability of the emulsion for 30 d. The HPH treatment decreased the lipid content in EYSMs while creating a more homogeneous protein-lipid arrangement, which provided EYSMs with balanced hydrophilic and hydrophobic sites to improve emulsifying properties. Furthermore, the free sulfhydryl groups and hydrophobic moieties exposed by HPH promoted -S-S- formation on the EYSMs surface, promoting the increase in surface hydrophobicity and emulsifying ability. The confocal laser scanning microscopy (CLSM) and cryogenic scanning electron microscopy (cryo-SEM) revealed that the EYSMs adsorbed at oil-water interface and formed an intercross-linked spatial three-dimensional network structure, which worked as a physical barrier to the stable emulsion formation. This study introduces a novel research concept and delves into the emulsification mechanism of protein-lipid composite particles, offering a fresh insight for the development and utilization of emulsifiers.

Rapid design and optimization of complex surfactant microemulsions for high-efficiency oil extraction processes integrating experimental and modeling approaches

Microemulsions have been widely used as a means of high-efficiency oil extraction processes in the field of oil recovery, separation, deposit removal, et al. Phase behavior is considered the most reliable evidence for formulating surfactant systems. There, however, few methods exist that can predict the phase behavior of microemulsions formed by complex surfactant compositions.This work developed a modified model based on the Hydrophilic Lipophilic Deviation-Net Average Curvature (HLD-NAC) model that could rapidly and accurately predict the phase behavior and phase evolution of complex surfactant microemulsions. The phase evolution of the microemulsions with equivalent alkane carbon number (EACN), surfactant concentration, and water–oil ratio (WOR) were explored. The results indicated that the new model successfully delineated the salinity boundaries of Winsor Type III microemulsion and predicted the inversions of phase behavior. A linear correlation between the EACN and the optimal salinity was demonstrated, with a precisely defined predictive range of EACN for Winsor Type III microemulsions. A fish diagram that illustrated the evolution path of the microemulsion phase was established through concentration scanning. The WOR test suggested that Winsor Type III microemulsion could be formed through salinity regulation once the surfactant concentration exceeded the critical micelle concentration (CMC).

High-Efficiency High-Temperature-Resistant Nanosilica Viscosity Reducer for Extra-Heavy Oil Viscosity Reduction.

Due to the fact that more conventional heavy oil recovery methods (heating, emulsification, dilution, and other methods) have many shortcomings, they cannot meet the demand of heavy oil exploitation. Therefore, there is a need for new recovery methods. In this paper, the surface of nano SiO2 was modified with a silane coupling agent, KH-560, to prepare a nanoviscosity reducer (NRV), which has high-temperature resistance (300 °C), calcium and magnesium resistance (Ca2+ + Mg2+ > 900 mg/L) and high viscosity reduction rate (>99%). FTIR and SEM measurements showed that KH560 has been successfully connected to the surface of SiO2. The particle size distribution of NRV is mainly distributed in 50-80 nm, which matches the results of SEM. The experimental results showed that the viscosity reduction rates of 1 wt % NRV on M-1 heavy oil before and after aging were 99.73% and 99.71%, respectively. The viscosity reduction effect of 1% NRV on M-1 heavy oil and the bleeding rate of emulsion formation were investigated when the oil-water ratio ranged from 9:1 to 1:9. The results showed that when the oil-water ratio was between 7:3 and 1:9, the viscosity reduction rate was greater than 99%. Besides, the bleeding rate of emulsion increases with the decrease of the oil-water ratio. What's more, static and dynamic adsorption experiments showed that the adsorption capacity of 1 wt % NRV was 1.746 mg/g and 1.668 mg/g sand, respectively. The interfacial tension experiment showed that the interfacial tension (IFT) between 1 wt % NRV and M-1 heavy oil was 0.052 mN/m, and low interfacial tension was beneficial to displace the oil in the formation pores. At the same time, the displacement effect of NRV on M-1 heavy oil at different concentrations (0.5, 1.0, and 1.5 wt %) and temperatures (200, 250, and 300 °C) was investigated by core flooding experiments. The results showed that the recovery rate increases with the increase of NRV concentration, and 1 wt % NRV at 300 °C will improve the recovery rate of M-1 heavy oil by 27.3% compared to steam flooding. NRV could reduce the viscosity of crude oil, which provides technical guidelines for the exploitation of heavy oil and extra heavy oil.

Development of xanthan gum intelligent oil-in-water ink and its application in pork freshness preservation

To optimize the stability of oil-based inks and ensure their wide application in freshness indication, new natural indicator inks were prepared using a stable oil-in-water structure. This study selected natural Lycium ruthenicum anthocyanin as the dye and glucose as the pigment carrier. Soybean oil was introduced as a linker and xanthan gum as a thickener, and an oil-in-water ink with the function of freshness indication was successfully developed. In ensuring the safety of ink labels for use on food packaging, particular attention is paid to the origin and properties of the materials used. All ingredients are of food-grade or bio-friendly provenance, thereby ensuring the safety of the product when in direct contact with food. We measured the viscosity, particle size and fineness of the ink for micro characterization and evaluated its macro printing performance by its printing effect on A4 paper. According to the experimental results, when the water-oil ratio of the ink is 10:5, the average particle size of the emulsion system is 822.83 nm, and the fineness reaches 5 μm. These values are relatively low, which indicates that the stability of the ink system is high at this time, and the ink shows excellent rheological and printing characteristics. With this water-to-oil ratio, the ink can show the best results when printed on A4 paper, clearly displaying image details. In addition, in fresh pork applications, inks with a 10: 5 water-to-oil ratio provide an accurate and highly sensitive indication of the freshness of pork. When the freshness of the pork changes, the ink color responds promptly. This high sensitivity makes the ink ideal for use as a food freshness indication tool, providing consumers with an intuitive and reliable reference for pork freshness. As a further innovation, combining this ink-printed label with a WeChat app not only allows consumers to know the freshness of the food in real-time but also tracks the supply chain information of the food, providing a more comprehensive application prospect for freshness-indicating products.

Preparation and application of oil-in-water structure linseed oil- EGCG nanoemulsion

The oil–in–water nanoemulsion of linseed oil and EGCG (LOE-NE) was successfully constructed by ultrasonic treatment. Optimized formula successfully prepared LOE–NE with excellent physicochemical characterization, average particle diameter 160–180 nm, PDI <0.2, Zeta potential ≈−60. Results showed that oil–water ratio had significant effect on the stability of LOE-NE but EGCG did not. Comprehensive characterization and nutritional contribution showed that the emulsion with 1:9 oil–water ratio and 1% EGCG was the best formula. The preferred LOE-NE at low temperature were conducive to reducing the EGCG loss and inhibiting its browning during long-term storage. Further application of the LOE-NE to high–oil foods indicated that addition of 10% LOE-NE and 0.1% neohesperidin dihydrochalcone (NHDC) to salad sauce could improve the sensory flavor, significantly enhancing the antibacterial and antioxidant activities and prolonging its quality stability. Moreover, the addition of LOE-NE can slow down the accumulation of acrylamide and reduce the loss of representative unsaturated fatty acids in the high–temperature baking of mooncakes. These findings will provide new methods and ideas for expanding the food application of high-nutrition linseed oil, and can offer theoretical support and application guidance for the practical development and utilization of nanoemulsion.

Construction of Pickering emulsion and its application in enzymatic synthesis of phytosteryl oleate

In this study, Janus nanoparticles were prepared and used to construct Pickering emulsion as an emulsifier in presence of lipase. The results showed that Janus nanoparticles could be used to stable water phase in emulsion and the average particle size of emulsion was 60 μm. Phytosterol ester was successfully synthesized in Pickering emulsion catalytic system by using oleic acid as acyl accepter, and the phytosterol conversion reached 91.65 ± 2.07% under the following conditions: emulsifier amount of 1.0 wt%, oil-water ratio of 6:1, phytosterol concentration of 110 mmol/L, lipase dosage of 20 g/L, reaction temperature of 45 °C. Compared with biphasic catalytic system, Pickering emulsion catalytic system could enhance the catalytic efficiency and shorten the reaction time due to large interface area and short molecule diffusion distance. At the end of reaction, Janus nanoparticles could be recovered by simple centrifugation, the relative activity of lipase remained 72.89 ± 1.83% after repeated use for 6 times. Overall, this paper provides a novel and high efficiency interfacial biocatalysis technique for the synthesis of phytosteryl oleate.

Characteristics and stabilization of Pickering emulsions constructed using myosin from bighead carp (Aristichthys nobilis)

Myosin from bighead carp (Aristichthys nobilis) as a main type of fish protein possesses a good emulsifying ability. However, whether bighead carp myosin (BCM) could construct stable Pickering emulsions is still unclear. Therefore, myosin particles and Pickering emulsions stabilized by bighead carp myosin (BCMPEs) were analyzed. The surface structure of BCM particles at 0.6 mol/L NaCl treatment was uniform and compact with a contact angle of 86.4 ± 2.7°, exhibiting the potential ability to construct O/W Pickering emulsions. The size and flocculation index (FI) of BCMPEs decreased with the increase in BCM concentrations of 1%–4% (w/v). Reversely, the size of BCMPEs increased with the increase in oil-water ratios. BCM particles could uniformly distribute at the oil-water interface to stabilize BCMPEs at a BCM concentration of 4% (w/v) and an oil-water ratio of 6:4 (v/v). This study could help explore fish proteins to construct Pickering emulsions for the deep processing of fish products.

Nano-hydroxyapatite Pickering emulsions as edible mayonnaise-like food sauce templates: A novel approach for food design

Pickering emulsions have the potential to enhance product stability and provide opportunities to create functional solutions that align with labelling requirements. The present work aims to develop Pickering emulsions stabilised by nano-hydroxyapatite (n-HAp) particles to replace traditional mayonnaises. The study addresses the effect of n-HAp solid particle concentration (5–15 wt%) and oil-water ratio (50:50, 60:40, 70:30, and 80:20, v/v) on emulsion stability, rheological properties, and oxidative stability. The results indicate that the produced Pickering emulsions have good stability for the tested period of 90 days, except for the 80:20 o/w emulsion that undergone a prompt quick phase separation. The Pickering emulsions produced with higher n-HAp concentration or oil content have a semi-solid structure, rendering them desirable options for replicating the texture of traditional mayonnaises. Regarding oxidative stability, the Pickering emulsions showed considerably improved stability compared to commercial mayonnaises (∼13 times higher), suggesting higher resistance to peroxidation and a longer shelf-life.

Study on the Technology of Ultrasonic, Chemical and Mechanical Combined Treatment of Oilfield Aging Oil

Aging oil is a common pollutant in petrochemical enterprises due to its severe emulsification and flocculation, poor settling performance, low oil recovery rate, and high difficulty in treatment. This article adopts the method of mechanical, ultrasonic, and chemical coupling demulsification to treat aging oil, with the water content and oil recovery rate of the treated aging oil as the inspection indicators. The experiment shows that when the oil-water ratio is 1:4, the heating temperature is 50℃, the stirring speed is 180rpm, the ultrasonic frequency is 25kHz, the power is 40W, the ultrasonic time is 25min, and the pH is adjusted to 3-4. The additional amount of FeSO4 is 160mg/L, the additional amount of H2O2 is 0.11%, and the heating stirring reaction is 40min. When the dosage of cationic PAM with an ion degree of 50 is 35mg/L, the centrifugation speed is 3200rpm. The centrifugation time is 20 min, the crude oil recovery rate after aging oil treatment can reach over 94.6%, and the water content of the treated crude oil is less than 0.5%, meeting the standards for crude oil gathering and transportation in China. The oil content in the water generated after aging oil treatment is about 150 mg.L-1, the suspended solids content is 200 mg.L-1, the oil content in the residue is 6%, and the water content is 53%. By analyzing the appearance of aging oil before and after treatment, it was found that when using this process to treat aging oil, the original spatial cross-linking network structure of the aging oil was broken, allowing the water droplets wrapped in the oil to be released, thereby significantly reducing the water content in the recovered oil and improving the oil recovery rate.

Agar-gelatin Maillard conjugates used for Pickering emulsion stabilization

A few protein- and polysaccharide-based particles have shown promising potential as stabilizers in multi-phase food systems. By incorporating polymer-based particles and modifying the wettability of colloidal systems, it is possible to create particle-stabilized emulsions with excellent stability. A Pickering emulsifier (AGMs) with better emulsifying properties was obtained by the Maillard reaction between acid-hydrolysed agar and gelatin. Laser confocal microscopy imaging revealed that AGMs particles can be used as solid emulsifiers to produce a typical O/W Pickering emulsion, with AGMs adsorbing onto the droplet surface to form a dense interfacial layer. Cryo-scanning electron microscopy analysis showed that AGMs self-assembled into a three-dimensional network structure, which prevented droplets aggregation through strong spatial site resistance, contributing to emulsion stabilization. These emulsions exhibited stability within a pH range of 1 to 11, NaCl concentrations not exceeding 300 mM, and at temperatures below 80 °C. The most stable emulsion oil-water ratio was 6:4 at a particle concentration of 0.75 % (w/v). AGMs-stabilized Pickering emulsion was utilized to create a semi-solid mayonnaise as a replacement for hydrogenated oil. Rheological analysis demonstrated that low-fat mayonnaise stabilized with AGMs exhibited similar rheological behavior to traditional mayonnaise, offering new avenues for the application of Pickering emulsions in the food industry.

Numerical investigation on dynamic characteristics of oil-water annular flow-induced vibration in curved pipes

To improve the stability of water-lubricated transportation and reliability of pipes in service, the fluid–structure interaction numerical model has been established to investigate the dynamic characteristics of oil-water annular flow-induced vibration in curved pipes and the effect of main parameters in this study. The results illustrate that a single vibration mode of curved pipes is excited by oil-water annular flow, and there exists no multi-modality due to the limited pulsation of pressure and interface of two-phase flow. The change of velocities and oil-water ratios leads to change of flow pattern, making the dynamic response severer. When the oil-water ratio is larger than 2.035, its effect is greater than velocity. The physical properties of oil have a significant effect on the dynamic response. The root-mean-square dimensionless displacement AY,RMS/D and maximum dimensionless displacement AY,MAX/D of fuel oil-water annular flow-induced vibration decrease to 75.6% and 76.5% respectively, which means that the increase of dynamic viscosity reduces the fluid force and suppresses the vibration. AY,RMS/D and AY,MAX/D increases by 1.62 times when the bending angle θ increases from 30° to 90°, indicating that the increase of bending angles also leads to the severer dynamic response.

Bacterial cellulose nanofibrils for the physical and oxidative stability of fish oil-loaded Pickering emulsions

Fish oil, a crucial unsaturated ω-3 unsaturated fatty acid supplement, is susceptible to oxidation. To improve the stability of fish oil, this study produced a fish oil Pickering emulsion via ultrahigh-pressure homogenization pressure (UHPH) using bacterial cellulose nanofibrils (BCNFs) as the water phase. The BCNFs exhibited a high aspect ratio fibril structure with an average diameter size of 12.64 nm. The results of particle size, zeta potential, emulsion properties, and oxidative stability showed that the emulsions with a 4:6 oil-water ratio and 0.15 % BCNFs exhibited excellent oxidative stability and good physical stability. The CLSM and rheological results suggested the BCNFs acted as a stabilizer and thickener, stabilizing the oil-water medium and enhancing the oxidation stability of fish oil Pickering emulsions. The Low-field nuclear magnetic analysis results indicated the emulsion had good physical stability, and water dispersed very well in the emulsion system. Moreover, the emulsions exhibited good stability at pH 6–12 and temperature 4–75 °C. This study provided a promising method for producing fish oil Pickering emulsions and improving the stability of fish oil.

COMPARISON OF PLOT ANALYTICAL METHODS FOR DETERMINING EXCESSIVE WATER PRODUCTION MECHANISMS IN OIL WELLS

Watering of production wells is an important factor leading to a decrease in production profitability and an increase in costs. There are several main mechanisms of excess water inflow. These are a leak in the production casing; a violation of contact between the production casing and the rock; a formation of a bottom water cone; a raising the WOC surface to the perforation interval; a breakthrough through a layer with high permeability. Mechanisms can complement each other, forming a complex integrated system. To identify them, there are three groups of diagnostic methods — geophysical research, hydrodynamic well testing and plot analytical studies. Each of these fundamentally different groups can be supplemented by field research. Specifically in this work, we considered the latter. The analysis is carried out using the example of wells in one of the deposits of an oil field of the Arkhangelsk region. In which the causes of unwanted water production have already been studied by other methods and can be considered known. The studied reservoir is massive, with carbonate hydrophobic rocks and the reserves of the entire field are predominantly concentrated in it (97 %); the oil field (in terms of reserves) is small. There are no injection wells, operation is carried out in a natural elastic water drive mode. In the article, in total, three plot analytical methods are analyzed, which are among the main ones and have different application algorithms. Both the physical principles of their application and their effectiveness in relation to specific oil field are considered. These are the methods of K. Chan; L.I. Merkulova and A.A. Ginzburg; R. Novotny. The first studies the dependence of the water-oil ratio and its derivative on time (WOR and WOR’(t)), is the most widely known and has a large number of modifications (however, here they are not considered in detail). The second is based on the study of the so-called «water-cut characteristics» (representing the dependence of the accumulated oil production vs accumulated liquid production during the water period of operation). It has more restrictions, but is also more comprehensive. The third is based on a comparison of the permeability properties of reservoirs that change during operation.