Anti-Foaming High-Performance Lubricants

Lubricating oil for spark-ignition engines that maintains low foaming and aeration while also providing good low-speed pre-ignition (LSPI) performance. The oil contains a low level of silicon from a polyalkylsiloxane antifoam polymer, as well as higher levels of silicon from silicon-containing compounds like trisiloxanes and silanes with molecular weights under 650. This composition allows reducing foaming and aeration compared to higher molecular weight silicon compounds. It also enables passing LSPI tests.

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A method for assessing the dispersing capacity of lubricating compositions and additives for internal combustion engines, comprising preparing a dispersion of carbonaceous particulate in the lubricating composition, analyzing the dispersion by optical microscopy, and calculating the degree of dispersion based on lacunarity. The method enables preliminary assessment of lubricating compositions and additives without engine testing, allowing for cost-effective selection of promising candidates for further evaluation.

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Antifoam compositions for diesel fuels comprising poly(acrylate) polymers prepared by polymerizing a combination of solubility monomers and surface tension monomers, particularly those comprising C1-C4 alkyl esters of (meth)acrylic acid and C5-C12 alkyl esters of (meth)acrylic acid. The poly(acrylate) polymers exhibit improved antifoam performance compared to conventional silicon-based antifoams, and are particularly effective in reducing foam generation during fuel fill-ups.

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The dilute-foam dispersion system improves oil recovery by reducing interfacial tension between oil and water, altering wettability, and diverting displaced fluids by plugging larger pores. An optimized foaming system is obtained by formability evaluation experiments, in which the half-life for drainage and foaming volume by different types and concentrations of surfactants are analyzed, followed by the addition of partially hydrolyzed polyacrylamide (HPAM) with varied concentrations to enhance the foam stability. Using COMSOL Multiphysics 5.6 software, the Jamin effect and plugging mechanism of the watergas dispersion system in narrow pore throats were simulated. This dispersion system is applied to assist CO2 huff-n-puff in a low-permeability core, combined with the online NMR method, to investigate its effects on enhanced oil recovery from the pore scale. Core-flooding experiments with double-pipe parallel cores are then performed to check the effect and mechanism of this dilute-foam dispersion system (DFDS) on enhanced oil recovery from the core scale. Results show that foam gen... Read More

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Abstract Recent studies on oil-foam interaction using different types of oil were limited to the aspect of alkane chain length, density and viscosity of crude oil. However, oil polarity toward foam stability to predict the significant variable of the foam half-life and its evaluation in macroscopic oil displacement is still elusive in literature. In this study, the effect of oil polarity on foam properties at bulk and macroscopic scales was investigated. The effect of electrolytes on surfactant foam stability was studied. Subsequently, the foam stability in the presence of polar and non-polar oil was determined. Thereafter, the macroscopic oil displacement efficiency of surfactant foam was evaluated. Finally, a multivariate linear regression analysis was used to predict the significant variable of the foam half-life. The results indicate that cocamidopropyl betaine (CAPB) foam had better stability under the influence of oil polarity, with a half-life decrease of 8% in hexane oil compared to 86% by sodium dodecyl sulfate (SDS). Moreover, SDS foam flooding recovered 10% additional oil ... Read More

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Abstract A key factor affecting foam stability is the interaction of foam with oil in the reservoir. This work investigates how different types of oil influence the stability of foams generated with binary surfactant systems under a high salinity condition. Foam was generated with binary surfactant systems, one composed of a zwitterionic and a nonionic surfactant, and the other composed of an anionic and a nonionic surfactant. Our results showed that the binary surfactant foams investigated are more tolerant under high salinity conditions and in the presence of oil. This was visually observed in our microscopic analysis and was further attributed to an increase in apparent viscosity achieved with binary surfactant systems, compared to single surfactant foams. To understand the influence of oil on foam stability, we performed a mechanistic study to investigate how these oils interact with foams generated with binary surfactants, focusing on their applicability under high salinity conditions. The generation and stability of foam are linked to the ability of the surfactant system to sol... Read More

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A lubricating oil composition for axles that maintains viscosity stability across a wide temperature range, comprising a Fischer-Tropsch derived base oil and a polyalkylene glycol high-viscosity component. The composition provides effective lubrication at both low and high temperatures, with the Fischer-Tropsch derived base oil providing low-temperature lubricity and the polyalkylene glycol component providing high-temperature wear protection. The composition also includes anti-foam additives that maintain their effectiveness across the temperature range, particularly a non-ionic surfactant-based anti-foam that provides excellent foaming results in both two-phase and single-phase states.

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In this study, the influence mechanism of typical fuels (oils) on the foam properties of mixture of hydrocarbon and fluorocarbon surfactants was investigated. A mixed solution was prepared based on a nonionic hydrocarbon surfactant (APG-0810) and a zwitterionic C6 fluorocarbon surfactant (short-chain). The effect of different oils (heptane, kerosene, diesel, and transformer oil) on the physical property parameters, foamability, oil resistivity of foam and single vertical liquid film of the mixture are systematically investigated. Results indicate that the viscosity of mixture increases, but the conductivity, surface activity, and initial foam height decreases with addition of the four oils. The drainage and volume decay of the foam are accelerated by the presence of oils. In addition, the presence of oils accelerates liquid film thinning through affecting drainage, especially for the oil with higher density, water solubility, and volatility. The four oils showed different effect on foam properties due to the difference in nature and emulsification of them. Among them, the foam proper... Read More

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Bitumen, sourced from different crude oils, exhibits distinct foaming properties that significantly influence the performance of foamed bitumen mixtures. This research investigates the relationship between the expansion ratio of foamed bitumen and its surface energy. A theoretical analysis was conducted on a single bitumen bubble to explore the equilibrium between internal steam work and surface energy during expansion. This led to a unique formula linking the bitumen bubble's expansion ratio to its surface energy. The validity of this formula was confirmed through empirical measurements of four different bitumens. Results reveal a significant exponential relationship between the expansion ratio of a single bituminous bubble and the bitumen surface energy. This correlation, supported by experimental data from four bitumen samples, suggests that bitumens with lower surface energy enhance foaming performance.

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Abstract This study investigated the factors affecting the foamability and stability of nonaqueous foams. The researchers systematically varied the formulation (surfactant and alcohol type and concentration) and flow parameters (viscosity and gas flow rate). A custom setup with an 80 cm temperaturecontrolled glass column was used for foam generation. Among the tested nonionic surfactants type sorbitan esters, the Span 80 (liquid W/O emulsifier and O/W emulsion stabilizer) produced the most voluminous foams. Interestingly, increasing surfactant concentration improved foamability but decreased foam stability. Similar trends were observed with the oil fraction and temperature (which affects viscosity). Higher viscosity led to more stable but less foamy structures. The study also explored the effect of different alcohols (ethanol to n decanol) at varying flow rates. While all alcohols generated some foam at lower flow rates (200 mL/min N 2 ), the effect diminished at higher flow rates. Additionally, foam stability and volume decreased with longer alcohol chains. These findings provid... Read More

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The primary recovery factor of extra-heavy oils with foamy oil flow characteristic is only 812%. In previous studies, an approach of chemical-assisted methane flooding to enhance recovery in foamy oil reservoirs after primary depletion was proposed. The approach includes injecting viscosity reducer naphtha, methane and surfactant solution slugs sequentially to recreate foamy oil flow in situ. This study further investigated the effect of the surfactant concentration on the process through indoor experiments. Extra-heavy crude oil sample with typical foamy oil features, taken from Venezuela Heavy-Oil-Belt, was adopted during the experiments. To begin with, 16 groups of interfacial tension test between oil added with surfactant solution of different concentration and methane were conducted. Afterwards, 6 groups of foam stabilization test were conducted to record the foam volume and the half-life period under different surfactant concentrations. Finally, 3 groups of 2D visualized micro-flow experiments were conducted to investigate the surfactant concentration effect on the generation ... Read More

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With the continuous improvement of the exploitation degree of oil fields, most of the domestic oil fields have entered the tertiary production stage. As a relatively mature oil production technology in the tertiary oil production stage, enhanced foam flooding technology is widely used in all oil fields. At the end of 2014, a combined station of an oil field began to carry out the production test of nitrogen foam drive. With the increase of the number of measure wells and the implementation of strengthening nitrogen bubble foam drive, the emulsion strength of the produced fluid entering the combined station gradually changed, and the difficulty of dehydration increased. Specifically, the water content at the outlet of the two-phase separator fluctuates seriously, the crude oil dehydration temperature rises, and the energy consumption increases; Due to the high degree of emulsification of the produced liquid, it is more difficult to dewater the crude oil, and the demulsifier needs to be adjusted repeatedly; The water content of crude oil is difficult to meet the standard, and it has oc... Read More

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Abstract Foam, as a gasinliquid colloid, has a higher appearance viscosity than the one of both gas and liquid that form it. Adjusting the mobility ratio of the injected fluidoil system and increasing gas diffusion in the foam injection process increase oil production. With these properties, foam as an injection fluid in fractured reservoirs has a major effect on oil production from the matrixes and prevents premature production of injection fluid. Surfactants are common foaming agents in injection water. Saponins are known as plantderived surfactants for forming stable foam. This feature, along with its cheap price and availability, can make them candidates for enhanced oil recovery (EOR) by the foam injection method. However, the utilization of CO 2 as the gaseous phase in foam introduces additional machanisms of CO 2 injection to the oil recovery operations. In this assessment, a nonionic green surfactant derived from the Anabasis setifera plant was used as a foaming agent, while CO 2 served as the gas phase. A series of surface tension tests in CO 2 environment were performe... Read More

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The primary objective of this review is to consolidate our current understanding of the factors controlling the foamability of surfactant solutions under hydrodynamic conditions realized in various laboratory tests. In particular, two regimes of foam generation are considered: at low surfactant concentrations where the coalescence between the bubbles plays a crucial role, and a high surfactant concentration range where the hydrodynamic conditions are much more important for the final outcome of foaming. The review discusses the role of surfactant concentration, dynamic surface coverage, and surface forces acting between film surfaces for the foam generated in the surfactant-poor regime. Additionally, the interplay between the hydrodynamic conditions and the viscosity of the formed foams in the surfactant-rich regime is also discussed.

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Currently, oily foam stability in CO2 injection for heavy oil recovery exhibits inadequacies that considerably constrain its extensive application. Some scholars have conducted research demonstrating that CO2-soluble surfactants can assist in inducing heavy oil to form oil-based foams (oily foam). In this study, stability tests for the oily foam were conducted at different surfactant concentrations using a visualized PVT cell. Oily foam stability was assessed by calculating the comprehensive foam index (S) and analyzing the bubble images. The research indicates that AOT can effectively reduce the interfacial tension between oil and gas. At a concentration of 0.1 wt % AOT, the interfacial tension can be effectively reduced from 1.75 to 1.14 mN/m. The concentration of 0.3 wt % AOT represents a turning point, with an S of 16 101.7 mLmin. Beyond this concentration, the increase in S becomes less pronounced. As the concentration of CO2-soluble surfactant is increased from 0.1 to 0.5 wt %, the average bubble radius decreases from 2.74 to 0.43 mm, while the number of bubbles per unit area ... Read More

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Oil-based foam has become a research hotspot in petroleum industry, whose stability plays a key role in the application. The employment of oil-based foam prevents the damage to water-sensitive reservoir. This paper focuses on the stabilization of oil-based foam by improving the viscoelasticity of foam film and the effect study of polymer-surfactant. The Polydimethylsiloxane (PDMS) and Natural rubber (NR) are employed to stabilize oil-based foam, and the comprehensive properties of foam which created by air flow method are evaluated by FCI. Besides, the behavior of interfacial adsorption foam film is analyzed through rheological study and molecular dynamics (MD) simulation. According to the results, the oil-based foam volume increases to 150 mL and the half-life time is extended to 140 s with the combination of NR and PDMS. It is ascribed that the synergistic effect of NR and PDMS molecules. The NR molecules, which are stretched and crimped corresponding to the change of external force, begin to move toward the interface after blending with PDMS to improve the viscoelasticity of the f... Read More

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Foam flooding technology can effectively enhance oil recovery (EOR) and has conformance control in heterogeneous reservoirs. However, the stability of foam migrating through porous media is still a challenge with individual surfactant. Herein, we developed viscoelastic surfactant (VES) via the synergisms of anionic (sodium dodecyl sulfate, SDS) and zwitterionic (erucamidopropyl hydroxysulfobetaine, EHSB) surfactants to strengthen the air foams stability. First, the VES formulation was optimized by investigating the initial foaming volume (V0), drainage half-life (td), and foam half-life (tf) for VES solutions. Then, the oilwater interfacial tension (IFT) and emulsification of the optimum VES system were systematically studied. Particularly, emphasizes were placed on the anti-gas channeling ability, EOR performance, and mechanisms using the core-flooding and microfluidic experiments. The results showed that the V0, td, tf of air forms could be greatly improved to 400 ml, 56.6 min, and 36 h, respectively, with 0.3 wt. % SDS:EHSB at mass ratio of 1:1.3. This was attributed to the syner... Read More

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Foam physics is a field of study that scientists and researchers are interested in due to the vast range of uses, e.g. foam-foamed materials, oil extraction, and food processing. This study proposes a new equation for the drainage of wet foam that could add to the science of foam. To improve our comprehension of the intricate behaviour of wet foam, this model expands on a theoretical derivation. The usage of a bubble size formula that was proposed using the experimental data is one of the model's distinguishing characteristics. The size of foam bubbles can be predicted using this formula more precisely. A thorough derivation of the theoretical model is provided in the paper. Finally, this work presents a novel wet foam drainage model that has the potential to enhance the field of foam physics. The results of this work have important implications for industries. Therefore, more study is needed for developing a two dimensional drainage equation.

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A lubricating oil composition that balances long-term anti-foaming performance with detergency, comprising a base oil and a silicone-based anti-foaming agent. The composition contains 50-4000 ppb silicon by mass, a range that enables both effective anti-foaming and satisfactory detergency.

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Abstract Foam flooding is a crucial enhanced oil recovery technique for profile control during the oil displacement process. The stability of the foam is the key factor for the success of foam flooding, but typical aqueous foams generally lose their stability in the presence of hydrocarbons because of their low oil tolerance. Non-aqueous foams possess outstanding stability in the presence of hydrocarbons as a result of their unique properties. However, few studies have been conducted on the stabilization mechanisms of non-aqueous foams in the presence of hydrocarbons. In this study, comparative experiments were performed to investigate differences in the stabilization mechanism between aqueous and non-aqueous foams. The results showed that a non-aqueous foam had excellent oil tolerance in a bulk foaming test. Then, the stabilization mechanisms of foams were investigated in terms of surface dilatational viscoelasticity and liquid film thinning. For a non-aqueous foam system, the maximum viscoelastic modulus of 55 mN/m occurred at a surfactant concentration of 5.0 wt%, which indicated ... Read More

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Global demand for energy is increasing day by day rapidly as a result of the population, industrial, and economic growth of developing countries, especially in emerging market economies. Hence, to meet this growing and continuing global crude oil demand, innovative enhanced oil recovery (EOR) techniques are required to emerge, and currently, implemented techniques need to be revisited and optimized to recover more residual oil trapped in the reservoirs. Among different chemicals, foam has good mobility control in the oil recovery method. Nowadays, the study on the stability of foam is an utmost interest for petroleum engineers to find a way to obtain stable foam for application in EOR. In this review, the basics of foam and its preparations, properties, application, and some special applications mainly in the oil industry have been depicted to convey an idea of the degree of foam research in EOR. Basically, this review will provide a detailed discussion on the applications of foam in oil recovery and some short ideas that can be applied in the near future for nanoparticle (NP)-assist... Read More

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The foam characteristics plays a key role towards the application of aviation apparatus, which also affected by several influencing factors. This paper focuses on researching the key factors of the foam characteristics of the domestic and imported aviation lubricating oils, by comparing a certain type of domestic aviation lubricating oil or imported aviation lubricating oils foam characteristics at different oxidation temperature or oxidation length by virtue of utilizing aviation lubricating oil oxidation experimental device. The influencing factors that impact foam characteristics were analyzed to provide important theoretic and experimental support.

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Foam flooding is a crucial enhanced oil recovery technique for profile control during the oil displacement process. The stability of the foam is the key factor for the success of foam flooding, but typical aqueous foams generally lose their stability in the presence of hydrocarbons because of their low oil tolerance. Non-aqueous foams could possess outstanding stability in the presence of hydrocarbons as a result of their unique properties. However, few studies have been conducted on the stabilization mechanisms of non-aqueous foams in the presence of hydrocarbons. In this study, comparative experiments are performed to investigate differences in the stabilization mechanism between aqueous and non-aqueous foams. The results show that a non-aqueous foam had excellent oil tolerance in a bulk foaming test. Then, the stabilization mechanisms of foams are investigated in terms of surface dilatational viscoelasticity and liquid film thinning. For a non-aqueous foam system, the maximum viscoelastic modulus of 55 mN/m occurs at the maximum surfactant concentration used which was 5.0 wt% for ... Read More

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Crude oil foam is a frequent problem faced in oil production operations that can cause the reduction of the separator efficiency, separator overflow, carry out of liquid by the gas stream, and other serious problems. Among the techniques used to attenuate foams in crude production, the injection of chemical additives is still considered one of the most efficient. However, the effectiveness of a foam control agent (FCA) is limited to the knowledge of its mechanisms of action on crude oil foams. The objective of this work is to show new fundamental aspects of how a PDMS(polydimethylsiloxane)-based FCA impacts on the bubble-collapsing rate of crude oil foams produced by decompression of oils pressurized with nitrogen gas. This study was performed with two crude oils in the temperature range of 25 55 C and FCA concentrations up to 75 ppm. The experimental results indicated a distinct mechanism of FCA action on both oils. While the FCA caused a decrease in the initial foam height for the heavier crude (oil A), acting as an inhibitor, for the lighter crude (oil B), it mostly performed a... Read More

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Stable foams frequently hinder the efficient treatment of liquids produced by chemical flooding. Studies into the formation and stabilization mechanisms of these foams, are therefore essential to overcoming this problem in oilfield surface systems. However, previous investigations have mainly focused on water-based foams. Although a small number of studies have examined oil-based foams, only a few well-known properties similar to those of water-based foams have been reported. Therefore, in this study, different oil-based foam systems were prepared to investigate the impact of the surfactant (sodium dodecyl benzene sulfonate, SDBS), the polymer (partially hydrolyzed polyacrylamide, HPAM), and physical properties of the crude oil, on the foaming characteristics and the foam liquid film drainage behavior of liquids produced by chemical flooding. For this purpose, molecular dynamics (MD) simulation were employed, and the simulation results were verified experimentally. It was found that the SDBS molecules aggregated to form micelles on the liquid film of the oil-based foam; this contrast... Read More

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Gas channeling easily occurs in CO2 flooding, leading to lower oil production efficiency. CO2 oil-based foam can effectively control gas channeling, so it is particularly important to study the stability of CO2 oil-based foam to improve oil recovery. In this paper, an oil-based foam system was constructed by evaluating many different surfactants, and then the viscosity of the base oil and the type of gas were changed to study their influence on the stability of the oil-based foam. The stability of CO2 oil-based foam under high temperature and high pressure was analyzed. Finally, the influence of CO2-oil interfacial tension (IFT) on the stability of oil-based foam was investigated. The results show that the CO2 oil-based foam system composed of compound foaming agent FS with a total concentration of 2 wt% and a ratio of FCO-80 to Span 20 of 3:7 and an oil phase with a viscosity of 2.98 mPas have excellent foaming performance. In Zones I and II, the CO2-oil IFT is too low, a miscible or near miscible system is formed, and the system cannot generate foam. Although the IFT in Zone III i... Read More

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Cold extra-heavy oil production in the Orinoco Heavy Oil Belt in Venezuela presents foamy oil behavior, with a primary recovery factor less than 12%. In previous studies, a novel non-thermal process, named Foamy Oil Recreation Process (FORP), was proposed. The process includes cyclic injection of compound fluid slugs, which is comprised of light hydrocarbon solvent as well as gas and surfactants (foaming agent and foam stabilizer), to promote the regeneration of foamy oil behavior, so called secondary foamy oil, in a huff-n-puff manner. Compared with ordinary heavy oils, the asphaltene content is much higher and the resin content is relatively lower in extra-heavy oil. This paper was an extending experimental investigation of the effect of asphaltene and resin content on the formation and stability of secondary foamy oil. A typical extra-heavy oil sample from the Heavy Oil Belt in Venezuela was adopted. Firstly, asphaltene and resin sub-fractions were obtained by heavy oil fraction separation, and then heavy oil samples with different asphaltene and resin contents, from 0 to 40 wt.% ... Read More

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AbstractThe use of foam injection as an enhanced oil recovery (EOR) technique has been suggested since the 1960s to address issues with gas injection. Foam is composed of gas, water, and surfactant, which is utilized to stabilize the foam. This study investigates the synergy effect of anionic surfactant and two zwitterionic surfactants on enhancing solution stability. The anionic surfactant used is sodium dodecyl sulfate, while the chosen zwitterionic surfactants are cocamidopropy hydroxy sultine and Cocamido Propyl Betaine. Analyzing the images of the generated foam showed that initially, the small and uniform bubbles are formed in all concentrations. The foam size is then increased and in concentrations higher than a critical value, the bubbles grow faster which is likely due to the formation of micelles and deposition of surfactants. This leads to early collapse of the foam structure. The quantitative half-life results approved that the most optimal compound was obtained with equal proportions of sodium dodecyl sulfate and Cocamido Propyl Betaine with concentration of 3 wt% (1:1 r... Read More

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Foams used in drilling can be contaminated by formation influx containing oil. The stability and flow behavior of foam are affected when it comes into contact with oil. The objective of this study is to investigate the impact of oil on foam drainage and rheology under high-pressure conditions. Drainage and rheology experiments were performed introducing different types of oils (mineral oil, light crude oil, and heavy crude oil) into the surfactant solution at varying concentrations. The tests were performed at three different foam qualities (40%, 50% & 60%). To determine the drainage, the foam was first generated in a flow loop and its rheology was measured. Subsequently, its drainage was evaluated by trapping it in a vertical test section (stability cell) and measuring the pressure profile of the foam column trapped in the cell using ten pressure sensors. The foam drainage was determined as a function of time by analyzing the pressure profile data. Tests were conducted under ambient temperature (25 3 C). The results show how the foam drainage and rheology were affected by oil typ... Read More

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In tertiary oil recovery technology, foam fluid is known as the "intelligent fluid" in oil fields.Foam can improve fluidity ratio by extrusion and emulsification, block large pores by column superposition, and have a certain oil-washing effect.But at the same time, this method has some defects, therefore, this study introduced a CO2 microbubble dispersion system on the basis of foam flooding technology to solve the injection problem and implement online injection miniaturization of equipment.In the system, bubble size is less than microns, the size is controllable and the system is characterized by good stability, strong toughness and variability, and can match different size pore throats.In this study, three kinds of foaming devices were designed and manufactured.The effect of microbubble CO2 flooding is studied by a microbubble displacement evaluation system and a microfluid chip system.The experimental results of this paper show that the optimal concentration of QPJ-4 is 0.5% considering factors such as economic, good salt resistance, acid and alkali resistance, and oil resistance... Read More

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Summary Depletion process, or so-called cold production, in the Orinoco Heavy Oil Belt presents foamy oil behaviour, with a primary recovery factor of only 812%. In previous studies, a novel non-thermal process, named Foamy Oil Recreation Process (FORP), to enhance the recovery was proposed. The process includes cyclic injection of solvent, gas and surfactants in sequence, to promote the regeneration of foamy oil, in a huff-n-puff manner. This paper was a continuing experimental investigation of the impact of surfactant concentration on the process. Three types of experimental tests were conducted in the study, including test on effective formation of foamy oil, test on 2D microscopic flow, and 1D sand-pack FORP test. The test on effective formation of foamy oil showed that an increase in surfactant concentration improves the stability of foam liquid film and prolongs foam life. The 2D micro-flow experiment results illustrated that the process presents obvious foamy oil flow behaviour when the surfactant concentration exceeds 2wt%. The sand pack experiment results indicated that the... Read More

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Abstract It is of great significance to study the stability of foams in the petroleum industry. Therefore, the stability mechanism of Span 20, the fluorinated surfactant FCO80 and their mixture FS in a CO 2 oilbased foam system were studied by molecular simulation. The sandwich model of CO 2 oilbased foam was constructed to reveal the stability of the foam system from the microscopic perspective. The result shows that under the synergistic effect of Span 20 and FCO80, the oilCO 2 distance of the FS foam system and the coordination number of oil molecules are larger than those of Span 20 and FCO80 foam system. In FS foam system, the diffusion coefficients of CO 2 molecules are small, and the surface tension is reduced, which can improve the stability of foam. The results can supplement previous experimental results on the stability of oilbased foam.

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Abstract Steam injection with foam presence (steam foam) was successfully implemented in the 1970's and 1980's. The purpose of having steam foam as a mobility control agent was to improve sweep efficiency by minimizing detrimental effects associated with steam injection processes such as viscous fingering, gravity override, loss to thief zones, etc. Previous work, published in SPE-190473-MS and SPE-193634-MS, discussed results on thermal stability and foamability of Alkyl Ether Carboxylate Acid (ECA) at temperatures up to 200C-250C in the presence/absence of bitumen. This paper, as a continuation of the work mentioned above, presents the blending of ECA with surfactant A (a chemically different surfactant) at 50/50 ratio and different injection foam qualities (30% to 90%) for further improvement of steam foam performance at 300C without bitumen. For safety reasons, thermal stability test at 300C using Parr reactors was not conducted because of identical rated temperature on the instrument. Surfactant foamability was evaluated through bulk foam test in a high temperature high pres... Read More

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The anomalously high recovery of solution gas drive in some heavy oil reservoirs has been associated with foamy oil. The effects of external factors such as temperature, permeability, and the pressure depletion rate on foamy oil flow have been studied sufficiently, but few studies are available on the effect of heavy oil itself. In order to investigate the effect of oil viscosity and the solution gas-oil ratio on foamy oil, 11 tests of solution gas drive through a sandpack were carried out in this work. The results show that a typical foamy oil solution gas drive exists in three stages, which are the oil phase expansion stage, the foamy oil flow stage, and the oil-gas two-phase flow stage. As the oil viscosity decreases, the foamy oil flow stage shortens, resulting in reduced recovery of this stage significantly. In the experiment with an oil viscosity of 200 mPas, foamy oil flow was not observed. A lower limit of oil viscosity should exist for steady flow of foamy oil, which is considered to be approximately 600 mPas according to the experimental results. As the solution gas-oil r... Read More

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Lubricating compositions for extreme operating conditions in naval applications, comprising a base oil component and an additive component. The additive component includes a non-silicone anti-foaming agent and one or more of an anti-wear agent, aryl amine antioxidant agent, metal deactivating agent, and anti-rust agent. The lubricating compositions are designed to replace existing mineral-oil based lubricants in naval applications, providing improved performance and reliability in harsh operating conditions.

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Oil foams stabilized by surface-active catalytic particles bearing fluorinated chains and Pd nanoparticles allowed fast and efficient aerobic oxidation of a variety of aromatic and aliphatic alcohols compared to bulk catalytic systems at ambient O2 pressure. High foam stability was achieved at low particle concentration (<1 wt %) provided that the contact angle locates in the range 41-73. The catalytic performance was strongly affected by the foaming properties, with 7-10 times activity increase in pure O2 compared to nonfoam systems. Intermediate foam stability was required to achieve good catalytic activity, combining large interfacial area and high gas exchange rate. Particles were conveniently recycled with high foamability and catalytic efficiency maintained for at least seven consecutive runs.

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In foam flooding ultralow oil/water IFT and superior foaming performance are usually not compatible, because both are achieved by surfactants at different conditions. In this paper we constitute a mixed surfactant system which can achieve both ultralow oil/water IFT and high foaming performance concurrently by means of synergistic effects between different surfactants. Aiming at the reservoir conditions of Daqing oilfield, China (45 C, total salinity 6,778 mg/L, pH = 89), a ternary surfactant mixture SDS/DTAB/APG at a mole fraction ratio of 0.36/0.24/0.4 was found to be an optimal surfactant system by which ultralow IFT and high foaming performance could be achieved concurrently at wide total concentrations (26.5 mM). Specifically, at a total concentration of 5 mM the IFT can be reduced to as low as 2.9 10-5 mN/m whereas the composite foaming index in the presence of crude oil can reach as high as 936 Ls. The SDS/DTAB binary mixture dominates the mixed monolayer at both air/water and oil/water interfaces as indicated by a high pseudo mole fraction of 0.94. The strong attraction ... Read More

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Lubricating oils consist of base oil, containing different hydrocarbons, and modifying components (additives) which improve the application performance. Some of these additives are able to stabilize entrained air bubbles, potentially causing serious problems for engines, transmissions and hydraulic systems. Here we evaluate the foamability and foam stability of model mineral oils (hexadecane, light oil, heavy oil and their mixtures) in the presence and in the absence of nanoparticles as additives, at several temperatures. The results allow us to categorize the systems studied into three groups: (1) Oils unable to entrap any air during the stirring period; (2) Oils able to entrap air during stirring, but unable to retain it after stopping the stirring; (3) Oils which form stable bubbles and foams. Hexadecane, with and without nanoparticles, falls into the first group. Heavy oil in the presence of nanoparticles falls into the third group, whereas all other mixtures are in the second group. The inability of hexadecane to entrain air is related to its low viscosity and very low foam film... Read More

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The use of liquid foams in enhanced oil recovery (EOR) applications requires the formation of stable foams under harsh reservoir conditions, such as a wide pH range, brines containing divalent cations, and high temperature and pressure. In this work, mixtures of the pH-responsive surfactant bis-(2-hydroxyethyl) cocoalkylamine (C12) with nonionic (tallow fatty amine, TFA20), zwitterionic (cocamidopropyl hydroxysultaine, CAHS) and anionic (sodium olefin sulfonate, AOS) surfactants were evaluated to obtain foams with improved stability under conditions relevant to CO2-based EOR. The presence of TFA20 in the foaming formulation increased the solubility of C12 at basic pH values, but impaired foam stability. In contrast, the surfactant mixtures containing CAHS exhibited a significant synergy regarding surface tension reduction and foam stabilization. The synergy was confirmed by the negative value of the interaction parameter, indicating strong attraction, likely electrostatic, between the surfactant molecules at the interface. This effect was evidenced in the decrease in the bubble growt... Read More

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Exploiting the large amount of foamy oil formed by gas injection cold recovery technology in heavy oil reservoirs is currently difficult to achieve in large-scale application. In this study, use of supercritical CO2 to carry the CO2-soluble surfactants is proposed to stimulate the interfacial activity between the gas and the heavy oil and gradually penetrate into the bulk phase from the edge layer of the heavy oil to realize surface erosion plus deep penetration between the gas and the heavy oil and generate a large amount of foamy oil. At present, surfactants are generally used to form water-based foam, but a few scholars have proposed research that demonstrates that CO2-soluble surfactant-assisted gas excites heavy oil to form oil-based foams (foamy oil). The research indicates that the higher the concentration of CO2-soluble surfactant, the smaller the average bubble radius of the foamy oil, and the higher the foam density of the foamy oil. By visualizing the reactor, the phase changes and interfacial phenomena of the mass transfer components of the foamy oil were analyzed. The re... Read More

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Cold extra-heavy oil production in the Orinoco Heavy Oil Belt in Venezuela presents foamy oil behavior, with a primary recovery factor less than 12%. Studies on post-cold production process in extra-heavy oil reservoirs draw more and more attention in recent years. In previous studies, a novel non-thermal process, named Foamy Oil Recreation Process (FORP), was proposed. The process includes cyclic injection of compound fluid slugs, which is comprised of light hydrocarbon solvent as well as gas and surfactants (foaming agent and foam stabilizer), to promote the regeneration of foamy oil behavior, in a huff-n-puff manner. This paper was an extending experimental investigation of the pore scale behavior of the process. A series of flow visualization experiments were carried out to understand the foamy oil generation mechanism in the process using an etched glass micro-model, and to examine the effect of injection sequence, injection timing, ratio of gas to liquid (surfactant solution), and surfactant concentration on the regeneration of flow behavior of dispersed gas bubble in oil phase... Read More

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Herein, three types of oil-containing foams, including oleofoams (OF), W/O and O/W emulsion gel foams (EGFs), with high overrun and desirable shaping properties were designed and prepared with sodium stearoyl lactylate (SSL). SSL-based OF and W/O EGFs were stabilized depending on the combination of the crystal adsorption at the O-A interface and viscosity enhancement in the continuous oil phase though the introduction of water droplets influenced the crystal size and distribution, while the dense assembly of oil droplets stabilized by SSL crystals jammed in the channels between bubbles was responsible for the stability and the enhancement in the strength of O/W EGFs. Of particular interest was that the introduction of concentrated air bubbles in oil-continuous foams greatly increased the strength of gel systems. Moreover, the type and water content of foams impacted both the texture and the rheology properties. The presence of three phases gave more length scales to the foaming systems and allowed finer property control through modifying various structural units. Tribological evaluat... Read More

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Foams occur in many industries, such as chemical and food industry, and also in everyday life. Foam is understood as a disperse system of gas and liquid with a dominating gas-vapor fraction. In the following, only fluid foams will be discussed. On the one hand, foam is desired and deliberately generated, as in the separation process of flotation or even the production of insulation materials, on the other hand, it is a very undesirable event when it occurs in separation apparatus, such as distillation or absorption columns, or in reactors. Foam formation is still not fully understood. Especially when it is undesirable, appears suddenly, and is the reason for operational disturbances, it is hardly predictable and difficult to diagnose with certainty, e.g., in columns. If foams occur unintentionally in chemical engineering equipment, they often cause major production problems, up to and including the shutdown of entire plants, which results in high economic losses. In columns, foam, among other things, is cited as a frequent cause of operational malfunctions. Here, fast and reliable di... Read More

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It is of great significance to study the stability of foams in the petroleum industry. Therefore, the stability mechanism of Span 20, the fluorinated surfactant FCO-80 and their compound system FS in a CO oil-based foam system was studied by molecular simulation. The sandwich model of CO oil-based foam was constructed to reveal the stability of the foam system from the microscopic perspective. The result shows that the oil-CO distance of the FS foam system is 16.087 , and the coordination number of oil molecules is 2.65. The diffusion coefficient of CO in the FS foam system is 3.9410 cm/s. This shows that under the synergistic effect of Span 20 and FCO-80, the diffusion coefficients of CO molecules are small, and the surface tension is reduced, which can improve the stability of foam. The results can supplement previous experimental results on the stability of oil-based foam.

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The foam performance in the presence of oil plays an essential role in foam application in enhancing oil recovery. This study systematically investigated whey protein isolate (WPI), the effectiveness of foam generation, the effect of three types of crude oil, surfactant concentration on foam performance and oil-water interfacial tension (IFT). The extraction of WPI was compared to sodium dodecyl sulfate (SDS) at the microscopic foam images to have a better understand of foaming in terms of performance. The results showed that the WPI lowers the surface tension, which also tends to disclose and stabilize the interface by forming a viscoelastic network. SDS reduced the surface tension compared to the WPI but did not produce a high modulus interface. WPI generated a more stable foam in oil than SDS foam. The WPI improved foam stability by increasing the gas-water interface dilatational viscoelasticity layers. WPI solution decreases bubble sizes and prevents oil from spreading at the foam lamellae. The WPI foam exhibits higher stability in Libya crude oil when the oil saturation is betwe... Read More

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Study of foam stability in the presence of oil components is mainly devoted to the impacts of aliphatic components like short- and long-chained alkanes. In this study, several experiments, including critical micelle concentration (CMC) determination, IFT measurement, high pressure bulk foam stability as well as foam texture visualization and analysis have been designed and performed in the presence of various oil solution samples to explore the impacts of aromatic components and compare them with the impacts of aliphatic components on CO2 foam stability. Alpha-Olefin-Sulfonate (AOS) surfactant solutions with different concentrations of surfactant in the presence of various synthetic oil solutions comprising toluene and n-heptane were prepared to compare the interfacial behavior and performance of the surfactant solutions containing aromatic and aliphatic components with regards to foam stability. The results revealed that, due to higher micellar solubilization of the n-heptane as the aliphatic component compared to toluene, surfactant surface activity would be more detrimentally impa... Read More

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Foaming issues are encountered at the stages in crude oil production, transportation, processing, especially in chemical flooding enhanced oil recovery (EOR) oilfields. These accumulated foams would cause a lot of trouble for downstream operation. The destruction of foams under ultrasonic has been increasingly paying attention in the background of green oilfield development. This study focuses on the decay kinetic characteristics of alkaline-surfactant-polymer-strengthened foams under the ultrasonic standing wave. The performance of the diverse foams was characterized. A decay kinetic model incorporating the energy correlation was developed and validated. The factors that affect the decay kinetic characteristics were discussed. The results indicated that the collapse rate and the collapse volume fraction decreased when the foam size decreased, the gas-liquid ratio decreased and the surface tension increased. Ultrasonic standing wave parameters have a significant impact on the decay behavior of the foam. Both the ultrasonic frequency and ultrasonic amplitude were increased by 50%, the... Read More

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Naturally fractured reservoirs are one of the hydrocarbon resources where the application of foam flooding is particularly recommended, as foam can divert the flow of displacing fluid from high-permeability regions (fracture networks) to low-permeability regions (rock matrix blocks). However, its application in heavy oil reservoirs is challenging and results in inadequate sweep efficiencies. The current practice of foam flooding (including polymer enhanced foam flooding, PEF) is inefficient in displacing high viscosity oils. This is due to large viscous forces associated with the oil phase flow and the high rate of bubbles coalescence (foam collapse), which make it difficult for foam to displace the heavy oil from the matrix. Thus, we investigated feasibility of polymer-enhanced surfactant alternating foam (PESAF) flooding (as a new hybrid enhanced oil recovery process) to displace the oil phase in porous media. We hypothesized that PESAF flooding can emulsify the oil phase and generate oil globules by reducing the interfacial tension forces between the oil and water phase, and also ... Read More

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This paper provides an experimental study on the foam behavior of aqueous solutions of MDEA and IPAE by the modified standard ASTM D892. The effect of different operating parameters, including temperature, amine concentration, and flow rate, in the range of 2535 C, 2040 wt%, and 13 L/min, respectively, were studied using the response surface method. The physical properties of solutions such as viscosity, density, and surface tension were measured. At first, foam tests were performed only with MDEA, a conventional amine in gas purification, to obtain the effect of different operating conditions and their interactions on the foam volume and break time. A specific operating condition was selected based on obtained responses, and IPAE was added to MDEA. The mixture of MDEA and IPAE had better foam behavior than pure MDEA. Foam tests in the presence of formaldehyde and formic acid proved that IPAE acts as a defoamer even in the presence of impurities. A silicone antifoam was used, and there was no definite trend for foam volume, but with increasing antifoam concentration, the break ti... Read More

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In the chemical and food industries the undesired formation of foams in thermal separation processes can lead to considerable losses in performance and efficiency. Existing methods cannot represent the foaming ability of boiling mixtures. Against this background, a novel laboratory-scale method, based on Bikermans established definition of foamability, is developed to characterise the foamability of evaporation-induced foams. Based on the measured maximum steady-state foam volume and the maximum foam growth rate, a dimensionless number is established, which allows the evaluation of the evaporation-induced foaming ability.

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