驱油阴/两性表面活性剂复配体系协同效应研究

针对某油藏A区块,利用阴离子/两性表面活性剂的协同作用,进而达到油水超低界面张力,且两性表面活性剂十二烷基甜菜碱在浓度为0.1%~0.5%的范围内,降低油水界面张力的效果达到10~(-2) mN/m数量级,在加入阴离子表面活性剂的条件下,复配体系可以使油水界面张力达到超低界面张力。通过探讨表面活性剂的总浓度以及复配比对油水界面张力的影响,最终得到阴离子/两性表面活性剂复配体系可在较高矿化度和较低的浓度(0.4%)范围内达到10~(-3) mN/m的超低界面张力,并在此基础上对两者的协同作用进行分析。     

Synthesis and Evaluation of New Anionic Gemini Dispersants as Oil Dispersants to Treat Crude Oil Spill Pollution

Floating petroleum oil spills on the marine ecosystem are generally associated with an escalation of serious environmental problems. This research aimed to synthesis five water-soluble anionic Gemini dispersants to minimize the effect of floating petroleum oil spills on the marine ecosystem. Referring to the spacer type, these dispersant are classified into two categories: the first category is the three acyl amine Gemini dispersants of N,N′- diacyl, (distearoyl-, dipalmitoy-, and dimyristoyl-) N,N-′ sodium 2-hydroxy 3-propane sulfonate propane 1,3 diamine, denoted S, P, and M, and the second category is two alkyl amine Gemini dispersants of N,N′dialkyl -(dicetyl-, and dilauryl-) N,N′-sodium 2-hydroxy 3-propane sulfonate propane 1,3 diamine, denoted C and L. Fourier transform infrared and ¹H NMR spectroscopy, gel permeation chromatography, and elemental analysis were used to verify the chemical formula of the synthesized dispersants. The effectiveness of the synthesized dispersants was investigated as regards their dynamic interfacial tension, carbon–chain length, and hydrophilic–lipophilic balance. The dispersion efficiency of the synthesized dispersant was detected qualitatively and quantitatively using the screen test and Warren Spring Laboratory methods, respectively. Experimental outcomes showed that the maximum dispersion efficiency of 94.7 wt% was achieved by dispersant C at a dispersantoil ratio of 1:20 at 25°C.     

Study of Foaming Properties and Effect of the Isomeric Distribution of Some Anionic Surfactants

Using different reaction conditions of photosulfochlorination of n-dodecane, two samples of anionic surfactants of sulfonate type are obtained. Their micellar behavior has been already reported and the relationship between their isomeric distribution and their chemical structures and micellar behaviors have been more thoroughly explored. In this investigation, we screened the foaming properties (foaming power and foam stability) by a standardized method very similar to the Ross–Miles foaming tests to identify which surfactants are suitable for applications requiring high foaming, or, alternatively, low foaming. The results obtained for the synthesized surfactants are compared to those obtained for an industrial sample of secondary alkanesulfonate (Hostapur 60) and to those of a commercial sample of sodium dodecylsulfate used as reference for anionic surfactants. The foam formation and foam stability of aqueous solutions of the two samples of dodecanesulfonate are compared as a function of their isomeric distribution. These compounds show good foaming power characterized in most cases by metastable or dry foams. The highest foaming power is obtained for the sample rich in primary isomers which also produces foam with a relatively high stability. For the sample rich in secondary isomers we observe under fixed conditions a comparable initial foam height but the foam stability turns out to be low. This property is interesting for applications requiring low foaming properties such as dishwashing liquid for machines. The best results are observed near and above the critical micellar concentrations and at 25 °C for both the samples.

椰子油乙氧基化物与阴离子表面活性剂协同效应

对椰子油乙氧基化物-30EO(COE-30)与直链烷基苯磺酸钠(LAS)、脂肪醇聚氧乙烯醚硫酸钠(AES-2)及脂肪醇聚氧乙烯醚羧酸钠(AEC-5)复配的二元体系进行研究,运用非理想溶液理论计算混合胶束和混合吸附层的组成及二者在混合胶束和混合吸附层中协同作用参数。结果表明,复配体系在混合胶束和混合吸附层显示出较强的协同作用,混合胶束中作用参数|βm|=2~6,混合吸附层中作用参数|βσ|=2~6。3个复配体系在形成胶束能力和降低表面张力效率方面存在协同增效作用,同时COE-30/AES-2和COE-30/AEC-5体系在降低表面张力能力方面也存在协同增效作用。     

Synergism and Performance for Systems Containing Binary Mixtures of Anionic/Cationic Surfactants for Enhanced Oil Recovery

The surfactant structure–performance relationship and application properties in enhanced oil recovery (EOR) for binary mixtures of anionic and cationic surfactants are presented and discussed. A polyoxyethylene ether carboxylate anionic surfactant was blended with a quaternary ammonium chloride cationic surfactant and tested for a high-temperature, low-salinity, and high-hardness condition as found in an oil reservoir. These mixtures were tailored by phase behavior tests to form optimal microemulsions with normal octane (n-C8) and crude oil having an API gravity of 48.05°. The ethoxy number of the polyoxyethylene carboxylate anionic surfactant and the chain length of the cationic surfactant were tuned to find an optimal surfactant blend. Interfacial tensions with n-C8 and with crude oil were measured. Synergism between anionic and cationic surfactants was indicated by surface tension measurement, CMC determination, calculation of surface excess concentrations and area per molecule of individual surfactants and their mixtures. Molecular interactions of anionic and cationic surfactants in mixed monolayers and aggregates were calculated by using regular solution theory to find molecular interaction parameters β ^σ and β ^M . Morphologies of surfactant solutions were studied by cryogenic TEM. The use of binary mixtures of anionic/cationic surfactants significantly broadens the scope of application for conventional chemical EOR methods.     

Synergistic Behavior of a Triblock Copolymer with Anionic and Cationic Surfactants in Aqueous Solution

The synergistic behavior of poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO–PPO–PEO) triblock copolymer in aqueous solution with the synthesized anionic surfactants [decyl sulfonate (A10), myristyl sulfonate (A14) and cetyl sulfonate (A16)] and cationic surfactants [decyl pyridinium bromide (C10), myristyl peridinium bromide (C14) and cetyl pyridinium bromide (C16)] was investigated using a surface tension technique at 25 °C. The results show that the CMC values of binary mixtures for anionic and cationic surfactants with the triblock copolymer are lower than that of single surfactants. The synergistic interaction between surfactant molecules and copolymer molecules in binary mixed solution enhance the adsorption of surfactant molecules at the interface. The micellar mole fractions (X _m) and the interaction parameter (β) of these surfactants in mixed micelles were determined.

Synthesis,Characterization, and Surface-Active Properties of Carboxylbetaine and Sulfobetaine Surfactants based on Vegetable Oil

A novel series of carboxylbetaine-type and sulfobetaine-type zwitterionic surfactants (castor oil amidoethyl betaine, castor oil amidoethyl sulfobetaine [CAAS], cottonseed oil amidoethyl betaine, and cottonseed oil amidoethyl sulfobetaine [COAS]) were synthesized via the reactions of nonedible vegetable oils (castor oil and cottonseed oil) with dimethylaminoethylamine, followed by the reaction with sodium chloroacetate and sodium 2-hydroxy-3-chloropropane sulfonate, respectively. Their chemical structures were confirmed using the electrospray ionization mass spectrum (ESI-MS) and infrared (IR) spectra. The surface activities of the prepared compounds were measured by surface tension. It was noticed that the sulfobetaine-type surfactants in aqueous solution performed slightly better at reducing surface tension than the carboxylbetaine-type surfactants. Meanwhile, the synthesized surfactants possess a broad range of isoelectric points, superior foam properties, and exhibit some antibacterial activity on Gram-positive and Gram-negative bacteria.     

A New Series of Double-Chain Single-Head Sulfobetaine Surfactants Derived from 1,3-Dialkyl Glyceryl Ether for Reducing Crude Oil/Water Interfacial Tension

A new series of sulfobetaine surfactants with double-chain single-head structure were derived from 1,3-dialkyl glyceryl ethers and their performances in reducing Daqing crude oil/connate water interfacial tension (IFT) in the absence of alkali were studied. With a large hydrophilic head group and double hydrophobic chains, these surfactants are efficient at reducing crude oil/connate water IFT. Those with didecyl and dioctyl are good hydrophobic surfactants that can reduce Daqing crude oil/connate water to ultra-low IFT by mixing with a small molar fraction of various conventional single-chain hydrophilic surfactants, such as α-olefin sulfonates, dodecyl polyoxyethylene (10) ether, and cetyl dimethyl hydroxypropyl sulfobetaine. The asymmetric double-chain sulfobetaine derived from 1-decyl-3-hexyl glyceryl ether can reduce Daqing crude oil/connate water IFT to ultra-low solely over a wide concentration range (0.03–10 mM or 0.0017–0.58 wt.%), which allows for use of an individual surfactant instead of mixed surfactants to avoid chromatographic separation in the reservoir. In addition, formulations rich in sulfobetaine surfactants show low adsorption on sandstone, keeping the negatively charged solid surface water-wet, and forming crude oil-in-water emulsions. These new sulfobetaine surfactants are, therefore, good candidates for surfactant-polymer flooding free of alkali.     

Optimization and Applicability of a Novel Sensor for Potentiometric Determination of Anionic Surfactants

Novel potentiometric sensors for anionic surfactant (AS) determination, with different percentages of tetraoctadecylammonium tetraphenylborate (TODA-TPB) as sensing materials and different electrolytes (sodium chloride, lithium chloride, sodium dodecyl sulfate (NaDS), sodium tetraphenylborate, sodium acetate, and potassium chloride) at varied concentration levels, were developed and compared. The sensor with best response characteristics was further characterized. It had a fast response time (5 s), a low signal drift (2.0 and 2.9 mV h⁻¹ in a detergent solution and NaDS, respectively), a wide pH working range (3–11), and a longer lifetime of 6 months. This novel sensor was characterized with Nernstian response toward NaDS (−58.0 mV decade⁻¹ of activity), a wide working range (1.3 · 10⁻⁷–5 · 10⁻³ M), and a low limit of detection (1.0 · 10⁻⁷ M). It proved to be an accurate and reliable sensor for AS determination in multicomponent mixtures of AS and household wastewater using a potentiometric titration method. Nonionic surfactants, which are commonly mixed with AS in commercial products to obtain better properties of products, had an insignificant impact on AS determination.     

Study of the Antioxidative Properties of Several Amino Acid-Type Surfactants and their Synergistic Effect in Mixed Micelle

Cysteine and methionine, two sulfur-containing amino acids (AA), were introduced in their surfactant forms as potential antioxidants. The antioxidative (AOX) properties of lauroyl methionine (C12-Met) and lauroyl cysteine (C12-Cys) was investigated by means of the oxygen radical absorbance capacity assay. Both the surfactants exhibited excellent AOX behavior at the premicellar state and micellar medium. The AOX behavior was found to be comparable for both the surfactants at their premicellar states. However, in micellar medium, C12-Met showed better AOX property than C12-Cys. The AOX power of the surfactants was compared with other previously developed AA-type surfactants. The order of the AOX power was found to be: C12-tryptophan > C12-tyrosine ≈ C12-methionine ≈ C12-cysteine > C12-histidine at the premicellar state and C12-tryptophan > C12-tyrosine > C12-methionine > C12-cysteine > C12-histidine at the micellar state. C12-Cys displayed lower AOX property in micellar medium due to its dimer formation tendency. Based on the HPLC and UPLC-Q-TOF-MS analysis, the dimer formation of C12-Cys was found to be accelerated due to the micellar environment and results into negative synergistic effect on other aromatic AA-type surfactants. However, the presence of C12-His in the micellar solution of C12-Cys resulted no synergistic effect due to stronger H-bonding between the surfactants and resulting less dimer formation.     

Ozonation of Anionic and Non-ionic Surfactants in Aqueous Solutions: Impact on Aquatic Toxicity

The objective of this study was to investigate the influence of ozonation of anionic and non-ionic surfactants on their aquatic toxicity. Toxicity values of various commercially important anionic and non-ionic surfactants have been determined using the luminescent bacterium Vibrio fischeri. Surface tension measurements were made to study the interfacial activity. The behavior depends on the chemical structure. Some intermediate ozonation products were found to be more toxic than the base surfactant and others were found to be less. Surfactants with aromatic rings such as linear alkyl benzene sulfonates, or surfactants with glycosidic groups such as alkylpolyglucosides, exhibit a lower toxicity after ozonation. On the other hand, ether groups present in the fatty-alcohol ethoxylates and ether carboxylic derivative surfactants, and carboxylic acid derivates present in the ether carboxylic derivative surfactants lead to increasing toxicity after ozonation. Surfactants with ether groups probably formed short-chain polyethoxylated compounds and carboxylic acids, which are possibly responsible for the surface-tension decrease that promotes the toxicity increase.     

The Effects of Dynamic Noncovalent Interaction between Surfactants and Additional Salt on the pH-Switchable Interfacial Tension Variations

The dynamic noncovalent interaction between the anionic surfactant sodium dodecyl benzene sulfonate (SDBS) and 1,3-diphenylguanidine (DPG) was employed to control the interfacial activity of the surfactant. At high HCl concentration (1000 mg L⁻¹), the SDBS/DPGⁿ⁺ system could reduce the water/oil interfacial tension (IFT) to 10⁻⁴ mN m⁻¹ order of magnitude, which was much lower than the IFT values in the SDBS/DPG⁺ system with a low HCl concentration (100 mg L⁻¹) and the individual SDBS system by three and four orders of magnitude, respectively. The pH-switchable protonation of amido groups in DPG molecules determines the SDBS/DPG molecular interaction and the amplitude of IFT reduction, which was confirmed by control experiments using two other surfactants (sodium dodecyl sulfate [SDS] and dodecyl trimethylammonium bromide [DTAB]). Moreover, the investigation of the NaCl and temperature effects on the IFT indicated the intensity of mixed SDBS/DPGⁿ⁺ adsorption layers at the water/oil interface.     

Recovery and Recycling of CO2/N2‐Switchable Anionic Surfactants in Emulsions

To develop a mild, effective, and clean strategy for recovery and recycling of anionic surfactants in CO₂/N₂‐switchable emulsions, a CO₂/N₂‐switchable anionic surfactant, which is a combination of dodecyl seleninic acid (DSA) and N,N,N′,N′‐tetramethyl‐1,2‐ethylenediamine (TMEDA), here referred to as DSA–TMEDA, was used to stabilize an oil‐in‐water (O/W) emulsion. Upon stimulation with CO₂, DSA–TMEDA was switched off to form insoluble DSA and the water‐soluble TMEDA bicarbonate. Upon N₂ bubbling and heating, the OFF state of DSA–TMEDA was restored to the surfactant of DSA–TMEDA. In this manner, O/W emulsions stabilized by DSA–TMEDA can be switched reversibly between demulsification (phase separation) and re‐emulsification (recovered emulsion) by triggering with CO₂/N₂ over ten times. After breakage of the emulsion, nearly all of the OFF state surfactant could be separated conveniently away from the oil phase, thus facilitating recovery and recycling of the surfactant afterward in emulsifying oil. No obvious adverse changes in the dispersed oil particles size and the relative stability of the regenerated emulsions were observed over five cycles, and the surfactant loss can be neglected during the recycling.     

Viscoelastic Surfactants with High Salt Tolerance,Fast‐Dissolving Property,and Ultralow Interfacial Tension for Chemical Flooding in Offshore Oilfields

Injected chemical flooding systems with high salinity tolerance and fast‐dissolving performance are specially required for enhancing oil recovery in offshore oilfields. In this work, a new type of viscoelastic‐surfactant (VES) solution, which meets these criteria, was prepared by simply mixing the zwitterionic surfactant N‐hexadecyl‐N,N‐dimethyl‐3‐ammonio‐1‐propane sulfonate (HDPS) or N‐octyldecyl‐N,N‐dimethyl‐3‐ammonio‐1‐propane sulfonate (ODPS) with anionic surfactants such as sodium dodecyl sulfate (SDS). Various properties of the surfactant system, including viscoelasticity, dissolution properties, reduction of oil/water interfacial tension (IFT), and oil‐displacement efficiency of the mixed surfactant system, have been studied systematically. A rheology study proves that at high salinity, 0.73 wt.% HDPS/SDS‐ and 0.39 wt.% ODPS/SDS‐mixed surfactant systems formed worm‐like micelles with viscosity reaching 42.3 and 23.8 mPa s at a shear rate of 6 s^?1, respectively. Additionally, the HDPS/SDS and ODPS/SDS surfactant mixtures also exhibit a fast‐dissolving property (dissolution time <25 min) in brine. More importantly, those surfactant mixtures can significantly reduce the IFT of oil–water interfaces. As an example, the minimum of dynamic‐IFT (IFT_min) could reach 1.17 × 10^?2 mN m^?1 between the Bohai Oilfield crude oil and 0.39 wt.% ODPS/SDS solution. Another interesting finding is that polyelectrolytes such as sodium of polyepoxysuccinic acid can be used as a regulator for adjusting IFT_min to an ultralow level (<10^?2 mN m^?1). Taking advantage of the mobility control and reducing the oil/water IFT of those surfactant mixtures, the VES flooding demonstrates excellent oil‐displacement efficiency, which is close to that of polymer/surfactant flooding or polymer/surfactant/alkali flooding. Our work provides a new type of VES flooding system with excellent performances for chemical flooding in offshore oilfields.     

Preparation and Characterization of an Anionic Gemini Surfactant for Enhanced Oil Recovery in a Hypersaline Reservoir

A new type of anionic Gemini surfactant (AGS) was designed and prepared by a simple, low–cost, and green method, and its properties were characterized. The results showed that the values of parameters such as critical micelle concentration (CMC) value, Γmax, Amin, and pC20 of AGS were 0.10 mmol L⁻¹, 1.62 mmol m⁻², 1.02 nm², and 4.60, respectively, indicating that AGS is highly surface active. AGS has a very good synergistic effect with lauryl diethanol amide (6501), and the mixture surfactant 6501DA (composed of AGS and 6501 with a mass ratio of 1:2.5) has good wetting and emulsifying ability of the crude oil and good resistance to calcium and magnesium ions. In the temperature range from 50 to 70 °C, salinity of 20,000–50,000 mg L⁻¹ of the simulated formation water, and dosage of 6501DA from 500 to 3000 mg L⁻¹, all the interfacial tension (IFT) values between the 6501DA solution and Bamianhe crude oil were lower than 10⁻² mN m⁻¹, and all the adsorption amounts of oil sand to 6501DA in solution were less than 2 mg g⁻¹, indicating that AGS has potential for application in EOR in a hypersaline reservoir.     

Improvement of the Selection Method of Surfactants and Their Mixtures for Chemical Enhanced Oil Recovery

Our research focuses on the evaluation of various surfactants by several test methods in order to develop the effective surfactants or their mixtures for Chemical Enhanced Oil Recovery (CEOR) and to characterize the most important surfactant properties.

Previously no correlation was found between the specific characteristics. Therefore, a complex evaluation (CE) method was developed to select the surfactants (Nagy et al., 2015 Nagy, R., Kothencz, R., Sallai, R., and Bartha, L. (2015). An improved method for the determination of HLB properties of nonionic surfactants, Int. J. Sci. Eng. Res., 6, 3. [Google Scholar]). A weak correlation was observed using the CE method. Thus, developments were needed to contribute significantly to the selection of nonionic surfactants and their mixtures for EOR applications. A new solubility property was incorporated to the screening method; therefore the correlation improved. A relationship was found between the additional oil yield and the solubility properties of anionic and nonionic surfactants. Therefore, the new evaluation method (CRE-complex rigorous evaluation) has a more accurate relationship with additional oil yield. This developed method can reduce the cost and time required for the applied screening method.     

大庆油田复合驱用表面活性剂的性能及发展方向

对大庆油田开展的三元复合驱进展概况作了综述,总结了国内外驱油用表面活性剂的研究现状和方向,提出了大庆油田复合驱用表面活性剂的性能指标和原料要求,以及大庆油田近期对表面活性剂的需求。针对目前形势,分析了复合驱用表面活性剂研制方面存在的问题及解决思路。     

喇一负压原油稳定系统改造分析研究

天然气分公司喇一油气处理站拥有一套350×104 t/a负压原稳装置,是大庆六厂地区重要的产能装置,由于原油组分变贫、压缩机效率偏低、加热率控制系统不稳定等原因,目前该装置轻烃产量偏低。本文通过对该装置存在的问题进行分析,提出了合理的装置改造方案,为天然气分公司的轻烃上产工作做出了积极探索。     

国内轻质油藏注空气、空气泡沫提高采收率效果分析

在重点调研国内油田空气、空气泡沫驱的基础上,论述了注空气、空气泡沫低温氧化技术的原理,对我国油田开展注空气、空气泡沫驱技术的实际效果以及潜力进行了的分析,认为注空气低温氧化工艺技术安全可控,不但可以解决我国储量丰富的低渗透油藏所面临的开发难题,而且可以进一步提高水驱、聚合物驱后油藏的采收率。随着技术进步,注空气低温氧化技术是我国乃至全世界注气提高采收率技术发展的必然趋势。并通过对现场应用情况分析,给出了对轻质油藏注空气、空气泡沫提高采收率的一些建议。     

Continuous Flow Methylene Blue Active Substances Method for the Determination of Anionic Surfactants in River Water and Biodegradation Test Samples

Anionic surfactants are commonly determined with the use of the methylene blue active substances (MBAS) standard method, which is time‐consuming and labor‐intensive. Therefore, new methods for determination of anionic surfactants are needed. In this study, the standard MBAS method for determination of anionic surfactants was modified and adjusted to work in a continuous flow system combined with spectrophotometric measurement. The developed method was found to be satisfactory in terms of sensitivity and precision, with a short time of analysis. The quantification limit for anionic surfactants was at 16 μg L^?1, with a relative standard deviation of 1.3 % for a model sample and 3.8 % for a river water sample. The results obtained for environmental samples were comparable to those obtained by using the standard MBAS method; however, the developed continuous flow method is faster, more sensitive and consumes smaller doses of chemical reagents.