Petroleum Sulfonate Research Articles

Interaction between Bohai heavy oil components and petroleum sulfonate for lowering interfacial tension

Molecular composition of Bohai heavy oil components was investigated by element analysis and high-resolution mass spectrometry. Moreover, partition coefficient and interfacial tension (IFT) in petroleum sulfonate (PS) solution/model oil system were measured in order to elucidate the oil components- PS interaction responsible for low IFT. The results demonstrate that, as the mass fraction of asphaltene model oil increases, the partition coefficients of PS increase steeply after a slow increase period. When the mass fraction reaches 1%, IFT in the range of 10−2 mN·m−1 is obtained at PS concentration as low as 500 mg·L−1. Due to high interfacial activity of asphaltene and its strong interactions with PS, more PS molecules are attracted to interface; meanwhile, the electrostatic repulsion between PS molecules at the interface is weakened by the inserted asphaltene molecules, which are the contributing mechanism for synergism for lowering IFT. However, with the concentration of resin or remaining fraction increasing, the partition coefficient of PS decreases and the equilibrium IFT increases firstly. It is because the adsorption of resin or remaining fraction which replaces PS molecules at the interface causes loose arrangement of interfacial active materials and increasing IFT, displaying antagonism.

Performance and optimization of biological and chemical composite flooding system for enhanced oil recovery

Biological and chemical compound flooding systems have excellent performance and broad application prospects in enhanced oil recovery. In this study, the most efficient and environmentally friendly type of bio-chemical compound alkaline-surfactant-polymer (ASP) flooding system, namely the ASP-PST85, is constructed with Na2CO3, petroleum sulfonate (NPS), biosurfactant surfactin, polyacrylamide, and Tween-85. The interfacial activity, dilution stability, adsorption stability, aging stability, temperature stability, and emulsification property of the ASP-PST85 system are evaluated. The results show that the range of interfacial tension of 10−4 mN/m between the ASP-PST85 system and crude oil is significantly expanded compared to that of the original ASP system, which is referred to as the ASP-PS system. Simultaneously, the emulsion and adsorption stability are also significantly improved. The microfluidic measurement results show that the ASP-PST85 system reaches the saturated adsorption of surfactant at the oil-water interface faster than the ASP-PS system, probably due to its higher emulsion stability. This study provides a reference for the construction of high-performance and bio-chemical compound flooding systems, providing a theoretical and methodological basis to obtain basic data of rapid adsorption kinetics at the oil-water interface.

Laboratory experimental study on the binary combination flooding system in low permeability conglomerate reservoir

In view of the poor injection-production effect of low permeability conglomerate complex fault block reservoir in Xinjiang Oilfield in the late development stage of high water cut, the indoor experimental study of binary compound flooding system was carried out. By compounding the petroleum sulfonate and polymer binary system, the viscosity and morphology parameters of the binary compound flooding system were measured. The microscopic pore structure of the core in this block was analyzed by GE Phoenix Nanotom S, and four groups of experimental schemes were designed to study the oil displacement efficiency of the whole diameter core binary compound flooding system. The experimental results showed that the binary system of surfactant and polymer showed additive synergistic effect. The performance of binary compound system is less affected by polymer molecular weight and solution concentration, which meets the viscosity requirement of low permeability conglomerate for binary compound flooding system. The porosity of samples is relatively small and the connectivity between pores is relatively poor. The experimental results of physical model oil displacement efficiency show that the oil recovery can be increased by more than 17% by injecting 0.3PV 1200mg/L polymer + 0.5% (w) surfactant binary compound system.

Wettability-Based Retention of Encapsulated Petroleum Sulfonate in Carbonate Rocks at High Temperature and High Salinity Conditions

Wettability-Based Retention of Encapsulated Petroleum Sulfonate in Carbonate Rocks at High Temperature and High Salinity Conditions

Pore-scale experiments on the synergistic EOR mechanisms between the main components of LASP (lipopeptide-alkali-surfactant-polymer) system

To improve the oil recovery efficiency of ASP (alkali-surfactant-polymer) flooding, lipopeptide surfactant was added into ASP to form a new system (LASP). Core flooding experiments and field pilots suggested that LASP can achieve better oil recovery with lower costs. To determine the synergistic effects of the LASP system, a series of pore-scale flooding experiments were performed to quantify the displacement and sweep efficiencies of the LASP system and its main components independently. The results suggested that the petroleum sulfonate tends to improve displacement efficiency (by 21.1%) and the polymer tends to widen the effective sweep area (by 14.2%). While lipopeptide improved both oil displacement efficiency (31.2%) and sweep efficiency (10.2%) depending on the oil emulsification. Their mixture, that is; LASP, reached a higher displacement (42.1%) and sweep efficiency (12.9%) that depended on synergistic effects between the components. For instance, the bio- and chemical surfactants and the polymer synergistically improved the stability and deformability of oil emulsion, which reduce flow resistance and then improve displacement efficiency. However, the throat-blocking mechanism, which expanded sweep area during lipopeptide flooding, no longer existed in the LASP system. Nevertheless, the LASP system can depend on high viscosity of polymer to effectively expand sweep area. Oil recovery in the LASP system is more than the sum of the mechanism of each component.

Effect of active substance content and molecular weight of petroleum sulfonate on fluorite flotation: Molecular dynamics simulation

Fluorite is an important non-metallic mineral, and the most efficient way to separate it from gangue is flotation. The commonly used collectors are oleic acid and oxidized paraffin soap, but those two collectors both have a problem of bad solubility, this phenomenon worsens at low temperature. Sodium petroleum sulfonate exhibits a good collecting performance on fluorite, but it has not been systematically studied. In this paper, different types of sodium petroleum sulfonate were used to evaluate the effect of active substance content and average molecular weight. Molecular dynamics simulation was used to understand the mechanism that causes the flotation difference between mono-sulfonate and di-sulfonate. This study identifies that active content has a positive effect on the flotation recovery of fluorite while the molecular weight plays a negative role. The reason why di-sulfonate’s performance is relatively weak at high concentration lies on the steric-hindrance effect, larger cross-sectional area limits the tail–tail interaction between sulfonates.

Comparison of Sodium Oleate and Sodium Petroleum Sulfonate for Low-Temperature Flotation of Fluorite and the Collecting Mechanisms

Comparison of Sodium Oleate and Sodium Petroleum Sulfonate for Low-Temperature Flotation of Fluorite and the Collecting Mechanisms

Synthesis of petroleum sulfonate via gas-phase sulfonation in rotating packed bed: Process optimization and interfacial tension-composition relationship

This study presents the synthesis of petroleum sulfonate (PS) via gas-phase SO3 sulfonation in a rotating packed bed (RPB) and the relationship between the interfacial tension (IFT) at the oil-aqueous interface and the composition of PS. Through the process optimization, the content of active matter in the prepared PS could reach up to 42.5%, which was significantly higher than that in the industrial production (38%). Moreover, the oil-aqueous IFT could reach an ultra-low value of 1.41×10-3 mN/m. The analysis results of PS composition and IFT indicated that the oil-aqueous IFT was mainly affected by the content of alkyl benzene, alkyl indane, alkyl acenaphthylene and alkyl naphthalene sulfonates in PS. In addition, a correlation coefficient, which was consistent with the interfacial tension, was established for evaluation of the similarity between PS samples.

Temperature-Responsive Hydrogel Carrier for Reducing Adsorption Loss of Petroleum Sulfonates.

As an effective anionic surfactant for chemical flooding, petroleum sulfonate (PS) is often used in conjunction with alkalis to reduce the adsorption loss of PS onto rock and clay surfaces. However, alkali injection can lead to scaling, aggravate the water-sensitive effect of clays, and accelerate polymer hydrolysis. Here, a temperature-responsive biohydrogel-based carrier (XLK) was designed to protect PS from adsorption onto geological features. XLK, an aqueous mixture containing 0.5% xanthan gum, 0.5% locust bean gum, and 2% KCl, was a gel at room temperature and transformed gradually into a sol above 50 °C (sol/gel transition temperature, Tsol/gel). Below the Tsol/gel, most PS was retained in the gel, preventing the adsorption of PS onto quartz sand. Above the Tsol/gel, PS was released into the surrounding medium. After it had been loaded with PS, the storage modulus (G', Pa) of XLK increased from 102 to 103 and the loss modulus (G″, Pa) increased from 101 to 102. Environmental scanning electron microscopy micrographs showed that PS filled gaps within the cross-linked network structure of XLK. Compared with the aqueous XLK formulation, the addition of hydrolyzed polyacrylamide (HPAM) decreased the melt rate of XLK and the interfacial tension (IFT) of PS. Among the constituents of XLK loaded with PS, KCl had the most obvious effect of lowering the shear modulus of HPAM. Sufficient amounts of KCl were effective in reducing the IFT of PS to ultralow levels (10-3 mN/m).

Synthesis and Characterization of Polymeric Surfactant from Palm Oil Methyl Ester and Vinyl Acetate for Chemical Flooding

Surfactants for enhanced oil recovery are generally made from non-renewable petroleum sulfonates and their prices are relatively expensive, so it is necessary to synthesis the bio-based surfactants that are renewable and ecofriendly. The surfactant solution can reduce the interfacial tension (IFT) between oil and water while vinyl acetate monomer has an ability to increase the viscosity as a mobility control. Therefore, polymeric surfactant has both combination properties in reducing the oil/water IFT and increasing the viscosity of the aqueous solution simultaneously. Based on the study, the Critical Micelle Concentration (CMC) of Polymeric Surfactant was at 0.5% concentration with an IFT of 7.72x10-2 mN/m. The best mole ratio of methyl ester sulfonate to vinyl acetate for polymeric surfactant synthesis was 1:0.5 with an IFT of 6.7x10-3 mN/m. Characterization of the product using FTIR and HNMR has proven the creation of polymeric surfactant. Based on the wettability alteration study, it confirmed that the product has an ability to alter from the initial oil-wet to water-wet quartz surface. In conclusion, the polymeric surfactant has ultralow IFT and could be an alternative surfactant for chemical flooding because the IFT value met with the required standard for chemical flooding ranges from 10-2 to 10-3 mN/m.Keywords: Enhanced Oil recovery, Interfacial Tension, Methyl Ester Sulfonate, Polymeric surfactant, vinyl acetate

Surface-charge-modified nanocapsules of petroleum sulfonate for reduced retention to carbonate rock surface in high-temperature and high-salinity reservoirs

Surface-charge-modified nanocapsules of petroleum sulfonate for reduced retention to carbonate rock surface in high-temperature and high-salinity reservoirs

Study on the pressure drop of crude oil-water with surfactant flow in porous media

An experimental study which aimed to analyze the pressure drop when the oil-water two-phase flow mixed with surfactant flows through porous medias was introduced. Porous media with the quartz sands mainly ranging from 0.2–1.2 mm and the oil-water two-phase system with Liaohe crude oil and water were prepared. Surfactant compounded with petroleum sulfonate (PS-30) and dodecyl dimethyl Betaine (BS-12) was used to improve the fluidity of oil-water mixture. The interfacial tension, viscosity and contact angle of the oil-water-surfactant mixture were tested. Then the pressure drop experiments were conducted, which considered three influence factors including the standard deviation of the granularity, the concentration of the surfactant and the ratio of oil to water. Forchheimer resistance model was used to fit the results, and the influence of three factors on the viscous resistance coefficient α −1 and inertial resistance coefficient C2 were discussed. The results indicated that the compound mixture PS-30/BS-12 is significantly better than other surfactants in terms of pressure drop, and the appropriate concentration of the surfactant is 0.3%. Pressure drop of the mixture can be well fitted by Forchheimer resistance model but α−1 and C2 still needed to be adjusted by test.

Petroleum sulfonates of the karpatol trademark as the most effective surfactants for acting on the formation of producing wells

Experimental studies and pilot test results of developed stimulation technologies with petroleum sulfonate indicate economic benefits of the use of Karpatol achieved due to significant reduction in interfacial tension surfactant-hydrocarbon (oil, condensate, petrol); increase of residual oil displacement factor, destruction of water-oil emulsions, partial permeability build-up of contaminated rock samples, advanced permeability of surfactants in nonuniform permeable and hydrophobic strata, influence on the rheology of viscous oils, improvement of wells development after stimulation, high technological efficiency of stimulation technologies using Karpatol, increase of production index after treatment.

Study on tribological behavior, lubrication and anti-corrosion properties of W/O microemulsion for cold rolling of copper strip

PurposeThe purpose of this paper is to improve lubrication and anti-corrosion properties of the water-in-oil (W/O) microemulsion for rolling of copper strip and sheet to replace the traditional rolling oil.Design/methodology/approachThe W/O microemulsion is prepared by using hydrogenated base oil, a deionized aqueous solution of 0.03 mol/L of Na2SO4 and composite emulsifier such as Sp20, Tx-7 or sodium petroleum sulfonate. Tribological behavior of the microemulsions and traditional cold rolling oil was conducted by MR-10A four-ball tester. The lubrication performance of microemulsion for cold rolling of copper strip was performed by cold-rolling experiment. The morphology of worn surface and the rolled copper was characterized. Anti-corrosion properties of microemulsion for rolled copper was investigated, and the corroded surface was analyzed by X-ray photoelectron spectrometer (XPS).FindingsThe results show that the extreme pressure and antiwear properties of the microemulsions have been improved; the average friction coefficient of the improved microemulsion is 0.065, which is 30% lower than the commercial cold rolling oil. For cold rolling of copper strip, the microemulsion has a higher thinning effect than the commercial cold rolling oil, and a smooth surface is obtained and the surface roughness (Sa) is decreased by 6.8%. The XPS analysis indicated microemulsion adsorbed on the copper surface mitigate the corrosion of oils.Originality/valueThis paper used the prepared W/O microemulsion as a new lubricant in the process of rolling for copper strip and sheet in industry, demonstrating the microemulsion has broad application prospects in the future.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0227/

The effect of sodium carbonate on reducing the interfacial tension of petroleum sulfonate

In current chemical flooding technology, surfactant and polymer (SP) rather than alkali, surfactant and polymer (ASP) flooding is preferred, because the addition of alkali in ASP flooding has been linked to environmental problems. However, in the absence of added alkali, the interfacial performance of petroleum sulfonate (PS) in SP flooding is greatly impaired. Therefore, an important task in SP flooding is to understand the interaction between PS and alkali in reducing interfacial tension (IFT), with the goal of finding a more eco-friendly alternative to alkali. In this study, PS was separated according to its composition: sodium PS, unsulfonated oil, inorganic salt and water. A comparison of the effects of Na2CO3, NaCl and ethanolamine on IFT showed that the electrolyte property of Na2CO3, rather than its alkalinity, played a major role in reducing the IFT. The unsulfonated oil was found to be an indispensable component of PS. A subsequent analysis showed that the unsulfonated oil and the hydrophobic chains of PS had similar carbon numbers, which explained the improved adsorption of PS at the oil-water interface. The oil-water partition coefficient and the minimum cross-sectional area of PS were also studied. The effect of NaCl on the oil-water partition coefficient was stronger than that of Na2CO3, and the effect of Na2CO3 on the minimum cross-sectional area was slightly stronger than that of NaCl. These results demonstrate the potential of NaCl to replace Na2CO3 in supporting the PS-mediated reduction of IFT in SP flooding.

Synthesis of new PPG and study of heterogeneous combination flooding systems

For the problem wherein a reservoir demonstrates strong heterogeneity after polymer flooding and the conventional oil displacement method cannot effectively displace the oil in the low-permeability layer, preformed particle gel (PPG) is synthesized and forms a heterogeneous composite oil displacement system with a weak-base alkali–surfactant–polymer (ASP) system. The core flow and oil displacement experiments were conducted to test the PPG performance. The injection parameters of the heterogeneous system were optimized, and the oil displacement effect was evaluated. Results show that the best synthesis parameters of PPG are as follows – 25% acrylamide, 25% degree of hydrolysis, 1.5 × 10–3 g of cross-linking agent, and 2.25 × 10–2 g of initiator. PPG can swell slowly and has good salt and temperature resistance; the particles with different particle sizes have good elasticity and strength after complete expansion, and they have good compatibility with cores having different permeability values. Compared with the weak-base ASP system, the heterogeneous system can maintain interfacial tension on the order of 10–3mN/m when the concentrations of the alkali and the surfactant are low. The heterogeneous system can (i) achieve adaptive sealing of the formation owing to its good deformation recovery ability, (ii) play the role of liquid flow steering, (iii) adjust the water absorption profile, and (iv) improve heterogeneity. The optimal component concentration of the heterogeneous system is 500 mg/L PPG, 1400 mg/L polymer, 0.3% petroleum sulfonate, and 1.2% sodium carbonate, the best injection method being one wherein a heterogeneous system and a weak-base ASP system are injected alternately.

Characterization of petroleum sulfonate synthesized via gas-phase SO3 sulfonation in rotating packed bed and its application in enhanced oil recovery

In this work, petroleum sulfonate (PS), which can be used for enhanced oil recovery (EOR), was synthesized by sulfonation of distillate oil using gaseous SO3 in a rotating packed bed. The prepared PS was characterized by FT-IR, NMR, negative electrospray ionization fourier transform ion cyclotron resonance mass spectrometry [(−) ESI FT-ICR MS] and thermal gravimetric analysis (TGA). Results showed that the PS contains N1, O1, O2, O3, N1O2, O3S, O4S, and N1O3S classes, among which O3S, O4S, and N1O3S are the three main classes. And the chemical composition of the PS was obtained by the combined analysis of the double-bond equivalent (DBE) and carbon number (CN). TGA results showed that PS is thermally stable at the conventional reservoir temperature (less than 200 °C). In addition, the EOR performance of PS was studied by measuring surface tension, interfacial tension (IFT), wettability alteration and core-flooding experiments. Critical micelle concentration (CMC) of the prepared PS with a value of 0.2% was also determined by surface tension method. An ultra-low oil-water IFT value 1.327 × 10−3 mN/m was obtained at the CMC of PS solution. It was also found that adding PS into brine can decrease the contact angle below 90°, indicating that it can alter the rock wettability from oil-wet to water-wet surface which contributes to enhancing oil recovery. Finally, core-flooding experiments were carried out with different PS concentrations. The results showed that an additional recovery of about 30% after conventional water flooding can be obtained at a PS concentration of 0.3%. This study indicated that the PS synthesized by gas-phase SO3 sulfonation in RPB has good EOR performance, and the work is helpful for the learning of the relationship between PS composition and EOR performance and give the guidance for PS’s synthesis.

Influence of lipophilic tail and linker groups on the surface and thermal properties of the synthesized dicationic surfactants for oilfield applications

Aqueous solubility and heat stability are the prerequisites for any surfactant design for oilfield applications. Commercial surfactants, including polyoxyethylene ether, petroleum sulfonate, and alky benzyl sulfonate, face stability issues when encounters with the harsh environment of the reservoir. In this work, we report the synthesis of four dicationic surfactants (DSs) that contain different lipophilic tail and linker groups. Confirmation of the chemical structure was done by the 1H NMR, 13C NMR, FT-IR, and ESI-MS techniques. The prepared DSs displayed good aqueous solubility due to the incorporation of ethoxylates in the backbone of the chemical structure. We examined the influence of the length of the lipophilic tail and linker group utilizing thermal and surface-active properties. The thermal decomposition behavior of DSs was studied using thermal gravimetric analysis. An increase in thermal stability was observed as the length of the lipophilic tail increased. On the other hand, the impact of the increasing length of the linker group seems to be insignificant in thermal stability experiments. Overall, the decomposition temperature of DSs was around 275 °C that is higher than that of reservoir temperature (≥100 °C). An investigation of the relations between critical micellar concentration with chemical structure indicates that increasing length of both lipophilic tail and linker group results in the reduction of critical micellar concentration. However, the effect of increasing length of lipophilic tail found to be more prominent as compared to the linker group. The conducted research revealed that the synthesized DSs are stable at high temperature and exhibited excellent physicochemical properties. The outcome of this research can help for a better understanding of the structure-property relationship and might be useful for the design and development of new material for oilfield applications.

A Surfactant for Enhanced Heavy Oil Recovery in Carbonate Reservoirs in High-Salinity and High-Temperature Conditions

In view of the difficulty of producing heavy oil from carbonate reservoirs, the surfactant SDY-1 was synthesized by homogeneous solution polymerization with a homogeneous solution polymerization technique using aliphatic amine polyoxyethylene ether (PAEn) H(OCH2CH2)nNR(CH2CH2O)nH as the raw material, epichlorohydrin as the reaction intermediate, tetrabutylammonium bromide and pentamethyldivinyltriamine as the promoters, and alkylphenol as the catalyst. Based on the analysis of reservoir fluid and rock properties, the performance of the surfactant SDY-1 was evaluated in terms of its heat resistance, its salinity tolerance, its ability to change the heavy oil–water interfacial tension and rock wettability and its oil washing efficiency. The results show that when the salinity of the formation water is 2.23 × 105 mg/L, the addition of surfactant SDY-1 can lower the super-heavy oil–water interfacial tension with an asphaltene concentration of 30.19 wt.%, which is aged at a temperature of 140 °C for 3 days, from 22.41 to 0.366 mN/m. In addition, the surfactant SDY-1 can change the contact angle of super-heavy oil–water–rock from 129.7 to 67.4° and reduce the adhesion of crude oil to the rock surface by 99.26%. The oil displacement experiment indicates that the oil washing efficiency of the surfactant SDY-1 can reach 78.7% after ageing at a temperature of 140 °C for 3 days. Compared with petroleum sulfonate flooding, the addition of SDY-1 can improve the displacement efficiency by 33.6%, and the adsorption loss is only 0.651 mg/g oil sand. It has broad application prospects for heavy oil reservoirs with high temperatures, high pressures and high asphaltene contents.

Precise Identification of Water Flooded Degree and Oil-water properties of Reservoir Based on Logging Interpretation

The crude oil reserves are very rich in the peripheral tight oil-water layer. However, due to the lack of effective production technical means, reserves utilization is relatively low. Imbibition flooding is one of the critical technical measures for the efficient development of (weak) hydrophilic tight oil-water layer. To obtain high efficiency production technology for weak hydrophilic tight oil-water layer, we investigated the imbibition flooding effect of negative/non-ionic surfactant “HLX”, “SYH (petroleum sulfonate) +Na2CO3”, cationic surfactant “YANG” and non-ionic surfactant “DCY” on weak hydrophilic core with permeability of about 2.0 × 10−3 μm2. The study results suggest that the imbibition recovery rate and imbibition rate are affected not only by the interfacial tension of the oil-water layer but also by the rock pore wettability. The physical simulation experimental results indicate that the “YANG” and “DCY” imbibition can change the wettability of rock pore surface and reduce the interfacial tension. Hence, the imbibition flooding effect is relatively good, and the recovery rate is significantly increased.