Tertiary Surfactant Flooding: Petroleum Sulfonate Composition-Efficacy Studies

1973 ◽  
Vol 13 (04) ◽  
pp. 191-199 ◽  
Author(s):  
Walter W. Gale ◽  
Erik I. Sandvik
Keyword(s):  
Interfacial Tension ◽  
Oil Recovery ◽  
Weight Distribution ◽  
Capillary Rise ◽  
Equivalent Weight ◽  
Residual Oil ◽  
Surfactant Flooding ◽  
Petroleum Sulfonate ◽  
Low Interfacial Tension ◽  
Oil Water

Abstract This paper discusses results of a laboratory program undertaken to define optimum petroleum program undertaken to define optimum petroleum sulfonates for use in surfactant flooding. Many refinery feedstocks, varying in molecular weight and aromatic content, were sulfonated using different processes, Resulting sulfonates were evaluated by measuring interracial tensions, adsorption-fractionation behavior, brine compatability, and oil recovery characteristics, as well as by estimating potential manufacturing costs. The best combination o[ these properties is achieved when highly aromatic feedstocks are sulfonated to yield surfactants having very broad equivalent weight distributions. Components of the high end of the equivalent weight distribution make an essential contribution to interfacial tension depression. This portion is also strongly adsorbed on mineral surfaces and has low water solubility. Middle Portions of the equivalent weight distribution serve as sacrificial adsorbates while lower equivalent weight components Junction as micellar solubilizers for heavy constituents. Results from linear laboratory oil-recovery tests demonstrate interactions of various portions of the equivalent weight distribution. portions of the equivalent weight distribution Introduction Four major criteria used in selecting a surfactant for a tertiary oil-recovery process are:low oil-water interfacial tension,low adsorption,compatibility with reservoir fluids andlow cost. Low interfacial tension reduces capillary forces trapping residual oil in porous media allowing the oil to be recovered. Attraction of surfactant to oil-water interfaces permits reduction of interfacial tension; however, attraction to rock-water interfaces can result in loss of surfactant to rock surfaces by adsorption. Surfactant losses can also arise from precipitation due to incompatibility with reservoir fluids. Low adsorption and low cost are primarily economic considerations, whereas low interfacial tension and compatibility are necessary for workability of the process itself. Petroleum sulfonates useful in surfactant flooding have been disclosed in several patents; however, virtually no detailed information is available in the nonpatent technical literature. Laboratory evaluation of surfactants consisted of determining their adsorption, interfacial tension, and oil recovery properties. Adsorption measurements were made by static equilibration of surfactant solutions with crushed rock and clays and by flowing surfactant solutions through various types of cores. Interfacial tensions were measured using pendant drop and capillary rise techniques. Berea, pendant drop and capillary rise techniques. Berea, Bartlesville, and in some cases, field cores containing brine and residual oil were flooded with sulfonate solutions in order to determine oil recovery. Fluids used in these displacement tests are described in Table 1. Unless otherwise specified, displacements of Borregos crude oil were carried out with Catahoula water as the resident aqueous phase after waterflooding and displacements of phase after waterflooding and displacements of Loudon crude oil with 1.5 percent NaCl as the resident aqueous phase. In those examples where banks of surfactants were injected, drive water following the surfactant had the same composition as the resident water. Concentrations of sulfonates are reported on a 100-percent activity basis. PETROLEUM SULFONATE CHEMISTRY PETROLEUM SULFONATE CHEMISTRY A substantial portion of the total research effort TABLE 1 - PROPERTIES OF FLUIDS USEDIN FLOODING TESTS

Competing Roles of Interfacial Tension and Surfactant Equivalent Weight in the Development of a Chemical Flood

1982 ◽  
Vol 22 (04) ◽  
pp. 472-480 ◽  
Author(s):  
S.L. Enedy ◽  
S.M. Farouq Ali ◽  
C.D. Stahl
Keyword(s):  
Interfacial Tension ◽  
Crude Oil ◽  
Oil Recovery ◽  
Salt Concentration ◽  
Surfactant Concentration ◽  
Evolutionary Process ◽  
Chemical Flooding ◽  
Equivalent Weight ◽  
Residual Oil ◽  
Tertiary Oil Recovery

Abstract This investigation focused on developing an efficient chemical flooding process by use of dilute surfactant/polymer slugs. The competing roles of interfacial tension (IFT) and equivalent weight (EW) of the surfactant used, as well as the effect of different types of preflushes on tertiary oil recovery, were studied. Volume of residual oil recovered per gram of surfactant used was examined as a function of these variables and slug size. Tertiary oil recovery increased with an increase in the dilute surfactant slug size and buffer viscosity. However, low IFT does not ensure high oil recovery. An increase in surfactant EW used actually can lead to a decrease in oil recovery. Tertiary oil recovery was also sensitive to preflush type. Reasons for the observed behavior are examined in relation to the surfactant properties as well as to adsorption and retention. Introduction Two approaches are being used in development of surfactant /polymer-type chemical floods:a small-PV slug of high surfactant concentration, ora large-PV slug of low surfactant concentration. This study deals with the latter-i.e., dilute aqueous slugs (with polymer added in many cases) containing less than or equal 2.0 wt% sulfonates and about 0. 1 wt% crude oil. Because the dilute slug contains little of the dispersed phase, an aqueous surfactant slug usually is unable to displace the oil miscibly; however, residual brine is miscible with the slug if the inorganic salt concentration is not excessive. The dilute, aqueous petroleum sulfonate slug lowers the oil/water IFT. overcoming capillary forces. This process commonly is referred to as locally immiscible oil displacement. Objectives The objective of this work was to develop an efficient dilute surfactant/polymer slug for the Bradford crude with a variety of sulfonate combinations. Effects of varying the slug characteristics such as equivalent weight, IFT, salt concentration, etc. on tertiary oil recovery were examined. Materials and Experimental Details The petroleum sulfonates and the dilute slugs used in this study are listed in Tables 1 and 2, respectively. The crude oil tested was Bradford crude 144 degrees API (0.003 g/cm3), 4 cp (0.004 Pa.s)]. The polymer solutions were prefiltered and driven by brines of various concentrations (0.02, 1.0, and 2.0% NACl). In many cases, the polymer was added to the slug. Conventional coreflood equipment described in Ref. 3 was used. Berea sandstone cores (unfired) 2 in, (5 cm) in diameter and 4 ft (1.3 m) in length were used for all tests, with a new core for each test. Porosity ranged from 19.3 to 21.0%, permeability averaged 203 md, and the waterflood residual oil saturation averaged 33.1%. IFT's were measured by the spinning drop method. Viscosities were measured with a Brookfield viscosimeter and are reported here for 6 rpm (0.1 rev/s). The dilute slugs containing polymer exhibited non-Newtonian behavior. Without polymer the behavior was Newtonian. Sulfonate concentration in the oleic phase was determined by an infrared spectrophotometer, while the concentration in the aqueous phase was measured by ultraviolet (UV) absorbance analysis. Discussion of Results Slug development in this investigation was an evolutionary process. Dilute slugs were developed and core tested in a sequential manner (Table 2). Slugs 100 through 200 yielded insignificant ternary oil recoveries (largely because of excessive adsorption and retention), but the results helped determine improvements in slug compositions and in the overall chemical flood. This paper gives results for the more efficient slugs only. SPEJ P. 472^

scholarly journals The Oscillatory Spinning Drop Technique. An Innovative Method to Measure Dilational Interfacial Rheological Properties of Crude Oil-Brine Systems in the Presence of Asphaltenes

2021 ◽  
Vol 5 (3) ◽  
pp. 42
Author(s):  
Ronald Marquez ◽  
Johnny Bullon ◽  
Ana Forgiarini ◽  
Jean-Louis Salager
Keyword(s):  
Interfacial Tension ◽  
Crude Oil ◽  
Rheological Properties ◽  
Oil Recovery ◽  
Interfacial Rheology ◽  
Drop Method ◽  
Natural Surfactants ◽  
Low Interfacial Tension ◽  
Oil Water ◽  
Drop Technique

The oscillatory spinning drop method has been proven recently to be an accurate technique to measure dilational interfacial rheological properties. It is the only available equipment for measuring dilational moduli in low interfacial tension systems, as it is the case in applications dealing with surfactant-oil-water three-phase behavior like enhanced oil recovery, crude oil dehydration, or extreme microemulsion solubilization. Different systems can be studied, bubble-in-liquid, oil-in-water, microemulsion-in-water, oil-in-microemulsion, and systems with the presence of complex natural surfactants like asphaltene aggregates or particles. The technique allows studying the characteristics and properties of water/oil interfaces, particularly when the oil contains asphaltenes and when surfactants are present. In this work, we present a review of the measurements of crude oil-brine interfaces with the oscillating spinning drop technique. The review is divided into four sections. First, an introduction on the oscillating spinning drop technique, fundamental and applied concepts are presented. The three sections that follow are divided according to the complexity of the systems measured with the oscillating spinning drop, starting with simple surfactant-oil-water systems. Then the complexity increases, presenting interfacial rheology properties of crude oil-brine systems, and finally, more complex surfactant-crude oil-brine systems are reviewed. We have found that using the oscillating spinning drop method to measure interfacial rheology properties can help make precise measurements in a reasonable amount of time. This is of significance when systems with long equilibration times, e.g., asphaltene or high molecular weight surfactant-containing systems are measured, or with systems formulated with a demulsifier which is generally associated with low interfacial tension.

Characterization of Petroleum Sulfonates by a Nonaqueous Titration Method

1981 ◽  
Vol 21 (06) ◽  
pp. 771-778 ◽  
Author(s):  
Kim R. Voss ◽  
Clark E. Bricker ◽  
M.J. Michnick ◽  
G.P. Willhite
Keyword(s):  
Molecular Weight ◽  
Interfacial Tension ◽  
Oil Recovery ◽  
Perchloric Acid ◽  
Molecular Species ◽  
New Method ◽  
Equivalent Weight ◽  
Petroleum Sulfonate ◽  
Wet Ashing

Summary A new method is described for the determination of the equivalent weight for petroleum sulfonates. The method is based on the direct acidimetric titration of the sulfonate in acetic acid/acetic anhydride solvent using a titrant of perchloric acid in dioxane. From the titration, the moles of perchloric acid required to react with the sulfonate is measured. The equivalent weight is calculated from the grams of sample titrated and the moles of acid used. The potentiometric titration can be carried out in less than 10 minutes and can be done with 10 to 100 mg of sample. The accuracy and precision of the procedure were examined by the titration of sodium salts of p-toleuene sulfonate, 2-naphthalene sulfonate, and petroleum sulfonates. In general, values for the equivalent weight were within 2% of those values determined by the Epton titration, by wet ashing methods, or from the theoretical value. The relative standard deviation (RSD) for the procedure is estimated to be 0.5%. For p-toluene sulfonate, an RSD of 0.15% was calculated. The new method was used to determine the equivalent weights for three fractions of a petroleum sulfonate obtained by the preferential elution from silica gel with alcohol. A series of samples with varying equivalent weight was prepared by proportional combination of the three fractions. Analysis by high-performance liquid chromatography (HPLC) gave a set of data points of peak areas for the series. A plot of equivalent weight as a function of disulfonate to total peak area ratio resulted in a straight line. The slope of this line is descriptive of the molecular weight range for the petroleum sulfonate. Introduction Petroleum sulfonates are used to liberate a residual oil from a porous medium in a tertiary oil-recovery process. One mechanism for the release of oil is the reduction of the interfacial tension between water and oil to values on the order of 10−3 dyne/cm.1–5 The performance of a sulfonate as a surfactant depends on its molecular size and structure. For a pure single-species sulfonate, these properties can be correlated with the alteration of the interfacial tension between water and oil. The same cannot be done for a petroleum sulfonate because the sulfonate is a mixture of molecular species with unknown structures. Previous studies6,7 have shown that the overall composition of a petroleum sulfonate is altered by the preferential partitioning of the molecular species to the oil, water, and rock phases. This causes the composition of the sulfonate to change constantly as it flows through the porous media contacting water and oil. To correlate oil-recovery efficiency with a property of the sulfonate, analytical methods are needed to characterize the effluent from core floods. One parameter for characterizing petroleum sulfonates is the average equivalent weight, which is the weight in grams containing 1 mol of sulfonate functional groups. Sufficient sample is often not available for the equivalent weight analysis by the ASTM wet ashing procedure, and the oil in the sample may often interfere with the Epton titrate method. Therefore, a study was initiated to develop a method for the determination of equivalent weight of petroleum sulfonates in the 10- to 100-mg range. Of equal importance is a method to count sulfonate groups and to differentiate mono- and disulfonate molecules. The latter can be achieved by HPLC using an anion exchange column.8 However, quantification of the effluent from the HPLC column remains a problem. No detector is available that responds specifically to the sulfonate functional group -SO3−. Specific ion-electrodes of the liquid- or solid-membrane type show varying response to sulfonates depending on the molecular weight of the sulfonate.9,10

Vesicular Dispersion Delivery Systems and Surfactant Waterflooding

1982 ◽  
Vol 22 (01) ◽  
pp. 37-52 ◽  
Author(s):  
Jorge E. Puig ◽  
Elias I. Franses ◽  
Yeshayahu Talmon ◽  
H. Ted Davis ◽  
Wilmer G. Miller ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Oil Recovery ◽  
Liquid Crystalline ◽  
Capillary Forces ◽  
Residual Oil ◽  
Interfacial Tensions ◽  
Low Concentration ◽  
Tertiary Oil Recovery ◽  
Oil Water ◽  
Recovery Methods

Abstract Surfactant waterflooding processes that rely on ultralow interfacial tensions suffer from surfactant retention by reservoir rock and from the need to avoid injectivity problems. New findings reported here open the possibility that by delivering the surfactant in vesicle form, more successful low-concentration, alcohol-free surfactant waterflooding processes can be designed. Basic studies of low concentration (less than 2 wt %) aqueous dispersions of lamellar liquid crystals of a model surfactant, Texas No. 1, have established the role of dispersed liquid crystallites in the achievement of ultralow tensions between oil and water. Recent work, including fast-freeze, cold-stage transmission electron microscopy (TEM), reveals that sonication both in the absence and the presence of sodium chloride converts particulate dispersions of Texas No. 1 into dispersions of vesicles, which are spheroidal bilayers or multilayers, less than 0.1 mum in diameter filled with aqueous phase. Vesicles ordinarily revert only very slowly to the bulk liquid crystalline state. We find, however, that their stability depends on their preparation and salinity history, and that contact with oil can accelerate greatly the reversion of a vesiculated dispersion and enable it to produce low tensions between oil and water. Tests with Berea cores show that surfactant retention and attendant pressure buildup can be reduced greatly by sonicating Texas No. 1 dispersions to convert liquid crystallites to vesicles. In simple core-flooding experiments both the unsonicated liquid crystalline dispersions and the sonicated vesicle dispersions are able to produce substantial amounts of residual oil. We point out implications and directions for further investigation. Introduction Methods of enhancing, petroleum recovery, especially tertiary recovery, following the primary and secondary stages, are under intense research and development. Among these are at least two classes of surfactant-based recovery methods-surfactant waterflooding and so-called micellar or microemulsion flooding. Gilliland and Conley suggest that of the various enhanced-recovery methods, surfactant waterflooding has the potential for the widest application in the U.S. Residual oil is trapped as blobs in porous rock by capillary forces. The number of mechanisms is limited both for reducing entrapment and for mobilizing that residual oil remaining entrapped, there by improving the microscopic displacement efficiency of a petroleum recovery process. Taber and Melrose and Brandner established that tertiary oil recovery by an immiscible flooding process is possible by increasing the capillary number, which measures the ratio of Darcy flow forces of mobilization to capillary forces of entrapment. In practice this can be achieved by lowering the oil-water interfacial tension to about 10 mN/m or less. That this is feasible in the surfactant waterflooding range-i.e. at surfactant concentration less than those characterizing the microemulsion flooding range-and in the absence of cosurfactants or cosolvents that typify microemulsions is well established. Gale and Sandvik suggested four criteria for selecting a surfactant for a tertiary oil-recovery process:low oil-water interfacial tension,low adsorption.compatibility with reservoir fluids, andlow cost. For a given oil and type of surfactant, it has been shown that the interfacial tensions are extremely sensitive to surfactant molecular weight. SPEJ P. 37^

A Study of Oil Displacement by Microemulsion Systems Mechanisms and Phase Behavior

1980 ◽  
Vol 20 (06) ◽  
pp. 459-472 ◽  
Author(s):  
G.P. Willhite ◽  
D.W. Green ◽  
D.M. Okoye ◽  
M.D. Looney
Keyword(s):  
Interfacial Tension ◽  
Phase Behavior ◽  
Oil Recovery ◽  
Surfactant Solution ◽  
Residual Oil ◽  
Surfactant Flooding ◽  
Displacement Efficiency ◽  
High Concentration ◽  
The Core ◽  
Oil Displacement

Abstract Microemulsions located in a narrow single-phase region on the phase diagram for the quaternary system consisting of nonane, isopropyl alcohol, Witco TRS 10-80 petroleum sulfonate, and brine were used to investigate the effect of phase behavior on displacement efficiency of the micellar flooding process. Microemulsion floods were conducted at reservoir rates in 4-ft (1.22-m) Berea cores containing brine and residual nonane. Two floods were made using large (1.0-PV) slugs. A third flood used a 0.1-PV slug followed by a mobility buffer of polyacrylamide. Extensive analyses of the core effluents were made for water, nonane, alcohol, and mono- and polysulfonates. An oil bank developed which broke through at 0.08 to 0.1 PV, and 48 to 700/0 of the oil was recovered in this bank which preceeded breakthrough of monosulfonate and alcohol. Coincidental with the arrival of these components of the slug, the effluent became a milky white macroemulsion which partially separated upon standing. Additional oil was recovered with the macroemulsion. Ultimate recoveries were 90 to 100% of the residual oil. Low apparent interfacial tension was observed between the emulsion and nonane. Alcohol arrived in the effluent at the same time as monosulfonate even though there was extensive adsorption of the sulfonate. Further, alcohol appeared in the effluent well after sulfonate production had ceased, indicating retention of the alcohol in the core. A qualitative model describing the displacement process was inferred from the appearance of the produced fluids and the analyses of the effluents. Introduction Surfactant flooding (micellar or microemulsion) is one of the enhanced oil recovery methods being developed to recover residual oil left after waterflooding. Two approaches to surfactant flooding have evolved in practice. In one, relatively large volumes (0.25 PV) of low-concentration surfactant solution are used to create low-tension waterfloods.1,2 Oil is mobilized by reduction of interfacial tension to levels on the order of about 10−3 dyne/ cm (10−3 mN/m). The second approach involves the application of small volumes (0.03 to 0.1 PV) of high-concentration solutions.3,4 These solutions are miscible to some extent with the formation water and/or crude oil. Consequently, miscibility between the surfactant solution and oil and/or low interfacial tensions contribute to the oil displacement efficiency. The relative importance of these mechanisms has been the subject of several papers5,6 and discussions.7,8

Ultra-Low Interfacial Tension of a Surfactant under a Wide Range of Temperature and Salinity Conditions for Chemical Enhanced Oil Recovery

2018 ◽  
Vol 55 (3) ◽  
pp. 252-257 ◽  
Author(s):  
Derong Xu ◽  
Wanli Kang ◽  
Liming Zhang ◽  
Jiatong Jiang ◽  
Zhe Li ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Wide Range ◽  
Low Interfacial Tension

scholarly journals Mechanism of active silica nanofluids based on interface-regulated effect during spontaneous imbibition

2021 ◽  
Author(s):  
Xu-Guang Song ◽  
Ming-Wei Zhao ◽  
Cai-Li Dai ◽  
Xin-Ke Wang ◽  
Wen-Jiao Lv
Keyword(s):  
Contact Angle ◽  
Interfacial Tension ◽  
Oil Recovery ◽  
Dynamic Contact Angle ◽  
Liquid Interface ◽  
Spontaneous Imbibition ◽  
Wettability Alteration ◽  
Low Permeability ◽  
Oil Water ◽  
Solid Liquid

AbstractThe ultra-low permeability reservoir is regarded as an important energy source for oil and gas resource development and is attracting more and more attention. In this work, the active silica nanofluids were prepared by modified active silica nanoparticles and surfactant BSSB-12. The dispersion stability tests showed that the hydraulic radius of nanofluids was 58.59 nm and the zeta potential was − 48.39 mV. The active nanofluids can simultaneously regulate liquid–liquid interface and solid–liquid interface. The nanofluids can reduce the oil/water interfacial tension (IFT) from 23.5 to 6.7 mN/m, and the oil/water/solid contact angle was altered from 42° to 145°. The spontaneous imbibition tests showed that the oil recovery of 0.1 wt% active nanofluids was 20.5% and 8.5% higher than that of 3 wt% NaCl solution and 0.1 wt% BSSB-12 solution. Finally, the effects of nanofluids on dynamic contact angle, dynamic interfacial tension and moduli were studied from the adsorption behavior of nanofluids at solid–liquid and liquid–liquid interface. The oil detaching and transporting are completed by synergistic effect of wettability alteration and interfacial tension reduction. The findings of this study can help in better understanding of active nanofluids for EOR in ultra-low permeability reservoirs.

Performance of alkali-free natural petroleum sulfonates: Ultra-low interfacial tension on oil/water interface

2015 ◽  
Vol 93 (8) ◽  
pp. 1410-1415 ◽  
Author(s):  
Zhan Weng ◽  
Peng-Yuan Zhang ◽  
Guang-Wen Chu ◽  
Wei Wang ◽  
Jimmy Yun ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Water Interface ◽  
Low Interfacial Tension ◽  
Oil Water
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