Soaps petroleum

The purpose of alkali flooding (Jennings et al., 1974) is to introduce alkali into a reservoir where it can react with organic acids in the oil to produce organic salts, which act as surfactants. The surfactants (or petroleum soaps ) generated reduce the surface tension between the oil and water and this in turn reduces the level of capillary trapping of the oil. Thus, more oil is recovered because less of it remains trapped in the formation s pore spaces. 

The presence of natural organic acids in some crude oils, especially asphaltic crude oils, may eliminate the need for expensive surfactants. These acids react with strong alkali (usually NaOH) to form petroleum soaps. These soaps diffuse into the oil-water interface, decrease interfacial tension, and form emulsions. Many researchers have used dilute alkali solutions (—0.1 wt% NaOH) to form stable oil-in-water emulsions containing up to 75% oil (i, 3). 

Alkaline flooding is an old concept, first patented by Atkinson (48) in 1927. Hydroxide ion in an alkaline solution reacts with acidic components present in some crude oils to produce petroleum soaps, which are generally sodium salts of carboxylic acids. These petroleum soaps are capable of adsorbing at the oil-water interface and lowering interfacial tension. Crude oils suitable... 

Many of the basic concepts of micellar-polymer flooding apply to alkaline flooding. However, alkaline flooding is fundamentally different because a surfactant is created in the reservoir from the reaction of hydroxide with acidic components in crude oil. This reaction means that the amount of petroleum soap will vary locally as the water-to-oil ratio varies. The amount of petroleum soap has a large effect on phase behavior in crude-oil-alkali-surfactant systems. 

Surfactant Mixing Rules. The petroleum soaps produced in alkaline flooding have an extremely low optimal salinity. For instance, most acidic crude oils will have optimal phase behavior at a sodium hydroxide concentration of approximately 0.05 wt% in distilled water. At that concentration (about pH 12) essentially all of the acidic components in the oil have reacted, and type HI phase behavior occurs. An increase in sodium hydroxide concentration increases the ionic strength and is equivalent to an increase in salinity because more petroleum soap is not produced. As salinity increases, the petroleum soaps become much less soluble in the aqueous phase than in the oil phase, and a shift to over-optimum or type H(+) behavior occurs. The water in most oil reservoirs contains significant quantities of dissolved solids, resulting in increased IFT. Interfacial tension is also increased because high concentrations of alkali are required to counter the effect of losses due to alkali-rock interactions. 

The mixing of a synthetic surfactant and a petroleum soap can be explained in terms of surfactant mixing rules proposed by Wade et al. in 1977 (53). These rules are based on previous studies (54) of the equivalent alkane carbon number (EACN) concept, which show that hydrocarbon behavior toward surfactants is additive and weighted by mole fraction according to the formula ... 

Phase Behavior. The use of phase-behavior diagrams in surfactant-enhanced alkaline flooding is more complicated than in micellar-polymer flooding for several reasons. One reason is that phase behavior is very sensitive to the water-to-oil ratio employed. From surfactant mixing rules, varying the amount of oil present will vary the amount of petroleum soap... 

Dynamic IFT arises from the reaction of acidic components in the crude oil to form petroleum soaps. Reaction of acidic surface-active materials in the crude oil with sodium hydroxide in the aqueous phase is assumed to occur rapidly at the interface, but desorption of these species is taken to be slower. This slower desorption leads to a maximum in the concentration of surface-active species at the interface at some point in time and hence an interfacial tension minimum. Subsequently, IFT increases as equilibrium is approached (58). 

The purpose of an activity map is to show at what range of concentrations in a system and how a chemical flood will work. For a given reservoir where the temperature, composition of crude oil, and residual oil saturation are fixed, five kinds of variables are under our control types of alkalis, concentrations of alkalis, types of surfactants, concentrations of surfactants, and salinity. Another important variable that is not under our direct control is the type and amount of petroleum acid that will convert to soap when contacted by the alkalis. As discussed earlier, the amount of soap will determine the concentrations of alkali and surfactant injected. In other words, to generate an activity map, we have to know the amount of soap that can be generated. Because the alkali concen-ttation typically is much greater than that required to convert all the petroleum acids in the oil to soap, the petroleum soap concentration (meq/L) is calculated... 

Janninga a Proceaaes, — lerata Process.—Violet a Palm-oil Soap.- Hampel s Shaving Soap,—Marriott a Process.—Sawduit in p —Lewis s Process.—Borai Soap.—Carapliar and Ammonia Soaps —Mackay and Seller s Process.-Petroleum Soap Baatet s Pro-... 

Petroleum Soap BasteVs Fjrocess.—Gaustio ley at 36 . is placed in a suitable vessel, and then equal parte of animat fatty matter and mineral oil are placed in separate vessels. The combined weight of the fatty matter and the mineral oil being taken as a standard, boracic acid sufiB.cient to dissolve the alkali is used the mineral oil is heated to a temperature of about 90° F., and the animal fatty matter is melted by steam heat, and while in this condition a quantity of boracic acid is dissolved therein, which, with that acid used as before, will make up one-half per cent, of the combined weight of the fatty matter and mineral oil employed. 

The base lubricant is usually a petroleum oil while the thickener usually consists of a soap or soap mixture. In addition they may contain small amounts of free alkali, free fatty acid, glycerine, anti-oxidant, extreme-pressure agent, graphite or molybdenum disulphide. 

Sodium compounds are important to the paper, glass, soap, textile, petroleum, chemical, and metal industries. Soap is generally a sodium salt of certain fatty acids. The importance of common salt to animal nutrition has been recognized since prehistoric times. 

Petroleum Oils. When satisfactorily stable kerosene—soap—water emulsions were produced in 1874, dormant (winter) oil sprays became widely used to control scale insects and mites (1). The first commercial emulsion or miscible oil was marketed in 1904 and by 1930 highly refined neutral or white oils, free from unsaturated hydrocarbons, acids, and highly volatile elements, were found to be safe when appHed to plant foHage, thus gready enlarging the area of usefulness of oil sprays (see Petroleum). 

In the other market areas, lead naphthenates are used on a limited basis in extreme pressure additives for lubricating oils and greases. Sodium and potassium naphthenates are used in emulsiftable oils, where they have the advantage over fatty acid soaps of having improved disinfectant properties. Catalyst uses include cobalt naphthenate as a cross-linking catalyst in adhesives (52) and manganese naphthenate as an oxidation catalyst (35). Metal naphthenates are also being used in the hydroconversion of heavy petroleum fractions (53,54) and bitumens (55). 

A significant advance in metal soap technology occurred in the 1920s with the preparation of the metal naphthenates. Naphthenic acids (qv) are not of precise composition, but rather are mixtures of acids isolated from petroleum. Because the mixture varies, so does acid number, or the combining equivalent of the acid, so that the metal content of the drier would not always be the same from lot to lot. The preparation of solvent solutions of these metal naphthenates gave materials that were easy to handle and allowed the metal content to be standardized. Naphthenates soon became the standard for the industry. 

Caustic soda by reaction of sodium amalgam and water Nitration of organic compounds with aqueous nitric acid Formation of soaps by action of aqueous alkahes on fats or fatty acids Sulfur removal from petroleum fractious by aqueous ethauolamiues Treating of petroleum products with sulfuric acid... 

Industry Agricultural chemicals Paints and allied products Petroleum refining plastic materials and resins Soap and other detergents... 

Phosphates Alkyl-alkalene diphosphates trihiityl phosphate in isopropanol Petroleum-oil systems foam control in soap solutions... 

Suitable organic solvents, such as ether, benzene, naphtha and the like, are more soluble than in water. This makes it possible to separate them from other substances which may accompany them in the water solution but which are not soluble in the solvents employed. Hence, one application of solvent extraction is the analytical determination of unsaponifiable oils and waxes in admixture with fatty material by submitting the mixture to vigorous saponification with alcoholic potash or, if necessary, sodium ethylate, and to dilute the product with water and extract with petroleum ether. The soaps remain in the aqueous solution while the unsaponifiable oils and waxes dissolved in the ether. The addition of a salt to an aqueous solution prior to extraction is sometimes practiced in some processes. In older processes, SOj is employed in the separation of aromatic and highly saturated hydrocarbons, taking advantage of the much greater solubility of the solubility of the aromatics and... 

Dispersants To keep insoluble combustion and oxidation products in suspension and dispersed Salts of phenolic derivatives polymers containing barium, sulphur and phosphorus calcium or barium soaps of petroleum sulphonic acids... 

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