SU668622A3 - Method of recovering oil from underground formations - Google Patents

Description

(54) METHOD FOR EXTRACTING OIL FROM UNDERGROUND FORLAATSG:

one

The invention relates to a method for extracting oil from subterranean formations and can be used in the oil industry.

Methods are known for extracting oil from subterranean formations using micellar dispersions 1, 2 and 3.

Closest to the invention is a method of extracting oil from subterranean formations by introducing into the latter a micellar dispersion consisting of a surfactant, a hydrocarbon, a co-surfactant, and water 4. The resulting mixture is displaced, the oil is separated.

However, the method is not sufficiently effective due to the difficulty in adjusting the viscosity of the dispersion used.

The aim of the invention is to increase the efficiency of the method by adjusting the viscosity of the injected dispersion.

The goal is achieved by the proposed method of extracting oil from subterranean formations by introducing into the latter a micellar dispersion consisting of a surfactant, carbohydrate.

kind of, on top of aches in act and and but 1o substance. water and additionally with base and amount of 0.25 - 6.00 vol. /, .. 15 cv.cc test and separation of oil.

Preferred using the dispersion, containing 0.001--10.0 weight. electrolyte, in KacheSGVS 1K) P, Cp 1K CT KL ;; kT VN

This substance is used in vitro digestion with 4N) nat, the content of monovalent cation.

The novel active compound may be anionic, non-active or cationic, or may be co6oii mixtures of these substances. Preferred is sulphonating oil sclfonate (crude oil, for example gas oil, oily or non-benzine oil, followed by neutralization with nomop: ammonium hydroxide or sodium hydroxide. It is advisable to use a copper phonate with an equivalent weight of 350-525. Preferably 460-390, more preferably 400-450.

Claims (4)

The water in the mixture can be distilled, fresh or contain moderate salts. As a rule, water contains about 5-50 000 million dissolved solids. It is desirable that the water does not contain a significant amount of butylvalent cations that can displace or replace the cations in the surfactant. The electrolytes used are water-soluble inorganic salts, inorganic bases, inorganic acids, or mixtures thereof. Typically, these are byproducts of a petroleum sulfonate reaction, for example, ammonium sulfate, ammonium sulfite, sodium sulfite. The electrolytes can be added or mixed with other electrolytes in the aqueous phase of the micellar dispersion mixture. The co-surfactant, also known as a semi-polar organic compound (co-solvent, stabilizing agent), is an organic compound containing 1-25 or more carbon atoms, more preferably 3-16 carbon atoms. It may be an alcohol, an amide, an amino compound, an ether, an aldehyde, a ketone, their complexes or a compound, one or more of its amido, hydroxy, bromo, chloro, carbonate, mercapto, oxo, hydroxy, carbonyl or similar groups or mixtures thereof. . Thus, isopropanol, butanol, amyl alcohols, hexanols, octanols, decyl alcohols, alkylaryl alcohols such as n-nopylphepol and isopropyl-1-p-1phenol, 2-butoxy | exapol are used. alcohol liquids such as fusel oil; mixed isomers of primary amyl or hexanol alcohols, mixtures (.12. -13, C | 4, C) 5, etc. of linear primary alcohols, ethoxylated alcohols, such as cnnpTiji, containing 4-16 carbon atoms, which are ethoxylated and can be succinct; hydrogenated coal tare, such as hydrogenated) top mass, 1o; amidated hydrocarbons and other similar substances. The content of the components of the micellar dispersion depends on the type of the component and the target properties. Typically, the content of surfactant is 4-20, preferably between 6 and 16, more preferably between 7 and 12 weight. The hydrocarbon content is 4-86, 5-50, 6-20 weight, respectively. %; the content of the co-surface active substance is respectively 0.01-20; 0.05-10, 0.1 - 3 weight. /about; water content 10-92, 40-91. 60--90 weight. %; electrolyte content is 0.001–10; 0.01-7.5; 0.25-5 weight. o / o The alcohol added to the dispersion is introduced at such a concentration that phase separation does not occur. The viscosity of the dispersion depends on the degree of hydrophilicity of the added alcohol. Thus, the use of a hydrophilic spiral leads to reduced viscosity values, the use of a less hydrophilic pier leads to higher values. The micelle dispersion is introduced into the formation in an amount of 1-5, preferably -15% of the volume of the cavity of the formation. The supply of mobility buffer, for example, an aqueous solution of a polymer that causes a decrease in the permeability of the formation, will increase the viscosity of the aqueous solution. The amount of buffer is 10–200% of the volume of the formation cavity. The micelle dispersion and mobility buffer are displaced with water and the oil is separated. Example 1. A mycelial dispersion is obtained by displacement of 11.7 wt. % ammonium sulfonate oil having an average equivalent weight of about 420 and containing 62 wt. % active sulfonate obtained by sulfating Gaizole with sulfuric anhydride 22.9% by weight of oil having a density of pij 0.8354, a viscosity of 7-9 cP, and 65.5% of water containing 400 million soluble solids and 10,000 million (NH .4) 4SO4. The total water content, including water from the sulfonate, is 70 wt. % To this mixture is added n-pentanol or n-hexanol. The dependence of the viscosity of the dispersion on the amount of alcohol added is shown in FIG. 1. When n-pentanol is added, a lower viscosity is obtained than with n-hexanol. Thus, for a given dispersion, the addition of alcohols with greater solubility in water results in a lower viscosity. The micelle dispersions are tested on a sandstone subterranean formation, 1.2 m in length, 0.075 m in diameter. The formations are filled with water, then with oil with a viscosity of about 7 cP and again with water. The micelle dispersions described in example 1 are introduced into the formations obtained in the amount of 2% of the sandstone pore volume. Then, 150% of the pore volume of an aqueous solution of a partially hydrolyzed polyacrylamide of high molecular weight is added. When using a dispersion containing 1 vol. (o) n-hexanol, the amount of recovered oil is 82 wt. /about; dispersion containing 0.5 vol. % n-hexanol, 60 wt. %; dispersion containing 3 vol. % n-pentanol, 90 wt. %; dispersion containing 1.5 vol. % n-pentanol, 60 wt.%. Example 2. A micellar dispersion is prepared by displacing 10% by weight of ammonium sulfonate oil, which contains 61% w / 1 of active sulphonate and has an average equivalent weight of about 440, 40% by weight. % hydrocarbon consisting of 60% of the oil of example 1 and 40% of heavy oil, 50 wt. ° / o water containing 400 million dissolved solids and 3,900 million (NH4) 2.SO +. The total water content of this mixture, including sulphonate water, is 54.5% by weight. Nonylphenol, n-hexanol, 2-hexanol and n-pentanol are added to the mixture. The dependence of the viscosity of the dispersion on the amount of added alcohol is shown in FIG. 2. Dispersions are tested by introducing the latter in an amount of 5% of the pore volume of the rock in a 1.2-meter-long sandstone formation with a diameter of 0.051 m, treated with water and oil of Example 1. After the dispersion is introduced into the formation, an aqueous solution of partially hydrolyzed polyacrylamide is introduced in an amount of 150 % of pore volume. When using a dispersion containing 0.8 vol. % n-pentanol, the amount of recovered oil is 85 wt. / o, a dispersion containing 1.2 vol. % n-pentanol, 94 wt. % Claim 1, A method for extracting oil from underground formations by introducing g25 Concentrations of alcohol, nS. / o fu.l Concentration of alcohol, oS. % 2 of the 2 mipellar dispersion, consisting of a surfactant, a hydrocarbon, a co-surfactant and water, displacement of the mixture and separation of oil, different temp. that, in order to determine the efficiency of the process, a psellally dispersion is used, additionally containing alcohol in a volume of 0.25–6.00 vol. Vc. 2. A method according to claim 1, characterized in that a dispersion is used containing 0.001-10.0 wt. % electrolyte. 3 The method according to claim K, characterized in that petroleum sulfo.nt is used as a surfactant. containing a monovalent cation. Sources 1-; nformation |.:, Taken into account by expert 1-; s 1.Patent USA.- Up to 3578082, cl. 166 - 252 1971. 2. US patent Law 3464194. cl. 208-11, 1972. 3. The patent of the school. Le Le 361378ti. cl. 166-273, 1971. 4. US Patent No. 3561530.C. 166-252 1971.