RU2715001C2 - Thickener of aqueous solution of acid and / or salt, method of thickening aqueous solution of acid and / or salt and method of oil production using said thickener, set of components for thickening of aqueous solution of acid and / or salt and composition for implementation of acid hydraulic fracturing of formation, including said thickener - Google Patents

Abstract

FIELD: chemistry.SUBSTANCE: invention relates to thickening of aqueous solutions of acids and salts and use of thickened solution for hydraulic fracturing of the formation. Use of the combination: a) a zwitterion compound of formula I,where R is a saturated, mono-, di- or tri-unsaturated hydrocarbon radical C-C; Rrepresents -COOor -CHCOO; R, R, R, Rindependently represent hydrogen, methyl, ethyl, propyl, isopropyl, allyl, vinyl, phenyl or benzyl; b) a compound selected from a group consisting of diethanolamides of C-Cfatty acids, alkyl dimethylamine oxide, hydroxyethyl alkyl imidazole, butyl glycol, cinnamaldehyde and oxycinnamates; and c) optionally, an iron converter for thickening the aqueous solution of the acid and / or salt.EFFECT: high efficiency of proppant transfer over a long period of time, high efficiency of extracting hydrocarbons from the formation.25 cl, 8 dwg, 9 tbl

Description

FIELD OF THE INVENTION

The present invention relates to a system for thickening surfactant-based acid solutions, a method for thickening acids and options for using a thickened acid solution, in particular in a hydraulic fracturing technique.

State of the art

Hydraulic fracturing (Fracturing) consists in the formation and expansion of cracks in the reservoir during the creation of high pressures at the bottom of the fluid pumped into the well. Propant, a granular proppant, is injected into the resulting cracks, so that the crack does not close after relieving pressure. This ensures the communication of the far zones of the formation with the bottomhole zone.

The rheological characteristics of standard thickened acid systems do not allow to hold the fracture and transfer proppant. To solve the problem of acid fracturing (HGR) with proppant, a technology of alternating packs of aqueous guar gel with the addition of proppant to water packs, buffer stages with subsequent injection of acid packs is implemented. In this technology, a proppant guar gel opens and holds the crack, and the next pack of acid etches the created crack. The main task, which is pursued in the "classical" acid fracturing technology, is to create bonds with the far zone of the formation using acid injection (the main working fluid); stage proppant injections are used to open and hold a crack, allowing acid to pass on and process the formation.

Also, in acid treatment, it is often necessary to increase the viscosity of the acid solution. This is necessary in order to reduce the kinetics of acid treatment, reduce acid loss during processing, ensure the efficiency of proppant transfer, as well as to control the size of cracks, etc.

This technology has several disadvantages, the main of which are the following:

1. The water gel contains a polymer thickener, for example, guar polysaccharide, which even when the cross and linear bonds are broken by a breaker or acid, forms an insoluble precipitate that is not completely removed and contaminates the fracture / formation, impairing permeability in the treatment zones.

2. Since the aqueous gel breaks upon contact with acid, the likelihood of prematurely stopping the gel injection caused by blockage (STOP) increases, the depth of penetration of the acid decreases.

3. The need to use a large number of various liquids, a large number of equipment and a capacitive park for kneading packs and the implementation of this technology.

To eliminate the above disadvantages, systems and compositions of surfactant-based acid thickeners have been developed that do not contain polymer compounds.

So, in US patent US 8895481 B2 describes a method of treating a subterranean formation by introducing a viscoelastic acidic fluid containing:

(i) 0.5-5.5% of the mass. zwitterionic surfactant formula

,

,

in particular the following betaine structure

,

,

where n is 3, p is 1, and R is a C17 hydrocarbon radical for BET-O-30 surfactant or R is a C21 hydrocarbon radical for BET-O-40 surfactant;

(ii) more than 15% of the mass. acids such as hydrochloric acid, and

(iii) a rheological enhancer.

It is indicated that the fluid may additionally carry proppant.

WO2003054352 A1 describes a method for processing underground hydrocarbon
formation by introducing a gelled acidic fluid containing a surfactant based on a betaine compound of the formula

and an acid such as hydrochloric acid. It is indicated that the fluid may further include a solvent, such as methanol.

US Patent Application US 2013306320 A1 describes a composition for treating carbonate reservoirs, comprising:

about 7.5 vol.% zwitterionic viscoelastic surfactant;

about 15.0 vol.% hydrochloric acid; and

about 0.6 vol.% corrosion inhibitor, the rest is brine.

The preferred zwitterionic viscoelastic surfactant is erucrylamidopropyl betaine.

In RF patent No. 2452851, issued on the basis of application WO2007 / 058813, a method for increasing oil production from a field is disclosed, including

a) the introduction of flooding fluid into the field, where the fluid includes:

i) water and

ii) a quantity of one or more non-polymeric viscoelastic surfactants sufficient to cause the flooding liquid to have a surface tension at the oil / water interface of about 1 mNm or less and a viscosity of about 10 cP or more, where one or more non-polymeric viscoelastic surfactants selected from the group of: one or more amine surfactants having the formula:

where R1 is a hydrophobic residue of alkyl, alkylarylalkyl, alkoxyalkyl, alkylaminoalkyl or alkylamidoalkyl, and where R1 includes about 16-22 carbon atoms and may be branched or unbranched, saturated or unsaturated;

where R2 and R3 independently represent i) an aliphatic group or ii) an aliphatic group associated with an aromatic or benzyl radical, one or more zwitterionic surfactants, one or more amphoteric surfactants, and combinations thereof;

b) oil recovery through the well at a location other than the point of introduction of the flooding fluid into the field.

The use of an organic acid to increase the viscosity of said liquid is also mentioned.

Eurasian Patent EA No. 2452851, issued on the basis of WO2003 / 054352, describes a method for treating an underground hydrocarbon reservoir, comprising contacting a formation with a treatment solution containing an aqueous solution, acid, alcohol and a surfactant acting as a gelling agent, consisting mainly of erucilamidopropyl betaine or its protonated / deprotonated homologue or salt.

However, the known systems proposed for the implementation of fracturing do not have a viscosity sufficient to transfer proppant for a long period of time necessary for the implementation of a full and effective fracturing. In particular, the known thickeners make it possible to achieve only a viscosity of 60-80 cps.

Thus, there is an urgent need to create systems for hydraulic fracturing with high viscosity to increase the efficiency of proppant transfer and increase the efficiency of hydrocarbon recovery from the formation. This application proposes a new thickening system for acid solutions based on a zwitterionic compound.

Disclosure of the invention.

The objective of the present invention is to expand the arsenal of technical means for the effective implementation of HFGR technology and to develop a chemical system for thickening an aqueous solution of acid and / or salt to produce a liquid or gel with a high viscosity sufficient for the effective implementation of HHF. It is also an object of the present invention to provide a simple and effective method for producing oil from a field using the method of acid hydraulic fracturing (hydraulic fracturing).

These problems are solved by developing a chemical system that allows the thickening of an aqueous acid solution from viscosity values of 2-15 cPa to 1800 cPa. The specified system contains a zwitterionic compound described below, another surfactant as an optional auxiliary component, and, optionally, an iron converter.

The first aspect of the present invention is the use of a combination

a) zwitterionic compounds of formula I

,

,

where R represents a saturated, mono-, di- or tri-unsaturated hydrocarbon radical With ₉ -C ₂₅ ; R ₁ represents —COO ^- or —CH ₂ COO ^- ; R ₂ , R ₃ , R ₄ , R ₅ independently represent hydrogen, methyl, ethyl, propyl, isopropyl, allyl, vinyl, phenyl or benzyl;

b) a compound selected from the group consisting of C ₁₀ -C ₂₀ fatty acid diethanolamides, alkyldimethylamine oxide, hydroxyethylalkylimidazole, butyl glycol, cinnamaldehyde and hydroxycinnamic acids; and

c) optionally, an iron converter,

for thickening a solution of acid and / or salt.

The first major component of the combination or composition of the present invention is a zwitterionic compound of the formula I. A preferred example of the zwitterionic compound of the formula I of the present invention is erucilamidopropyl betaine (EAAH, synonym for 2- [3- [docos-13-enoyl] aminopropyl-dimethylammonium] acetate).

A second auxiliary optional component of the combination or composition of the present invention is a compound selected from the group consisting of C ₁₀ -C ₂₀ fatty acid diethanolamides, alkyl dimethyl amine oxide, hydroxyethyl alkyl imidazole, butyl glycol (butyl cellosolve), cinnamaldehyde and hydroxycinnamic acids. Examples of C ₁₀ -C ₂₀ fatty acid diethanolamides are coconut oil diethanolamides.

The acid whose solution is to be thickened according to the present invention can be any acid. For example, the acid may be an acid selected from the group consisting of hydrochloric acid, hydrobromic acid, hydrofluoric acid, hydroiodic acid, sulfuric acid, nitric acid, chromic acid, methanesulfonic acid, trifluoromethanesulfonic acid, trichloroacetic acid, dichloroacetic acid, bromoacetic acid, bromoacetic acid, chloroacetic acid, cyanoacetic acid, 2-chloropropanoic acid, 2-oxobutanoic acid, 2-chlorobutanoic acid, 4-cyanobutanoic acid, perchloric acid and phosphoric acid acid, etc. In a preferred embodiment, the acid is an inorganic acid. In some embodiments, an acid is any combination of acids. In a preferred embodiment, a solution of hydrochloric acid, traditionally used in the fracturing technology, is thickened.

The present invention can also be used to thicken solutions of organic acids, which include organic substances that exhibit acidic properties, including carboxylic acids containing a carboxyl group —COOH, and sulfonic acids containing a sulfo group with the general formula SO ₃ H. Non-limiting examples of organic acids solutions of which can be thickened in accordance with the present invention include acids such as formic acid, acetic acid, benzoic acid, lactic acid, malic acid ota, propionic acid, butanoic (butyric) acid, hexanoic acid, formic acid, octanoic acid, formic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, docosanoic acid, hexanoic acid, mi palmitoleic acid, oleic acid, linoleic acid, linolenic acid, gadoleic acid, arachidonic acid, eicosapentaenoic acid, docosapentaenoic acid, erucic acid, hyal uronic acid and the like

The following is a partial list of acids for thickening which you can use the method or system according to the present invention: abietic acid, abrin, abscisic acid, agaricic acid, adipic acid, azaronic acid, azelaic acid, aconitic acid, aconic acid, acrylic acid, α-alanine , aleuritic acid, allantoic acid, allocoric acid, alloxanic acid, allosanthenic acid, D-alloslizic acid, allophanic acid, angelic acid, anhydroecgonin, p-anisic acid a, anthranilic acid, 1-anthroic acid, 2-anthroic acid, 9-anthroic acid, apocamphoric acid, apofenchocamphoric acid, arachidonic acid, arachinic acid, arginine, arecaidine, aristolochic acid, asparagine, aspartic acid, atrolactic acid, atropic acid, atropic acid acetylenedicarboxylic acid, acetoacetic acid, acetic acid, baicain, behenic acid, behenolic acid, benzylic acid, benzoic acid, berberonic acid, betulinic acid, bilianic acid, biotin, brassidine hydrochloric acid, brassilic acid, valerianic acid, valine, valproic acid, vanillyl mandelic acid, vanillic acid, waxenic acid, veratric acid, vernolic acid, tartaric acid, grape acid, gadoleic acid, galactaric acid, D-galacturonic acid, gallic acid, gallic acid acid, hematinic acid, hemellitic acid, hemimellitic acid, hemipinic acid, gentisic acid, geronic acid, hesperetic acid, heteroauxin, hydantoic acid, hydrocarp I acid, hydraacrylic acid, hydratropic acid, hydrocinnamic acid, hippuric acid, histidine, glycolic acid, glycocholic acid, glyoxylic acid, glyceric acid, glycine, glycyrrhizic acid, glutaconic acid, glutamine, glutamic acid, glutaric acid, gluconic acid , homovanilinic acid, homoveratric acid, homogentisic acid, homocamphoric acid, homoserin, homophthalic acid, homocysteine, gondoic acid, gorlic acid, throat acid, pomegranate acid, guavacin, dalapon, dehydrocholic acid, deoxycholic acid, digallic acid, diglycolic acid, dimolactic acid, dinicotinic acid, dipicolinic acid, diphenic acid, doisinoleic acid, durylic acid, diencolic acid, isatropic acid, jasperonic acid , isovanilinic acid, isohemipinic acid, isoheronic acid, isodehydroacetate acid, isodiphenic acid, α-isoduric acid, β-isoduric acid, γ-isoduric acid that, isocamphoric acid, isocaproic acid, isocoric acid, isocrotonic acid, isoxylic acid, isolauronolic acid, isoleucine, isolimonic acid, isobutyric acid, isonicotinic acid, isosaccharic acid, isoferulic acid, isophthalic acid, isocinnocharic acid, isocinnoric acid, isocinnoric acid, isocinnoric acid , indogenic acid, indoxilic acid, itaconic acid, kainic acid, α-camolenic acid, campanic acid, camphenylanic acid, camphenyl acid, camphenic acid lot, camphoric acid, camphoric acid, α-campholenic acid, β-campholeic acid, campholytic acid, camphoric acid, camphonic acid, camphonic acid, camphoric acid, camphoric acid, camphoric acid, camphoric acid, caprylic acid, capric acid, capron , carbamic acid, carbanilic acid, carbodinicotinic acid, α-carbocinchomeric acid, β-carbocinchomeric acid, carboxylic acid, carmesic acid, ketopinic acid, L-kinurenine, nurenic acid, comenic acid, cinnamic acid, cinnamic acetic acid, cotaric acid, caffeic acid, creatine, o-cresotinic acid, crotonic acid, crocetin, xanthan acid, 2,4-xylic acid, 2,6-xylic acid, 3,4 xylic acid, xymenic acid, curbic acid, cumalic acid, coumaric acid, coumaric acid, coumaric acid, o-coumaric acid, m-coumaric acid, p-coumaric acid, coumidic acid, cumic acid, lactaric acid, lactobacillic acid ota, lanthionine, lauric acid, lauroleic acid, laceric acid, levulinic acid, leucine, leucine acid, lecanoric acid, lignoceric acid, lysergic acid, lysine, licanic acid, citric acid, citric acid, linoleic acid, 10,12-linoleic , α-linolenic acid, lipoic acid, α-lithocholic acid, β-lithocholic acid, loiponic acid, lutidic acid, maleic acid, malonic acid, malvic acid, margaric acid, butyric acid, mevalon I acid, mesaconic acid, mesitylic acid, mesic acid, mesoxalic acid, meconic acid, melilic acid, melissovy acid, mellitic acid, metaemipic acid, methacrylic acid, methionine, mycomycin, mandelic acid, myriocin, myristic acid, myristoleic acid, myristoleic acid , monocrotaline acid, montanoic acid, mucobromic acid, muconic acid, mucochloric acid, formic acid, mucic acid, narcein, naphthalic acid, α-naphthoic acid, β-naphtha Ninic acid, Nemotinic acid, Nepal acid, Nepet acid, Neponic acid, Nervonic acid, Nephrosteric acid, Niacin, Nipecotinic acid, Nopinic acid, Norkamorphic acid, Norkinic acid, Oxaluric acid, Oxamic acid, Oleic acid, Olivetolic acid, Opi , ornithine, ornithuric acid, orotic acid, o-orsellic acid, palmitic acid, palmitoleic acid,

pantoic acid, pantoic acid, pantothenic acid, paraconic acid, parinaric acid, pelargonic acid, penicillamine, penicillanic acid, penicillic acid, petroselinic acid, pivalic acid, picolinic acid, pimaric acid, pimelic acid, pinic acid, pin pinononic acid, pipecolic acid, pipecolic acid, piperic acid, piperonic acid, pyruvic acid, pyruvic acid, pyroglutamic acid, pyrocatechol hydrochloric acid, pyromellitic acid, pyroslytic acid, pyrocinchonic acid, podocarpic acid, porphobilinogen, pregnitilic acid, prefenic acid, priristic acid, cork acid, L-proline, propargylic acid, propiolic acid, propionic acid, prostanoic acid, protocatechoic acid, protolicholeic acid, protol , psillastearic acid, pteroylglutamic acid, α-resorcylic acid, β-resorcylic acid, γ-resorcylic acid, rhein, ricinoleic acid, salicylic acid, cis-santa new acid, trans-santenic acid, sebacic acid, selacholic acid, L-serine, sialic acid, sylvinic acid, sinapinic acid, synapic acid, lilac acid, mucus acid, sorbic acid, stearic acid, stearoxyl acid, stearic acid, steric acid , stillingic acid, stipitic acid, suberic acid, succinamic acid, tapsic acid, tartaric acid, tartronic acid, teraconic acid, terebic acid, terephthalic acid, terpenyl I acid, tetrolic acid, tiglinic acid, thymnodonic acid, thioctic acid, L-tyrosine, thyroxine, o-toluic acid, m-toluic acid, p-toluic acid, traumatic acid, L-threonine, tricarballic acid, trimesic acid, trimesitic acid Acid, Trimellitic Acid, L-Tryptophan, Tricyclic Acid, Tropic Acid, Tropic Acid, α-Truxylic Acid, Truxinic Acid, Tubaic Acid, Tuberculostearic Acid, Tuberonic Acid, Uvitic Acid, Acetic Acid, Umbellin Acid acid, ursodeoxycholic acid, ursocholanic acid, feist acid, phenanthic acid, L-phenylalanine, ferulic acid, phytanic acid, phloretic acid, folic acid, phthalamic acid, phthalic acid, fumaric acid, haulmugroic acid, chelidonic acid, hydrochloride acid , quinic acid, quinic acid, quinolinic acid, cholic acid, chorismic acid, chrysanthemum acid, cervonic acid, ceroplastic acid, cerotinic acid, cetoleic acid slots, cephalosporanic acid, cilianic acid, cineolic acid, cinchomeronic acid, cinchoninic acid, cinchonic acid, L-cysteine, cysteic acid, cystine, citraconic acid, Shikimovy acid, oxalic acid, oxalacetic acid, ecocarbonacetic acid, echocarbonacetic acid, tartaric acid , elaidic acid, eleostearic acid, enanthic acid, epitruxilic acid, erythrogenic acid, erucic acid, malic acid, succinic acid, japonic acid.

The salt to be thickened according to the present invention can be selected from the group consisting of sodium chloride, magnesium chloride, potassium chloride, calcium chloride, aluminum chloride, nickel chloride, sodium nitrate, sodium hydrogen carbonate, aluminum sulfate, copper sulfate. Preferred is the use of chlorides, such as aluminum chloride. In some embodiments, a salt is any mixture of salts. Also provided is a thickening solution containing one or more acids and one or more salts.

Additionally, the combination or composition according to the invention may comprise an iron converter.

An iron converter is a compound or composition of compounds capable of reducing Fe (III) to Fe (II) with the conversion of iron to a more soluble divalent form and the formation of stable chelate complexes with Fe (III), preventing the formation of an amorphous precipitate of iron hydroxide Fe (OH ) ₃ , which in addition to the negative effect on the permeability of the formation is an intermediate product during rusting of iron. The use of an iron converter is desirable, for example, when using metal equipment, and also because iron (III) salts reduce the viscosity of gelled aqueous acid solutions.

Examples of iron converters include, but are not limited to, ascorbic acid, citric acid, a mixture of mercaptoethanol, copper chloride and methanol, an iron converter AS-IR.

When implementing the present invention, various ratios of components of the chemical system can be used: the zwitterionic compound of the formula I and the compound selected from group b). The specialist will be able to choose the optimal ratio through routine experiments. In particular, the ratio of any two components may be approximately 0.1: 100, 1: 100, 1:50, 1:20, 1:10, 1: 5, 1: 3, 1: 2: 1: 1, 2: 1, 3: 1, 5: 1, 10: 1, 20: 1, 50: 1, 100: 1, 100: 0.1. In the broadest sense, the lower limit or the upper range of the content of each component in the system can be approximately 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 84, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99.

The content of each of these components, or combinations thereof, in the final composition can be about 20%, about 15%, about 10%, about 5%, about 2.5%, about 2%, about 1%, about 0.5% , about 0.1% or less, including all intermediate ranges and values.

In one embodiment, the zwitterionic compound content is 1-7% or 1-5%, and the content of the auxiliary component is 1-7%.

The indicated values of the content of the components can be calculated both by weight and by volume. It is assumed that all values are approximate and take into account possible tolerances of ± 15% or ± 10% of the values given.

In some embodiments, the system is presented in the form of a solution, in particular, an aqueous solution containing salt.

Without intending to limit the functionality of the invention to a theoretical justification, the authors believe that the zwitterionic molecules in solutions are able to assemble into aggregates called micelles. First, spherical micelles are formed, then with increasing concentration of surfactants they begin to interact with each other, which leads to their deformation. As a result, micelles tend to take a cylindrical, disk-like, lamellar or rod-shaped form. Because of this, surfactants can form worm-shaped micelles, which tend to form a network of spatial links, as a result of which the solution acquires visco-elastic properties. These properties depend on the properties of the medium, in particular, pH. A zwitterionic surfactant, such as EAFB, is capable of forming vermiform micelles in saline. With decreasing pH, betaine is protonated and is present in the solution in the form of spherical micelles. Interaction with other types of surfactants allows one to obtain a spatial network that provides high viscosity under various environmental conditions. Obtaining high viscosity cannot obviously be predicted on the basis of available information about the behavior of each of the components of the system in an acid and / or salt solution.

A second aspect of the present invention is a method for thickening an aqueous acid solution, comprising adding to the said aqueous acid solution a combination of the compounds described above and, optionally, an iron converter. The substances according to the present invention and the iron converter can be added to the thickened acid solution both simultaneously, for example, in the form of a single composition, or in any combination or separately.

A third aspect of the present invention is a kit of components of a chemical system for use in thickening an aqueous solution of an acid and / or salt, or for implementing the described method of thickening an aqueous solution of an acid and / or salt. The kit contains the components described above and, optionally, an iron converter and / or salt.

A fourth aspect of the present invention is a composition for performing an acid hydraulic fracturing process comprising an aqueous solution of acid and / or salt, the above set of components of a chemical system, and, optionally, proppant.

As the acid, any acid, for example, an inorganic acid, can be used. Preferred is the use of hydrochloric acid.

The acid content in the specified aqueous solution and the resulting gel may be in the range from 10% to 20%, optionally 12 to 16%. In one embodiment, a 15% aqueous hydrochloric acid solution is used.

The salt content in the solution is 5.0 to 6.0 wt.%, Preferably 6%. It is preferable to use chlorides, in particular calcium chloride and aluminum chloride.

The preferred content of the components in the proposed composition containing an aqueous solution of an acid or salt, the following:

- a compound of formula I 2.5 to 5.0 wt.%; - a compound selected from group b) 0.5 - 7.0 wt.% and one of the following: inorganic acid 12.0 - 16.0 mass. % and - optional, iron converter 0.2 to 1.0 wt.%; or - inorganic salt 5.0 - 6.0 wt.%; - the rest -  water.

All components of the composition can be used in the form of solutions in suitable solvents. Such solvents can be selected by one skilled in the art based on general knowledge and relevant literature data. Non-limiting examples of solvents include methanol, ethanol, isopropanol, dichloromethane.

The present invention can be applied in any areas where it is desirable to obtain a solution of acid and / or salts of high viscosity and / or reduce the rate of interaction with acid. In particular, gelled acid solutions can be used as cleaning agents and in cosmetology. Accordingly, for any embodiment disclosed herein, it is intended to be used in these areas. In particular, an additional embodiment of the invention is a cosmetic composition comprising a solution of salt and / or acid, thickened and / or gelled in accordance with the present invention. Another further embodiment of the invention is a cleaning agent or composition for use as a cleaning agent, containing a salt and / or acid solution, thickened and / or gelled in accordance with the present invention. Such compositions may contain any additional components used in the relevant field, provided that they do not exclude the possibility of increasing the viscosity of the composition as a whole, achieved in accordance with the present invention.

In one embodiment, the composition comprises proppant.

Proppant (or proppant, from the English propping agent - "proppant") is a granular material that is used in the oil industry to increase the efficiency of well returns using hydraulic fracturing technology. Serves for fixing (preventing closure under the influence of rock pressure) of cracks created during hydraulic fracturing. It is a pellet of a similar size, with a typical diameter of 0.5 to 1.2 mm. According to the present invention, any proppant commonly used in fracturing technology can be used.

The proppant is added in amounts usually used in the implementation of the fracturing. In some embodiments, the proppant is added at the rate of 800 kg / m ^{3 of} gel.

A fifth aspect of the present invention is a method for producing oil from a field using an acid hydraulic fracturing method, comprising introducing the composition described above into a field and recovering oil from said field.

Oil extraction from the field can be carried out using standard tools and methods used in this field, for example, described in the following sources: Bulatov A.I. and others. Technique and technology for drilling oil and gas wells: Textbook for universities - M: Nedra - Business Center LLC 2003 - 1007 p .; Usachev P.M. Hydraulic fracturing - M .: Nedra, 1986. - 165 p.

Preferred is the use of the present invention in deposits containing carbonate rocks.

The technical result of the proposed technology is to increase the viscosity of the acid solution, which, among other things, makes it possible to effectively transfer proppant, and also provides an effective process of fracturing. It should be noted that the authors of the present invention managed to create a thickener composition for an aqueous acid solution with a high degree of viscosity, up to 1800 cPs, sufficient to hold and transfer proppant for a long time, necessary for the implementation of a full and highly effective fracturing.

At the same time, using one acid or salt gel obtained, it is possible to simultaneously create a hydraulic fracture, transfer proppant, fix the fracture with proppant, treat the carbonate formation with acid and create highly permeable channels in the critical zone of the fracture, thereby allowing more efficient and prolonged operation of the hydraulic fracture.

In other words, the present invention makes it possible to replace the hydraulic fracturing fluid with a salt gel or to use a new technology with one working fluid.

The stage-by-stage processing of the deposit by traditional methods, without applying the present invention is as follows:

- Preparatory packs

- Water gel with proppant - hydraulic fracturing

- Buffer stage

- 15% hydrochloric acid - increase in crack length

- Buffer stage

- Water gel with proppant - clogging

- Buffer stage

- 15% hydrochloric acid

- Buffer stage

- Water gel with proppant

- Buffer stage

- 15% hydrochloric acid

- Sales of hydraulic fracturing fluids and by-product removal.

At different stages, a large number of liquids are used, the implementation of each of them requires a separate tank and mixer.

The application of the present invention allows to significantly simplify the scheme of hydraulic fracturing, minimizing the fluids, tanks and equipment involved:

- Preparatory packs

- Acid gel - the formation of hydraulic fractures and acid treatment, retention of the crack

- Acid gel with proppant - fixing cracks, acid treatment, crack retention

- Sales of hydraulic fracturing fluids and by-product removal.

Briefly, the advantages of the method of oil production according to the present invention include the following:

1. Ease of use, since there is no need to use a large number of reagents used in the traditional hydraulic fracturing technology (crosslinkers, breakers, biocides, stabilizers, demulsifier, etc.)

2. A much smaller amount of equipment and tank fleet is required to prepare the composition compared to traditional hydraulic fracturing technology.

3. The ability to create a longer crack by using only one fluid for the entire treatment. This is achieved through the formation of micelles, which give the acid a gel-like structure. The gel formed clogs the etched channels and increases the time of their interaction with acid.

4. The stage of using a pack with an aqueous polymer gel based on guar is excluded, while this acid system is completely destroyed. The resulting reaction products dissolve well in water and are easily removed from the bottomhole zone during washing.

5. Acid entering the formation interacts with carbonate rocks, as a result of which its concentration decreases, and the content of Ca ^{2+ ions} increases, which leads to a decrease in the swelling of clay layers.

6. The use of only one fluid, which has the necessary characteristics for conducting fracturing with propant.

7. Double system of destruction of the gel (decrease in acid concentration, mixing with hydrocarbons).

8. Low friction loss.

9. Significantly reduced the cost of work due to the reduction in the number of reagents and stages of processing.

In the proposed technology, essentially only one liquid is used. Compared with classic and combined (alternating guar gel with propant-acid) fracturing schemes, the following advantages can be achieved:

the absence of a polymer component, the maximum conductivity of the crack and the permeability of the walls of the crack,

vertical crack propagation restriction (increase in “areal” concentration of proppant in the productive zone),

minimized fluid injection

high sand-bearing ability of the liquid, minimal subsidence of the proppant and, as a result, uniform distribution of proppant in the crack.

Below, the present invention will be explained in more detail with reference to the Figures and Examples, given solely for illustrative purposes, not limiting the scope of the present invention.

A brief description of the drawings.

In FIG. Figure 1 shows a graph of the dependence of the viscosity of the solution on the concentration of diethanolamide of coconut oil acids.

In FIG. Figure 2 shows a graph of the dependence of the viscosity of the solution on the concentration of alkyldimethylamine oxide.

In FIG. Figure 3 shows a graph of the dependence of the viscosity of the solution on the concentration of hydroxyethylalkylimidazole.

In FIG. Figure 4 shows a graph of the dependence of the viscosity of the solution on the concentration of alkyldimethylamine oxide.

In FIG. Figure 5 shows a graph of the dependence of the viscosity of the solution on the concentration of cinnamaldehyde at various temperatures.

In FIG. Figure 6 shows the results of a study of the proppant retention by a composition based on EAAB and alkyldimethylamine oxide.

In FIG. 7 shows the results of a study of the proppant retention by a composition based on EAFB and coconut oil diethanolamide.

In FIG. Figure 8 shows the results of a study of the proppant retention by a composition based on EAAB and cinnamaldehyde.

The implementation of the invention.

Example 1. Preparation of a hydrochloric acid solution composition according to the present invention.

The composition was prepared as follows. In a 15% synthetic hydrochloric acid with stirring on a top-drive mixer, a Hi-Iron iron converter manufactured by Special Oilfield Chemistry CJSC (a mixture of mercaptoethanol, copper chloride and methanol) was added to a concentration of 0.3-0.5% and one of the compounds selected from the group consisting of coconut oil diethanolamide, alkyldimethylamine oxide, hydroxyethylalkylimidazole, cinnamaldehyde and hydroxycinnamic acids. The resulting solution was stirred.

Then, a zwitterionic compound, namely erucilamidopropyl betaine, was added to the resulting solution with vigorous stirring on a lower drive mixer. The viscosity of the solution increased significantly.

Typical concentrations of the components are presented in the table:

Gelled surfactant based on 15% HCl Iron converter 0.3 to 0.5 mass. % Erucilamidopropyl betaine 1.5 to 8.0 mass. % Coconut oil diethanolamide, alkyldimethylamine oxide, hydroxyethylalkylimidazole, cinnamaldehyde or hydroxycinnamic acid 0.1 to 7.0 mass. %

To study the rheological characteristics of the obtained system, we used a Brookfield viscometer model DV2TLVTJ0, LV4 spindle (64), at a speed of 100 rpm.

Example 2. Assessment of the viscosity of hydrochloric acid solutions of EAA and diethanolamide acids of coconut oil

The dependence of the viscosity of the hydrochloric acid solution on the concentration of the reagents of the composition according to the present invention was determined. The specified solution was prepared by the method described above in Example 1.

To study the rheological characteristics of the obtained system, a Brookfield viscometer model DV2TLVTJ0, spindle LV4 (64), 100 rpm were used.

The data obtained are presented in Table 1 and in FIG. 1.

Table 1. The dependence of the viscosity of the acid (SPZ) on the content of diethanolamide acids of coconut oil (cocodiethanolamide).

Composition Content, mass. % Viscosity, cP Cocodiethanolamide
EAAP
Hi iron 0.5
5
0.3 60 Cocodiethanolamide
EAAP
Hi iron 1
5
0.3 68 Cocodiethanolamide
EAAP
Hi iron 1,5
5
0.3 102 Cocodiethanolamide
EAAP
Hi iron 2.0
5
0.3 210 Cocodiethanolamide
EAAP
Hi iron 2,5
5
0.3 528 Cocodiethanolamide
EAAP
Hi iron 3.0
5
0.3 1002 Cocodiethanolamide
EAAP
Hi iron 3,5
5
0.3 1068 Cocodiethanolamide
EAAP
Hi iron 4.0
5
0.3 1434 Cocodiethanolamide
EAAP
Hi iron 4,5
5
0.3 1386

The maximum viscosity of the composition, equal to 1434 cPs, was achieved using a composition containing 5% EAA, 4% cocodiethanolamide and 0.3% Hi Iron converter.

Example 3. Evaluation of the viscosity of hydrochloric acid solutions of solutions EAAB and alkyldimethylamine

The dependence of the viscosity of the hydrochloric acid solution on the concentration of the reagents of the composition according to the present invention was determined. The specified solution was prepared by the method described above in Example 1.

To study the rheological characteristics of the obtained system, a Brookfield viscometer model DV2TLVTJ0, spindle LV4 (64), 100 rpm were used.

The data obtained are presented in Table 2 and in FIG. 2.

Table 2. The dependence of the viscosity of the solution (SPZ) on the content of alkyldimethylamine oxide (as an example, Amonxid Norkem NOROXIDE ™ DMA18, C12-C18 alkyldimethylamine oxide, CAS 69955-55-5).

Composition Content, mass. % Viscosity, cP Alkyldimethylamine oxide C12-C18 30%
EAAP
Hi iron 1,5
5
0.3 450 Alkyldimethylamine oxide C12-C18 30%
EAAP
Hi iron 2.0
5
0.3 540 Alkyldimethylamine oxide C12-C18 30%
EAAP
Hi iron 2,5
5
0.3 558 Alkyldimethylamine oxide C12-C18 30%
EAAP
Hi iron 3.0
5
0.3 594 Alkyldimethylamine oxide C12-C18 30%
EAAP
Hi iron 3,5
5
0.3 598 Alkyldimethylamine oxide C12-C18 30%
EAAP
Hi iron 4.0%
5
0.3 900 Alkyldimethylamine oxide C12-C18 30%
EAAP
Hi iron 4,5
5
0.3 972 Alkyldimethylamine oxide C12-C18 30%
EAAP
Hi iron 5,0
5
0.3 1200 Alkyldimethylamine oxide C12-C18 30%
EAAP
Hi iron 5.5
5
0.3 1626 Alkyldimethylamine oxide C12-C18 30%
EAAP
Hi iron 6.0
5
0.3 1654 Alkyldimethylamine oxide C12-C18 30%
EAAP
Hi iron 6.5
5
0.3 1680 Alkyldimethylamine oxide C12-C18 30%
EAAP
Hi iron 7.0
5
0.3 1758

The maximum viscosity of the composition, equal to 1758 cPs, was achieved using a composition containing 5% EAA, 7% alkyldimethylamine oxide and 0.3% Hi Iron converter.

Example 4. Evaluation of the viscosity of hydrochloric acid solutions of EAAB and hydroxyethylalkylimidazole

The dependence of the viscosity of the hydrochloric acid solution on the concentration of the reagents of the composition according to the present invention was determined. The specified solution was prepared by the method described above in Example 1.

To study the rheological characteristics of the obtained system, a Brookfield viscometer model DV2TLVTJ0, spindle LV4 (64), 100 rpm were used.

The data obtained are presented in Table 3 and in FIG. 3.

Table 3. The dependence of the viscosity of the solution (SPZ) on the content of hydroxyethylalkylimidazole.

Composition % Downloads Viscosity, cP Hydroxyethylalkylimidazole
EAAP
Hi iron 0.5
5
0.3 28 Hydroxyethylalkylimidazole EAAP
Hi iron 1
5
0.3 42 Hydroxyethylalkylimidazole
EAAP
Hi iron 1,5
5
0.3 258 Hydroxyethylalkylimidazole
EAAP
Hi iron 2.0
5
0.3 390 Hydroxyethylalkylimidazole
EAAP
Hi iron 2,5
5
0.3 654 Hydroxyethylalkylimidazole
EAAP
Hi iron 3.0
5
0.3 426 Hydroxyethylalkylimidazole
EAAP
Hi iron 3,5
5
0.3 350

The maximum viscosity of the composition, equal to 654 cPs, was achieved using a composition containing 5% EAFB, 2.5% hydroxyethylalkylimidazole and 0.3% Hi Iron transducer.

Example 5. Evaluation of the viscosity of hydrochloric acid solutions of EAAB and alkyldimethylamine oxide

The dependence of the viscosity of the hydrochloric acid solution on the concentration of the reagents of the composition according to the present invention was determined. The specified solution was prepared by the method described above in Example 1.

To study the rheological characteristics of the obtained system, a Brookfield viscometer model DV2TLVTJ0, spindle LV4 (64), 100 rpm were used.

The data obtained are presented in Table 4 and in FIG. 4.

Table 4. The dependence of the viscosity of the solution (SPZ) on the content of alkyldimethylamine oxide (Norkem NOROXID ™ DMA18, C12-C18 alkyldimethylamine oxide, CAS 69955-55-5).

Composition % Downloads Viscosity, cP Alkyldimethylamine oxide
EAAP
Hi iron 1
5
0.3 402 Alkyldimethylamine oxide
EAAP
Hi iron 2
5
0.3 462 Alkyldimethylamine oxide
EAAP
Hi iron 3.0
5
0.3 702 Alkyldimethylamine oxide
EAAP
Hi iron 4.0
5
0.3 1470 Alkyldimethylamine oxide
EAAP
Hi iron 5,0
5
0.3 1536 Alkyldimethylamine oxide
EAAP
Hi iron 4.0
3
0.3 762 Alkyldimethylamine oxide
EAAP
Hi iron 5,0
3
0.3 942 Alkyldimethylamine oxide
EAAP
Hi iron 6.0
3
0.3 936 Alkyldimethylamine oxide
EAAP
Hi iron 7.0
3
0.3 852

The maximum viscosity of the composition, equal to 1536 cPs, was achieved using a composition containing 5% EAA, 5% alkyldimethylamine oxide and 0.3% Hi Iron converter.

Example 6. Evaluation of the viscosity of hydrochloric acid solutions of EAAB and cinnamaldehyde solutions at various temperatures

The dependence of the viscosity of the hydrochloric acid solution on the concentration of cinnamaldehyde at various temperatures was determined. The specified solution was prepared by the method described above in Example 1, except that a solution of 12% hydrochloric acid was used. The content of EAFB was 8%, the content of the iron transducer was 0.5%.

To study the rheological characteristics of the obtained system, a Brookfield viscometer model DV2TLVTJ0, spindle LV4 (64), 100 rpm were used.

The data obtained are presented in Table 5 and in FIG. 5.

Table 5. The dependence of the viscosity of the solution (SPZ) on the content of cinnamaldehyde.

The content of cinnamaldehyde, wt.% Viscosity, cPz, at temperature 20 ° C 60 ° C 70 ° C 80 ° C 0,0 738 692 691 690 0.1 642 558 576 846 0.2 444 606 954 618 0.3 654 1230 1434 444 0.4 978 1398 1068 thirty 0.5 1272 1650 1104 24

The maximum viscosity of the composition, equal to 1650 cPs, was achieved at a temperature of 60 ° C when using a composition containing 8% EAFB, 0.5% cinnamaldehyde and 0.5% Hi Iron transducer.

Example 7. Preparation of an inorganic salt solution composition according to the present invention.

The composition was prepared as follows. 5% erucilamidopropyl betaine and 0.75% butyl glycol (butyl cellosolve) were dissolved in distilled water. An easily flowing, inviscid solution was obtained.

6% inorganic salt was added to the aqueous solution with stirring on an overhead stirrer. The viscosity of the solution increased.

To study the rheological characteristics of the obtained system, we used a Brookfield viscometer model DV2TLVTJ0, LV4 spindle (64), at a speed of 100 rpm.

Example 8. Evaluation of the viscosity of saline solutions of EAAB and alkyldimethylamine oxide and butyl glycol (butyl cellosolve)

The viscosities of solutions of various inorganic salts and reagents of the composition of the present invention were determined. The specified solution was prepared by the method described above in Example 6.

To study the rheological characteristics of the obtained system, a Brookfield viscometer model DV2TLVTJ0, spindle LV4 (64), 100 rpm were used.

The data obtained are presented in Table 6.

Salt Viscosity, cP NaCl 138 MgCl ₂ 138 Kcl 560 CaCl ₂ 1008 AlCl ₃ 1158 NiCl ₂ 118 NaNO ₃ 228 NaHCO ₃ 396 Al ₂ (SO ₄ ) ₃ 96 CuSO ₄ 186

The maximum viscosity of the composition, equal to 1158 cPs, was achieved using a composition containing 5% EAFB, 0.75% butyl glycol and 6% aluminum chloride.

Example 9. Study of the proppant retention by a composition based on EAAB and alkyldimethylamine oxide (Norkem NOROXIDE ™ DMA18, C12-C18 alkyldimethylamine oxide, CAS 69955-55-5).

To study the proppant retention by a composition based on EAFB and alkyldimethylaminoxide, a solution was prepared containing the following components:

Gelled surfactant based on 15% HCl Iron converter 0.5% Erucilamidopropyl betaine 5% Alkyldimethylamine oxide 4%

Propant (fractions 16/20) was added to the thickened acid at the rate of 800 kg / m ³ and the resulting mixture was placed in a graduated cylinder. Observed the settling of the proppant over time. The experimental results are shown in FIG. 6.

It was found that the proppant in this mixture completely settled in 30 minutes.

Example 10. The study of the proppant retention of the composition based on EAFB and coconut oil diethanolamide

To study the proppant retention by a composition based on EAFB and coconut oil diethanolamide, a solution was prepared containing the following components:

Gelled surfactant based on 15% HCl Iron converter 0.5% Erucilamidopropyl betaine 5% Cocodimethanolamide 2%

Propant (fractions 16/20) was added to the thickened acid at the rate of 800 kg / m ³ and the resulting mixture was placed in a graduated cylinder. Observed the settling of the proppant over time. The experimental results are shown in FIG. 7.

It was found that the proppant in this mixture does not settle even in 1.5 hours.

Example 11. The study of the retention of proppant composition based on EAAB and cinnamaldehyde

To study the proppant retention by a composition based on EAFB and cinnamaldehyde, a solution was prepared containing the following components:

Gelled surfactant based on 12% HCl Iron converter 0.5% Erucilamidopropyl betaine 8% Cinnamaldehyde 0.5%

Propant (fractions 16/20) was added to the thickened acid at the rate of 800 kg / m ³ and the resulting mixture was placed in a graduated cylinder. Observed the settling of the proppant over time. The experimental results are shown in FIG. 8.

It was found that the proppant in this mixture completely settled in 90 minutes, which is enough to carry out work on hydraulic fracturing.

Other variants of the system according to the present invention are investigated in accordance with a similar experimental design.

You must understand that the previous description is provided solely for the purpose of explaining the present invention. Those of ordinary skill in the art can develop various alternatives and modifications without departing from the scope of the present invention as defined by the claims. Thus, it is intended that the present invention covers all such alternative variations, modifications and variations that fall within the scope of the appended claims. All numerical values given in this document are approximate and allow normal variations, for example, within +/- 10-15% of the specified value. The percentages indicated may refer to mass, volume, or mass-volume percent.

Claims (45)

1. Application of the combination: a) zwitterionic compounds of formula I

, where R represents a saturated, mono-, di - or trisaturated hydrocarbon radical With ₉ -C ₂₅ ; R ₁ represents —COO ^- or —CH ₂ COO ^- ; R ₂ , R ₃ , R ₄ , R ₅ independently represent hydrogen, methyl, ethyl, propyl, isopropyl, allyl, vinyl, phenyl or benzyl; b) a compound selected from the group consisting of C ₁₀ -C ₂₀ fatty acid diethanolamides, alkyldimethylamine oxide, hydroxyethylalkylimidazole, butyl glycol, cinnamaldehyde and hydroxycinnamic acids; and c) optionally, an iron converter for thickening an aqueous solution of an acid and / or salt. 2. The use according to claim 1, characterized in that erucilamidopropyl betaine (EAAB) is used as the compound of formula I. 3. The use according to claim 1, characterized in that the diethanolamides of the C ₁₀ -C ₂₀ fraction use diethanolamides of coconut oil acids. 4. The use according to any one of paragraphs. 1-3, characterized in that as a converter of iron using a mixture of mercaptoethanol, copper chloride and methanol. 5. The method of thickening an aqueous solution of acid and / or salt, comprising adding to the specified aqueous solution of acid and / or salt a) zwitterionic compounds of formula I

, where R represents a saturated, mono-, di - or trisaturated hydrocarbon radical With ₉ -C ₂₅ ; R ₁ represents —COO ^- or —CH ₂ COO ^- ; R ₂ , R ₃ , R ₄ , R ₅ independently represent hydrogen, methyl, ethyl, propyl, isopropyl, allyl, vinyl, phenyl or benzyl; b) a compound selected from the group consisting of C ₁₀ -C ₂₀ fatty acid diethanolamides, alkyldimethylamine oxide, hydroxyethylalkylimidazole, butyl glycol, cinnamaldehyde and hydroxycinnamic acids; and c) optionally, an iron converter. 6. The method according to claim 5, characterized in that erucilamidopropyl betaine (EAAB) is used as the compound of formula I. 7. The method according to p. 5, characterized in that as diethanolamides of fatty acids of fraction C ₁₀ -C ₂₀ use diethanolamides of coconut oil acids. 8. The method according to any one of paragraphs. 5-7, characterized in that a mixture of mercaptoethanol, copper chloride and methanol is used as an iron converter. 9. The method according to any one of paragraphs. 5-8, characterized in that the compound of formula I, a compound selected from the group consisting of C ₁₀ -C ₂₀ fatty acid diethanolamides, alkyl dimethyl amine oxide, hydroxyethyl alkyl imidazole, butyl glycol, cinnamaldehyde, hydroxy cinnamic acids, and optionally an iron converter are added together . 10. The method according to any one of paragraphs. 5-8, characterized in that the compound of formula I, a compound selected from the group consisting of C ₁₀ -C ₂₀ fatty acid diethanolamides, alkyl dimethyl amine oxide, hydroxyethyl alkyl imidazole, butyl glycol, cinnamaldehyde, hydroxy cinnamic acids, and optionally an iron converter are added separately . 11. A set of components for use according to any one of paragraphs. 1-4 or the implementation of the method according to any one of paragraphs. 5-10, containing: a) zwitterionic compound of the formula I

, where R represents a saturated, mono-, di - or trisaturated hydrocarbon radical With ₉ -C ₂₅ ; R ₁ represents —COO ^- or —CH ₂ COO ^- ; R ₂ , R ₃ , R ₄ , R ₅ independently represent hydrogen, methyl, ethyl, propyl, isopropyl, allyl, vinyl, phenyl or benzyl; b) a compound selected from the group consisting of C ₁₀ -C ₂₀ fatty acid diethanolamides, alkyldimethylamine oxide, hydroxyethylalkylimidazole, butyl glycol, cinnamaldehyde and hydroxycinnamic acids; and c) optionally, an iron converter. 12. The kit according to claim 11, characterized in that erucilamidopropyl betaine (EAAB) is used as the compound of formula I. 13. The kit according to claim 11, characterized in that the diethanolamides of the C ₁₀ -C ₂₀ fraction use diethanolamides of coconut oil acids. 14. Set according to any one of paragraphs. 11-13, characterized in that a mixture of mercaptoethanol, copper chloride and methanol is used as an iron converter. 15. A set of components according to any one of paragraphs. 11-13, made in the form of a composition, preferably in the form of an aqueous solution containing a salt, preferably ammonium chloride. 16. The composition for the implementation of hydraulic fracturing, containing an aqueous solution of acid and / or salt, a set of components according to any one of paragraphs. 11-15 and proppant. 17. The composition according to p. 16, characterized in that said acid is hydrochloric acid. 18. The composition according to p. 17, characterized in that the content of hydrochloric acid is 12-16 wt.%, Preferably 15 wt.%. 19. The composition according to p. 16, characterized in that said salt is selected from the group comprising sodium chloride, magnesium chloride, potassium chloride, calcium chloride, aluminum chloride, nickel chloride, sodium nitrate, sodium hydrogen carbonate, aluminum sulfate, copper sulfate. 20. The composition according to p. 19, characterized in that the salt content is 5.0-6.0 wt.%, Preferably 6 wt.%. 21. The composition according to p. 16, characterized by the following components: compound of formula I                                     2.5-5.0 wt.% a compound selected from group b)             0.5-7.0 wt.% and one of the following: acid                                                        12.0-16.0 wt.% and optionally an iron converter 0.2-1.0 wt.% or salt                                                           5.0-6.0 wt.% rest                                                    water and proppant 22. A method of producing oil from a field using an acid hydraulic fracturing method, including: - the introduction of a composition according to any one of paragraphs. 16-21 to the deposit and - oil recovery from the field. 23. The method according to p. 22, characterized in that the method of acid hydraulic fracturing is used and the composition used contains acid. 24. The method according to p. 23, characterized in that the acid is hydrochloric acid. 25. The method according to p. 22, characterized in that the said deposit contains carbonate rocks.

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