DD202303A5 - METHOD FOR STIMULATING NATURAL GAS AND PETROLEUM DRILLING - Google Patents

Abstract

The invention relates to a method for stimulating natural gas and Erdoelbohrungen for use as a friction reducer in Drucksaeuerung. The aim of the invention is to increase the Foerderrate and the Foerdermenge. According to the invention, the acid solution for the pressure aeration contains 0.06 to 0.12% by weight of a copolymer soluble in water or aqueous acids, i. in its macromolecule at least 5% by weight of units having a formylamino group d. Formula IV, wherein R is high-1 hydrogen, methyl or hydroxymethyl, and at least 10 wt .-% of units having an aminocarbonyl group of the formula V, contains. The copolymer is in a static distribution to 5 to 50 wt .-% of units of the formula I 10 to 95 wt .-% of units d. Formula II u. 0 to 85 wt .-% of units d. Formula III together. R is high = hydrogen, methyl or hydroxymethyl; R deep 2 = hydrogen or methyl; X = cyano, carboxyl and the like - Formulas IV and V -.

Description

Berlin, 12th May 1982 AP G OS F / 235 743/0 (60 133/11)

Method for stimulating iurdgas- and BrdÖlbohrungen Field of application of the invention

The invention relates to a method for stimulating Srdgas- and oil wells by pressure acidification with an acid solution.

The invention further relates to novel water-soluble and acid-resistant copolymers which are added to the acids used for the pressure acidification as Reibungsverininderer, and their preparation and use ·

Characteristic of the known technical solutions

Sine known stimulation technology for oil and gas gas wells, which is used for the purpose of increasing the production rate and the overall yield of underground Garbonatformationen is called. Pressure acidification. Carbonate formations in this sense are, for example, dolomite, limestone or other storage rocks containing calcareous material. The pressure acidification is usually carried out so that an aqueous acid, which may optionally contain so-called proppants, is pumped into the bore to be stimulated, under a pressure which exceeds the formation pressure. As a result, new cracks and channels, so-called fractures, are blown up into the formation. In the pressurized acid technique, the pressed-in acid additionally etches the surfaces of the rock fractures and, if so

O Ο ς 7/3 O ~ ^1a ~ 12.5.1932

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The acid additionally contains a proppant, this proppant is transported into the open fractures, Both the irregular etching of the heterogeneous fracture surface as well as the inclusion of the support material cause the fractures after pressure relief can not fully close · In any case arises so

235743 O ² Ref. 3198

a more permeable channel that allows petroleum or natural gas to flow to the production well after pressure has been applied.

In the case of the acidification process, it is necessary to pump the acid, the so-called fluid, into the well at high speed in order to be able to build up the required explosive pressure for the rock. It turns out that a serious proportion of the injection pressure is lost by frictional forces that occur between the fluid flowing in turbulent flow and the duct walls _. the so-called Reibungsdruck.with the injection rate increases, with increasing injection rate, an ever lower pressure component as treatment pressure is hydraulically transferred to the formation Ί By adding low concentrations of polymers to the treatment fluid, the flow of the pumped fluid is now laminarized, so that even at high injection speeds of the Friction pressure is significantly reduced, and thus a much larger proportion of the head pressure is transmitted to the storage rock.

Common friction reducers used in carrying out the pressurized acidification are polysaccharides, e.g. Hydroxyethylcellulose, xanthan gum (metabolite of Xanthomonas campestris) hydroxypropylated guar gum (from the seeds of Cyanaposis tetragoiiöiibüs) or synthetic polymers based on polyacrylamide *

When using polysaccharides as Reibüngsverminderer thereby problems arise that these compounds: are not very stable in highly concentrated acids. »Usually polysaccharides are hydrolyzed or degraded in strong acids while the friction-reducing effect is lost. The use of synthetic polyacrylamides as Reibüngsverminderer has technical disadvantages!

In the presence of strong acids, polyacrylamides are rapidly hydrolyzed to insoluble degradation products. These precipitate from the treatment fluids and can be blocked

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lead to obstruction of the oil or gas flow and thus to serious damage to the deposit.

Aim of the invention;

The aim of the invention is the provision of novel friction reducers, which are acid-stable and provide no insoluble degradation products, so that an increase in the flow rate is made possible.

Explanation of the essence of the invention

The invention has for its object to find new compounds with the desired properties, which are suitable as a friction reducer in intended for the pressure acidification acids.

According to the invention there is provided a copolymer which contains in statistical distribution in its macromolecule at least 5% by weight of units which have a formylamino group (A) and at least 10% by weight of units containing an aminocarbonyl group (B ) contain

R ^X H. ₂

The gopolymer of the invention can be used as an improved friction reducer for the pressure acidification of subterranean, calcareous formations. The invention

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Corresponding polymer is acid-soluble, and its degradation products are both acid-soluble and stable.

Preferably, the new copolymers of the invention together from 5 to 50% by weight of units of the formula I.

-GH ₂ -GH-O

R ¹ ^ 10 to 95% by weight of units of the formula II

-CH ₂ -GH-

'(ID

and 0 to 85% by weight of units of formula III

f -GH ^ -C- -. (III)

1 2

wherein R is hydrogen, methyl or hydroxymethyl and R is hydrogen or methyl and X is cyano, carboxyl, or its alkali or ammonium salts, alkoxycarbonyl having 1 to 6, preferably 1 to 3 carbon atoms, hydroxyalkoxycarbonyl having 1 to 3 carbon atoms; N-methylolamidocarbonyl of the formula HOCELUH-CO-, whose methylol group may optionally be etherified with alkanols having 1 to 4 carbon atoms; Alkanoylamino of 1 to 4 carbon atoms which may optionally be N-substituted by methylol or alkyl of 1 to 4 carbon atoms; Pyrrolidonyl (1); phenyl; pyridinium; the sulfonic acid group; Sulfoalkylamidocarbonyl having 1 to 4 carbon atoms; the phosphonic acid group, wherein sulfonic acid and phosphonic acid groups may also be present as alkali metal or ammonium salts; a radical of formula IV

^ OJ / HJ \ J

-COOCH ₀ CH ₀ -OPR ³ (IY)

^{Δ Δ} ti 4

O Λ

wherein R and R are the same or different and are alkyl of 1 to 4, preferably 1 or 2 _; Carbon atoms stand; a radical of the formula V

R ³

-COO-CH ₉ -N ^ ₄ (V)

P 2p 4

Wherein R and R have the meanings given above and ρ is a number from 1 to 4; or a radical of the formula VI

- ^CONH - ^C p ^H 2p - ^N _NR 6

Wherein R "and R are the same or different and are alkyl having 1 to 4, preferably 1 or 2, carbon atoms and ρ is a number from 1 to 4; and the corresponding formulas V and VI, for example by dimethyl sulfate or methyl chloride quaternized groups means.

The copolymers of the invention are random, i. that the distribution of units I to III in the macromolecule; is statistical.

Of course, the copolymers of the invention may contain several different units of formulas I and III, e.g. different units of formula III, which are

'"' 2

differ by different meaning of the radicals X or R from each other. As a rule, in a single macromolecule X no more than 3, preferably no more than two, have different meanings. Copolymers of this type are prepared by adding several different comonomers, usually not more than three, preferably not more than two, characterized by different meanings of the radical

X and / or R different from each other, used in the copolymerization. In general, the copolymers of this invention have K values (see Fikentscher, "Cellulose Chemistry" Bd 13 , p. 58 (1932)) between 25 and 250, which corresponds to molecular weights between 20,000 and 15 χ 10. As friction reduction

g Λ ^v Ί / LL "1 Il" «ei. ο j. σ υ

those preferred are those copolymers according to the invention which have K values of between 50 and 200, corresponding to molecular weights of between 100,000 and 4 × 10.

Preferred copolymers of the invention consist of

5 to 30% by weight of units of the formula I, 50 to 80% by weight of units of the formula II and 1 to 60% by weight of units of the formula III.

Furthermore, preference is given to those copolymers in which

ο R is hydrogen or methyl or those in which X

Carboxyl, the sulfonic acid group; 3-sulfo-2-methyl-propyl- (2) -amidocarbonyl of the formula CH ₃

^ CONH-C-CH ₂ -SO ₃ H

Alkanoylamino having 1 to 4 carbon atoms, which may optionally be N-substituted with methylol or alkyl having 1 to 4 carbon atoms, pyrrolidonyl (l) or a radical of the above-defined and defined formulas V or VI, wherein each acid group is also referred to as sodium-potassium - Or ammonium salt may be present.

Particularly preferred for use as a friction reducer in the stimulation of natural gas or oil wells are such copolymers according to the invention in which the units of formula I by concomitant use of N-vinylformamide and the units of formula III by concomitant use of N-vinyl-N-methyl-acetamide , N-vinylpyrrodilone or 2-acrylamido-2-methylpropane-sulfonic acid or mixtures thereof were introduced in the copolymerization.

The copolymers of the invention are readily soluble in water or aqueous acids and therefore can be handled easily. When used in pressure acidification processes, the polymers can be added to the acid in the form of aqueous 0.5 to 6% strength by weight solutions (polymer solutions having a concentration of more than 6% by weight are too viscous and therefore difficult to handle), in the form of hydrocarbons. dis-

I JD / 4 OU ° -

or emulsions and 20 to 50% by weight of the polymer or in the form of oil-in-water or water-in-oil emulsions containing emulsifiers and 20 to 50% by weight of the polymer. The copolymers according to the invention are preferably used in the form of a Vasser-in-oil emulsion having the highest possible polymer content, normally from 20 to 75% by weight. Oils which are suitable for the preparation of these water-in-oil emulsions include, for example, branched or unbranched paraffin-hydrocarbon fractions

a boiling range of 150 to 250 C. Depending on the monomer composition and the resulting properties, the novel copolymers in concentrations of 0.06 to 0.12% by weight, at temperatures from normal room temperature to temperatures above 80 ° C as highly effective Lungs reducer, the duration of action long. Time, for example, lasts more than 10 days. Even upon the occurrence of hydrolytic degradation of side chains of the copolymers, the degradation products remain acid-soluble and do not separate from the solution. The novel copolymers are preferably combined with acids which are liquid under normal conditions and in particular with inorganic or strong lower organic acids. Examples of acids which can be used together with the copolymer according to the invention are hydrofluoric acid, hydrochloric acid, formic acid, acetic acid, monochloroacetic acid, dichloroacetic acid or trichloroacetic acid. The most common is the use of hydrochloric acid, which is used in concentrations of 3 to 28 wt.%, Depending on the required treatment conditions and the properties of the deposit.

Pie copolymers of the invention are prepared by copolymerization of 5 to 50 wt.% Of an optionally N-substituted vinyl formamide of the formula Ia

Z ^ H IQ to 95 wt.% Acrylamide and 0 to 85 wt.% Of an ethylenic

unsaturated monomer of the formula IIIa

H ² 'CH ₂ -CX ^(IIIa)

1 2 wherein R, R and X have the meanings given above.

Preferably, from 5 to 30% by weight of the vinylformamide of the formula (Ia), from 50 to 80% by weight of acrylamide and from 1 to 60% by weight of the monomer of the formula IIIa are copolymerized. A particularly preferred composition is 10 to 20% by weight of N-vinylformamide, 50 to 70% by weight of acrylamide and 10 to 40% by weight of a monomer of the formula IIIa.

If copolymers are to be prepared which are several different

"'ο' radicals X and / or R in the component III, so are used for the copolymerization several different, usually 3, or preferably 2, different comonomers of the formula HIa.

The copolymerization can be carried out by all known polymerization processes in the range of pH 4 to 12, preferably 6 to 9.

To adjust the pH, it is expedient to use alkaline salts of alkali metals, for example alkali metal carbonates, alkali metal bicarbonates, alkali borate 6, di- or tri-alkali metal phosphates, alkali metal hydroxides, ammonia or organic amines of the formula NR ₃ , where R is hydrogen, alkyl having 1 to 4 carbon atoms or Hydroxyethyl is and where

Preferred at least one of the radicals R is different from hydrogen. Preferred bases for adjusting the pH are the abovementioned alkali compounds, in particular sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbopnate and potassium bicarbonate and sodium or potassium borates. Another preferred base is NH ₃ .

Polymerization reaction can be initiated by high-energy electromagnetic or corpuscular radiation or duy substances which form radicals. Accordingly, suitable as polymerization initiators are organic per compounds,

eg benzoyl peroxide, alkyl hydroperoxide such as butyl hydroperoxide, cumene hydroperoxide, p-menthane hydroperoxide, dialkyl peroxides such as z, B. Di- _{; t} tert butyl peroxide or inorganic per-compounds, w ^ e, for example, potassium or ammonium persulfate and hydrogen peroxide, azo compounds such as azobisisobutyronitrile, 2,2'-azobis (2-amidinopropane) hydrochloride or azobis-rbis ^ ispbutyramid. It is advantageous to use the organic or inorganic per compounds in combination with reducing substances. Examples of suitable reducing substances are Natriurapyrosulfit, sodium hydrogen sulfite or condensation products of formaldehyde with Sulfoxylaten.BEsonders let the polymerization using Mannich adducts of sulfinic acids, aldehydes and amino compounds perform, as for example in German Patent 1,301,566 have been described.

It is also known to add to the polymerization batches small amounts of so-called moderators, which harmonize the course of the reaction by flattening the reaction rate-time diagram. They lead to an improvement in the reproducibility of the reaction and thus make it possible to produce uniform products with extremely low quality deviations. Examples of suitable moderators of this type are nitro-tris-propionylamide., Or the hydrohalides of monoalkylamines, dialkylamines or trialkylamines, e.g. Dibutylamine. Also in the preparation of the copolymers according to the invention, such moderators can be used with advantage.

Furthermore, so-called regulators can be added to the polymerization batches; these are those compounds which affect the 4-isomer molecular weight of the polymers produced. Useful known regulators are e.g. Alcohols, such as methanol, ethanol, propanol, isopropanol, n-butanol, sec-butanol and amyl alcohols, alkylmercaptans, e.g. Dodecylmercaptan and tert-dodecylmercaptan, isooctylthioglycolate and some halogen compounds, e.g. Carbon tetrachloride, chloroform and methylene chloride.

Usually, the polymerization is carried out in a protective gas atmosphere, preferably under nitrogen.

The reaction may be carried out in solution, in emulsion or under the conditions of precipitation polymerization at temperatures of up to 120 ° C, preferably from 40 to 100 ° C. If water is used as solvent for the polymerization reaction _? so it runs in solution, and an aqueous viscous solution of the copolymer is obtained. The reaction product can be isolated, either by distilling off the water from the solution, or by mixing the aqueous solution with organic solvents which are completely miscible with water, but in which the copolymer is unlüslicti, When such organic solvents are added to the aqueous Polymer solution precipitates the resulting polymer or Cöpolymerisat and can verden separated from the liquid phase, for example by filtration. Preferably, the resulting aqueous solution of the polymer or glycerylate is obtained. directly for the. used further, optionally after adjustment to a certain desired concentration.

When the copolymerization in an organic solvent such as, in a lower alkanol, e.g. in tert-butanol, so, it proceeds under the conditions of precipitation polymerization. In this case, the resulting polymer or copolymer precipitates in the course of the reaction in an ester form and can easily be removed in a customary manner, e.g. by suction and subsequent drying. Of course it is also possible and in some cases bjeyo'rssugt to distill the solvent from the reaction mixture out.

Monomers which introduce into the copolymers units of the formula I are N-vinyl formamide, N-vinyl-N-methylformamide and N-vinyl-N-hydroxymethylformamide / wherein the first two mentioned are preferred. The concomitant use of acrylamide in the copolymerization units of the formula II in

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introduced the copolymer. Units of the formula III are introduced into the copolymer according to the invention by co-use of one or more, preferably 2 monomers of the formula 2

CH ₂ - C ^

wherein R and X have the following meanings:

R ² -H -GH -H -OH ₃ -H -H X -G N -G N -CöÖiß -GOOiP -COOGH ₃ -NH-GHO

R ² -GH ₃ -H -GH ₃ -H -CH ₃ X -GOOGH ₃ -GOOG ₂ H ₅ -COOG ₀ H ₅ - 2 5 -GOOC ₄ H ₉ -COOC ₄ H ₉ '

R ² -H -H , 0H -CH ₃ -H -CH ₃ X -COOG ₆ H ₁₃ --COOC, -COOG ₂ H ₄ OH -COOC ₃ H ₆ OH -COOG HgOH

-H

CH,

-H

CH,

-GONHGH ₀ OH -H

-CONHCH ₀ OH

-GH,

-COIiCH ₂ OCH -H

-GONHCH ₂ OGH ₃

-GONHCH ₂ OC ₂ H ₅

-CONHCH ₂ OC ₂ H ₅

-CONHCH ₂ OC ₄ H ₉

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-H

-H

-H -CH

-NHGOGH

-NHCOCJI

^2H 5

-NHCOC ₃ H ₇

-N-CHO GH ₂ OH

!-H

-H

-H -H

-N-GOGH, GH ₂ OH

CH ₂ OH

-N-COG-H ₇ CH ₂ OH

-N-GHO GH ₃

-H-CHO GH ₂ -OH

R ² -H -H -H X -N-COCH-GH ₃ -N-COC ₃ H, - i 3 ο GH ₃ . -N-COC ₀ Hc-O ₂ H ₅

-H

-fl

-CH, -H

-H

N-GOCH ₃

CH,

-N

-9

-so

-H-CH,

X -SO ₃ H

R ² -H -H X -CONH-GH ₂ SO ₃ H ^ -CONHCH ₂ GH ₂ GH ₂ So Η®

-H

-GONHG ₂ H ₄ -SO Η -CONHCH-CH ₀ -SO-

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2 X -H -H -00-.H-CH ₂ Ch ₂ CH ₂ OH ₂ -SO ₃ HS) -GO-NH-Gh-GH ₀ CH ₀ -SO _ηΦ t <- t-J CH ₃

-H

CH-

CO-NH-C-CH ₀ -SO-H '$ 2

CH ₃

-GH,

.COHH-C ₂ H ₄ SO ₃ H

_T 1

-ή

-CO-NH-C-GH ₂ SO ₃ I

XX ₃

-GOO-CH ₀ CH ₀ -Im

-GOO-GH ₀ CH ₀ -N

-H

.GOO-CH ₀ CH ₀ -N

' η XJ

'2 ^1X 5

-COO-GH ₂ CH ₂ -N,

.C ₃ H ₇

R ² -H -H X 4 ° ^Η 9 -GOO GH-GH _{2 2} -N 'G ₄ H ₉ / ^C 4 ^H 9 -COO-OH ₂ CH ₂ -H

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R ² -H -CH ₃ X ^ CH ₃ -GOO-GH ₂ GH ₂ GH ₂ -N CH- OH ₃ - -COO-GH ₂ CH ₂ GH ₂ -N. GH ₃

-H

-GH,

GOO-GH-GH ₂ -N'GH _n

G ₂ H ₅

.GH

-COO-GH-GH ₀ -N' 2

GH ₃

GH.

R ² -H -GH ₃ X / CH ₂ -CONH-CH ₂ GH ₂ -N _x ^J -GONH-GH ₂ CH ₂ -N _χ ³ OH

R ² -H -OH, X / ^C 2 ^H 5 -GONH-GH ₀ GH ₀ -N 2 2 \ O ₂ H ₅ / ^C 2 ^H 5 -CONH-OH ₂ CH ₂ -Ii; ^X C ₂ H ₅

R ² -H -H X C ₃ H ₇ -GONH-GH ₀ CH ₀ -N ^ d ά \ GH ₃ ^ G ₄ H ₉ -CONH-GH ₂ GH ₂ -N ^'C 4 ^H 9

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CONH-CH ₂ CH ₂ CH ₂ -N

-CONH-CH-CH ₀ -N CH ₃

2 Σ -CH -H -H -CONH-CH-CH ₂ -N ^ ³ CH ₃ - ^CH 3   © -CONH-G-CH ₀ -N. ³ ι * PTT CH ₃ ^GH 3

CH,

CH,

-H

-N

-COO-CH CH ₂ -N ^

C ₂ H ₅

-COO-CH ₂ CH ₂ -N

CH,

(T) Since N-vinylarnides are not stable under acidic conditions, mixtures containing acidic substances must be neutralized prior to polymerization, for example with the inorganic or organic bases or basic comonomers indicated above. »

Examples of preferred monomers which introduce units of the formula III into the copolymers according to the invention are:

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N-ylylmorphamide, N-vinyl-H-methylformamide, N-vinylacetamide, I-vinyl-IT-methyl-acetamide, II - vinylpyrrolidone, acrylic acid, alkali metal or ammonium salts of acrylic acid,

CH., I 3

CHp-CH-CONH-G-CHp-SO ^ H or their alkali metal or ammonium triTT salts,

3.

GH ₂ = GH-GOO-GH ₂ GH ₂ -N '

/ ^CH 3

ί, or

GH ₃

CH

To the best of our knowledge, the copolymers according to the invention described above are novel with the exception of those in which X represents a sulfo group, or a sulfoalkyl-amidocarbonyl group, or a salt of one of these groups (cf., US Patent No. 4,048,077).

The Gopdymerisate invention described above can also be used for thickening or for gelling acid solutions, z. In the process of pressurized acidification as described in our copending application entitled "Water Soluble Crosslinkable Polymer Composition, Its Preparation and Use" and in the copending United States Patent Application entitled "Water Soluble Crosslinkable Polymer Compositions Containing a Metal .. Compound , Their Preparation and Use, by Jeffery C, Dawson ,. Robert R. Mc-Daniels and Lawrence Sedillo is described.

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Embodiment ·

The following examples illustrate the preparation of the copolymers according to the invention.

The abbreviations used in the examples and tables have the following meanings:

YSSNa:

VΙΓ A:

acrylamide

N-YiJiyl-N-methylacetamide S-acrylamido-S-methylpropane-sulphonic acid where the exponent

1) the, amine salt,

2) d, the salt with dimethyl-.beta.-hydroxyethylamine, 3) the potassium salt and

4) the sodium salt means

acrylic acid

Methacrylic acid N-methylol-acrylamide

Na salt of vinylsulfonic acid

N-methylol-vinylacetamide yinylacetamide vinylformamide vinyl-methyl-formamide N-methylol-vinylformamide N-methylol-vinylacetamide vinylphorophosphonic acid ammonium sulphoxide

A combination of ammonium peroxydisulfate +

Dibutylammonium hydrochloride +

Soo-CH-NH-COOCH,

'3Λ J azido-isobutyronitrile

COOH

example 1

A flask equipped with a water bath, stirrer, reflux condenser, dropping funnel and gas inlet is charged with 400 ml of deionized water and 17.7 ml of a 25% strength by weight aqueous ammonia solution. With the introduction of a weak stream of nitrogen, 9.3 g of acrylamido-methylpropanesulfonic acid and, as soon as a clear solution is present, 60 g of acrylamide, 18.6 g of N-vinylpyrrolidone and 14.7 g of N-vinylformamide are added. The piJ value of the solution is 6.5. The mixture is heated to 50 ° C and the polymerization initiated by the addition of 5 ml of a 20 wt.% Aqueous solution of ammonium peroxydisulfate. After an induction period of about 10 minutes starts

the reaction, the temperature rises to 65 ° C and the mixture becomes viscous. The batch is then warmed to 8O ⁰ C and held at this temperature for 2 hours. After cooling to room temperature, a highly viscous solution of the copolymers is obtained,

Example 2

In a 2 1 flask equipped with a water bath, stirrer, reflux condenser, dropping funnel and gas inlet tube, 500 ml of tert-butanal are introduced and 20 g of AMPS are suspended therein with stirring,

Pann are introduced 2.2 1 ammonia gas and 65 g of acrylamide and 15 g of N-Vinylfprmamid added. While introducing a gentle stream of nitrogen, the mixture is warmed to 50 ° C and Ig azo-iso-butyronitrile added. After an induction period of a few minutes, the polymerization reaction starts. The temperature rises to 8I ⁰ C and the polymer precipitates. The reaction mixture is kept for a further 2 hours at 80 C, resulting in a viscous suspension. The polymer can be isolated by suction and dried at 50 C in a vacuum. However, it is also possible to isolate the polymer by distilling off the solvent under reduced pressure. The resulting polymer is a white, light powder which is readily soluble in water. The value of Fikentscher is 148,

According to the above embodiments, the copolymers of the following Tables 1 and 2 can also be prepared:

T 3. h ε 1 le

Example Wr. AT THE When " Kon AHPS ze'ntra VIFA \ tion of VIMFA. " s Mono VIMA ' work VIA you: SWi.%) MVJA WVII ¹ A ^ other additives, . * -. ' Verk .: ae & ktions medium jKoaasen: tx, a ± l «nj pflv! yert · Katalx-sa tor Ani angs ^ tempera door ° C 3 '- 65 20 ] 15 155 water IB] P. , A 5O 4 65 20 15 129 Il 18: P. 4 , A. 50 5 65 20 15 193 Il 18 4.β A 50 6 65 20 15 149 Il 18 8th A 50 7 65 2O 15 169 D 18 4.8 A 50 8th 65 20 15 124 It 18 8.3 A 50 9 65 2O 15 154 ti 18 4.9 A 50 10 65 20 15 122 Il 18 8.0 A 50 11 90.6 9.4 13Ο Il 21 10 B 20 12 81.1 18.9 111 Il 21 9.8 B 20 13 81.1 9.4 9.4 14Ο 11 21 7.8 B 20 14 65 20 15 208.5 Il 18 8.3 A 40 15 65 2O 15 188 Il 18 4.9 A 40 '16 65 2O 15 199 Il 18 8.2 A 40 17 65 2O 15 216.5 Il 18 4.9 A 4O

table

{Continuation)

example AT THE AS Kon AMPS zentra VIFA ition d £ VIMFA ir mono VIMA work VIA ι (Ge MAM MVIA MVIFA Other additives K value Reaction ^ ' medium Komzen_ - tration ίΟβΜ.%) pH Kataljt sator · Beginning tempera door C 18 50 5O 60.5 water 25 4.0 A 23 19 20 80 51 water 25 4.2 A 23 20 100 25 water 25 8th A 23 21 65 20 15 203 water 18 7 A 40 22 65 20 15 201 water 18 8th A 40 23 65 2O 15 223 water 18 7 A 40 pounds 24 65 20 15 223 water 18 8th A 40 25 65 20 15 182 water 18 7 A 40 26 65 20 15 187 water 18 7 A 40 27 90.6 9.4 borax 130 ' water 21 10.1 B 35 28 81.2 9.4 9.4 borax 175 water 21 7.9 B 35 29 65 20 15 164 water 10 5 A 40 30 65 20 15 120 ' water 5 5 A 4O 31 71.7 9.4 18.9 136 water 21 8.0 B 35 32 71.7 9.4 18.9 143 water 21 8.3 B 35

Tabe 11 e

("Continuation)

Example i AT THE : AS _; «OB AMPS; zentra VIfA tion -x VIMFA> т Mono VlMA Merei I do MAM w, %) MVIA MVlFA Further ; additions x- Wsrt fiedlet i s_ ] ^ medium: Konzeii tratlon pH χ value '; sator I start ^ tempera door ^Ö C ~ 33 FIS 15 188: "Water 18 B A 4O 34 61 14 25 174 water 18 8.2 A 40 35 56.8 13.2 30 171 water 18 8th A 40 36 85 ] 15 2O 144 "Water IO 8th A 40 37 61 14 25 139 water 10 8th A 40 38 56.8 13.2 30 131 water 10 8th A 40 39 56.8 13.2 30 139.5 water 10 8.1 A 40 4O 71.7 9.4 18.ί borax 188 water 21.6 8.4 B £ 35 41 71.7 9.4 18 £ borax 149 water 21.6 7.9 B 35 42 65 20 15 151 water 10 7.3 A 40 43 65 20 15 143 water 10 7 A 40 44 80 20 borax 92 water 21.6 7.5 B 35 45 70.5 9.4 2O.1 borax 131 water 21.6 7.5 B 35 46 60 20 15 5 186 water 17 4.8 A 40 47 60 2O 15 5 172.7 water 17 4.8 A 4O

table

(Continuation)

Concentration of the monomers (% by weight)

Example "\

AT THE

AS

AHP

VIFA YIMFA

VIMA VIA MAM

MVIA MVIFA

Other additives

K- wcrt

Iteaction_ medium

Concentration {Qev. %)

pH • Who *

sat or

Beginning ^ tempera door ⁸ C "

βθ 6Ο 60 51. f 51. ί 51.fi

20 20

13.5 13.2

20

15 15 15 3Ο 3Ο 30

5 5

210.9

138

164

132.8

131.5

117.4

Water water water water water water

17 17

17 IO IO 10

4.8 4.8 4.7 4.8 4.8 4.8

A A A A

40 40 40 40 40 40

; T a * e lie II

AT THE AS: Concentration of the tlowons (Gev.%) Yifa VIMFA VI19Ä VIA HAM MVIA MVIFA Further . JC- ':. feuktics: Iunzeii pH. Catal ^ Top ^ example AMPS 1 additions value  medium joined! on value sator tempera 65 2O 15 148 fcert- 20 9.1 C 5O 54, butanol 65 15 178 π 2O 9.1 C 50 55 65 2O 20 15 142 Il 20 9.0 C 50 56 65 - 15 176 Il 2O 9.1 C 50 57: 65 20 2O 15 131.5 "1 20 9.2 C 50 58 65 15 157 Il 20 8.8 C 50 M M 59 65 2O 20 15 141 Il 20 8.9 C 50 60 60 20 15 5 144.5 Il 17.5 9.0 C 50 61 60 15 5 179.5 11 17.5 9.6 C 50 62 60 20 20 15 5 177 Il 17.5 9.3 C 50 63 60 .15 5 181.5 Il 17.5 8.9 C 5O 64 60 20 20 15 5 146.2 η 17.5 8.6 C 50 65 60 15 5 182.7 Il 17.5 8.9 C 50 66 20

I ό b I 4 ό U ^{22 Ref} · ³¹⁹⁶

Example 67

In a 5OO ml flask equipped with a water bath, stirrer, reflux condenser, dropping funnel and gas inlet, a solution of 0.23 g sorbitan monolaurate, 1.09 sorbitan monostearate, 0.14 g sorbitan monooleate and 3.61 g polyoxyethylene sorbitan Monostearate in 56.4 g of a straight-chain paraffinic hydrocarbon fraction (Narpar 13 from Exxon) submitted. While introducing nitrogen, the solution is heated to 60.degree.

In a separate vessel, dissolving 33.6 g of acrylamide gives 5.4 g of AMPS, 6.6 g of N-methyl-N-vinylacetamide, 6.6 g of N-vinylformamide and 7.8 g of vinylpyrrolidone in a mixture of 78.8 g of deionized water and 2.6 ml of 10 wt% sodium hydroxide solution prepared a monomer solution. The pH of this solution is 7.4. The monomer solution is 23 mg of 2, 2 '-A ^z O ⁱ - ° is' - (2-amidinopropane) hydrochloride was added and then quickly dropped in the presented organic Emulgatorenlösung with vigorous stirring _y being a milky white emulsion is obtained. Once the temperature of the batch has risen again to 6Q ° C, the stirring speed is reduced to about 60 revolutions per minute. After an induction time of IQ minutes, a temperature increase begins, at about 80 ° C the emulsion becomes transparent _; and the stirring speed is increased. The temperature continues to rise to max. 97 ° C. After the batch has cooled back to 80 ° C, stirring is continued at this temperature for 2 hours. A stable emulsion containing 30% by weight of active polymer is obtained.

Example 68

In an 11 polymerization vessel, 67 g of a deodorized Kerosinfraktion with a boiling range of 190 to 24O ° C (JJxsol D, sales product of Esso Chemie, Germany) heated to a temperature of 60 C. With gentle stirring, 0.27 g of sorbitan monolaurate, 1.3 g of sorbitan monostearate, 0.17 g of sorbitan monooleate and 4.3 g of polyoxyethylene sorbitan monostearate are dissolved successively. With further gentle stirring and introduction of a stream of nitrogen

235743 O - ^2> 12. _5β

AP G 08 F / 235 74 3/0 (60 183/11)

then the solution is heated to 60 ⁰ G. In a second vessel are dissolved in 94 ml of water, 6.4 g · MPS, 44.8 g of acrylamide, 9.2 g of vinylpyrrolidone and 10.6 g of U-vinyl-formamide with stirring. The solution thus obtained is added by dropwise addition adjusted to a pH of 8 to 10 of 10 wt .-% aqueous Hatriumhydroxydlösung and treated with 0.1 g of ammonium persulfate · The resulting aqueous monomer solution is added dropwise with rapid stirring through a dropping funnel into the initially charged organic emulsifier and emulsified. Die polymerization started after about 30 min. under increase of the temperature · in the course of 15 min., the temperature rises to 80 to 90 ⁰ C. liach decay of the polymerization, the solution is stirred for a further 2 hours at 80 ⁰ G. A stable emulsion having a polymer content of 30% by weight is obtained. The molecular weight of the polymer is 95,000.

Example 69

1.85 g of sorbitan monostearate are dissolved in a technical isomeric hydrocarbon mixture having a boiling range of 200 to 240 ⁰ C. This solution is presented in a 2-1-ß-reaction flask equipped with stirrer, thermometer and gas inlet tube, »

In a separate vessel, a monomer solution is then prepared by dissolving 25 g of acrylamide, 3.7 g of acrylic acid and 9.2 g of N-vinylformamide in 40 ml of deionized water, and the pH of this solution by adding an aqueous 20 wt. -% sodium hydroxide solution adjusted to 8.5. With vigorous stirring, the aqueous monomer solution is slowly run into the organic sorbitan monostearate solution · and then the air in the reaction vessel is displaced by nitrogen.

235743 O ~ ²⁴ ~ 12.5.1932

AP C 08 P / 235 743/0 (60 183/11)

To. Addition of. 0.07 g of 2,2'-azobisisobutyronitrile, dissolved in acetone, the emulsion is heated slowly with stirring to 60 ⁰ G. To. The polymerization is complete for 2.5 hours and a stable emulsion of the copolymers is obtained.

Example 70

67 g of a technical isomeric hydrocarbon fraction having a boiling range of from 200 to 240 ^° C. are placed in a 1-1 polymerization vessel and heated to 60 ° C. While stirring, 0.27 g of sorbitan monolaurate, 1.3 g of sorbitan monostearate, 0.17 g of sorbitan monooleate and 4.3 g of polyoxyethylene sorbitan monostearate are successively dissolved.

In a separate vessel, 12.8 g of VIMA, 39.8 g of acrylamide, 12.0 g of vinylpyrrolidone and 6.6 g of H-vinylformamide are dissolved with stirring in 94 ml of water. The pH of this solution is adjusted to 8 to 10 by the dropwise addition of 10% by weight aqueous sodium hydroxide solution, and then 0.1 g of ammonium persulfate is added thereto. This monomer solution is then added dropwise with vigorous stirring through a dropping funnel into the initially introduced organic emulsifier solution and emulsified therein. The polymerization reaction .startet after about 30 min, wherein in the course of 15 min., The reaction temperature rises to 30 to 90 ⁰ C. After the reaction has subsided, the solution is stirred for 2 hours at 80 ⁰ G. This gives a stable emulsion having a polymer content of 30 wt .-%. The molecular weight of the polymer is 95,000.

235 7 43 O - ^24a - ¹² · ⁵ · ¹⁹⁸²

AP C 08 P / 235 74 3/0 (60 183/11)

According to the embodiments 68 to 70, the products of the following Table III can be prepared, which can also be used as valuable Reibververinderer for aqueous acids ,,

Table III M AS AMPS VF 'h / rel, K-value

65 20 15 6.59 148

65 20 15 10.05 165.8

65 20 15 9.36 T63

60 20 5 HMA 17.27 186.

235743 ü

Ref. 3196

AT THE AS AMPS VF 5 NMVA I ^ / Tel. K value 60 20 15 5 NMVF 11.97 172.7 60 20 15 5 NMVF 11.0 169.4 60 20 15 5 NMVF 7.0 151.2 60 20 15 5 NMA 9.47 164 60 20 15 5 NMVF 35.0 210.9 60 20 15 5 NMA 24.43 193 51.8 13.2 30 5 NMVA 4.66 132.8 51.8 13.2 30 5 NMVF 4.53 131.5 51.8 13.2 30 5 NMA 3.41 117.4 51.8 i3 _? a 30 5 NMVA 12.16 173 51.8 13.2 30 5 NMVF 9.1 162.32 51.8 13.2 30 5 NMA 9.3 163.16 6O 20 15 5 NMVF 31.44 207.4 51.8 13.2 30 20 VIPs 3.57 119.0 65 10 5 29.3 204

All amounts in Table III are parts by weight

Examples 71

In order to demonstrate the friction-reducing property of the copolymers according to the invention, flow tests were carried out with 7.5% strength by weight hydrochloric acid once without and once with an addition of the copolymer according to the invention prepared according to Example 1,

In order to carry out the experiment, a pipe loop was used in which the fluid was pumped through a series of pipes of known length and diameter at a certain flow rate. The hydro-mechanical pressures are measured at both ends of a given, defined pipe section. Since one knows the Dur.chflußgeschwindigkeit and the pressure differences at the relevant pipe section, it is thus possible, the friction pressure of different fluid as a function of the flow rate of the fluid

235743 O ^{26 Ref} ·

to graph in the tube.

The first experiment was carried out with 208 l of 7.5% by weight hydrochloric acid containing 760 ml of a commercially available corrosion inhibitor, with pumping speeds of 38 to 57 l / min using a pipe having an inner diameter of 0.925 cm, 19 to 170 l using a tube having an inner diameter of 1.25 cm and 19 to 454 l / min using a tube of 2.66 cm inside diameter. After this series of experiments, 224 g of the copolymer prepared in Example 1 were added to the 7.5% strength by weight hydrochloric acid corresponding to a copolymer concentration of 0.1% by weight in the acid. The flow experiment was repeated with this polymer-containing acid. The measurement results obtained in both cases on the 0.925 cm 1.25 cm and 2.66 cm inner diameter tube sections have been illustrated in Figures 1, 2 and 3, respectively.

Example 72

In order to demonstrate the acid solubility of copolymers according to the invention, they were subjected to the following experiment in comparison with commercial friction reducers:

200 ml of 15% strength by weight hydrochloric acid were introduced into three 225 ml tubes. The acid in vessel 1 was then made 2.0 g of the polymer of the invention according to Example 2, in vessel 2, 2.9 g of a commercial friction reducer emulsion LFR-l _; and in vessel 3, 3.2 g of a commercial friction reducer emulsion LFR-2 was added. The commercial products LFR-I and LFR-2 are copolymers of acrylamide and acrylic acid with molecular weights of 500,000 to 2,000,000. The polymer contents of the emulsions LFR-I and LFR-2 are unknown, but it is believed that differences exist between the two products in terms of the amount of the active copolymer, the comonomer ratio of the polymers and the type of emulsifier. The samples in the three vessels were heated to 60 ° C for 24 hrs. After this time, the solution in vessel 1, which contains the copolymer of the invention, was still completely clear, the copolymer was therefore completely saturated.

235743 O -27-

05/12/1932

08 G 08 F / 235 74 3/0

(60 183/11)

constantly soluble ,. In contrast, vessels 2 and 3 each had white precipitate pots formed. The precipitated solids were filtered off with suction and washed with water and then with methanol. Thereafter, the filter residues were dried in a vacuum at 40 ⁰ C over laughing. The amounts obtained are shown in Table IV below

table

IV

sample

initial weight

Weight of insoluble deposit

% insoluble precipitate

Erfindungsge-

moderate copolymer 2.0

LFR-1 emulsion

2.9.0 g "

1.15 g

39

, 6 g

LFR-2 emulsion

3.20 g

0.82 g

25.6 g

⁺ The indicated weight in these cases refers to emulsion, not to pure polymer.

2 3 5 7 A 3 O -28- 12.5.1982

AP C 08 F / 235 743/0 (60 183/11)

Example 73

For the acidification, a natural gas well in Texas is selected. The hole has a production interval between a depth of 1100 to 1120 meters. The sole temperature in this interval is 43 C »the permeability of the formation an average of 0.15 md (millidarcy). The pipe diameter is 6.0 cmj. The spontaneous productivity of the hole before treatment is about 168 m ^ gas per day.

The pressure acidifying fluid to be used is prepared by first mixing 3785 l of 28% strength hydrochloric acid with 3596 l of fresh water and then the resulting dilute "acid 79 *> 5 l (0.2% by weight) of that prepared according to Example 3 Adding polymer emulsion The resulting fluid is injected into the well at a rate of 1589 »8 l / min under a pressure of 310.5 bar, after 25 minutes the pumping is complete and the well is capped to allow the acid opportunity give to react with the rock.

After 60 minutes, the pressure at the head of the bore is relieved and the production is restored. Measuring the delivery rate results in a substantial increase in the productivity of the well.

100 on ι \ L • i ( 1 i 1 0 2 ] / • R 3 Dhrgr 0 4 O öß 3 e 11 50 6 r / , 364 0708 / Zo 09C I j U / Innendur) 100 Dhm ess he η bU QA ~ J_ f y I - -fl 80 70 cn _ j / U You 50 J C η η 7, 5 ⁶ y IC ~ [ / O ς MU I / in \ A JU \ - J L U y CO <Λ 10 1 9- D _ / Z 0 1 7 fi - / I R- 3 L - \ 4 I I J J 1 / 0.1% Polvmer solution 9 / L f y 1 Γ I / / IE

3 *. 5 6 7 8 910

30 40 50 60708090100

Flow rate feet per second

CJT

FIG.1

IOD

33

COCOr ~~ LO LO

CO CU

c:

C =

crt

cn

C =) CU: o cn

LO

C =). LO

cn co-

LO-LO

• 0.17o polymer solution S \ \ \ \ V, \ S S > \ S \ S, s. S. \ \ v. N \ S _n > \ S, .S S O O IO

- CVI

CD

cn CU CD CTJ CD -a C =) C = LO C => _m d LO LJ CO C = J CU cn C = CU

-co

-ao

LO-LO

ISd dV

> I ι • 1 0 J R 20 j / ear 3 size 0 /, /. / / 3 50 6 / i / i / f IZ 07 oil 08 / OS If 01 Outer diameter 00 j / UU J γ / * / f X / ι / r V 70 / 60 cn HCl / / YOU J / η r mU in 7,57o y J / 9Π 10 β -J 7 _ I J / C J J j /, ^r  3 JL J / 9 L 1 0,1,7o polymer L'dsunc /

2 3 h 5 6 7 8 910

30 40 50 60708090100

Flow rate foot per second

 9 8

 6

FIG.3

Claims (5)

A? G 08 £ 7235 74 3/0 (60 183/11) 1 method for stimulating 3rdgas- and oil drilling by pressurized acidification with an acid solution, characterized in that the acid 0.06 to 0.12 wt .-% in water or aqueous acids soluble copolymer containing in its macromolecule at least 5 wt. % of units containing a formylamino group of the formula Have -W-G, wherein R is hydrogen, methyl or hydroxymethyl and at least 10% by weight of units containing an amino bony group of the formula have, contains » 2, method according to item 1, characterized in that the copolymer in a statistical distribution to -GH ₀ -GH- _r 2 ι ^ P NG / (I) R ¹ ^ ^H From 10 to 95% by weight of units of the formula II --CH ₂ --CH-- CO-EH ₂ (II) and 0 to 85 wt .-% of units of the formula III -GH ₅ -O- (III) composed, 235 7 43 O - ³⁰ - ¹² · ⁵ · ¹⁹⁸² AP C 08 F / 235 743/0 (60 183/11) wherein R is hydrogen, methyl or hydroxymethyl and R is hydrogen or methyl, and X ^G yan, carboxyl, or its alkali or ammonium salts, alkoxycarbonyl having 1 to 6 carbon atoms, hydroxyalkoxycarbonyl having 1 to 3 carbon atoms; H-methylolamidocarbonyl of the formula HOCHpHH-CO-, whose methylol group may optionally be etherified with alkanols: having 1 to 4 carbon atoms; Alkanoylamino having 1 to 4 carbon atoms, which may optionally be U-substituted by methylol or alkyl having 1 to 4 carbon atoms; Pyrrolidonyl (1); phenyl; pyridinium; the sulfonic acid group; Sulfoalkylamidocarbonyl having 1 to 4 carbon atoms; the phosphonic acid group, wherein sulfonic acid and phosphonic acid groups may also be present as alkali metal or ammonium salts; a radical of formula IV -GOOCH ₀ GH ₀ -OPR ³ (IV), • R ⁴ wherein R 1 and R 3 are the same or different and are alkyl of 1 to 4 carbon atoms; a radical of the formula V ρ 2p ¹ p. R ⁴ wherein R ^ and R have the meanings given above and ρ is a number from 1 to 4; or a radical of the formula VI ~ * ~ ρ 2p ~ "" "-p ^ vVJ.>, 5 6 wherein R 1 and R 3 are the same or different and are alkyl of 1 to 4 carbon atoms and ρ is a number from 1 to 4; and the formula V and VI corresponding quaternized ^G 'groups means · 235 7 A3 O - ³¹ - ¹² · ⁵ · ¹⁹⁸² AP G 08 P / 235 74 3/0 (60 133/11) 3. Procedure according to points 1 and. 2, characterized in that the copolymer comprises 5 to 30% by weight of units of the formula I, 50 to 80% by weight of units of the formula II and 1 to 60% by weight of units of the formula III * Process according to items 1 to 3, characterized in that a copolymer is used in which X is carboxyl, the sulfonic acid group, 3-sulfo-2-methylpropyl- (2) -amidocarbonyl of the formula CH-, -COWH-C-CH ₀ H -SO- Alkanoylamino with 1 to 4 carbon atoms, which may optionally be! -Substituiert with methylol or alkyl having 1 to 4 carbon atoms, pyrrolidonyl (1) or a radical of the abovementioned and defined formulas V or VI, wherein each acid group as sodium, potassium or Ammonium salt can be present « 5. Method according to items 1 to 4, characterized in that a copolymer is used having a K value between 25 and 250, corresponding to a molecular weight weight from 20 000 to 15 x 10 °, For this JL. Pages tables