CN104250347A - Acrylamide copolymer, and preparation method and application thereof - Google Patents

Abstract

The invention discloses an acrylamide copolymer, and a preparation method and application thereof. The acrylamide copolymer contains a constitutional unit A, a constitutional unit B, and a constitutional unit C, wherein the constitutional unit A is a constitutional unit represented by formula (1), the constitutional unit B is a constitutional unit represented by formula (2), and the constitutional unit C is a constitutional unit represented by formula (3) and/or (4), the acrylamide copolymer contains 5-95 mol % of the constitutional unit A, 2.5-90 mol % of the constitutional unit B and 0.5-90 mol % of the constitutional unit C on the basis of total mole number of the constitutional units in the acrylamide copolymer, and the viscosity average molecular weight of the acrylamide copolymer is 2,000,000-15,000,000. The acrylamide copolymer has the advantages of high drag reduction rate, high salt resistance, good high-shear resistance, good water solubility, good compatibleness with clay inhibitors (alcohols), low viscosity average molecular weight and low damages to the stratum.

Description

A kind of acrylamide based copolymer and its preparation method and application

Technical field

The present invention relates to the application as flow improver of a kind of acrylamide based copolymer, two kinds of preparation methods of acrylamide based copolymer and described acrylamide based copolymer.

Background technology

As unconventional petroleum resources utilize Typical Representative---the exploitation of shale gas (oil) resource has become a revolution in global unconventional petroleum resources field, the development and utilization of current shale gas has become countries in the world and has paid close attention to emphatically and the focus technology developed.Because the ultimate attainment close hydrocarbon-bearing pools such as shale gas reservoir have the advantages that rate of permeation extremely low (being generally less than 0.5mD), frac pressure are high, easily cause formation damage." drag reduction water (slippery water) pressure break " technique must be adopted to exploit.

" drag reduction water (slippery water) pressure break " is the one of waterfrac treatment.Compared with current conventional pressure break system (modifyed guar gum cross-linking system), drag reduction water (slippery water) pressure break is not rely on high viscosity colloid to take sand, but takes sand with high infusion discharge capacity, realizes final purpose reservoir fracturing being reticulated crack.Compared with conventional pressure break system, while drag reduction water (slippery water) pressure break has greater advantage on cost, the injury of formation is less.

Drag reduction water fracturing liquid core auxiliary agent is water-based drag reducer, in practice of construction, adding of water-based drag reducer overcomes the friction resistance of working fluid in pipeline, ensure that the raising of infusion discharge capacity, pressure acted on to greatest extent press off stratum and extend formation fracture, what can be used as water-based drag reducer at present mainly contains guanidine glue and derivative thereof, derivatived cellulose, acrylamide copolymer.

At present, adopt that guanidine glue, cellulose and its derivates improve infusion discharge capacity to a certain extent as the flow improver during drag reduction hydraulic pressure splits, the friction resistance (US5697444 reduced in pipeline, US5271466), but still the requirement that drag reduction hydraulic pressure splits cannot be met, there is following shortcoming mainly due to above-mentioned biopolymer: (1) resistance-reducing performance is limited; (2) due to guanidine glue, cellulose and its derivates have a small amount of insolubles very easily formation damage; (3) dissolution time is longer.

In drag reduction water pressing crack construction, friction reducer in adopting acrylamide copolymer (partial hydrolysis acrylamide or anionic acrylamide copolymer) to split as drag reduction hydraulic pressure more, greatly enhance infusion discharge capacity, reduce the friction resistance in pipeline, but use as the flow improver that shale gas reservoir drag reduction hydraulic pressure splits, there is following major defect: (1) is in order to reduce " the water-sensitive effect " in fracturing process, suppress the hydration swelling of clay composition in shale, small molecules cationic clay stablizer must be added (as Repone K in fracturing liquid, tetramethyl ammonium chloride etc.).The compatibleness of partial hydrolysis acrylamide or anionic acrylamide copolymer and product emulsion and above-mentioned clay stabilizer is poor, very easily produces precipitation; (2) partial hydrolysis acrylamide or anionic acrylamide copolymer use anti-filtration property poor as the flow improver that shale gas reservoir drag reduction hydraulic pressure splits, and this kind of drag reduction water fracturing liquid is very easily in the middle of leak-off to stratum; (3) heat and salt resistance is poor, and especially under high salinity high divalent ion content condition, molecular structure is unstable, and resistance reducing effect declines very fast.

Patent US20090298721A1 discloses the of the fracturing fluid formula of a kind of drag reduction water: in 1000 gallons of deionized water, add 0.5 gallon of acrylic acidcoacrylamide thing (FR-56 ^tM) etc. anionic acrylamide copolymer emulsion as flow improver, add the complexing agents such as 0.15wt% sodium carbonate or EDTA-2Na again, this drag reduction water fracturing liquid has excellent resistance-reducing performance, indoor average resistance-reducing yield reaches 65.0%, improvement has to a certain degree been had to salt tolerance (especially to the tolerance of divalent calcium ions), but this kind of drag reduction hydraulic pressure splits system and uses as shale gas drag reduction water fracturing liquid, there are the following problems: (1) is poor with the compatibleness of clay stabilizer and alcohol, very easily produces precipitation; (2) anti-filtration property is poor, and this kind of drag reduction water fracturing liquid is very easily in the middle of leak-off to stratum; (3) in practice of construction, " water-sensitive effect " is remarkable; (4) very easily " water blocking " is produced; (5) resistance to high speed shear poor performance, unstable under high speed shear effect, resistance-reducing yield declines very fast; (6) heat-resistant salt-resistant is poor, and especially under high salinity high divalent ion content condition, molecular structure is unstable, and resistance reducing effect declines very fast; (7) not easily degrade, easily cause permanent type to injure to extremely fine and close shale formation, pollute stratum, then affect oil and gas production.

Compared with above-mentioned partial hydrolysis acrylamide or anionic acrylamide copolymer, the acrylamide copolymer of cationic high-molecular amount is as flow improver (US356226, US3868328) also report is had, the compatibleness of this kind of structure copolymer and alcohol is better, better with small molecules clay stabilizer (as KCl, tetramethyl ammonium chloride etc.) consistency, " water-sensitive effect " is not remarkable, and not easily " water blocking ", polymkeric substance itself has the effect of certain suppression hydration and expansion of clay.But this type of friction reducer molecular weight is higher, not easily degrades, and easily causes possible permanent damage to the shale of densification.

Therefore, how to improve the resistance to high speed shear performance of flow improver further, improve fracturing liquid to the inhibition of clay and anti-leak-off, the injury that the stability improving the drag reducing efficiency under high temperature and high salt shear conditions reduces polymkeric substance formation is simultaneously still a still open question.

Summary of the invention

The object of the invention is the defect overcoming prior art, provide that a kind of viscosity-average molecular weight is low, drag reducing efficiency is high, heat-resisting and salt tolerance is high, anti-high-shear performance is good, good water solubility, with clay stabilizer, there is good compatibleness and formation injures little acrylamide based copolymer and its preparation method and application.

The invention provides a kind of acrylamide based copolymer, wherein, described acrylamide based copolymer contains structural unit A, structural unit B and structural unit C, wherein, described structural unit A is the structural unit shown in formula (1), described structural unit B is the structural unit shown in formula (2), and described structural unit C is the structural unit shown in the structural unit shown in formula (3) and/or formula (4); And with the total mole number of structural unit in described acrylamide based copolymer for benchmark, the content of described structural unit A is 5-95 % by mole, the content of described structural unit B is 2.5-90 % by mole, and the content of described structural unit C is 0.5-90 % by mole; The viscosity-average molecular weight of described acrylamide based copolymer is 2,000,000-1,500 ten thousand;

Wherein, R ₁, R ₂, R ₄and R ₇be the straight or branched alkyl of H or C1-C4 independently of one another; R ₃for the straight or branched alkylidene group of connecting key or C1-C6; R ₅and R ₆be the straight or branched alkyl of H or C1-C20 independently of one another, and R ₅and R ₆be asynchronously H; R ₈for the straight chain branched-chain alkyl of C1-C20; X ^-for Cl ^-, Br ^-, I ^-, SCN ^-,

The present invention also provides a kind of preparation method of acrylamide based copolymer, under this preparation method is included in the solution polymerization condition of alkene, under initiator exists, a kind of monomer mixture is made to carry out polyreaction in water, wherein, described monomer mixture contains monomer D, monomer E and monomer F, described monomer D is the monomer shown in formula (5), described monomer E is the monomer shown in formula (6), described monomer F is the monomer shown in the monomer shown in formula (7) and/or formula (8), with the total mole number of monomer in described monomer mixture for benchmark, the content of described monomer D is 5-95 % by mole, the content of described monomer E is 2.5-90 % by mole, the content of described monomer F is 0.5-90 % by mole, after the condition of described solution polymerization makes polyreaction, the viscosity-average molecular weight of resulting polymers is 2,000,000-1,500 ten thousand,

Wherein, R ₁, R ₂, R ₄and R ₇be the straight or branched alkyl of H or C1-C4 independently of one another; R ₃for the straight or branched alkylidene group of connecting key or C1-C6; R ₅and R ₆be the straight or branched alkyl of H or C1-C20 independently of one another, and R ₅and R ₆be asynchronously H; R ₈for the straight chain branched-chain alkyl of C1-C20; X ^-for Cl ^-, Br ^-, I ^-, SCN ^-,

The present invention also provides a kind of preparation method of acrylamide based copolymer, this preparation method comprises aqueous phase and oil phase is mixed to form reversed-phase emulsion, then under emulsion polymerization condition, under the existence of initiator, this reversed-phase emulsion is carried out polyreaction, described aqueous phase is the aqueous solution containing monomer mixture, described oil phase contains organic solvent and emulsifying agent, wherein, described monomer mixture contains monomer D, monomer E and monomer F, described monomer D is the monomer shown in above-mentioned formula (5), described monomer E is the monomer shown in above-mentioned formula (6), described monomer F is the monomer shown in the monomer shown in above-mentioned formula (7) and/or formula (8), with the total mole number of monomer in described monomer mixture for benchmark, the content of described monomer D is 5-95 % by mole, the content of described monomer E is 2.5-90 % by mole, the content of described monomer F is 0.5-90 % by mole, after the condition of described emulsion polymerization makes polyreaction, the viscosity-average molecular weight of resulting polymers is 2,000,000-1,500 ten thousand.

In addition, present invention also offers the application of described acrylamide based copolymer as flow improver.

In described acrylamide based copolymer provided by the invention, by the hydrophobic structure unit of the triphenyl phosphonium salt system's hydrophobic structure unit shown in drawing-in system (2) and formula (3), and control relatively low viscosity-average molecular weight, make this acrylamide based copolymer have higher drag reducing efficiency under high temperature and high salt shear conditions, and with clay stabilizer (as KCl, NaCl), there is higher compatibleness.

And acrylamide based copolymer of the present invention water insoluble matter content when being used as flow improver is obviously lower; Good consistency is had with cleanup additive (as methyl alcohol); Formation injury is low.

Particularly, the viscosity-average molecular weight of obtained in embodiment 1-6 acrylamide based copolymer all can reach less than 1,500 ten thousand; Insolubles content in water is only 0.01 % by weight; Under the shearing rate of 2500rpm, this polymkeric substance does not produce precipitation at water/alcoholic solution, can dissolve completely; It is in NaCl or the KCl solution of 2 % by weight, 4 % by weight, 8 % by weight, 10 % by weight, 12 % by weight that acrylamide based copolymer obtained in embodiment 1-6 is dissolved in concentration, be mixed with the solution of 500mg/L and 1000mg/L, drag reducing efficiency at 25 DEG C all can reach more than 60%, in addition, the drag reducing efficiency under the condition of 60 DEG C also can reach more than 50%; In addition, the injury of obtained in embodiment 1-6 acrylamide based copolymer formation is less than 10%.

In addition, preparation method's (solution polymerization process and reversed emulsion polymerization) of acrylamide based copolymer provided by the invention has easy and that monomer conversion is high advantage.

Other features and advantages of the present invention are described in detail in embodiment part subsequently.

Embodiment

Below the specific embodiment of the present invention is described in detail.Should be understood that, embodiment described herein, only for instruction and explanation of the present invention, is not limited to the present invention.

(1) acrylamide based copolymer

The invention provides a kind of acrylamide based copolymer, wherein, described acrylamide based copolymer contains structural unit A, structural unit B and structural unit C, wherein, described structural unit A is the structural unit shown in formula (1), described structural unit B is the structural unit shown in formula (2), and described structural unit C is the structural unit shown in the structural unit shown in formula (3) and/or formula (4); And with the total mole number of structural unit in described acrylamide based copolymer for benchmark, the content of described structural unit A can be 5-95 % by mole, be preferably 10-70 % by mole, be more preferably 50-70 % by mole; The content of described structural unit B is 2.5-90 % by mole, is preferably 20-50 % by mole, is more preferably 20-30 % by mole; The content of described structural unit C is 0.5-90 % by mole, is preferably 10-40 % by mole, is more preferably 10-20 % by mole; The viscosity-average molecular weight of described acrylamide based copolymer is 2,000,000-1,500 ten thousand, is preferably 2,000,000-600 ten thousand,

Wherein, R ₁for the alkyl of H or C1-C4, be preferably H or methyl; R ₂, R ₄and R ₇be the straight or branched alkyl of H or C1-C4 independently of one another, be preferably H; R ₃for the straight or branched alkylidene group of connecting key or C1-C6, be preferably connecting key or methylene radical; R ₅and R ₆be the straight or branched alkyl of H or C1-C20 independently of one another, and R ₅and R ₆be asynchronously H, under preferable case, R ₅and R ₆be the straight or branched alkyl of H or C1-C5 independently of one another, and R ₅and R ₆be asynchronously H, under further preferable case, R ₅and R ₆be H, methyl, ethyl, sec.-propyl or the tertiary butyl independently of one another, and R ₅and R ₆be asynchronously H; R ₈for the straight or branched alkyl of C1-C20, be preferably the straight or branched alkyl of C1-C5, more preferably methyl, ethyl, sec.-propyl or the tertiary butyl; X ^-for Cl ^-, Br ^-, I ^-, SCN ^-, be preferably Br ^-.

The present inventor finds under study for action, and the acrylamide ter-polymers be made up of specific structural unit A, structural unit B and structural unit C can obtain fabulous resistance reducing effect.Preferably, R ₁for H or methyl, R ₂, R ₄and R ₇be H, R independently of one another ₃for connecting key or methylene radical; R ₅and R ₆be the straight or branched alkyl of H or C1-C5 independently of one another, and R ₅and R ₆be asynchronously H; R ₈for the straight or branched alkyl of C1-C5; X ^-for Br ^-, that is, described structural unit A is the structural unit shown in formula (1), wherein, and R ₁for H or methyl; Described structural unit B is the structural unit shown in the structural unit shown in formula (9) and/or formula (10), and described structural unit C is formula (11), at least one in formula (12), the structural unit shown in formula (13) and formula (14),

In the present invention, the example of the alkyl of described C1-C4 can include but not limited to: methyl, ethyl, n-propyl, sec.-propyl, normal-butyl, sec-butyl, isobutyl-and the tertiary butyl.

In the present invention, described alkyl can be straight chain, also can be side chain.The example of the straight or branched alkyl of described C1-C20 can include but not limited to: methyl, ethyl, n-propyl, sec.-propyl, normal-butyl, sec-butyl, isobutyl-, the tertiary butyl, n-pentyl, isopentyl, tert-pentyl, neo-pentyl, n-hexyl, n-heptyl, n-octyl, positive decyl, dodecyl, hexadecyl and eicosyl.

Described alkylidene group refer to alkane lose two hydrogen atoms after residue, described two hydrogen atoms can be two hydrogen atoms on same carbon atom, also can two hydrogen atoms on different carbon atom, it can be straight chain, also can be side chain, such as, described ethylidene can be-CH ₂cH ₂-or-CH (CH ₃)-.

In the present invention, the example of the alkylidene group of described C1-C4 can include but not limited to: methylene radical, ethylidene, sub-n-propyl, isopropylidene, sub-normal-butyl, sub-sec-butyl, isobutylidene and the sub-tertiary butyl.

(2) solution polymerization process

In addition, the present invention also provides a kind of preparation method of acrylamide based copolymer, under this preparation method is included in the solution polymerization condition of alkene, under initiator exists, a kind of monomer mixture is made to carry out polyreaction in water, wherein, described monomer mixture contains monomer D, monomer E and monomer F, described monomer D is the monomer shown in formula (5), described monomer E is the monomer shown in formula (6), described monomer F is the monomer shown in the monomer shown in formula (7) and/or formula (8), and with the total mole number of monomer in described monomer mixture for benchmark, the content of described monomer D is 5-95 % by mole, be preferably 10-70 % by mole, be more preferably 50-70 % by mole, the content of described monomer E is 2.5-90 % by mole, is preferably 20-50 % by mole, is more preferably 20-30 % by mole, the content of described monomer F is 0.5-90 % by mole, is preferably 10-40 % by mole, is more preferably 10-20 % by mole, after the condition of described solution polymerization makes polyreaction, the viscosity-average molecular weight of resulting polymers is 2,000,000-1,500 ten thousand, is preferably 2,000,000-600 ten thousand,

Wherein, R ₁for the alkyl of H or C1-C4, be preferably H or methyl; R ₂, R ₄and R ₇be the straight or branched alkyl of H or C1-C4 independently of one another, be preferably H; R ₃for the straight or branched alkylidene group of connecting key or C1-C6, be preferably connecting key or methylene radical; R ₅and R ₆be the straight or branched alkyl of H or C1-C20 independently of one another, and R ₅and R ₆be asynchronously H, under preferable case, R ₅and R ₆be the straight or branched alkyl of H or C1-C5 independently of one another, and R ₅and R ₆be asynchronously H, under further preferable case, R ₅and R ₆be H, methyl, ethyl, sec.-propyl or the tertiary butyl independently of one another, and R ₅and R ₆be asynchronously H; R ₈for the straight or branched alkyl of C1-C20, be preferably the straight or branched alkyl of C1-C5, more preferably methyl, ethyl, sec.-propyl or the tertiary butyl; X ^-for Cl ^-, Br ^-, I ^-, SCN ^-, be preferably Br ^-.

According to the present invention, when described polyreaction starts, the ratio of the gross weight of the weight of described monomer mixture and water and monomer mixture is various ratio known in those skilled in the art, usually, the ratio of the gross weight of the weight of described monomer mixture and water and monomer mixture can be 0.05-0.5:1, is preferably 0.15-0.4:1.

According to the present invention, described initiator can be the various initiator in this area.Such as, azo series initiators and redox series initiators is selected from.With the total mole number of monomer in described monomer mixture for benchmark, the consumption of described azo series initiators is 0-10 % by mole, the consumption of described redox series initiators is 0-10 % by mole, and total consumption of described azo initiator and redox initiator preferably meets: total consumption of described initiator is the 0.0001-10 % by mole of the total mole number of monomer in monomer mixture.

In the present invention, preferably, described azo series initiators is for being selected from Diisopropyl azodicarboxylate, 2,2'-Azobis(2,4-dimethylvaleronitrile), the two methylpent hydrochlorate, 2 of azo, 2 '-azo diisobutyl amidine hydrochloride and 2, at least one in 2 '-azo two [2-(2-tetrahydroglyoxaline-2-propane)-dihydrochloride], more preferably 2,2 '-azo diisobutyl amidine hydrochloride and/or 2,2 '-azo two [2-(2-tetrahydroglyoxaline-2-propane)-dihydrochloride].

Described redox series initiators comprises Oxidizing and Reducing Agents, preferably, the mol ratio of described oxygenant and described reductive agent is 0.5-3.5:1, under meeting the condition of aforementioned proportion, the consumption of described oxygenant can be the 0.0001-0.01 % by mole of the total mole number of monomer in monomer mixture, is preferably the 0.001-0.008 % by mole of the total mole number of monomer in monomer mixture; Under preferable case, described oxygenant is selected from least one in ammonium persulphate, Potassium Persulphate, Sodium Persulfate and hydrogen peroxide, more preferably ammonium persulphate and/or Potassium Persulphate; The consumption of described reductive agent can be the 0.0001-0.005 % by mole of the total mole number of monomer in monomer mixture, is preferably the 0.001-0.004 % by mole of the total mole number of monomer in monomer mixture; Described reductive agent can be inorganic reducing agent (helping reductive agent) and/or organic reducing agent (chainextender), preferably, described inorganic reducing agent is be selected from least one in sodium bisulfite, S-WAT, rongalite, Sulfothiorine, ferrous sulfate, vat powder, xitix and urea, more preferably sodium bisulfite and/or Sulfothiorine; Described organic reducing agent is for being selected from N, N '-dimethyl quadrol, N, N '-dimethyl-1,3-propylene diamine, N, N, N ', at least one in N '-Tetramethyl Ethylene Diamine, N, N-dimethyl amine, 3-methylamino-propylamine, Dimethylaminoethyl Methacrylate, N-(3-dimethylamino-propyl) Methacrylamide, 1-(dimethylamino)-2-propylamine and diethylenetriamine, more preferably N, N '-dimethyl quadrol, N, N '-dimethyl-1,3-propylene diamine and N, N, N ', N ' at least one in-Tetramethyl Ethylene Diamine.

According to the present invention, described polyreaction can also be carried out under various auxiliary agent exists, and described auxiliary agent can be selected from least one in sequestrant and other auxiliary agents; With the total mole number of monomer in described monomer mixture for benchmark, the consumption of described sequestrant is 0-2 % by mole, be preferably 0.0001-1 % by mole, more preferably 0.0001-0.05 % by mole, the consumption of other auxiliary agents described can be 0-2 % by mole, be preferably 0.0001-1 % by mole, more preferably 0.0001-0.2 % by mole; Preferably, the consumption of described sequestrant and other auxiliary agents makes: with the total mole number of monomer in described monomer mixture for benchmark, the consumption of described auxiliary agent is 0.0001-4 % by mole.

According to the present invention, described sequestrant can for being selected from least one in disodium ethylene diamine tetraacetate (EDTA), Triethylene Diamine pentaacetic acid, citric acid, Citrate trianion and poly-hydroxyl acrylic, at least one more preferably in EDTA, Citrate trianion and Triethylene Diamine pentaacetic acid, described Citrate trianion can be Tripotassium Citrate, Trisodium Citrate, citrate of lime and ammonium citrate etc.

According to the present invention, other auxiliary agents described for being selected from least one in urea, sodium formiate, Virahol, Trimethyllaurylammonium bromide and sodium hypophosphite, can be preferably urea and/or sodium formiate.

The present inventor finds, under there is the condition of above-mentioned various initiator and auxiliary agent at the same time, solution polymerization process can obtain the controlled acrylamide based copolymer of viscosity-average molecular weight.

According to the present invention, the condition of described polyreaction can be the condition of this area routine.Such as, described solution polymerization carries out in the presence of an inert gas, and polymeric reaction condition can comprise: temperature is 0-80 DEG C, and the time is 1-24 hour, and pH value is 5-13; Under preferable case, temperature is 4-60 DEG C, and the time is 4-24 hour, and pH value is 5-9.Described pH value can by adding acid or alkali regulates, and described acid is preferably mineral acid, and described mineral acid is preferably at least one in hydrochloric acid, sulfuric acid, sulfonic acid, nitric acid and phosphoric acid; Described alkali can be mineral alkali or organic amine compound, such as, can be selected from least one in sodium hydroxide, potassium hydroxide, ammoniacal liquor, methylamine, ethamine, thanomin and trolamine, is preferably sodium hydroxide.

The present inventor finds under study for action, take following condition can improve the molecular weight of polymkeric substance further: namely, preferably, the process of described solution polymerization comprises the three phases carried out successively: the reaction conditions of first stage comprises: temperature is 0-10 DEG C, be preferably 4-10 DEG C, time is 1-15 hour, is preferably 3-10 hour; The reaction conditions of subordinate phase comprises: temperature is 15-30 DEG C, and be preferably 20-30 DEG C, the time is 3-8 hour, is preferably 3-5 hour; The reaction conditions of phase III comprises: temperature is 35-60 DEG C, and be preferably 45-55 DEG C, the time is 2-14 hour, is preferably 2-12 hour.

In addition, the present inventor finds under study for action, when selecting specific monomer D, monomer E and monomer F to react, can improve the resistance reducing effect of the polymkeric substance of gained further.Preferably, R ₁for H or methyl, R ₂, R ₄and R ₇be H, R independently of one another ₃for connecting key or methylene radical; R ₅and R ₆be the straight or branched alkyl of H or C1-C5 independently of one another, and R ₅and R ₆be asynchronously H; R ₈for the straight or branched alkyl of C1-C5; X ^-for Br ^-, that is, described monomer D is the monomer shown in formula (5), wherein, and R ₁for H or methyl; Described monomer E is the monomer shown in the monomer shown in formula (15) and/or formula (16), and described monomer F is formula (17), at least one in formula (18), the monomer shown in formula (19) and formula (20),

(3) reversed emulsion polymerization

In addition, the present invention also provides a kind of preparation method of acrylamide based copolymer, this preparation method comprises aqueous phase and oil phase is mixed to form reversed-phase emulsion, then under emulsion polymerization condition, under the existence of initiator, this reversed-phase emulsion is carried out polyreaction, described aqueous phase is the aqueous solution containing monomer mixture, described oil phase contains organic solvent and emulsifying agent, wherein, described monomer mixture contains monomer D, monomer E and monomer F, described monomer D is the monomer shown in above-mentioned formula (5), described monomer E is the monomer shown in above-mentioned formula (6), described monomer F is the monomer shown in the monomer shown in formula (7) and/or formula (8).The selection of monomer shown in formula (5)-Shi (8) with describe identical above, do not repeat them here.

According to the present invention, described aqueous phase is the aqueous solution containing monomer mixture.The selection of the ratio of the gross weight of the weight of described monomer mixture and water and monomer mixture with describe identical above, do not repeat herein.

According to the present invention, the part by weight of described aqueous phase and oil phase is had no particular limits, as long as make described aqueous phase and oil phase be thoroughly mixed to form reversed-phase emulsion, under preferable case, the part by weight of described aqueous phase and oil phase is 1:0.1-2, more preferably 1:0.3-0.8.

According to the present invention, described organic solvent can be the various nonpolar or organic solvent that polarity little mutual exclusive with water for letex polymerization in this area, it can be such as at least one in toluene, dimethylbenzene, hexane, hexanaphthene, normal heptane, isomery paraffin, isoparaffin, gasoline, kerosene and white oil, under preferable case, described organic solvent is be selected from least one in toluene, dimethylbenzene, normal heptane, isoparaffin, hexanaphthene and kerosene.

According to the present invention, described oil phase contains organic solvent and emulsifying agent.To the not special requirement of the consumption of described organic solvent, can change in wider scope, as long as described organic solvent and emulsifying agent are mixed to form oil phase, under preferable case, with the gross weight of described emulsion for benchmark, the consumption of described organic solvent can be 10-60 % by weight, more preferably 20-35 % by weight.

According to the present invention, described emulsifying agent can be the various nonionic emulsifier for letex polymerization in this area, it can be such as sorbitan fatty acid ester, alkylphenol polyoxyethylene, isomeric alcohol polyethenoxy ether, ethoxylated dodecyl alcohol, propylene glycol fatty acid ester, laureth, benzylphenol oxygen Soxylat A 25-7, styroyl phenol polyethenoxy ether, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester ethylene oxide adduct, benzyl dimethyl phenol polyethenoxy ether, at least one in fatty alcohol-polyoxyethylene ether and aliphatic amine polyoxyethylene ether.Under preferable case, described emulsifying agent is selected from sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene nonylphenol ether, polyoxyethylene octylphenol ether, benzylphenol oxygen Soxylat A 25-7, styroyl phenol polyethenoxy ether, isomerous tridecanol polyoxyethylene ether, at least one in ethoxylated dodecyl alcohol and benzyl dimethyl phenol polyethenoxy ether, the hydrophile-lipophile balance value be more preferably made up of two or more emulsifying agent above-mentioned is the compound emulsifying agent of 5-9, can be such as sorbitan fatty acid ester and polyoxyethylene nonylphenol ether.

According to the present invention, the consumption of described emulsifying agent is not particularly limited, can change in wider scope, as long as described emulsifying agent and described organic solvent are mixed to form oil phase, under preferable case, with the gross weight of described emulsion for benchmark, the consumption of described emulsifying agent can be 1-15 % by weight, more preferably 2-10 % by weight.

According to the present invention, described initiator can be various initiator in this area, the selection of described initiator with describe identical above, repeat no more herein.

In the present invention, under preferable case, first azo series initiators can be added aqueous phase, then be mixed to form reversed-phase emulsion with oil phase, then reversed-phase emulsion be contacted with redox series initiators, by redox initiator initiated polymerization.

According to the present invention, described polyreaction can also be carried out under various auxiliary agent exists, and described auxiliary agent can be selected from least one in sequestrant and other auxiliary agents, the selection of described auxiliary agent with describe identical above, repeat no more herein.

According in the present invention, to not special requirement on the reinforced opportunity of described sequestrant, as long as make sequestrant and metal ion generation sequestering action to make to play static stabilization to multipolymer, can select to add at aqueous phase or add in oil phase, under preferable case, in order to make sequestrant play stably more fully effect, can select to add sequestrant in aqueous phase.

According to the present invention, the selection of described sequestrant with describe identical above, repeat no more herein.

Equally, the present inventor finds, under there is the condition of above-mentioned various initiator and auxiliary agent at the same time, reversed emulsion polymerization can obtain the controlled and acrylamide based copolymer that dissolution rate is fast of viscosity-average molecular weight.

According to the present invention, the condition of described emulsion polymerization can be the condition of this area routine.The selection of described polymeric reaction condition with describe identical above, repeat no more herein.

Equally, the present inventor finds under study for action, take following condition can improve the molecular weight of polymkeric substance further: namely, preferably, the process of described emulsion polymerization comprises two stages of carrying out successively: the reaction conditions of first stage comprises: temperature is 0-20 DEG C, be preferably 5-10 DEG C, the time is 1-15 hour, is preferably 1-5 hour; The reaction conditions of subordinate phase comprises: temperature is 20-60 DEG C, and be preferably 25-55 DEG C, the time is 2-8 hour, is preferably 2-5 hour.

According to the present invention, after the method is also included in described polyreaction, described polyreaction products therefrom is contacted with phase inversion agent, dissolve in water fast in fracturing liquid application to make described polyreaction products therefrom.Described phase inversion agent can for this area be for the various phase inversion agent of letex polymerization, as long as make described the water-soluble of polyreaction products therefrom increase, it can be such as polyoxyethylene sorbitan fatty acid ester, polyoxyethylene nonylphenol ether, polyoxyethylene octylphenol ether, Ben-zylphenol Polyoxyethyl Ether, styroyl phenol polyethenoxy ether, isomery ten polyoxyethylenated alcohol, isomery undecyl alcohol Soxylat A 25-7, at least one in the nonionic emulsifier of isomerous tridecanol polyoxyethylene ether and aliphatic amine polyoxyethylene ether, under preferable case, described phase inversion agent is for being selected from polyoxyethylene sorbitan fatty acid ester, isomery ten polyoxyethylenated alcohol, isomery undecyl alcohol Soxylat A 25-7, isomerous tridecanol polyoxyethylene ether, at least one in polyoxyethylene nonylphenol ether and polyoxyethylene octylphenol ether.

According to the present invention, to the not special requirement of the consumption of described phase inversion agent, as long as described polyreaction products therefrom can be made to dissolve in water fast in fracturing liquid application, the consumption of described phase inversion agent makes: with the gross weight of described emulsion for benchmark, the consumption of described phase inversion agent can be 0.5-10 % by weight, is preferably 1-4 % by weight.

In addition, the present inventor finds under study for action, when selecting specific monomer D, monomer E and monomer F to react, can improve the resistance reducing effect of the polymkeric substance of gained further.Preferably, R ₁for H or methyl, R ₂, R ₄and R ₇be H, R independently of one another ₃for connecting key or methylene radical; R ₅and R ₆be the straight or branched alkyl of H or C1-C5 independently of one another, and R ₅and R ₆be asynchronously H; R ₈for the straight or branched alkyl of C1-C5; X ^-for Br ^-namely, described monomer D is the monomer shown in formula (5), described monomer E is the monomer shown in the monomer shown in formula (15) and/or formula (16), described monomer F is formula (17), at least one in formula (18), the monomer shown in formula (19) and formula (20), the selection of monomer shown in formula (5), formula (15)-Shi (20) with describe identical above, do not repeat them here.

In addition, present invention also offers the application of described acrylamide based copolymer in flow improver.Adopt described acrylamide based copolymer provided by the invention as fracturing liquid flow improver, high and stable drag reducing efficiency can be obtained, the technology that concrete application method is well known to those skilled in the art.

Below will be described the present invention by embodiment.Should be understood that, embodiment described herein, only for instruction and explanation of the present invention, is not limited to the present invention.

Intrinsic viscosity measures according to GB12005.1-89 polyacrylamide For Intrinsic Viscosity Measurements method; Viscosity-average molecular weight is according to formula M _v=([η]/K) ^{1 α}, wherein K=4.5 × 10 ^-3, α=0.80 calculates; Dissolution time is undertaken measuring (sample quality is all by straight polymer quality in sample) by GB12500.8-89, and the powdered samples dissolution time recorded all is less than 20min, and samples of latex dissolution time is all less than 5min; The composition of molecular structure and structural unit adopt IR spectrum and ¹³c-NMR measures; Water insoluble matter content is pressed SY/T5862-1993 and is measured; Indoor drag reducing efficiency is pressed SY/T6376-2008 and is measured.

Monomer M 1 shown in following embodiment Chinese style (21) is purchased from Sigma-Aldrich company; Monomer M 2 shown in formula (23) is according to document (Synthesis of triphenylmethyl-substituted conjugated dienes via Wittig reaction, Huaxue Shiji, 2011,33 (9), 782-784) method recorded in obtains.

In addition, unless specifically indicated, the reagent etc. used in embodiment, comparative example and test case is commercially available product.

Embodiment 1

The present embodiment prepares acrylamide based copolymer for illustration of solution polymerization process provided by the invention.

Under room temperature, the N,N-DMAA of the M1 monomer shown in the formula (21) of the acrylamide (AM) of 21.32g, 66.40g and 11.90g is joined in reaction flask, adds deionized water 564.48g, stir and monomer is dissolved completely, and stir.Respectively to the EDTA aqueous solution 5.5g adding 1 % by weight in flask, 1 % by weight azo diisobutyl amidine hydrochloride aqueous solution 2.1g, chainextender N ', N-dimethyl-ethylenediamine 0.002g, add 0.1% sodium sulfite solution 1.1g, urea 0.11g, fully stir and make it mix.Sodium hydroxide solution with 1 % by weight regulates pH to 7.5.Hierarchy of control initial temperature to 4 DEG C, logical nitrogen deoxygenation, after 30 minutes, adds 1 % by weight ammonium persulfate aqueous solution 0.75g, and continues letting nitrogen in and deoxidizing 20 minutes.Reactor is airtight, remain on 4 DEG C, react after 8 hours, react 5 hours after temperature being risen to 20 DEG C, then temperature is risen to 50 DEG C of reactions 2 hours, the gum-like product obtained is taken out, acrylamide copolymer p 1 can be received through granulation, drying, pulverizing.

Various mensuration is carried out to P1, in IR spectrum, 1660cm ^-1and 1635cm ^-1there is belonging to the amide Ⅰ absorption peak (C=O stretching vibration) of amide group in place and acid amides II is with absorption peak (N-H flexural vibration), at 1430cm respectively ^-1there is the stretching vibration absorption peak of C-N in place; 1356cm ^-1and 1401cm ^-1there is typical methyl symmetric curvature vibration absorption peak, 1506,1577,1600cm ^-1peak, place belongs to the stretching vibration of C=C on phenyl ring; 1437cm ^-1peak, place belongs to Ar-P stretching vibration; 691,724,747cm ^-1peak, place belongs to Ar-H out-of plane bending vibration on phenyl ring.Can determine that the copolymer molecule obtained has the structure shown in formula (22), recording its viscosity-average molecular weight Mv by viscosity method is 4,200,000, and monomer conversion is more than 99.9%.Wherein, formula (22) and x, y and z only indicate type and the number of structural unit, and do not represent the mode of connection of structural unit.The concrete numerical value of x, y and z is determined by charging capacity, and the composition of molecular structural formula and structural unit adopts quantitatively ¹³c-NMR composes mensuration, obtains x:y:z=1:0.6:0.4.

Comparative example 1

Acrylamide based copolymer is prepared according to the method for embodiment 1, unlike, acrylamide is carried out polyreaction with (3-acrylamido-3-methyl) butyl trimethyl ammonium chloride of identical mole number, thus obtain copolymer DP1, recording its viscosity-average molecular weight Mv is 1,050 ten thousand.

Embodiment 2

The present embodiment prepares acrylamide based copolymer for illustration of solution polymerization process provided by the invention.

The NIPA of the M2 monomer shown in the formula (23) of AM, 45.94g of 29.85g and 6.79g is joined in polymerization bottle, add 192.69g deionized water, stirring makes monomer dissolve completely, respectively to the EDTA aqueous solution 4.65g adding 1 % by weight in flask, add 1 % by weight azo diisobutyl amidine hydrochloride aqueous solution 1.23g, add chainextender N, N '-dimethyl quadrol 0.002g, add 0.1% sodium sulfite solution 1.15g, add urea 0.11g, fully stir and make it mix.Sodium hydroxide solution with 1 % by weight regulates pH to 7.1.Hierarchy of control initial temperature to 10 DEG C, logical nitrogen deoxygenation, after 30 minutes, adds 1 % by weight ammonium persulfate aqueous solution 0.6g, and continues letting nitrogen in and deoxidizing 10 minutes.Reactor is airtight, remain on 10 DEG C, react after 3 hours, be warming up to 30 DEG C, react after 3 hours, be warming up to 55 DEG C of reactions 12 hours, the gum-like product obtained is taken out, acrylamide copolymer p 2 can be received through granulation, drying, pulverizing.

Various mensuration is carried out to P2,1660cm in IR spectrum ^-1and 1635cm ^-1there is belonging to the amide Ⅰ absorption peak (C=O stretching vibration) of amide group in place and acid amides II is with absorption peak (N-H flexural vibration), at 1430cm respectively ^-1there is the stretching vibration absorption peak of C-N in place; 2923,2852cm ^-1peak, place belongs to-CH respectively ₂-,-CH ₃c-H stretching vibration, 1506,1577,1600cm ^-1peak, place belongs to the stretching vibration of C=C on phenyl ring; 1437cm ^-1peak, place belongs to Ar-P stretching vibration; 691,724,747cm ^-1peak, place belongs to Ar-H out-of plane bending vibration on phenyl ring.Can determine that the copolymer molecule obtained has the structure shown in formula (24), recording its viscosity-average molecular weight Mv by viscosity method is 5,430,000, and monomer conversion is more than 99.9%.Wherein, formula (24) and x, y and z only indicate type and the number of structural unit, and do not represent the mode of connection of structural unit.The concrete numerical value of x, y and z is determined by charging capacity, and the composition of molecular structural formula and structural unit adopts quantitatively ¹³c-NMR composes mensuration, obtains x:y:z=1:0.3:0.14.

Embodiment 3

Under room temperature, by the Methacrylamide of 5.11g, the M1 monomer shown in formula (21) of 110.66g and the N tert butyl acrylamide of 30.52g join in polymerization bottle, add 219.44g deionized water, stirring makes monomer dissolve completely, respectively to the EDTA aqueous solution 11.63g adding 1 % by weight in flask, add 1 % by weight azo diisobutyl amidine hydrochloride aqueous solution 2.13g, add chainextender N ', N-dimethyl-ethylenediamine 0.001g, add 0.1 % by weight sodium sulfite solution 1.13g, add urea 0.20g, , Trimethyllaurylammonium bromide 0.01g, abundant stirring makes it mix.Sodium hydroxide solution with 1 % by weight regulates pH to 7.3.Hierarchy of control initial temperature to 2 DEG C, logical nitrogen deoxygenation, after 30 minutes, adds 1% ammonium persulfate aqueous solution 0.8g, and continues letting nitrogen in and deoxidizing 10 minutes.Reactor is airtight, remain on 8 DEG C, react after 10 hours, be warming up to 25 DEG C, react after 4 hours, be warming up to 45 DEG C of reactions 7 hours, the gum-like product obtained is taken out, acrylamide copolymer p 3 can be received through granulation, drying, pulverizing.

Various mensuration is carried out to P3,1660cm in IR spectrum ^-1and 1635cm ^-1there is belonging to the amide Ⅰ absorption peak (C=O stretching vibration) of amide group in place and acid amides II is with absorption peak (N-H flexural vibration), at 1430cm respectively ^-1there is the stretching vibration absorption peak of C-N in place; 2923,2852cm ^-1place goes out peak and belongs to-CH respectively ₂-,-CH ₃c-H stretching vibration, 1506,1577,1600cm ^-1go out the stretching vibration that peak belongs to C=C on phenyl ring; 1437cm ^-1go out peak and belong to Ar-P stretching vibration; 691,724,747cm ^-1go out peak and belong to Ar-H out-of plane bending vibration on phenyl ring.Can determine that the copolymer molecule obtained has the structure shown in formula (25), recording its viscosity-average molecular weight Mv by viscosity method is 3,600,000, and monomer conversion is more than 99.9%.Wherein, formula (25) and x, y and z only indicate type and the number of structural unit, and do not represent the mode of connection of structural unit.The concrete numerical value of x, y and z is determined by charging capacity, and the composition of molecular structural formula and structural unit adopts quantitatively ¹³c-NMR composes mensuration, obtains x:y:z=1:5:4.

Embodiment 4

The present embodiment prepares acrylamide based copolymer for illustration of reversed emulsion polymerization provided by the invention.

(1) by the N of the M1 monomer shown in the formula (21) of the Methacrylamide of 5.11g, 110.66g, 23.79g, N-DMAA joins in configuration bottle, add 227.7g deionized water, stirring makes monomer dissolve completely, respectively to the EDTA aqueous solution 14.61g adding 1 % by weight in flask, chainextender N ', N-dimethyl-ethylenediamine 0.001g, add 1 % by weight azo diisobutyl amidine hydrochloride aqueous solution 1.03g, add urea 0.15g, abundant stirring makes it mix, and the sodium hydroxide solution with 10 % by weight regulates pH to 7.1, obtains aqueous phase.

(2) by sorbitan fatty acid ester (span60, Sigma-Aldrich company, identical below) 45g, alkylphenol polyoxyethylene (Igepal CA720, Sigma-Aldrich company, identical below) 23.95g, 237.49g kerosene is mixed into oil phase, and the aqueous phase obtained in step (1) is joined in whole oil phase, join in reactor by mixing at a high speed formation reversed-phase emulsion.

(3) hierarchy of control initial temperature 5 DEG C, logical nitrogen deoxygenation, after 30 minutes, adds 1 % by weight aqueous solution of sodium bisulfite 0.25g, then adds 1 % by weight ammonium persulfate aqueous solution 1.0g and continue letting nitrogen in and deoxidizing 10 minutes.Reactor is airtight, remain on 5 DEG C, react after 5 hours, be warming up to 55 DEG C, react 2 hours.After question response temperature cool to room temperature, add 13.79g polyoxyethylene nonylphenol ether (Sigma-Aldrich company, identical below), obtain emulsion-formulated products with 80 order filter-cloth filterings.After reversed-phase emulsion product acetone and methanol mixed solvent being precipitated out, acrylamide copolymer p 4 can be obtained.

Various mensuration is carried out to P4,1660cm in IR spectrum ^-1and 1635cm ^-1there is belonging to the amide Ⅰ absorption peak (C=O stretching vibration) of amide group in place and acid amides II is with absorption peak (N-H flexural vibration), at 1430cm respectively ^-1there is the stretching vibration absorption peak of C-N in place; 1356cm ^-1and 1401cm ^-1there is typical methyl symmetric curvature vibration absorption peak, 1506,1577,1600cm ^-1go out the stretching vibration that peak belongs to C=C on phenyl ring; 1437cm ^-1go out peak and belong to Ar-P stretching vibration; 691,724,747cm ^-1go out peak and belong to Ar-H out-of plane bending vibration on phenyl ring.Can determine that the copolymer molecule obtained has the structure shown in formula (26), recording its viscosity-average molecular weight Mv by viscosity method is 3,780,000, and monomer conversion is more than 99.9%.Wherein, formula (26) and x, y and z only indicate type and the number of structural unit, and do not represent the mode of connection of structural unit.The concrete numerical value of x, y and z is determined by charging capacity, and the composition of molecular structural formula and structural unit adopts quantitatively ¹³c-NMR composes mensuration, obtains x:y:z=1:5:4.

Comparative example 2

Acrylamide based copolymer is prepared according to the method for embodiment 4, unlike, Methacrylamide is carried out polyreaction with (3-acrylamido-3-methyl) butyl trimethyl ammonium chloride of identical mole number, thus obtain copolymer DP2, recording its viscosity-average molecular weight Mv is 9,250,000.

Embodiment 5

The present embodiment prepares acrylamide based copolymer for illustration of emulsion polymerization provided by the invention.

(1) NIPA of the M2 monomer shown in the formula (23) of the Methacrylamide of 35.74g, 45.94g and 6.79g is joined in configuration bottle, add 353.88g deionized water, stirring makes monomer dissolve completely, respectively to the EDTA aqueous solution 7.63g adding 1 % by weight in flask, chainextender N ', N-dimethyl-ethylenediamine 0.001g, add 1 % by weight azo diisobutyl amidine hydrochloride aqueous solution 2.03g, add urea 0.10g, abundant stirring makes it mix, sodium hydroxide solution with 15 % by weight regulates pH to 7.0, obtains aqueous phase.

(2) by sorbitan fatty acid ester (span60) 35g, alkylphenol polyoxyethylene (Igepal CA720) 21.52g, 169.54g kerosene is mixed into oil phase, and the aqueous phase obtained in step (1) is all joined in oil phase, join in reactor by mixing at a high speed formation reversed-phase emulsion.

(3) hierarchy of control initial temperature 10 DEG C, logical nitrogen deoxygenation, after 30 minutes, adds 1 % by weight aqueous solution of sodium bisulfite 0.13g, then adds 1 % by weight ammonium persulfate aqueous solution 0.63g and continue letting nitrogen in and deoxidizing 10 minutes.Reactor is airtight, remain on 10 DEG C, react after 1 hour, be warming up to 30 DEG C, react 5 hours, after question response temperature cool to room temperature, add 20.35g polyoxyethylene nonylphenol ether, obtain emulsion-formulated products with 80 order filter-cloth filterings.After reversed-phase emulsion product acetone and methanol mixed solvent being precipitated out, acrylamide copolymer p 5 can be obtained.

Various mensuration is carried out to P5,1660cm in IR spectrum ^-1and 1635cm ^-1there is belonging to the amide Ⅰ absorption peak (C=O stretching vibration) of amide group in place and acid amides II is with absorption peak (N-H flexural vibration), at 1430cm respectively ^-1there is the stretching vibration absorption peak of C-N in place; 1356cm ^-1and 1401cm ^-1there is typical methyl symmetric curvature vibration absorption peak, 1506,1577,1600cm ^-1go out the stretching vibration that peak belongs to C=C on phenyl ring; 1437cm ^-1go out peak and belong to Ar-P stretching vibration; 691,724,747cm ^-1go out peak and belong to Ar-H out-of plane bending vibration on phenyl ring.Can determine that the copolymer molecule obtained has the structure shown in formula (27), recording its viscosity-average molecular weight Mv by viscosity method is 4,630,000, and monomer conversion is more than 99.9%.Wherein, formula (27) and x, y and z only indicate type and the number of structural unit, and do not represent the mode of connection of structural unit.The concrete numerical value of x, y and z is determined by charging capacity, and the composition of molecular structural formula and structural unit adopts quantitatively ¹³c-NMR composes mensuration, obtains x:y:z=1:0.29:0.14.

Embodiment 6

The present embodiment prepares acrylamide based copolymer for illustration of emulsion polymerization provided by the invention.

(1) by the acrylamide of 19.19g, the M1 monomer shown in formula (21) of 66.40g and the N tert butyl acrylamide of 19.08g join in configuration bottle, add 593.13g deionized water, stirring makes monomer dissolve completely, respectively to the EDTA aqueous solution 8.5g adding 1 % by weight in flask, chainextender N ', N-dimethyl-ethylenediamine 0.001g, add 1 % by weight azo diisobutyl amidine hydrochloride aqueous solution 2.1g, add urea 0.08g, Trimethyllaurylammonium bromide 0.01g, abundant stirring makes it mix, sodium hydroxide solution with 10 % by weight regulates pH to 7.1, obtain aqueous phase.

(2) by sorbitan fatty acid ester (span60) 10g, alkylphenol polyoxyethylene (Igepal CA720, Sigma-Aldrich company, identical below) 18.34g, 184.2g kerosene is mixed into oil phase, and join in oil phase by obtaining aqueous phase in step (1), join in reactor by mixing at a high speed formation reversed-phase emulsion.

(3) hierarchy of control initial temperature 8 DEG C, logical nitrogen deoxygenation, after 30 minutes, adds 1 % by weight aqueous solution of sodium bisulfite 0.18g, then adds 1 % by weight ammonium persulfate aqueous solution 1.3g, and continue letting nitrogen in and deoxidizing 10 minutes.Reactor is airtight, remain on 8 DEG C, react after 3 hours, be warming up to 40 DEG C, react 4 hours, after question response temperature cool to room temperature, add 9.21g polyoxyethylene nonylphenol ether, obtain emulsion-formulated products with 100 order filter-cloth filterings.After reversed-phase emulsion product acetone and methanol mixed solvent being precipitated out, acrylamide copolymer p 6 can be obtained.

Various mensuration is carried out to P6,1660cm in IR spectrum ^-1and 1635cm ^-1there is belonging to the amide Ⅰ absorption peak (C=O stretching vibration) of amide group in place and acid amides II is with absorption peak (N-H flexural vibration) respectively, and 2923,2852cm ^-1peak, place belongs to-CH respectively ₂-,-CH ₃c-H stretching vibration, 1506,1577,1600cm ^-1peak, place belongs to the stretching vibration of C=C on phenyl ring; 1437cm ^-1peak, place belongs to Ar-P stretching vibration; 691,724,747cm ^-1peak, place belongs to Ar-H out-of plane bending vibration on phenyl ring.Can determine that the copolymer molecule obtained has the structure shown in formula (28), recording its viscosity-average molecular weight Mv by viscosity method is 5,600,000, and monomer conversion is more than 99.9%.Wherein, formula (28) and x, y and z only indicate type and the number of structural unit, and do not represent the mode of connection of structural unit.The concrete numerical value of x, y and z is determined by charging capacity, and the composition of molecular structural formula and structural unit adopts quantitatively ¹³c composes mensuration, obtains x:y:z=1:0.67:0.56.

Test case 1

Water-insoluble measures according to the method specified in SY/T5862-1993.The hydroxypropyl guar gum (JXY wellfracturing hydroxypropyl melon rubber powder, Shandong Juxin Chemical Co., Ltd., identical below) cooking flow improver conventional in P1-P6, DP1 and DP2 and site operation is carried out water-soluble mensuration, and result is as shown in table 1.

Table 1

As can be seen from Table 1, water insoluble matter content in acrylamide copolymer p 1-P6 prepared by two kinds of methods provided by the invention is starkly lower than the conventional hydroxypropyl guar gum cooking flow improver in site operation, this illustrates compared with hydroxypropyl guar gum, use P1-P6 as shale gas pressure break flow improver, the injury of formation is lower.

Test case 2

Under 2500rpm shearing rate, respectively by P1-P6, DP1, DP2 and partial hydrolysis polypropylene amine (HPAM, Zibo Tian Jian Chemical Co., Ltd., trade mark TJY-1, viscosity-average molecular weight is 1000-1300 ten thousand) slowly join in the water/alcoholic solution (using methyl alcohol in this test case) of volume ratio 80/20 and 60/40 respectively, the consumption of P1-P6, DP1, DP2 and partially hydrolyzed polyacrylamide is 0.01 % by weight (sample quality is by straight polymer quality in sample) of water/alcoholic solution, dissolution time is 30min, and result is as shown in table 2.

Table 2

As can be seen from Table 2, use P1-P6 prepared by two kinds of methods provided by the invention as shale gas pressure break flow improver, compared with partially hydrolyzed polyacrylamide, good with the compatibleness of cleanup additive (for methyl alcohol).

Test case 3

At temperature is 25 DEG C, by P1-P6, DP1, DP2, HPAM and hydroxypropyl guar gum are dissolved in pure water respectively and concentration is 2 % by weight, 4 % by weight, 8 % by weight, 10 % by weight, in NaCl or the KCl solution of 12 % by weight, the solution (sample quality is by straight polymer quality in sample) of 500mg/L and 1000mg/L be mixed with, then on GLM-1 pipeline frictional resistance determinator, the drag reducing efficiency (test condition: the internal diameter of test section pipeline is 8mm of above-mentioned solution is measured according to the method specified in SY/T6376-2008, the length of test section pipeline is 9m, infusion discharge capacity is 30L/min), result as shown in Table 3 and Table 4.

At the temperature of 60 DEG C, P1-P6, DP1, D2 and HPAM are dissolved in respectively pure water and concentration is in the NaCl solution of 2 % by weight, 4 % by weight, 8 % by weight, 10 % by weight, 12 % by weight, the solution of 500mg/L and 1000mg/L be mixed with, according to the method specified in SY/T6376-2008 (condition determination is identical with at above-mentioned 25 DEG C), measurement result is in table 5.

Table 3

Table 4

Table 5

As can be seen from table 3-table 5, compare with DP2 with hydroxypropyl guar gum, HAPM, DP1 cooking flow improver conventional in site operation, acrylamide copolymer P1-P6 prepared by method provided by the invention is as shale air pressure flow improver, with clay stabilizer (as, KCl and NaCl) compatibleness is better, and anti-salt property is more excellent; In addition, the drag reducing efficiency of acrylamide based copolymer provided by the invention at 25 DEG C all can reach more than 60%, drag reducing efficiency at 60 DEG C also can reach more than 50%, illustrates that acrylamide based copolymer provided by the invention still has higher drag reducing efficiency under high temperature and high salt shear conditions.

Test case 4

Friction reducer carries out matrix permeability of rock core infringement experiment by fracturing liquid filtrate in oil and gas industry standard SY/T5107-2005 " aqueous fracturing fluid method of evaluating performance " the nocuity of rock core, American core company formation injury tester device (FDS-800) tests, and the matrix permeability of rock core is 2md.

P1-P6, DP1 and DP2 are dissolved in pure water respectively, be mixed with the solution (sample quality is by straight polymer quality in sample) of 1000mg/L, above test it to the nocuity of rock core in American core company formation damage test macro (FDS-800), result is as shown in table 6.

Table 6

As can be seen from Table 6, the injury of acrylamide copolymer p 1-P6 to rock core prepared by two kinds of methods provided by the invention is starkly lower than the conventional comparative sample cooking flow improver in site operation, and this illustrates that use P1-P6 is low as the injury of shale gas pressure break flow improver formation.

Above-mentioned test result illustrates, the insolubles content of acrylamide based copolymer of the present invention in water is only 0.01 % by weight; Under the shearing rate of 2500rpm, can be dissolved in completely in water/alcoholic solution, good with the compatibleness of alcohol; Owing to improving with the compatibleness of alcohol and clay stabilizer (NaCl or KCl), improve anti-filtration property; And still have high drag reducing efficiency under the condition of high salt and high temperature, and have relatively low viscosity-average molecular weight, formation injury is low, and has relatively low viscosity-average molecular weight, and the injury of formation is low.In addition, the preparation method of acrylamide based copolymer provided by the invention has easy and that monomer conversion is high advantage.

More than describe the preferred embodiment of the present invention in detail; but the present invention is not limited to the detail in above-mentioned embodiment, within the scope of technical conceive of the present invention; can carry out multiple simple variant to technical scheme of the present invention, these simple variant all belong to protection scope of the present invention.

It should be noted that in addition, each concrete technical characteristic described in above-mentioned embodiment, in reconcilable situation, can be combined by any suitable mode, in order to avoid unnecessary repetition, the present invention illustrates no longer separately to various possible array mode.

In addition, also can carry out arbitrary combination between various different embodiment of the present invention, as long as it is without prejudice to thought of the present invention, it should be considered as content disclosed in this invention equally.

Claims (18)

1. an acrylamide based copolymer, it is characterized in that, described acrylamide based copolymer contains structural unit A, structural unit B and structural unit C, wherein, described structural unit A is the structural unit shown in formula (1), described structural unit B is the structural unit shown in formula (2), and described structural unit C is the structural unit shown in the structural unit shown in formula (3) and/or formula (4); And with the total mole number of structural unit in described acrylamide based copolymer for benchmark, the content of described structural unit A is 5-95 % by mole, the content of described structural unit B is 2.5-90 % by mole, and the content of described structural unit C is 0.5-90 % by mole; The viscosity-average molecular weight of described acrylamide based copolymer is 2,000,000-1,500 ten thousand;

Wherein, R ₁, R ₂, R ₄and R ₇be the straight or branched alkyl of H or C1-C4 independently of one another; R ₃for the straight or branched alkylidene group of connecting key or C1-C6; R ₅and R ₆be the straight or branched alkyl of H or C1-C20 independently of one another, and R ₅and R ₆be asynchronously H; R ₈for the straight chain branched-chain alkyl of C1-C20; X ^-for Cl ^-, Br ^-, I ^-, SCN ^-,

2. acrylamide based copolymer according to claim 1, wherein, with the total mole number of structural unit in described acrylamide based copolymer for benchmark, the content of described structural unit A is 10-70 % by mole, the content of described structural unit B is 20-50 % by mole, the content of described structural unit C is 10-40 % by mole, and the viscosity-average molecular weight of described acrylamide based copolymer is 2,000,000-600 ten thousand.

3. acrylamide based copolymer according to claim 1, wherein, R ₁for H or methyl, R ₂, R ₄and R ₇be H, R independently of one another ₃for connecting key or methylene radical; R ₅and R ₆be the straight or branched alkyl of H or C1-C5 independently of one another, and R ₅and R ₆be asynchronously H; R ₈for the straight or branched alkyl of C1-C5; X ^-for Br ^-.

4. the preparation method of an acrylamide based copolymer, under this preparation method is included in the solution polymerization condition of alkene, under initiator exists, a kind of monomer mixture is made to carry out polyreaction in water, wherein, described monomer mixture contains monomer D, monomer E and monomer F, described monomer D is the monomer shown in formula (5), described monomer E is the monomer shown in formula (6), described monomer F is the monomer shown in the monomer shown in formula (7) and/or formula (8), with the total mole number of monomer in described monomer mixture for benchmark, the content of described monomer D is 5-95 % by mole, the content of described monomer E is 2.5-90 % by mole, the content of described monomer F is 0.5-90 % by mole, after the condition of described solution polymerization makes polyreaction, the viscosity-average molecular weight of resulting polymers is 2,000,000-1,500 ten thousand,

Wherein, R ₁, R ₂, R ₄and R ₇be the straight or branched alkyl of H or C1-C4 independently of one another; R ₃for the straight or branched alkylidene group of connecting key or C1-C6; R ₅and R ₆be the straight or branched alkyl of H or C1-C20 independently of one another, and R ₅and R ₆be asynchronously H; R ₈for the straight chain branched-chain alkyl of C1-C20; X ^-for Cl ^-, Br ^-, I ^-, SCN ^-,

5. the preparation method of an acrylamide based copolymer, this preparation method comprises aqueous phase and oil phase is mixed to form reversed-phase emulsion, then under emulsion polymerization condition, under the existence of initiator, this reversed-phase emulsion is carried out polyreaction, described aqueous phase is the aqueous solution containing monomer mixture, described oil phase contains organic solvent and emulsifying agent, wherein, described monomer mixture contains monomer D, monomer E and monomer F, described monomer D is the monomer shown in formula (5), described monomer E is the monomer shown in formula (6), described monomer F is the monomer shown in the monomer shown in formula (7) and/or formula (8), with the total mole number of monomer in described monomer mixture for benchmark, the content of described monomer D is 5-95 % by mole, the content of described monomer E is 2.5-90 % by mole, the content of described monomer F is 0.5-90 % by mole, after the condition of described emulsion polymerization makes polyreaction, the viscosity-average molecular weight of resulting polymers is 2,000,000-1,500 ten thousand,

Wherein, R ₁, R ₂, R ₄and R ₇be the straight or branched alkyl of H or C1-C4 independently of one another; R ₃for the straight or branched alkylidene group of connecting key or C1-C6; R ₅and R ₆be the straight or branched alkyl of H or C1-C20 independently of one another, and R ₅and R ₆be asynchronously H; R ₈for the straight chain branched-chain alkyl of C1-C20; X ^-for Cl ^-, Br ^-, I ^-, SCN ^-,

6. preparation method according to claim 5, wherein, the weight ratio of described aqueous phase and oil phase is 1:0.1-2, is preferably 1:0.3-0.8.

7. preparation method according to claim 5, wherein, with the gross weight of described emulsion for benchmark, the consumption of described organic solvent is 10-60 % by weight, the consumption of described emulsifying agent is 1-15 % by weight, preferably, the consumption of described organic solvent is 20-35 % by weight, and the consumption of described emulsifying agent is 2-10 % by weight.

8. preparation method according to claim 5, wherein, contacts described polyreaction products therefrom with phase inversion agent after the method is also included in described polyreaction.

9. preparation method according to claim 8, wherein, with the gross weight of described emulsion for benchmark, the consumption of described phase inversion agent is 0.5-10 % by weight, is preferably 1-4 % by weight.

10. the preparation method according to claim 4 or 5, wherein, with the total mole number of monomer in described monomer mixture for benchmark, the content of described monomer D is 10-70 % by mole, the content of described monomer E is 20-50 % by mole, and the content of described monomer F is 10-40 % by mole; After the condition of described polyreaction makes polyreaction, the viscosity-average molecular weight of resulting polymers is 2,000,000-600 ten thousand.

11. preparation methods according to claim 4 or 5, wherein, R ₁for H or methyl, R ₂, R ₄and R ₇be H, R independently of one another ₃for connecting key or methylene radical; R ₅and R ₆be the straight or branched alkyl of H or C1-C5 independently of one another, and R ₅and R ₆be asynchronously H; R ₈for the straight or branched alkyl of C1-C5; X ^-for Br ^-.

12. preparation methods according to claim 4 or 5, wherein, the ratio of the gross weight of the weight of described monomer mixture and water and monomer mixture is 0.05-0.5:1, is preferably 0.15-0.4:1.

13. preparation methods according to claim 4 or 5, wherein, described initiator is selected from azo series initiators and redox series initiators, with the total mole number of monomer in described monomer mixture for benchmark, the consumption of described azo series initiators is 0-10 % by mole, the consumption of described redox series initiators is 0-10 % by mole, and total consumption of described initiator is 0.0001-10 % by mole, described azo series initiators is for being selected from Diisopropyl azodicarboxylate, 2,2'-Azobis(2,4-dimethylvaleronitrile), the two methylpent hydrochlorate, 2 of azo, 2 '-azo diisobutyl amidine hydrochloride and 2, at least one in 2 '-azo two [2-(2-tetrahydroglyoxaline-2-propane)-dihydrochloride], described redox series initiators comprises Oxidizing and Reducing Agents, the mol ratio 0.5-3.5:1 of described oxygenant and described reductive agent, described oxygenant is be selected from least one in ammonium persulphate, Potassium Persulphate, Sodium Persulfate and hydrogen peroxide, described reductive agent is inorganic reducing agent and/or organic reducing agent, described inorganic reducing agent is for being selected from sodium bisulfite, S-WAT, rongalite, Sulfothiorine, ferrous sulfate, vat powder, at least one in xitix and urea, described organic reducing agent is for being selected from N, N '-dimethyl quadrol, N, N '-dimethyl-1, 3-propylene diamine, N, N, N ', N '-Tetramethyl Ethylene Diamine, N, N-dimethyl amine, 3-methylamino-propylamine, Dimethylaminoethyl Methacrylate, N-(3-dimethylamino-propyl) Methacrylamide, at least one in 1-(dimethylamino)-2-propylamine and diethylenetriamine.

14. preparation methods according to claim 4 or 5, wherein, described polyreaction is carried out under auxiliary agent exists, and described auxiliary agent is be selected from least one in sequestrant and other auxiliary agents; With the total mole number of described monomer mixture for benchmark, the consumption of described sequestrant is 0-2 % by mole, the consumption of other auxiliary agents described is 0-2 % by mole, and with the total mole number of monomer in described monomer mixture for benchmark, total consumption of described auxiliary agent is 0.0001-4 % by mole; Described sequestrant is be selected from least one in disodium ethylene diamine tetraacetate, Triethylene Diamine pentaacetic acid, citric acid, Citrate trianion and poly-hydroxyl acrylic, and other auxiliary agents described are be selected from least one in urea, sodium formiate, Virahol, Trimethyllaurylammonium bromide and sodium hypophosphite.

15. preparation methods according to claim 4 or 5, wherein, described solution polymerization and described emulsion polymerization carry out separately in the presence of an inert gas, and polymeric reaction condition comprises: temperature is 0-80 DEG C, and the time is 1-24 hour, and pH value is 5-13.

16. preparation methods according to claim 4 or 15, wherein, the process of described solution polymerization comprises the three phases carried out successively, and the reaction conditions of first stage comprises: temperature is 0-10 DEG C, and the time is 1-15 hour; The reaction conditions of subordinate phase comprises: temperature is 15-30 DEG C, and the time is 3-8 hour; The reaction conditions of phase III comprises: temperature is 35-60 DEG C, and the time is 2-14 hour.

17. preparation methods according to claim 5 or 15, wherein, the process of described emulsion polymerization comprises two stages of carrying out successively, and the reaction conditions of first stage comprises: temperature is 0-20 DEG C, and the time is 1-15 hour; The reaction conditions of subordinate phase comprises: temperature is 20-60 DEG C, and the time is 2-8 hour.

Acrylamide based copolymer in 18. claim 1-3 described in any one or the acrylamide based copolymer that prepared by the method in claim 4-17 described in any one are as the application of flow improver.