CN103788289B

CN103788289B - A kind of acrylamide based copolymer and its preparation method and application

Info

Publication number: CN103788289B
Application number: CN201210420912.5A
Authority: CN
Inventors: 杜凯; 黄凤兴; 林蔚然
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2012-10-29
Filing date: 2012-10-29
Publication date: 2016-06-29
Anticipated expiration: 2032-10-29
Also published as: CN103788289A

Abstract

The invention discloses a kind of acrylamide based copolymer and its preparation method and application, wherein, described acrylamide based copolymer contains construction unit A, construction unit B, construction unit C and construction unit D, wherein, described construction unit A is for having the construction unit shown in formula (1) and/or having the construction unit shown in formula (2), described construction unit B is for having formula (3), formula (4), one or more in construction unit shown in formula (5) and formula (6), described construction unit C is for having the construction unit shown in formula (7) and/or having the construction unit shown in formula (8), described construction unit D is for having the construction unit shown in formula (9) and/or having the construction unit shown in formula (10)；The viscosity-average molecular weight of described acrylamide based copolymer is 2,000,000-2,500 ten thousand.Acrylamide based copolymer drag reducing efficiency provided by the invention is high, heat-resisting and salt tolerance high shear performance high, anti-is good, good water solubility and clay inhibitor (alcohol) have good compatibility and formation damage is little.

Description

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

Technical field

The present invention relates to a kind of acrylamide based copolymer and its preparation method and application.

Background technology

The exploitation of Typical Representative shale gas (oil) resource utilized as unconventional petroleum resources has become as a revolution in unconventional petroleum resources field, the whole world, and the development and utilization of current shale gas has become countries in the world and paid close attention to emphatically and the focus technology developed.Due to the ultimate attainment close oil-gas reservoirs such as shale gas reservoir there is permeability extremely low (being generally less than 0.5mD), frac pressure is high, easily cause the feature of 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 fracturing.Compared with conventional pressure break system (modifyed guar gum cross-linking system) at present, drag reduction water (slippery water) pressure break does not rely on high viscosity colloid and takes sand, but takes sand with high infusion discharge capacity, it is achieved reservoir fracturing reticulates the final purpose in crack.Drag reduction water (slippery water) pressure break more conventional pressure break system is less to the injury on stratum while having greater advantage on cost.

Drag reduction water fracturing fluid core auxiliary agent is water base friction reducer, in practice of construction, the addition of water-based drag reducer overcomes working solution frictional resistance in pipeline, ensure that the raising of infusion discharge capacity, make pressure act on to greatest extent press off stratum and extend formation fracture, currently available make water base friction reducer mainly have guanidine glue and derivant, cellulose derivative, acrylamide copolymer.

At present, frictional resistance (the US5697444 that drag reducer in adopting guanidine glue and derivant thereof, cellulose and its derivates to split as drag reduction hydraulic pressure improves infusion discharge capacity to a certain extent, reduces in pipeline, US5271466), but still the requirement that drag reduction hydraulic pressure splits cannot be met, have the disadvantage in that (1) resistance-reducing performance is limited mainly due to above-mentioned biopolymer；(2) owing to guanidine glue and derivant thereof, cellulose and its derivates have a small amount of insoluble matter and very easily stratum damaged；(3) dissolution time is longer.

In drag reduction water pressing crack construction, drag reducer in adopting acrylamide copolymer (partially hydrolyzed polyacrylamide (PHPA)) to split as drag reduction hydraulic pressure more, greatly enhance infusion discharge capacity, reduce the frictional resistance in pipeline, but the drag reducer split as shale gas reservoir drag reduction hydraulic pressure uses, there is following major defect: (1) " water-sensitive effect " in order to reduce in fracturing process, suppress the hydration swelling of clay composition in shale, the of the fracturing fluid row of returning is helped to reduce " water blocking ", part alcohol must be added in fracturing fluid, but the compatibility of partially hydrolyzed polyacrylamide (PHPA) and product emulsion and alcohol is poor, very easily produce precipitation；(2) partially hydrolyzed polyacrylamide (PHPA) uses anti-filtration property poor as the drag reducer that shale gas reservoir drag reduction hydraulic pressure splits, and this kind of drag reduction water fracturing fluid very easily leak-off is in the middle of stratum；(3) heat and salt resistance is poor, and especially when high salinity high divalent ion content, molecular structure is unstable, and resistance reducing effect declines very fast；(4) acrylamide copolymer of traditional high relative molecular mass is not degradable, it is easy to cause permanent type to injure extremely fine and close shale formation.

Patent US20090298721A1 discloses a kind of of the fracturing fluid formula of drag reduction water: add 0.5 gallon of acrylic acidcoacrylamide thing (FR-56 in 1000 gallons of deionized water^TM) etc. anionic acrylamide copolymer emulsion as drag reducer, add the chelating agent such as 0.15wt% sodium carbonate or EDTA-2Na, this drag reduction water fracturing fluid has excellent resistance-reducing performance, indoor average resistance-reducing yield reaches 65.0%, salt tolerance (especially the toleration to divalent calcium ions) there is a degree of improvement, but this kind of drag reduction hydraulic pressure splits system and uses as shale gas drag reduction water fracturing fluid, there are the following problems: the compatibility of (1) and alcohol is poor, very easily produces precipitation with the alcohol effect such as methanol；(2) anti-filtration property is poor, and this kind of drag reduction water fracturing fluid very easily leak-off is in the middle of stratum；(3) in practice of construction, " water-sensitive effect " is notable；(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 quickly；(6) heat-resistant salt-resistant is poor, and especially when high salinity high divalent ion content, molecular structure is unstable, and resistance reducing effect declines very fast；(7) not degradable, it is easy to cause permanent type to injure extremely fine and close shale formation, pollute stratum, then affect oil and gas production.

Compared with above-mentioned partial hydrolysis acrylamide, the acrylamide copolymer of cationic high-molecular amount also has been reported that as drag reducer (US356226, US3868328).US3868328 discloses a kind of polymer, and this polymer contains (3-acrylamido-3-methyl) butyl trimethyl ammonium chloride and/or reducing agent, adds or not acid adding.This kind of structure copolymer is better with the compatibility of alcohol, better with clay inhibitor (such as the KCl) compatibility, " water-sensitive effect " is not notable, not easily " water blocking ", but this type of friction reducer macromole is not easy to degraded, it is easy to cause permanent type to injure extremely fine and close shale formation.

But how to improve the resistance to high speed shear performance of drag reducer further, improve fracturing fluid to the inhibition of clay and anti-leak-off, the stability improving the drag reducing efficiency under high temperature and high salt shear conditions has degradability simultaneously, reduce the polymer injury to stratum, be still a problem needing solution badly.

Summary of the invention

It is an object of the invention to overcome the defect of above-mentioned prior art, a kind of high molecular, drag reducing efficiency height, good water solubility and clay inhibitor is provided to have good compatibility, there is degradability, formation damage is little, and the acrylamide based copolymer that dissolution time is short, and the preparation method and application of this acrylamide based copolymer.

The present inventor is through research, it is surprised to find that, by the polymerizable functional monomer method by copolymerization, it is incorporated into containing, on acrylamide macromolecular chain, obtaining the copolymer of high molecular by controlling polymerizing condition, the drag reducing efficiency under high temperature and high salt shear conditions can also be improved simultaneously, improve the compatibility with clay inhibitor, reduce the generation of water-sensitive and water blocking phenomenon, there is degradability, the injury to stratum can be reduced, thus obtaining the present invention.

The present invention provides a kind of acrylamide based copolymer, wherein, described acrylamide based copolymer contains construction unit A, construction unit B, construction unit C and construction unit D, wherein, described construction unit A is the construction unit shown in formula (1) and/or the construction unit shown in formula (2), described construction unit B is for having formula (3), formula (4), one or more in construction unit shown in formula (5) and formula (6), described construction unit C is the construction unit shown in formula (7) and/or the construction unit shown in formula (8), described construction unit D is the construction unit shown in formula (9) and/or the construction unit shown in formula (10)；And with the total mole number of construction unit in described acrylamide based copolymer for benchmark, the content of described construction unit A is 5-95 mole of %, the content of described construction unit B is 2.5-90 mole of %, the content of described construction unit C is 0.5-90 mole of %, and the content of described construction unit D is 0.0001-1 mole of %；Preferably, the content of described construction unit A is 10-70 mole of %, and the content of described construction unit B is 5-60 mole of %, and the content of described construction unit C is 5-30 mole of %, and the content of described construction unit D is 0.001-0.5 mole of %；The viscosity-average molecular weight of described acrylamide based copolymer is 2,000,000-2,500 ten thousand, it is preferred to 4,000,000-1,500 ten thousand；

Wherein, R₁、R₁’、R₄And R₄' it is each independently the alkylidene of C1-C4；R₂、R₃、R₅、R₆、R₇、R₁₂、R₁₃、R₂’、R₃’、R₅’、R₆’、R₇’、R₁₂' and R₁₃' it is each independently the alkyl of C1-C4；R₈And R₉It is each independently the straight or branched alkyl of H, C1-C20 and R₈And R₉It is asynchronously H；R₈' for the straight chain branched alkyl of C1-C20；R₁₀、R₁₁、R₁₀' and R₁₁' it is each independently the straight or branched alkylidene of C1-C20；M is at least one in H, K and Na；X^-For Cl^-, Br^-, I^-, SCN^-,

The preparation method that present invention also offers a kind of acrylamide based copolymer, this preparation method includes, when the solution polymerization of alkene, under initiator exists, a kind of monomer mixture is made to carry out polyreaction in water, it is characterized in that, described monomer mixture contains monomer E, monomer F, monomer G and monomer H, described monomer E is the monomer shown in formula (19) and/or the monomer shown in formula (20), described monomer F is formula (21), formula (22), one or more in monomer shown in formula (23) and formula (24), described monomer G is the monomer shown in formula (25) and/or the monomer shown in formula (26), described monomer H is the monomer shown in formula (27) and/or the monomer shown in formula (28)；

Wherein, R₁、R₁’、R₄And R₄' it is each independently the alkylidene of C1-C4；R₂、R₃、R₅、R₆、R₇、R₁₂、R₁₃、R₂’、R₃’、R₅’、R₆’、R₇’、R₁₂' and R₁₃' it is each independently the alkyl of C1-C4；R₈And R₉It is each independently the straight or branched alkyl of H, C1-C20 and R₈And R₉It is asynchronously H；R₈' for the straight or branched alkyl of C1-C20；R₁₀、R₁₁、R₁₀' and R₁₁' it is each independently the straight or branched alkylidene of C1-C20；M is at least one in H, K and Na；X^-For Cl^-, Br^-, I^-, SCN^-,

In addition, the preparation method that present invention also offers a kind of acrylamide based copolymer, this preparation method includes aqueous phase and oil phase are mixed to form reversed-phase emulsion, then when emulsion polymerization, this reversed-phase emulsion is contacted with initiator, described aqueous phase is the aqueous solution containing monomer mixture, described oil phase contains oil and emulsifying agent, the condition of contact makes monomer mixture generation polyreaction, wherein, described monomer mixture contains monomer E, monomer F, monomer G and monomer H, described monomer E is the monomer shown in above-mentioned formula (19) and/or the monomer shown in formula (20), described monomer F is above-mentioned formula (21), formula (22), one or more in monomer shown in formula (23) and formula (24), described monomer G is the monomer shown in formula (25) and/or the monomer shown in formula (26), described monomer H is the monomer shown in above-mentioned formula (27) and/or the monomer shown in formula (28).

It addition, present invention also offers the acrylamide based copolymer prepared by said method, and the application that described acrylamide based copolymer is in drag reducer.

The acrylamide based copolymer of the present invention has high viscosity-average molecular weight, and the viscosity-average molecular weight of the copolymer prepared in embodiment 1-6 is all up to more than 4,000,000；Insolubles content in water is only 0.01 weight %；In NaCl or the KCl solution that concentration is 2 weight %, 4 weight %, 8 weight %, 10 weight %, 12 weight % and at pH value when 2.5-10, drag reducing efficiency all can reach more than 60%；Under the shear rate of 2500rpm, this polymer does not produce precipitation at water/alcoholic solution, it is possible to be completely dissolved；During when pH value is less than 2.5, this polymer can be degraded, to the injury on stratum less than 10%.Illustrate that the acrylamide based copolymer of the present invention still has high drag reducing efficiency under high salt, shear conditions, the good compatibility is had with inhibitor (such as KCl) conventional in fracturing fluid formula, cleanup additive (such as methanol), and to stratum Low Damage.Additionally, two kinds of preparation methoies (solution polymerization process and reversed emulsion polymerization) of acrylamide based copolymer provided by the invention have simplicity and the high advantage of monomer conversion.

Other features and advantages of the present invention will be described in detail in detailed description of the invention part subsequently.

Detailed description of the invention

Hereinafter the specific embodiment of the present invention is described in detail.It should be appreciated that detailed description of the invention described herein is merely to illustrate and explains the present invention, it is not limited to the present invention.

(1) acrylamide based copolymer

The present invention provides a kind of acrylamide based copolymer, wherein, described acrylamide based copolymer contains construction unit A, construction unit B, construction unit C and construction unit D, wherein, described construction unit A is the construction unit shown in formula (1) and/or the construction unit shown in formula (2), described construction unit B is formula (3), formula (4), one or more in construction unit shown in formula (5) and formula (6), described construction unit C is the construction unit shown in formula (7) and/or the construction unit shown in formula (8), described construction unit D is the construction unit shown in formula (9) and/or the construction unit shown in formula (10)；And with the total mole number of construction unit in described acrylamide based copolymer for benchmark, the content of described construction unit A is 5-95 mole of %, the content of described construction unit B is 2.5-90 mole of %, the content of described construction unit C is 0.5-90 mole of %, and the content of described construction unit D is 0.0001-1 mole of %；Preferably, the content of described construction unit A is 10-70 mole of %, and the content of described construction unit B is 5-60 mole of %, and the content of described construction unit C is 5-30 mole of %, and the content of described construction unit D is 0.001-0.5 mole of %；It is highly preferred that the content of described construction unit A is 50-70 mole of %, the content of described construction unit B is 20-40 mole of %, and the content of described construction unit C is 5-20 mole of %, and the content of described construction unit D is 0.005-0.2 mole of %；The viscosity-average molecular weight of described acrylamide based copolymer is 2,000,000-2,500 ten thousand, it is preferred to 4,000,000-1,500 ten thousand；

Wherein, R₁And R₁' it is each independently the alkylidene of C1-C4, it is preferable that in situation, R₁And R₁' for methylene；R₄And R₄' it is each independently the alkylidene of C1-C4, it is preferable that in situation, R₄And R₄' it is sub-n-pro-pyl, more preferably-CH₂CH₂CH₂-；R₂、R₃、R₅、R₆、R₇、R₁₂、R₁₃、R₂’、R₃’、R₅’、R₆’、R₇’、R₁₂' and R₁₃' it is each independently the alkyl of C1-C4, it is preferred to methyl；R₈And R₉It is each independently the straight or branched alkyl of H, C1-C20, it is preferred to the straight or branched alkyl of H or C1-C5, and R₈And R₉It is asynchronously H；R₈' for the straight or branched alkyl of C1-C20, it is preferred to the straight or branched alkyl of C1-C5, more preferably methyl, ethyl, isopropyl, the tert-butyl group；R₁₀、R₁₁、R₁₀' and R₁₁' it is each independently the straight or branched alkylidene of C1-C20, it is preferred to the straight or branched alkylidene of C1-C3, more preferably ethylidene, it is most preferred that for-CH₂CH₂-；M is at least one in H, K and Na, it is preferred to H；X^-For Cl^-, Br^-, I^-, SCN^-,It is preferably Cl^-。

The present inventor finds under study for action, and the polymer being made up of specific construction unit B, construction unit C and construction unit D can obtain fabulous resistance reducing effect.

Such as, preferably, described construction unit B is one or more in the construction unit shown in formula (11), formula (12) and formula (13), described construction unit C is one or more in the construction unit shown in formula (14), formula (15), formula (16) and formula (17), described construction unit D is the construction unit shown in formula (18)

Wherein, R₁Alkylidene for C1-C4, it is preferable that in situation, R₁For methylene；R₄And R₄' it is each independently the alkylidene of C1-C4, it is preferable that in situation, R₄And R₄' it is sub-n-pro-pyl, more preferably-CH₂CH₂CH₂-；R₁₀' and R₁₁' for the straight or branched alkylidene of C1-C20, it is preferred to the straight or branched alkylidene of C1-C3, more preferably ethylidene, it is most preferred that for-CH₂CH₂-。

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

Described alkylidene refer to alkane lose two hydrogen atoms after residue, said two hydrogen atom can be two hydrogen atoms on same carbon atom, it is also possible to two hydrogen atoms on different carbon atoms, it can be straight chain, can also be side chain, for instance, described ethylidene can be-CH₂CH₂-or-CH (CH₃)-。

In the present invention, described alkyl can be straight chain, it is also possible to be side chain.The example of the straight chained alkyl of described C1-C20 or the branched alkyl of C3-C20 can include but not limited to: methyl, ethyl, n-pro-pyl, isopropyl, normal-butyl, sec-butyl, isobutyl group, the tert-butyl group, n-pentyl, isopentyl, tertiary pentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, positive decyl, dodecyl, cetyl and eicosyl.

In the present invention, described alkylidene can be straight chain, it is also possible to be side chain.The example of the straight or branched alkylidene of described C1-C20 can include but not limited to: methylene, ethylidene, sub-n-pro-pyl, isopropylidene, sub-normal-butyl, sub-sec-butyl, isobutylidene, the sub-tert-butyl group, sub-n-pentyl, isoamylidene, sub-tertiary pentyl, sub-neopentyl, sub-n-hexyl, sub-n-heptyl, sub-n-octyl, sub-positive decyl, sub-dodecyl, sub-cetyl and sub-eicosyl.

(2) solution polymerization process

The preparation method that the present invention also provides for a kind of acrylamide based copolymer, this preparation method includes, when the solution polymerization of alkene, under initiator exists, a kind of monomer mixture is made to carry out polyreaction in water, it is characterized in that, described monomer mixture contains monomer E, monomer F, monomer G and monomer H, described monomer E is the monomer shown in formula (19) and/or the monomer shown in formula (20), described monomer F is formula (21), formula (22), one or more in monomer shown in formula (23) and formula (24), described monomer G is the monomer shown in formula (25) and/or the monomer shown in formula (26), described monomer H is the monomer shown in formula (27) and/or the monomer shown in formula (28)；And with the total mole number of monomer in described monomer mixture for benchmark, the content of described monomer E is 5-95 mole of %, the content of described monomer F is 2.5-90 mole of %, and the content of described monomer G is 0.5-90 mole of %, and the content of described structures alone H is 0.0001-1 mole of %；Preferably, the content of described monomer E is 10-70 mole of %, and the content of described monomer F is 5-60 mole of %, and the content of described monomer G is 5-30 mole of %, and the content of described structures alone H is 0.001-0.5 mole of %；It is highly preferred that the content of described monomer E is 50-70 mole of %, the content of described monomer F is 20-40 mole of %, and the content of described monomer G is 5-20 mole of %, and the content of described monomer H is 0.005-0.2 mole of %；After the condition of described polyreaction makes polyreaction, the viscosity-average molecular weight of resulting polymers is 2,000,000-2,500 ten thousand, it is preferred to 4,000,000-1,500 ten thousand；

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, the ratio of the gross weight of the weight of described monomer mixture and water and monomer mixture is preferably 0.05-0.5:1, more preferably 0.15-0.4:1, it is most preferred that for 0.2-0.35:1.

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

In the present invention, preferably, described azo series initiators selected from azodiisobutyronitrile, 2,2'-Azobis(2,4-dimethylvaleronitrile), the double; two methylpent hydrochlorate of azo, 2,2 '-azo diisobutyl amidine hydrochlorate and 2, at least one in 2 '-azo two [2-(2-imidazoline-2-propane)-dihydrochloride], more preferably 2,2 '-azo diisobutyl amidine hydrochlorate and 2, at least one in 2 '-azo two [2-(2-imidazoline-2-propane)-dihydrochloride].

Described oxidoreduction series initiators includes Oxidizing and Reducing Agents, preferably, the mol ratio of described oxidant and described reducing agent is 0.5-2:1, when meeting aforementioned proportion, the 0.0001-0.01 mole of %, more preferably 0.001-0.008 mole of % of the total mole number that the consumption of described oxidant is preferably in monomer mixture monomer；Under preferable case, described oxidant at least one in Ammonium persulfate., potassium peroxydisulfate, sodium peroxydisulfate and hydrogen peroxide, the more preferably at least one in Ammonium persulfate., potassium peroxydisulfate and sodium peroxydisulfate；0.0001-0.005 mole of % of the total mole number that the consumption of described reducing agent is preferably in monomer mixture monomer, it is preferred to 0.001-0.004 mole of % of the total mole number of monomer in monomer mixture；Described reducing agent can be inorganic reducing agent (helping reducing agent), preferably, described inorganic reducing agent at least one in sodium sulfite, sodium sulfite, rongalite, sodium thiosulfate, ferrous sulfate, sodium hydrosulfite, ascorbic acid and urea, more preferably sodium sulfite and/or sodium thiosulfate.

In the present invention, needs particularly point out ground, described monomer H simultaneously works as the effect of chain extender and organic reducing agent in the course of the polymerization process, organic reducing agent need not be added again in polymerization process, while this double bond group being possibly due in described monomer H may participate in polyreaction, the tertiary amine group of end may participate in redox initiation reaction, produces free radical in terminal methyl group, then on terminal methyl, continue trigger monomer polymerization, be similar to " bridge formation ".

It addition, the injury of acrylamide based copolymer layer over the ground provided by the invention reduces, this is likely due in this polymer have ester carbonyl group, degradation reaction easily occurs in acid condition.

According to the present invention, described polyreaction can also carry out under various auxiliary agents exist, and described auxiliary agent can be selected from chelating agen and/or other auxiliary agents；In described monomer mixture, the total mole number of monomer is for benchmark, the consumption of described chelating agen is 0-2 mole of %, it is preferably 0.0001-1 mole of %, more preferably 0.0001-0.05 mole of %, the consumption of other auxiliary agents described can be 0-2 mole of %, it is preferably 0.0001-1 mole of %, more preferably 0.0001-0.2 mole of %；Preferably, the consumption of described chelating agen and other auxiliary agents makes: in described monomer mixture, the total mole number of monomer is for benchmark, and the consumption of described auxiliary agent is 0.0001-4 mole of %.

Described chelating agen can be selected from least one in disodiumedetate (EDTA), triethylenediamine pentaacetic acid, citric acid, citrate and poly-hydroxy acrylic acid, more preferably one or more in EDTA and/or citrate, described citrate can be potassium citrate, sodium citrate, calcium citrate and ammonium citrate etc..

Other auxiliary agents described can be selected from least one in carbamide, sodium formate, isopropanol and sodium hypophosphite, it is preferred to carbamide and/or sodium formate.

It was found by the inventors of the present invention that when existing concurrently with above-mentioned various initiator and auxiliary agent, solution polymerization process can obtain the acrylamide based copolymer that viscosity-average molecular weight is controlled.

According to the present invention, the condition of described polyreaction can be the condition that this area is conventional.Such as, described polyreaction carries out in the presence of an inert gas, and described polymeric reaction condition may include that 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, and described pH value is adjusted by adding acid or alkali, and described acid is preferably mineral acid, and described mineral acid is preferably at least one in hydrochloric acid, sulphuric acid, sulfonic acid, nitric acid and phosphoric acid；Described alkali can be inorganic base or organic amine compound, as being selected from least one in sodium hydroxide, potassium hydroxide, ammonia, methylamine, ethamine, ethanolamine and triethanolamine, it is preferred to sodium hydroxide.

The present inventor finds under study for action, take following condition can improve the molecular weight of polymer further: namely, preferably, described polyreaction includes the three phases being sequentially carried out: the reaction condition of first stage includes: temperature is 0-10 DEG C, it is preferably 4-10 DEG C, time is 1-15 hour, it is preferred to 3-10 hour；The reaction condition of second stage includes: temperature is 15-30 DEG C, it is preferred to 20-30 DEG C, and the time is 3-8 hour, it is preferred to 3-5 hour；The reaction condition of phase III includes: temperature is 35-60 DEG C, it is preferred to 45-55 DEG C, and the time is 2-14 hour, it is preferred to 2-12 hour.

Additionally, the present inventor finds under study for action, when selecting specific monomer F, monomer G to react with monomer H, it is possible to improve the resistance reducing effect of the polymer of gained further.Such as, preferably, described monomer F is one or more in the monomer shown in formula (29), formula (30) and formula (31), described monomer G is one or more in the monomer shown in formula (32), formula (33), formula (34) and formula (35), described monomer H is the monomer shown in formula (36)

(3) reversed emulsion polymerization

In addition, the preparation method that present invention also offers a kind of acrylamide based copolymer, this preparation method includes aqueous phase and oil phase are mixed to form reversed-phase emulsion, then when emulsion polymerization, this reversed-phase emulsion is contacted with initiator, described aqueous phase is the aqueous solution containing monomer mixture, described oil phase contains oil and emulsifying agent, the condition of contact makes monomer mixture generation polyreaction, wherein, described monomer mixture contains monomer E, monomer F, monomer G and monomer H, described monomer E is the monomer shown in above-mentioned formula (19) and/or the monomer shown in formula (20), described monomer F is above-mentioned formula (21), formula (22), one or more in monomer shown in formula (23) and formula (24), described monomer G is the monomer shown in above-mentioned formula (25) and/or the monomer shown in formula (26), described monomer H is the monomer shown in above-mentioned formula (27) and/or the monomer shown in formula (28)；And with the total mole number of monomer in described monomer mixture for benchmark, the content of described monomer E is 5-95 mole of %, the content of described monomer F is 2.5-90 mole of %, and the content of described monomer G is 0.5-90 mole of %, and the content of described monomer H is 0.0001-1 mole of %；Preferably, the content of described monomer E is 10-70 mole of %, and the content of described monomer F is 5-60 mole of %, and the content of described monomer G is 5-30 mole of %, and the content of described structures alone H is 0.001-0.5 mole of %；It is highly preferred that the content of described monomer E is 50-70 mole of %, the content of described monomer F is 20-40 mole of %, and the content of described monomer G is 5-20 mole of %, and the content of described structures alone H is 0.005-0.2 mole of %；After the condition of described polyreaction makes polyreaction, the viscosity-average molecular weight of resulting polymers is 2,000,000-2,500 ten thousand, it is preferred to 4,000,000-1,500 ten thousand.

The elaboration of monomer shown in formula (19)-Shi (28) and preferable case and described above identical, do not repeat them here.

According to the present invention, described aqueous phase is the aqueous solution containing monomer mixture.The elaboration of the ratio of the gross weight of the weight of described monomer mixture and water and monomer mixture and preferable case and described above identical, 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 making described aqueous phase and oil phase be thoroughly mixed to form reversed-phase emulsion, it is preferable that in situation, the part by weight of described aqueous phase and oil phase can be 1:0.1-2, more preferably 1:0.2-0.8

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

According to the present invention, described oil phase contains oil and emulsifying agent.The not special requirement of consumption to described oil, it is possible to change in wider scope, as long as described oil 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 oil can be 10-60 weight %, more preferably 15-35 weight %.

According to the present invention, described emulsifying agent can be the various nonionic emulsifier for emulsion polymerization in this area, for instance can be sorbitan fatty acid ester, alkylphenol polyoxyethylene, isomeric alcohol polyethenoxy ether, polyoxyethylene lauryl ether, methyl glycol fatty acid ester, laureth, benzylphenol oxygen polyoxyethylene ether, phenethyl 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, it is preferable that in situation, described emulsifying agent is selected from sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, NPE, OPEO, benzylphenol oxygen polyoxyethylene ether, phenethyl phenol polyethenoxy ether, isomerous tridecanol polyoxyethylene ether, at least one in polyoxyethylene lauryl ether and benzyl dimethyl phenol polyethenoxy ether, it is preferred that be the compound emulsifying agent that hydrophile-lipophile balance value is 5-9 being made up of above two or two or more emulsifying agents, for instance can be sorbitan fatty acid ester and NPE.

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 oil 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 1-10 weight %, more preferably 2-9 weight %.

According to the present invention, described initiator can be various initiators in this area, the elaboration of described initiator and preferable case and described above identical, repeats no more herein.

In the present invention, it is preferable that in situation, 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 oxidoreduction series initiators, by redox initiator initiated polymerization.

According to the present invention, described polyreaction can also carry out under various auxiliary agents exist, and described auxiliary agent can be selected from chelating agen and/or other auxiliary agents, the elaboration of described auxiliary agent and preferable case and described above identical, repeats no more herein.

According in the present invention, not special requirement on reinforced opportunity to described chelating agen, as long as making chelating agen and metal ion generation chelation so that copolymer is played static stabilization, can select to add at aqueous phase or add in oil phase, under preferable case, in order to make chelating agen play stably more fully effect, it is possible to select to add chelating agen in aqueous phase.

According to the present invention, the elaboration of described chelating agen and preferable case and described above identical, repeat no more herein.

Equally, it was found by the inventors of the present invention that when existing concurrently with above-mentioned various initiator and auxiliary agent, reversed emulsion polymerization can obtain the acrylamide based copolymer that viscosity-average molecular weight is controlled and dissolution velocity is fast.

According to the present invention, the condition of described polyreaction can be the condition that this area is conventional.The elaboration of described polymeric reaction condition and preferable case and described above identical, repeat no more herein.

Equally, the present inventor finds under study for action, take following condition can improve the molecular weight of polymer further: namely, preferably, described polyreaction includes two stages being sequentially carried out: the reaction condition of first stage includes: temperature is 0-20 DEG C, being preferably 5-10 DEG C, the time is 1-15 hour, it is preferred to 1-5 hour；The reaction condition of second stage includes: temperature is 20-60 DEG C, it is preferred to 25-55 DEG C, and the time is 2-8 hour, it is preferred to 2-5 hour.

According to the present invention, described polyreaction products therefrom is contacted after being additionally included in described polyreaction by the method with phase inversion agent.Described phase inversion agent can for this area various phase inversion agent for emulsion polymerization, as long as making described polyreaction products therefrom quickly dissolve in water in fracturing fluid is applied, it can be such as polyoxyethylene sorbitan fatty acid ester, NPE, OPEO, Ben-zylphenol Polyoxyethyl Ether, phenethyl phenol polyethenoxy ether, isomery ten polyoxyethylenated alcohol, isomery undecyl alcohol polyoxyethylene ether, 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 selected from polyoxyethylene sorbitan fatty acid ester, isomery ten polyoxyethylenated alcohol, isomery undecyl alcohol polyoxyethylene ether, isomerous tridecanol polyoxyethylene ether, at least one in NPE and OPEO.

According to the present invention, the not special requirement of consumption to described phase inversion agent, as long as described polyreaction products therefrom can be made quickly to dissolve in water in fracturing fluid is applied, 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 weight %, it is preferred to 1-5 weight %.

Additionally, the present inventor finds under study for action, when selecting specific monomer F, monomer G to react with monomer H, it is possible to improve the resistance reducing effect of the polymer of gained further.Such as, preferably, described monomer F is one or more in the monomer shown in formula (29), formula (30) and formula (31), described monomer G is one or more in the monomer shown in formula (32), formula (33), formula (34) and formula (35), described monomer H is the monomer shown in formula (36), the elaboration of monomer shown in formula (29)-Shi (36) and preferable case and described above identical, do not repeat them here.

Present invention also offers the acrylamide based copolymer prepared according to above two method.

Additionally, present invention also offers the application in drag reducer of the described acrylamide based copolymer.Adopt described acrylamide based copolymer provided by the invention as fracturing fluid drag reducer, it is possible to obtain high and stable drag reducing efficiency, the technology that concrete application process is well known to those skilled in the art.

By the following examples the specific embodiment of the present invention is described in detail.It should be appreciated that detailed description of the invention described herein is merely to illustrate and explains the present invention, it is not limited to the present invention.

Intrinsic viscosity is measured 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 is calculated；Dissolution time is measured by GB12500.8-89, and (sample quality is all by straight polymer quality in sample), the powdered samples dissolution time recorded is respectively less than 20min, and samples of latex dissolution time is respectively less than 5min；The composition of molecular structure and construction unit adopt IR spectrum and¹³C-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；Matrix permeability of rock core is damaged experiment by fracturing fluid filtrate in oil and gas industry standard SY/T5107-2005 " aqueous fracturing fluid method of evaluating performance " by the nocuity of rock core by friction reducer to be carried out.

Monomer M1 shown in following embodiment Chinese style (37) and the monomer M3 shown in formula (40) is all purchased from Sigma-Aldrich company, 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 is used for illustrating that solution polymerization process provided by the invention prepares acrylamide based copolymer.

Under room temperature, by the acrylamide (AM) of 38.38g, 39.65g formula (37) shown in M1 monomer, 4.03g N, the M2 monomer shown in formula (38) of N-DMAA (purchased from Sigma-Aldrich company) and 0.41g is (according to document MacromolecularBioscience, 2006,6 (7), the method of 540-554 prepares, identical below) join in reaction bulb, add deionized water 329.88g, stirring makes monomer be completely dissolved, and stirs.The EDTA aqueous solution 5.4g of 1 weight % is added respectively in flask, 1 weight % azo diisobutyl amidine hydrochlorate aqueous solution 2.0g, carbamide 0.12g, it is sufficiently stirred for and makes its mix homogeneously.With the sodium hydroxide solution pH to 7.4 of 1 weight %, add 0.5 weight % sodium sulfite solution 1.1g, control system initial temperature to 4 DEG C, after leading to nitrogen deoxygenation 30 minutes, add 1 weight % ammonium persulfate aqueous solution 1.1g, and continue letting nitrogen in and deoxidizing 20 minutes.Reactor is airtight, it is maintained at 4 DEG C, after reacting 10 hours, react 5 hours after temperature is risen to 20 DEG C, then temperature rises to 50 DEG C react 5 hours, the gum-like product that obtain is taken out, through pelletize, dry, pulverize and can obtain high molecular weight acrylamide based copolymer P1.

P1 is carried out various mensuration, in IR spectrum, 1660cm^-1And 1635cm^-1Place occurs belonging to amide Ⅰ absworption peak (C=O stretching vibration) and amide II band absworption peak (N-H bending vibration), the 2792cm of amide groups respectively^-1For the methyl C-H asymmetrical stretching vibration absworption peak of quaternary ammonium group, at 1430cm^-1There is the stretching vibration absworption peak of C-N, 1729cm in place^-1Occur in that the feature stretching vibration peak of M2 monomeric ester carbonyl, 2936cm^-1Appearance-CH₃Absworption peak, 1356 and 1401cm^- ¹Typical methyl symmetric curvature vibration absorption peak occur, it may be determined that the copolymer molecule obtained has the structure shown in formula (39), recording its viscosity-average molecular weight Mv by viscosity method is 13,910,000, and monomer conversion is more than 99.9%.Wherein, formula (39) and x₁、x₂、y₁、y₂、z₁、z₂Only represent type and the number of construction unit with u, and do not indicate that the connected mode of construction unit.X₁、x₂、y₁、y₂、z₁、z₂Determining by inventory with the concrete numerical value of u, the composition of molecular structural formula and construction unit adopts quantitatively¹³C composes mensuration, obtains (x₁+x₂): (y₁+y₂): (z₁+z₂): u=1:0.35:0.08:0.003.

Comparative example 1

Acrylamide based copolymer is prepared according to the method for embodiment 1, the difference is that, being added without N,N-DMAA and M2 monomer, thus obtaining copolymer DP1, recording its viscosity-average molecular weight M_vIt is 14,000,000.

Comparative example 2

Acrylamide based copolymer is prepared according to the method for embodiment 1, the difference is that, (3-acrylamido-3-methyl) butyl trimethyl ammonium chloride of acrylamide Yu identical molal quantity being carried out polyreaction, thus obtaining bipolymer DP2, recording its viscosity-average molecular weight M_vIt is 13,700,000.

Embodiment 2

Under room temperature, by the Methacrylamide of 35.23g, 72.1g formula (40) shown in M3 monomer, the M2 monomer shown in the tert-butyl acrylate of 10.25g and the formula (38) of 0.01g join in polymerization bottle, add 218.38g deionized water, stirring makes monomer be completely dissolved, the EDTA aqueous solution 7.56g of 1 weight % is added respectively in flask, add 1 weight % azo diisobutyl amidine hydrochlorate aqueous solution 2.13g, add 0.1 weight % sodium sulfite solution 3.2g, add carbamide 0.20g, be sufficiently stirred for and make its mix homogeneously.Control system initial temperature, to 8 DEG C, after leading to nitrogen deoxygenation 30 minutes, adds 1% ammonium persulfate aqueous solution 1.0g and continues letting nitrogen in and deoxidizing 10 minutes.Reactor is airtight, be maintained at 8 DEG C, after reacting 8 hours, be warming up to 30 DEG C, after reacting 3 hours, be warming up to 55 DEG C and react 2 hours, the gum-like product that obtain is taken out, through pelletize, dry, pulverize the acrylamide copolymer p 2 that can obtain high molecular.

P2 is carried out IR spectroscopic assay, 1660cm in IR spectrum^-1And 1635cm^-1Place occurs belonging to amide Ⅰ absworption peak (C=O stretching vibration) and amide II band absworption peak (N-H bending vibration), the 2792cm of amide groups respectively^-1For the methyl C-H asymmetrical stretching vibration absworption peak of quaternary ammonium group, 1394cm^-1In appearance tert-butyl acrylate-(CH₃)₃Absworption peak, 1729cm^-1Occur in that the feature stretching vibration peak of M2 monomeric ester carbonyl.May determine that the copolymer molecule obtained has the structure shown in formula (41), recording its viscosity-average molecular weight Mv by viscosity method is 14,670,000, and monomer conversion is more than 99.9%.Wherein, formula (41) and x₁、x₂、y₁、y₂、z₁、z₂Only represent type and the number of construction unit with u, and do not indicate that the connected mode of construction unit.X₁、x₂、y₁、y₂、z₁、z₂Determining by inventory with the concrete numerical value of u, the composition of molecular structural formula and construction unit adopts quantitatively¹³C composes mensuration, obtains (x₁+x₂): (y₁+y₂): (z₁+z₂): u=1:0.79:0.19:0.0001.

Embodiment 3

Under room temperature, by the Methacrylamide of 14.38g, 11.61g formula (42) shown in M4 monomer, the M2 monomer shown in the N tert butyl acrylamide of 7.12g and the formula (38) of 0.06g join in reaction bulb, add deionized water 77.26g, stirring makes monomer be completely dissolved, and stirs.The EDTA aqueous solution 4.65g of 1 weight % is added respectively in flask, 1 weight % azo diisobutyl amidine hydrochlorate aqueous solution 1.03g, carbamide 0.21g, it is sufficiently stirred for and makes its mix homogeneously.With sodium hydrate solid, pH is adjusted to 7.1.Add 0.5 weight % sodium sulfite solution 1.1g, control system initial temperature to 10 DEG C, after leading to nitrogen deoxygenation 30 minutes, add 1 weight % ammonium persulfate aqueous solution 1.1g, and continue letting nitrogen in and deoxidizing 20 minutes.Reactor is airtight, it is maintained at 10 DEG C, after reacting 3 hours, react 4 hours after temperature is risen to 25 DEG C, then temperature rises to 45 DEG C react 12 hours, the gum-like product that obtain is taken out, through pelletize, dry, pulverize and can obtain high molecular weight acrylamide based copolymer P3.

P3 is carried out various mensuration, in IR spectrum, 1660cm^-1And 1635cm^-1Place occurs belonging to amide Ⅰ absworption peak (C=O stretching vibration) and amide II band absworption peak (N-H bending vibration), the 1729cm of amide groups respectively^-1Occur in that the feature stretching vibration peak of M2 monomeric ester carbonyl, at 1040cm^-1There is the stretching vibration absworption peak of O-S in place, at 601cm^-1There is the stretching vibration absworption peak of C-S, 2936cm in place^-1Appearance-CH₃Absworption peak, 1380cm^-1Tert-butyl acrylate-(CH occurs₃)₃Absworption peak, it may be determined that the copolymer molecule obtained has the structure shown in formula (43), recording its viscosity-average molecular weight Mv by viscosity method is 8,450,000, and monomer conversion is more than 99.9%.Wherein, formula (43) and x₁、x₂、y₁、y₂、z₁、z₂Only represent type and the number of construction unit with u, and do not indicate that the connected mode of construction unit.X₁、x₂、y₁、y₂、z₁、z₂Determining by inventory with the concrete numerical value of u, the composition of molecular structural formula and construction unit adopts quantitatively¹³C composes mensuration, obtains (x₁+x₂): (y₁+y₂): (z₁+z₂): u=1:0.33:0.33:0.002.

Embodiment 4

The present embodiment is used for illustrating that emulsion polymerization provided by the invention prepares acrylamide based copolymer.

(1) by the acrylamide of 12.01g, 11.61g formula (42) shown in M4 monomer, the M2 monomer shown in the NIPA of 6.34g and the formula (38) of 0.06g join in configuration bottle, add 70.05g deionized water, stirring makes monomer be completely dissolved, the EDTA aqueous solution 4.65g of 1 mass % is added respectively in flask, add 1 weight % azo diisobutyl amidine hydrochlorate aqueous solution 1.03g, add carbamide 0.21g, it is sufficiently stirred for and makes its mix homogeneously, with sodium hydrate solid, pH is adjusted to 7.1, obtains aqueous phase.

(2) by sorbitan fatty acid ester (span60, Sigma-Aldrich company, identical below) 3.5g, alkylphenol polyoxyethylene (IgepalCA720, Sigma-Aldrich company, identical below) 2g, 45.54g kerosene is mixed into oil phase, and the aqueous phase obtained in step (1) is joined in oil phase, form reversed-phase emulsion by mixing at a high speed and join in reactor.

(3) control system initial temperature 5 DEG C, after leading to nitrogen deoxygenation 30 minutes, add 1 weight % aqueous solution of sodium bisulfite 2.0g, add 1 weight % ammonium persulfate aqueous solution 4.0g, and continue letting nitrogen in and deoxidizing 10 minutes.Reactor is airtight, it is maintained at 5 DEG C, after reacting 5 hours, is warming up to 55 DEG C, react 2 hours.After question response temperature is cooled to room temperature, adds 7.2g phase inversion agent NPE (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.

P4 is carried out IR spectroscopic assay, 1660cm in IR spectrum^-1And 1635cm^-1Place occurs belonging to amide Ⅰ absworption peak (C=O stretching vibration) and the amide II band absworption peak (N-H bending vibration) of amide groups respectively, 1729cm^-1Occur in that the feature stretching vibration peak of M2 monomeric ester carbonyl, at 1040cm^-1There is the stretching vibration absworption peak of O-S in place；At 601cm^-1There is the stretching vibration absworption peak of C-S, 1387cm in place^-1、1367cm^-1Occur that the bimodal of formation is divided in the symmetrical deformation vibration coupling of double; two methyl on isopropyl.May determine that the copolymer molecule obtained has the structure shown in formula (44), recording its viscosity-average molecular weight Mv by viscosity method is 12,800,000, and monomer conversion is more than 99.9%.Wherein, formula (44) and x₁、x₂、y₁、y₂、z₁、z₂Only represent type and the number of construction unit with u, and do not indicate that the connected mode of construction unit.X₁、x₂、y₁、y₂、z₁、z₂Determining by inventory with the concrete numerical value of u, the composition of molecular structural formula and construction unit adopts quantitatively¹³C composes mensuration, obtains (x₁+x₂): (y₁+y₂): (z₁+z₂): u=1:0.33:0.33:0.002.

Comparative example 3

Acrylamide based copolymer is prepared according to the method for embodiment 4, the difference is that, being added without NIPA and M2 monomer, thus obtaining copolymer DP3, recording its viscosity-average molecular weight M_vIt is 12,000,000.

Comparative example 4

Acrylamide based copolymer is prepared according to the method for embodiment 4, the difference is that, (3-acrylamido-3-methyl) butyl trimethyl ammonium chloride of acrylamide Yu identical molal quantity being carried out polyreaction, thus obtaining bipolymer DP4, recording its viscosity-average molecular weight M_vIt is 13,250,000.

Embodiment 5

(1) by the acrylamide of 38.17g, 96.1g formula (40) shown in M3 monomer, 10.71g N, the M2 monomer shown in formula (38) of N-DMAA and 0.01g joins in configuration bottle, add 269.27g deionized water, stirring makes monomer be completely dissolved, the EDTA aqueous solution 5.2g of 1 mass % is added respectively in flask, add 1 weight % azo diisobutyl amidine hydrochlorate aqueous solution 1.0g, add carbamide 0.58g, it is sufficiently stirred for and makes its mix homogeneously, with the sodium hydroxide solution pH to 7.1 of 1 weight %, obtain aqueous phase.

(2) by sorbitan fatty acid ester (span60) 38g, alkylphenol polyoxyethylene (IgepalCA720) 16.98g, 240.72g kerosene is mixed into oil phase, and the aqueous phase obtained in step (1) is joined in oil phase, form reversed-phase emulsion by mixing at a high speed and join in reactor.

(3) control system initial temperature 5 DEG C, after leading to nitrogen deoxygenation 30 minutes, add 1 weight % aqueous solution of sodium bisulfite 0.80g, add 1 weight % ammonium persulfate aqueous solution 2.5g and continue letting nitrogen in and deoxidizing 10 minutes.Reactor is airtight, it is maintained at 8 DEG C, after reacting 1 hour, is warming up to 25 DEG C, react 5 hours, after question response temperature is cooled to room temperature, adds 15.8g NPE, obtain emulsion-formulated products with 80 order filter-cloth filterings.After reversed-phase emulsion product acetone and methanol mixed solvent being precipitated out, the acrylamide copolymer p 5 of high molecular can be obtained.

P5 is carried out IR spectroscopic assay, 1660cm in IR spectrum^-1And 1635cm^-1Place occurs belonging to amide Ⅰ absworption peak (C=O stretching vibration) and amide II band absworption peak (N-H bending vibration), the 2792cm of amide groups respectively^-1For the methyl C-H asymmetrical stretching vibration absworption peak of quaternary ammonium group, 1729cm^-1Occur in that the feature stretching vibration peak of M2 monomeric ester carbonyl, at 1430cm^-1There is the stretching vibration absworption peak of C-N, 2936cm in place^-1Appearance-CH₃Absworption peak, 1356 and 1401cm^- ¹Typical methyl symmetric curvature vibration absorption peak occur, it may be determined that the copolymer molecule obtained has the structure shown in formula (45), recording its viscosity-average molecular weight Mv by viscosity method is 14,980,000, and monomer conversion is more than 99.9%.Wherein, formula (45) and x₁、x₂、y₁、y₂、z₁、z₂Only represent type and the number of construction unit with u, and do not indicate that the connected mode of construction unit.X₁、x₂、y₁、y₂、z₁、z₂Determining by inventory with the concrete numerical value of u, the composition of molecular structural formula and construction unit adopts quantitatively¹³C composes mensuration, obtains (x₁+x₂): (y₁+y₂): (z₁+z₂): u=1:0.81:0.20:0.0001.

Embodiment 6

(1) by the Methacrylamide of 47.06g, 36.55g formula (37) shown in M1 monomer, the M2 monomer shown in the tert-butyl acrylate of 5.25g and the formula (38) of 0.41g join in configuration bottle, add 357.08g deionized water, stirring makes monomer be completely dissolved, the EDTA aqueous solution 8.0g of 1 mass % is added respectively in flask, add 1 weight % azo diisobutyl amidine hydrochlorate aqueous solution 4.1g, add carbamide 0.3g, it is sufficiently stirred for and makes its mix homogeneously, with the sodium hydroxide solution pH to 7.1 of 1 weight %, obtain aqueous phase.

(2) by sorbitan fatty acid ester (span60) 13g, alkylphenol polyoxyethylene (IgepalCA720) 1.7g, 95.51g kerosene is mixed into oil phase, and the aqueous phase obtained in step (1) is joined in oil phase, form reversed-phase emulsion by mixing at a high speed and join in reactor.

(3) control system initial temperature 35 DEG C, after leading to nitrogen deoxygenation 30 minutes, add 1 weight % aqueous solution of sodium bisulfite 0.150g, add 1 weight % ammonium persulfate aqueous solution 0.6g and continue letting nitrogen in and deoxidizing 10 minutes.Reactor is airtight, it is maintained at 10 DEG C, after reacting 4 hours, is warming up to 40 DEG C, react 4 hours, after question response temperature is cooled to room temperature, adds 5.0g NPE, obtain emulsion-formulated products with 80 order filter-cloth filterings.After reversed-phase emulsion product acetone and methanol mixed solvent are precipitated out, the acrylamide copolymer p 6 of high molecular can be obtained.

P6 is carried out IR spectroscopic assay, 1660cm in IR spectrum^-1And 1635cm^-1Place occurs belonging to amide Ⅰ absworption peak (C=O stretching vibration) and amide II band absworption peak (N-H bending vibration), the 2792cm of amide groups respectively^-1Methyl C-H asymmetrical stretching vibration absworption peak for quaternary ammonium group.1394cm^-1Tert-butyl acrylate-(CH3) 3 absworption peak, 1729cm occur^-1Occur in that the feature stretching vibration peak of M2 monomeric ester carbonyl,.May determine that the copolymer molecule obtained has the structure shown in formula (46), recording its viscosity-average molecular weight Mv by viscosity method is 7,500,000, and monomer conversion is more than 99.9%.Wherein, formula (46) and x₁、x₂、y₁、y₂、z₁、z₂Only represent type and the number of construction unit with u, and do not indicate that the connected mode of construction unit.X₁、x₂、y₁、y₂、z₁、z₂Determining by inventory with the concrete numerical value of u, the composition of molecular structural formula and construction unit adopts quantitatively¹³C composes mensuration, obtains (x₁+x₂): (y₁+y₂): (z₁+z₂): u=1:0.32:0.07:0.003.

Test case 1

Water-insoluble is to measure according to the method for regulation in SY/T5862-1993.P1-P6, DP1-DP4 and hydroxypropyl guar gum (JXY wellfracturing hydroxypropyl melon rubber powder, Shandong Juxin Chemical Co., Ltd., identical below) are carried out water solublity mensuration, and result is as shown in table 1.

Table 1

As can be seen from the above table, in acrylamide copolymer p 1-P6 prepared by two kinds of methods provided by the invention, water-insoluble is significantly lower than commonly using the hydroxypropyl guar gum cooking drag reducer in site operation, and this illustrates it is use P1-P6 compared with hydroxypropyl guar gum, the injury on stratum is low as shale gas pressure break drag reducer.

Test case 2

Under 2500rpm shear rate, respectively by P1-P6, DP1-DP4, partially hydrolyzed polyacrylamide (PHPA) (HPAM, Zibo Tian Jian Chemical Co., Ltd., trade mark TJY-3, viscosity-average molecular weight are 1800-2000 ten thousand, identical below) it is slowly added in water/alcoholic solution (using methanol in this test case) that volume ratio is 80/20 and 60/40 respectively, P1-P6, DP1-DP4, partially hydrolyzed polyacrylamide (PHPA) are the 0.01 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

From Table 2, it can be seen that acrylamide copolymer p 1-P6 prepared by two kinds of methods provided by the invention is as shale gas pressure break drag reducer, compared with partially hydrolyzed polyacrylamide (PHPA), good with the compatibility of alcohol.

Test case 3

When temperature is 25 DEG C, by P1-P6, DP1-DP4, HPAM and hydroxypropyl guar gum are dissolved in pure water respectively and concentration is 2 weight %, 4 weight %, 8 weight %, 10 weight %, in NaCl or the KCl solution of 12 weight %, the solution of 500mg/L and the 1000mg/L (sample quality is by straight polymer quality in sample) being configured to, then on GLM-1 pipeline frictional resistance determinator, the drag reducing efficiency of above-mentioned solution is measured according to the method for regulation in SY/T6376-2008, (test condition: the internal diameter of test section pipeline is 8mm, the length of test section pipeline is 9m, infusion discharge capacity is 30L/min), result is as shown in Table 3 and Table 4.

Table 3

Table 4

Can be seen that from table 3 and table 4, acrylamide copolymer p 1-P6 prepared by two kinds of methods provided by the invention is as shale gas pressure break drag reducer, compared with hydroxypropyl guar gum, HPAM and DP1-DP4, with clay inhibitor (as, KCl) compatibility is good, and anti-salt property is excellent.

Test case 4

Drag reducing efficiency is to measure according to the method for regulation in SY/T6376-2008.P1-P6, DP1-DP4 being dissolved in pure water respectively, is configured to the solution (sample quality is by straight polymer quality in sample) of 500mg/L, by adding HCl or NaOH, the pH value of regulation system changes between 2.5-10, and result is as shown in table 5.

Table 5

Solution ph	2.5	3.0	4.0	5.0	6.0	7.0	8.0	9.0	10.0
										P1(500mg/L)	38%	55%	69%	69%	68%	71%	70%	66%	65%
P2(500mg/L)	42%	60%	70%	73%	69%	72%	70%	67%	66%
										P3(500mg/L)	39%	51%	71%	70%	70%	71%	69%	68%	67%
P4(500mg/L)	37%	55%	69%	70%	71%	72%	71%	68%	66%
										P5(500mg/L)	45%	58%	71%	72%	72%	74%	72%	70%	68%
P6(500mg/L)	37%	66%	69%	70%	71%	73%	72%	70%	67%
										DP1(500mg/L)	36%	53%	64%	64%	65%	65%	65%	64%	63%
DP2(500mg/L)	29%	37%	58%	59%	60%	61%	58%	50%	45%
										DP3(500mg/L)	38%	52%	65%	65%	66%	67%	66%	65%	61%

DP4(500mg/L)

25%

37%

57%

58%

59%

60%

58%

50%

43%

As can be seen from Table 5, the acrylamide copolymer p 1-P6 that prepared by two kinds of methods provided by the invention as shale gas pressure break drag reducer compared with all having good resistance reducing effect in very big pH value range.

Test case 5

Matrix permeability of rock core is damaged experiment by fracturing fluid filtrate in oil and gas industry standard SY/T5107-2005 " aqueous fracturing fluid method of evaluating performance " by the nocuity of rock core by friction reducer to be carried out, testing in American core company formation injury tester (FDS-800), the matrix permeability of rock core is 2md.

P1-P6, DP1-DP4 are dissolved in respectively pure water, it is configured to the solution (sample quality is by straight polymer quality in sample) of 1000mg/L, by adding HCl, the pH value regulating solution is 2, at American core company formation injury tester (FDS-800) its nocuity to rock core of upper test, result is as shown in table 6.

Table 6

As can be seen from the above table, acrylamide copolymer p 1-P6 prepared by two kinds of methods provided by the invention to the injury of rock core significantly lower than in site operation the conventional comparative sample cooking drag reducer, this illustrates it is use P1-P6 as shale gas pressure break drag reducer, the injury on stratum is low.

Above-mentioned test result illustrates, acrylamide based copolymer provided by the invention has good water solublity, and the injury on stratum is low；And can be dissolved completely in water-alcohol solution, good with the compatibility of alcohol；Owing to the compatibility with alcohol and clay inhibitor (NaCl or KCl) improves so that the moisture in frac water not easily runs off, and improves anti-filtration property；And under high salt, wider pH value condition, still there is high drag reducing efficiency；There is degradability, the degradable when pH value is less than 2.5 is low to the injury on stratum.Additionally, the preparation method of acrylamide based copolymer provided by the invention has simplicity and the high advantage of monomer conversion.

Claims

1. an acrylamide based copolymer, it is characterized in that, described acrylamide based copolymer contains construction unit A, construction unit B, construction unit C and construction unit D, wherein, described construction unit A is the construction unit shown in formula (1) and/or the construction unit shown in formula (2), described construction unit B is formula (3), formula (4), one or more in construction unit shown in formula (5) and formula (6), described construction unit C is the construction unit shown in formula (7) and/or has the construction unit shown in formula (8), described construction unit D is the construction unit shown in formula (9) and/or the construction unit shown in formula (10)；And with the total mole number of construction unit in described acrylamide based copolymer for benchmark, the content of described construction unit A is 5-95 mole of %, the content of described construction unit B is 2.5-90 mole of %, the content of described construction unit C is 0.5-90 mole of %, and the content of described construction unit D is 0.0001-1 mole of %；The viscosity-average molecular weight of described acrylamide based copolymer is 2,000,000-2,500 ten thousand；

2. acrylamide based copolymer according to claim 1, wherein, in described acrylamide based copolymer, the total mole number of construction unit is for benchmark, the content of described construction unit A is 10-70 mole of %, the content of described construction unit B is 5-60 mole of %, the content of described construction unit C is 5-30 mole of %, and the content of described construction unit D is 0.001-0.5 mole of %；The viscosity-average molecular weight of described acrylamide based copolymer is 4,000,000-1,500 ten thousand.

3. acrylamide based copolymer according to claim 1 and 2, wherein, described construction unit B is one or more in the construction unit shown in formula (11), formula (12) and formula (13), described construction unit C is one or more in the construction unit shown in formula (14), formula (15), formula (16) and formula (17), described construction unit D is for having the construction unit shown in formula (18)

Wherein, R₁、R₄And R₄' it is each independently the alkylidene of C1-C4；R₁₀' and R₁₁' for the straight or branched alkylidene of C1-C20.

4. the preparation method of an acrylamide based copolymer, this preparation method includes, when the solution polymerization of alkene, under initiator exists, a kind of monomer mixture is made to carry out polyreaction in water, it is characterized in that, described monomer mixture contains monomer E, monomer F, monomer G and monomer H, described monomer E is the monomer shown in formula (19) and/or the monomer shown in formula (20), described monomer F is formula (21), formula (22), one or more in monomer shown in formula (23) and formula (24), described monomer G is the monomer shown in formula (25) and/or the monomer shown in formula (26), described monomer H is the monomer shown in formula (27) and/or the monomer shown in formula (28)；

In described monomer mixture, the total mole number of monomer is for benchmark, and the content of described monomer E is 5-95 mole of %, and the content of described monomer F is 2.5-90 mole of %, and the content of described monomer G is 0.5-90 mole of %, and the content of described monomer H is 0.0001-1 mole of %；After the condition of described polyreaction makes polyreaction, the viscosity-average molecular weight of resulting polymers is 2,000,000-2,500 ten thousand.

5. the preparation method of an acrylamide based copolymer, this preparation method includes aqueous phase and oil phase are mixed to form reversed-phase emulsion, then when emulsion polymerization, this reversed-phase emulsion is contacted with initiator, described aqueous phase is the aqueous solution containing monomer mixture, described oil phase contains oil and emulsifying agent, the condition of contact makes monomer mixture generation polyreaction, wherein, described monomer mixture contains monomer E, monomer F, monomer G and monomer H, described monomer E has the monomer shown in formula (19) and/or the monomer shown in formula (20) described in claim 4, described monomer F is formula (21) described in claim 4, formula (22), one or more in monomer shown in formula (23) and formula (24), described monomer G is the monomer shown in formula (25) described in claim 4 and/or the monomer shown in formula (26), described monomer H is the monomer shown in formula (27) described in claim 4 and/or the monomer shown in formula (28)；

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

7. preparation method according to claim 6, wherein, the weight ratio of described aqueous phase and oil phase is 1:0.2-0.8.

8. preparation method according to claim 5, wherein, with the gross weight of described emulsion for benchmark, the consumption of described oil is 10-60 weight %, and the consumption of described emulsifying agent is 1-10 weight %.

9. preparation method according to claim 8, wherein, with the gross weight of described emulsion for benchmark, the consumption of described oil is 15-35 weight %, and the consumption of described emulsifying agent is 2-9 weight %.

10. preparation method according to claim 5, wherein, described polyreaction products therefrom is contacted after being additionally included in described polyreaction by the method with phase inversion agent.

11. preparation method according to claim 10, wherein, with the gross weight of described emulsion for benchmark, the consumption of described phase inversion agent is 0.5-10 weight %.

12. preparation method according to claim 11, wherein, with the gross weight of described emulsion for benchmark, the consumption of described phase inversion agent is 1-5 weight %.

13. the preparation method according to claim 4 or 5, wherein, in described monomer mixture, the total mole number of monomer is for benchmark, the content of described monomer E is 10-70 mole of %, the content of described monomer F is 5-60 mole of %, the content of described monomer G is 5-30 mole of %, and the content of described monomer H is 0.001-0.5 mole of %；After the condition of described polyreaction makes polyreaction, the viscosity-average molecular weight of resulting polymers is 4,000,000-1,500 ten thousand.

14. the preparation method according to claim 4 or 5, wherein, described monomer F is one or more in the monomer shown in formula (29), formula (30) and formula (31), described monomer G is one or more in the monomer shown in formula (32), formula (33), formula (34) and formula (35), described monomer H is the monomer shown in formula (36)

15. the preparation method 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.

16. preparation method according to claim 15, wherein, the ratio of the gross weight of the weight of described monomer mixture and water and monomer mixture is 0.15-0.4:1.

17. the preparation method according to claim 4 or 5, wherein, described initiator is selected from azo series initiators and oxidoreduction series initiators, in described monomer mixture, the total mole number of monomer is for benchmark, the consumption of described azo series initiators is 0-10 mole of %, the consumption of described oxidoreduction series initiators is 0-10 mole of %, and total consumption of described initiator is 0.0001-10 mole of %；Described azo series initiators is selected from azodiisobutyronitrile, 2,2'-Azobis(2,4-dimethylvaleronitrile) and 2, at least one in 2 '-azo diisobutyl amidine hydrochlorate, described oxidoreduction series initiators includes Oxidizing and Reducing Agents, the mol ratio 0.5-2:1 of described oxidant and described reducing agent, described oxidant at least one in Ammonium persulfate., potassium peroxydisulfate, sodium peroxydisulfate and hydrogen peroxide；Described reducing agent is inorganic reducing agent, described inorganic reducing agent at least one in sodium sulfite, sodium sulfite, sodium thiosulfate, ferrous sulfate and sodium hydrosulfite.

18. the preparation method according to claim 4 or 5, wherein, described polyreaction carries out under auxiliary agent exists, described auxiliary agent at least one in chelating agen and other auxiliary agents；With the total mole number of described monomer mixture for benchmark, the consumption of described chelating agen is 0-2 mole of %, the consumption of other auxiliary agents described is 0-2 mole of %, and with the total mole number of monomer in described monomer mixture for benchmark, total consumption of described auxiliary agent is 0.0001-4 mole of %；Described chelating agen at least one in disodiumedetate, citric acid, citrate and poly-hydroxy acrylic acid, other auxiliary agents described at least one in carbamide, sodium formate, isopropanol and sodium hypophosphite.

19. the preparation method according to claim 4 or 5, wherein, described polyreaction carries out in the presence of an inert gas, and described polymeric reaction condition includes: temperature is 0-80 DEG C, and the time is 1-24 hour, and pH value is 5-13.

20. preparation method according to claim 4, wherein, described polyreaction includes the three phases being sequentially carried out, and the reaction condition of first stage includes: temperature is 0-10 DEG C, and the time is 1-15 hour；The reaction condition of second stage includes: temperature is 15-30 DEG C, and the time is 3-8 hour；The reaction condition of phase III includes: temperature is 35-60 DEG C, and the time is 2-14 hour.

21. preparation method according to claim 5, wherein, described polyreaction includes two stages being sequentially carried out, and the reaction condition of first stage includes: temperature is 0-20 DEG C, and the time is 1-15 hour；The reaction condition of second stage includes: temperature is 20-60 DEG C, and the time is 2-8 hour.

22. the acrylamide based copolymer that the preparation method according to any one in claim 4-21 prepares.

23. acrylamide based copolymer described in any one application in drag reducer in claim 1-3 and 22.