Macroinitiator, block polymerization macromolecular surfactant as well as preparation method and application of macroinitiator and block polymerization macromolecular surfactant

Abstract

The invention provides a macromolecular initiator, a block polymerization macromolecular surfactant as well as a preparation method and application of the macromolecular initiator and the block polymerization macromolecular surfactant. Based on the total weight of the macroinitiator being 100%, the macroinitiator comprises 10-35% of a functional polymeric monomer; 2-15% of other components; the balance is a solvent; the other components comprise a functional initiator, a catalyst A and a catalyst ligand A in a molar ratio of 1: (0.1-5): (0.1-5); based on 100 parts by weight of a polymeric monomer, the block polymerization macromolecular surfactant comprises 100 parts by weight of the polymeric monomer; 60 to 180 parts by weight of deionized water; 6-25 parts by weight of a macroinitiator; 1.2-15 parts by weight of a catalyst B and a catalyst ligand B; the mass ratio of the catalyst B to the catalyst ligand B is 1: (0.1-5); the prepared block polymerization macromolecular surfactant has the advantages of high viscosity, high interfacial activity and quick interface effect, and is suitable for enhanced oil extraction operation.

Description

Technical Field

[0001] The present invention relates to the technical field of oil production. Further, it relates to a macromolecular initiator, a block-polymerized macromolecular surfactant, and their preparation methods and applications. Background Art

[0002] At present, the major oil fields in China have entered the tertiary oil recovery stage. Nowadays, the current crude oil production work is increasingly developing towards harsh reservoirs with extremely high levels (high recovery rate and high permeability). The remaining oil underground is difficult to drive, and it is necessary to improve the displacement efficiency by methods such as increasing the swept volume of the displacement fluid and reducing the capillary force of the displacement fluid. The main enhanced oil recovery methods at home and abroad currently are the use of polymers and surfactants. Polymers can increase the viscosity of the displacement fluid to increase the swept volume, and surfactants can reduce the interfacial tension between the displacement fluid and the crude oil to reduce the capillary force. Using both simultaneously is generally called polymer-surfactant binary flooding, which can increase viscosity and reduce interfacial tension at the same time. However, due to the large difference in the molecular weights of the polymer and the surfactant, chromatographic separation will inevitably occur underground, affecting the use efficiency.

[0003] Based on this problem, some practitioners have proposed the design of polymeric macromolecular surfactants, which can play the role of increasing viscosity and reducing tension with one chemical agent, avoiding chromatographic separation. However, some problems have also been found during the use process. For example, the viscosity and interfacial activity of macromolecular surfactants are a pair of contradictory unity, which is difficult to balance during development. At the same time, the arrangement of macromolecular surfactants at the oil-water interface is relatively slow, and it takes a relatively long time to achieve a low interfacial tension, etc.

[0004] In the research of polymers, living polymerization is a synthesis method that can effectively control the polymer structure. The polymer structure can be designed through living polymerization to obtain polymers with block structures. However, due to the limitations of the harsh polymerization conditions required for living polymerization, currently living polymerization is mostly used for the development of polymer materials and not for the development of macromolecular surfactants used as oil displacement aids. Aiming at the problems of macromolecular surfactants in the tertiary oil recovery process, the structure of macromolecular surfactants can be designed through living polymerization to propose a macromolecular surfactant with better performance, and solve the problems that the viscosity and interfacial activity of macromolecular surfactants for oil fields in the prior art cannot be unified and the interfacial effect takes a long time. Summary of the Invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides a macromolecular initiator, a block-polymerized macromolecular surfactant, and their preparation methods and applications.

[0006] The structures of the existing polymer surfactants are basically random. The present invention first prepares a macromolecular initiator in which the surface-active structural units are concentrated. When using it to prepare a block copolymer polymer surfactant, the surface-active structural units can be concentrated at the middle position of the chain, and the oil-water interfacial activity of the polymer surfactant can be significantly improved. At the same time, the two tail segments of the long chain of the polymer surfactant are still hydrophilic, and the polymer surfactant still maintains good water solubility and the ability to thicken in aqueous solution. At the same time, since the synthesis of the polymer surfactant is a controlled polymerization, the structure of the polymer surfactant can be adjusted. As long as the amount of raw materials is simply adjusted, the oil-water interfacial activity of the polymer surfactant can be controlled, and the unity of the oil-water interfacial activity and thickening property of the polymer surfactant is improved without changing the raw material composition.

[0007] The block copolymer macromolecular surfactant prepared by the present invention has active units concentrated together, high viscosity, high interfacial activity, and fast interfacial action. It solves the problems in the prior art that the viscosity and interfacial activity of the macromolecular surfactant for oil fields cannot be unified and the interfacial action is slow. At the same time, the amount of chemical additives is reduced, which is suitable for enhanced oil recovery operations. It solves the technical problems that under harsh conditions such as high temperature and high salinity, the enhanced oil recovery chemical additives can thicken and reduce the interfacial tension at the same time, avoid chromatographic separation, and improve the effect of chemical additives and reduce the amount of chemical additives.

[0008] One of the purposes of the present invention is to provide a macromolecular initiator, which is prepared from raw materials including the following components based on 100% of the total weight of the macromolecular initiator:

[0009] Functional polymer monomer: 10-35%; preferably 10-30%;

[0010] Other components: 2-15%; preferably 2-10%;

[0011] The balance is solvent;

[0012] The other components include a functional initiator, catalyst A, and catalyst ligand A;

[0013] Among them, the molar ratio of catalyst A, functional initiator, and catalyst ligand A is 1:(0.1-5):(0.1-5), preferably 1:(0.2-2):(0.5-3).

[0014] In a preferred embodiment of the present invention,

[0015] The functional polymer monomer is an olefin monomer with oil / water interfacial activity, and the structural formula is preferably

[0016] Wherein, M 1 is -C 4 H 8 -SO 3 Na, -CH2 -N + -(CH 3 ) 3 Cl or -(CH 2 CH 2 O) m H, where m is an integer between 8 and 24;

[0017] M 2 is -(C 6 H 4 ) n1 -H, -(OCH(CH 3 )CH 2 ) n2 -H, -(CH 2 ) n3 -H, -(CH 2 ) n4 -(C 6 H 4 ) n5 -H or -(C 6 H 4 ) n6 -(CH 2 ) n7 -H, where n1 is an integer between 2 and 4, n2 is an integer between 5 and 10, n3 is an integer between 8 and 20, n4 is an integer between 6 and 12, n5 is an integer between 1 and 3, n6 is an integer between 1 and 3, and n7 is an integer between 6 and 12.

[0018] In a preferred embodiment of the present invention,

[0019] the functional initiator is one of polyhaloaromatic hydrocarbons and polyhalo fatty acid esters, preferably one of p-dibromobenzyl, p-dichlorobenzyl, diethyl 2,5-dibromohexanedioate, diethyl 2,5-dichlorohexanedioate, ethyl dibromoacetate, and ethyl dichloroacetate;

[0020] the catalyst A is at least one of halides of transition metals, preferably at least one of iron(III) chloride, iron(III) bromide, copper(II) chloride, copper(II) bromide, iron(II) chloride, iron(II) bromide, copper(I) chloride, and copper(I) bromide, more preferably at least one of iron(III) chloride, iron(III) bromide, copper(II) chloride, and copper(II) bromide;

[0021] the catalyst ligand A is at least one of polyamines, polybipyridines, and hybrid phenanthrenes, preferably at least one of 1,10-phenanthroline, o-phenanthroline, 2,2'-bipyridine, and 4,4'-bipyridine;

[0022] The solvent is a mixed solvent obtained by mixing an organic solvent and water; the organic solvent is preferably at least one of methanol, ethanol, propanol, isopropanol, toluene, tetrahydrofuran, and N,N-dimethylformamide; the water is preferably deionized water; more preferably, the mass ratio of the organic solvent to water is (0.5 to 3):1, preferably (1 to 2):1.

[0023] The second object of the present invention is to provide a method for preparing a macromolecular initiator, comprising the following steps:

[0024] (1) Dissolving the functional polymerizable monomer in the solvent to obtain a functional polymerizable monomer solution;

[0025] (2) First, adding the catalyst A and the catalyst ligand A into the reaction vessel, then adding the functional initiator and the functional polymerizable monomer solution obtained in step (1), mixing and then freeze-drying, reacting under the protection of a protective gas, and obtaining the macromolecular initiator after post-treatment of the product.

[0026] In a preferred embodiment of the present invention,

[0027] Step (2),

[0028] The functional initiator and the functional polymerizable monomer solution are added after the catalyst A and the catalyst ligand A change color;

[0029] The freeze-drying step is to introduce frozen nitrogen, evacuate, thaw, and introduce nitrogen, preferably repeating 3 to 5 times;

[0030] The protective gas is at least one of nitrogen and inert gas;

[0031] The reaction temperature is 40 to 90 °C;

[0032] The reaction time is 4 to 10 hours;

[0033] The post-treatment is filtration, washing, and drying; preferably, after filtration, it is repeatedly washed with ethanol or isopropanol 2 to 5 times and then dried. Preferably, the drying temperature is 40 to 60 °C and the drying time is 0.5 to 2 hours.

[0034] The third object of the present invention is to provide a block polymerized macromolecular surfactant, the structural formula of which is shown in formula (I):

[0035]

[0036] Among them, R 1 is one of the groups of the following structures: *-C 4 H 8 -SO 3 Na, *-CH 2 -N+ -(CH 3 ) 3 Cl, *-(CH 2 CH 2 O) m1 H, m 1 is an integer between 8 and 24;

[0037] R 2 is one of the groups of the following structures: *-(C 6 H 4 ) m2 -H, *-(OCH(CH 3 )CH 2 ) m3 -H, *-(CH 2 ) m4 -H, *-(CH 2 ) m5 -(C 6 H 4 ) m6 -H or *-(C 6 H 4 ) m7 -(CH 2 ) m8 -H; m2 is an integer between 2 and 4, m3 is an integer between 5 and 12, m4 is an integer between 8 and 20, m5 is an integer between 6 and 12, m6 is an integer between 1 and 3, m7 is an integer between 1 and 3, m8 is an integer between 6 and 12;

[0038] R 1 and R 2 in formula (I) the access key position is *-;

[0039] The RR segment contains R II , capped with -H; Optionally, the RR segment may also contain R I ;

[0040] R I is one of the groups of the following structures:

[0041]

[0042] R II is one of the groups of the following structures:

[0043]

[0044]

[0045] When the RR segment contains both R I and R II at the same time, RI and R II The structural units of and R are randomly distributed in RR of formula (I);

[0046] In formula (I), n:(p + q) = 1:(20 - 100); when p ≠ 0, p:q = 1:(10 - 25).

[0047] In a preferred embodiment of the present invention,

[0048] Based on 100 parts by weight of the polymerization monomer, the block copolymer macromolecular surfactant is prepared from raw materials including the following components:

[0049]

[0050] Among them, the macromolecular initiator is the above-mentioned macromolecular initiator or the macromolecular initiator obtained by the above-mentioned preparation method.

[0051] In a preferred embodiment of the present invention,

[0052] Based on parts by weight, the polymerization monomer includes 80 - 100 parts by weight of non-ionic monomers and 0 - 20 parts by weight of anionic monomers; preferably,

[0053] The non-ionic monomer is at least one of acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, allyl acrylamide;

[0054] The anionic monomer is at least one of sodium acrylate, sodium methacrylate, 2-acrylamido-2-methylpropanesulfonic acid sodium salt, sodium vinyl sulfonate, sodium allyl sulfonate, sodium vinyl benzene sulfonate;

[0055] The catalyst B is at least one of halides of transition metals, preferably at least one of ferric chloride, ferric bromide, copper chloride, copper bromide, ferrous chloride, ferrous bromide, cuprous chloride, cuprous bromide;

[0056] The catalyst ligand B is at least one of polyamines, polybipyridines, hybrid phenanthrenes, preferably at least one of o-phenanthroline, o-phenanthroline, 2,2'-bipyridine, 4,4'-bipyridine;

[0057] The fourth object of the present invention is to provide a preparation method of a block copolymer macromolecular surfactant, including the following steps:

[0058] (1) Dissolve the polymerization monomer in deionized water to obtain a monomer solution;

[0059] (2) Dissolve the macromolecular initiator in deionized water to obtain an initiator solution;

[0060] (3) Add catalyst B and catalyst ligand B into the reaction vessel. Under the protection of a protective gas, add the monomer solution obtained in step (1), and then add the initiator solution obtained in step (2). React to obtain a hydrogel containing block polymer macromolecular surfactant, and obtain the block polymer macromolecular surfactant after post-treatment.

[0061] In a preferred embodiment of the present invention,

[0062] In step (1),

[0063] The concentration of the monomer solution is 40-60%;

[0064] The pH value of the monomer solution is adjusted to 7.5-8.5; preferably, the pH value is adjusted with a NaOH solution. Further preferably, the concentration of the NaOH solution used to adjust the pH value is 30.0±2.0%;

[0065] In step (2), the concentration of the macromolecular initiator solution is 20-40%;

[0066] In step (3),

[0067] Pass a protective gas through catalyst B and catalyst ligand B. After it changes color, add the monomer solution;

[0068] Keep passing the protective gas and add the initiator solution;

[0069] The way to add the initiator solution into the monomer solution is dropwise addition; preferably, the dropwise addition of the initiator solution is completed within 30 min;

[0070] The protective gas is at least one of nitrogen and inert gas;

[0071] The temperature during the dropwise addition of the initiator solution is 5-10°C; and / or,

[0072] After the dropwise addition of the initiator solution is completed, seal the reaction vessel for reaction;

[0073] The reaction temperature is 35-50°C;

[0074] The reaction time is 2-4 hours;

[0075] The post-treatment includes granulation, drying, and pulverization; preferably, after granulation, it is placed in a vacuum oven and dried at 100-140°C for 60-120 min and then pulverized.

[0076] The fifth object of the present invention is to provide an application of a block polymer macromolecular surfactant in oil recovery, preferably in enhanced oil recovery operations.

[0077] In a preferred embodiment of the present invention,

[0078] Dissolve the block copolymer macromolecular surfactant in injection water matching the target formation to obtain a solution with a mass concentration of the block copolymer macromolecular surfactant of 0.05-0.15%; preferably,

[0079] the viscosity of the solution of the block copolymer macromolecular surfactant at 90 °C is 15-25 mPas;

[0080] the interfacial tension between the solution of the block copolymer macromolecular surfactant and crude oil reaches below 3×10 - 2 mN / m within 2 hours;

[0081] the interfacial tension between the solution of the block copolymer macromolecular surfactant and crude oil is ultimately less than 1×10 -2 mN / m;

[0082] This solution is used in enhanced oil recovery operations to improve the oil recovery rate.

[0083] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0084] The macromolecular initiator prepared in the present invention, when used to prepare a block-type poly-surfactant, can make the surface-active structural units concentrated in the middle section of the chain, significantly improving the oil-water interfacial activity of the poly-surfactant. At the same time, the two tail segments of the long chain of the poly-surfactant are still hydrophilic, and the poly-surfactant still maintains good water solubility and the ability to increase viscosity in aqueous solution.

[0085] The synthesis of the poly-surfactant of the present invention is a controllable polymerization, and the structure of the poly-surfactant can be adjusted. As long as the raw material dosage is simply adjusted, the oil-water interfacial activity of the poly-surfactant can be regulated, achieving the unity of the oil-water interfacial activity and thickening property of the poly-surfactant without changing the raw material composition.

[0086] The block copolymer macromolecular surfactant prepared in the present invention has high viscosity, high interfacial activity, and fast interfacial action, solving the problems in the prior art that the viscosity and interfacial activity of macromolecular surfactants for oilfields cannot be unified and the interfacial action is slow. At the same time, it reduces the dosage of chemical additives, is applicable to enhanced oil recovery operations, and solves the technical problems that under harsh conditions of high temperature and high salinity, the enhanced oil recovery chemical additives can increase viscosity and reduce interfacial tension at the same time, avoid chromatographic separation, and improve the effect of chemical additives and reduce the dosage of chemical additives. It can provide good viscosity and interfacial activity within a relatively wide range of salinity and temperature without the need for major structural redesign. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Figure 1 It is the NMR spectrum of the poly-surfactant prepared in Example 5 and Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0088] The present invention will be specifically described below in conjunction with specific embodiments. It is necessary to point out here that the following embodiments are only used for further illustration of the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the protection scope of the present invention.

[0089] The raw materials used in the examples are all conventional commercially available raw materials.

[0090] Testing method:

[0091] Viscosity: The testing instrument is a Brookfield LV2T rotational viscometer or a similar type of viscometer; the constant temperature water bath is set to the formation temperature, the 0# rotor is connected to the viscometer, about 16 mL of the solution to be tested is poured into the sample cup, after constant temperature for 4 min, the rotation speed is set to 6 rpm, after rotating for 4 min, the viscosity value is started to be recorded, and after the viscosity value is stable, the viscosity data within 30 s is recorded and its average value is taken as the viscosity test result.

[0092] Interfacial tension: The rotation method is used for testing, and the testing instrument is a KRUSSS DT rotational drop interfacial tensiometer or a similar type of interfacial tensiometer; the high-density phase is the polymer surfactant solution; the low-density phase is the target formation crude oil; the testing temperature is the target formation temperature; the testing rotation speed is 6000 rpm.

[0093] Example 1

[0094] Preparation of the macromolecular initiator:

[0095] 30 g of H-(OCH 2 CH 2 ) 12 -CH=CH-C 6 H 12 -C 6 H 5 is added to a mixed solution composed of 100 g each of deionized water and isopropanol to obtain a monomer solution.

[0096] 2 g of CuCl 2 and 3 g of o-phenanthroline are added to a 0.5 L round-bottom flask, and nitrogen is introduced. After it changes color, the monomer solution is gently added, and then 2 g of diethyl 2,5-dichlorohexanedioate is added. Nitrogen is introduced for freezing, vacuum is pumped, thawed, and nitrogen is introduced, and this cycle is repeated 3 times, and then freeze-drying is carried out.

[0097] The round-bottom flask is placed in a 45 °C water bath, and nitrogen is introduced to react for 5 hours, and then air is introduced to stop the reaction.

[0098] After filtering the precipitate from the liquid in the round-bottom flask, it is washed twice with 50 mL of isopropanol and placed in a 50 °C vacuum oven and dried for 1.5 hours to obtain the macromolecular initiator.

[0099] Example 2

[0100] Preparation of macromolecular initiator:

[0101] 50 g of H-(C 6 H 4 ) 2 -CH=CH-C 4 H 8 -SO 3 Na was added to a mixed solution composed of 50 g of deionized water and 100 g of ethanol to obtain a monomer solution.

[0102] 12 g of CuBr and 6 g of o-phenanthroline were added to a 0.5 L round-bottom flask, and nitrogen was introduced. After it changed color, the monomer solution was gently added, and then 2.4 g of ethyl dichloroacetate was added. Nitrogen was introduced, vacuum was pumped, thawed, and nitrogen was introduced, and the cycle was repeated 3 times, followed by freeze-drying. 2 12 g, 6 g of o-phenanthroline, and nitrogen was introduced. After it changed color, the monomer solution was gently added, and then 2.4 g of ethyl dichloroacetate was added. Nitrogen was introduced, vacuum was pumped, thawed, and nitrogen was introduced, and the cycle was repeated 3 times, followed by freeze-drying.

[0103] The round-bottom flask was placed in a 40 °C water bath, and nitrogen was introduced to react for 10 hours, and then air was introduced to stop the reaction.

[0104] After filtering the precipitate from the liquid in the round-bottom flask, it was washed three times with 60 mL of ethanol, placed in a 40 °C vacuum oven, and dried for 2 hours to obtain the macromolecular initiator.

[0105] Example 3

[0106] Preparation of macromolecular initiator:

[0107] 80 g of H-(CH 2 (CH 3 )CHO) 12 -CH=CH-CH 2 -N + (CH 3 ) 3 Cl - was added to a mixed solution composed of 120 g of deionized water and 60 g of N,N-dimethylformamide to obtain a monomer solution.

[0108] 2 g of FeCl 2 2 g and 6 g of 2,2’-bipyridine were added to a 0.5 L round-bottom flask, and nitrogen was introduced. After it changed color, the monomer solution was gently added, and then 4 g of ethyl dibromoacetate was added. Nitrogen was introduced, vacuum was pumped, thawed, and nitrogen was introduced, and the cycle was repeated 5 times, followed by freeze-drying.

[0109] The round-bottom flask was placed in a 90 °C water bath, and nitrogen was introduced to react for 5 hours, and then air was introduced to stop the reaction.

[0110] After filtering the precipitate from the liquid in the round-bottom flask, wash it five times with 80 mL of isopropanol, place it in a vacuum oven at 55 °C, and dry it for 1.5 hours to obtain the macromolecular initiator.

[0111] Example 4

[0112] Preparation of macromolecular initiator:

[0113] Add 60 g of C 16 H 33 -CH=CH-C 4 H 8 -SO 3 Na to a mixed solution composed of 100 g of deionized water and 120 g of methanol to obtain a monomer solution.

[0114] Add 8 g of FeBr 2 and 8 g of 4,4'-bipyridine to a 0.5 L round-bottom flask, and introduce nitrogen. After it changes color, smoothly add the monomer solution, and then add 12 g of p-dichlorobenzyl. Introduce cold nitrogen, evacuate, thaw, and introduce nitrogen, repeat the cycle 4 times, and perform freeze-drying.

[0115] Place the round-bottom flask in a water bath at 50 °C, keep nitrogen flowing and react for 6 hours, then introduce air to stop the reaction.

[0116] After filtering the precipitate from the liquid in the round-bottom flask, wash it twice with 50 mL of ethanol, place it in a vacuum oven at 60 °C, and dry it for 1 hour to obtain the macromolecular initiator.

[0117] Example 5

[0118] Preparation of block copolymer macromolecular surfactant:

[0119] Weigh 100 g of deionized water in a 500 mL beaker, add 120 g of acrylamide, stir evenly, and adjust the pH value to 8.1 with 30 wt% NaOH solution to obtain a monomer solution.

[0120] Weigh 50 g of deionized water in a 200 mL beaker, add 20 g of the macromolecular initiator obtained in Example 1, and dissolve it evenly to obtain an initiator solution.

[0121] Add 5 g of CuCl 2 and 5 g of o-phenanthroline to a 0.5 L glass bottle, and introduce nitrogen. After it changes color, smoothly add the monomer solution, set the external water bath temperature to 5 °C, introduce nitrogen, dropwise add the initiator solution completely within half an hour, remove nitrogen, seal the glass bottle, and raise the external water bath temperature to 45 °C in 3 steps within half an hour, and keep reacting for 3 hours to obtain a block copolymer macromolecular surfactant gel.

[0122] The gel is granulated, placed in a vacuum oven at 120 °C and dried for 1.5 hours, then pulverized to obtain the dry powder of the block copolymer macromolecular surfactant.

[0123] The structural formula of the obtained block copolymer macromolecular surfactant is:

[0124]

[0125] In this example, p = 0, and n:q is approximately 1:(28 - 29).

[0126] Example 6

[0127] Preparation of the block copolymer macromolecular surfactant:

[0128] Weigh 100 g of deionized water in a 500 mL beaker, add 100 g of acrylamide and 20 g of sodium p-vinylbenzenesulfonate, stir evenly, and adjust the pH value to 8.2 with 30 wt% NaOH solution to obtain the monomer solution.

[0129] Weigh 50 g of deionized water in a 200 mL beaker, add 20 g of the macromolecular initiator obtained in Example 1, and dissolve evenly to obtain the initiator solution.

[0130] Add CuCl 2 5 g and 5 g of o-phenanthroline into a 0.5 L glass bottle, and introduce nitrogen. After it changes color, smoothly add the monomer solution, set the external water bath temperature to 5 °C, introduce nitrogen, dropwise add the initiator solution completely within half an hour, remove nitrogen, seal the glass bottle, and raise the external water bath temperature to 45 °C in 3 steps within half an hour, and maintain the reaction for 3 hours to obtain the block copolymer macromolecular surfactant gel.

[0131] The gel is granulated, placed in a vacuum oven at 120 °C and dried for 1.5 hours, then pulverized to obtain the dry powder of the block copolymer macromolecular surfactant.

[0132] The structural formula of the obtained block copolymer macromolecular surfactant is:

[0133]

[0134] In this example, p:q is approximately 1:13 - 14, and n:(p + q) is approximately 1:(27 - 28).

[0135] Example 7

[0136] Preparation of the block copolymer macromolecular surfactant:

[0137] Weigh 135 g of deionized water in a 500 mL beaker, add 100 g of methacrylamide, stir evenly, and adjust the pH value to 8.0 with 30 wt% NaOH solution to obtain the monomer solution.

[0138] Weigh 30 g of deionized water in a 200 mL beaker, add 8 g of the macroinitiator obtained in Example 2, and dissolve it evenly to obtain an initiator solution.

[0139] Add CuBr 2 0.4 g and 1.2 g of o-phenanthroline into a 0.5 L glass bottle, and introduce nitrogen. After it changes color, gently add the monomer solution. Set the external water bath temperature to 5 °C, introduce nitrogen, and slowly add the initiator solution drop by drop completely within half an hour. Then remove the nitrogen, seal the glass bottle, and increase the external water bath temperature to 35 °C in 3 steps within half an hour, and keep the reaction for 3 hours to obtain a block copolymer macromolecular surfactant gel.

[0140] Granulate the gel, place it in a vacuum oven at 120 °C for drying for 1.5 hours, and then pulverize it to obtain a block copolymer macromolecular surfactant dry powder.

[0141] The structural formula of the obtained block copolymer macromolecular surfactant is:

[0142]

[0143] In this example, p = 0, and n:(p + q) is approximately 1:(24 - 26).

[0144] Example 8

[0145] Preparation of block copolymer macromolecular surfactant:

[0146] Weigh 100 g of deionized water in a 500 mL beaker, add 90 g of acrylamide and 10 g of sodium allylsulfonate, stir evenly, and adjust the pH value to 7.9 with 30 wt% NaOH solution to obtain a monomer solution.

[0147] Weigh 48 g of deionized water in a 200 mL beaker, add 12 g of the macroinitiator obtained in Example 3, and dissolve it evenly to obtain an initiator solution.

[0148] Add FeCl 2 5 g and 3 g of 2,2'-bipyridine into a 0.5 L glass bottle, and introduce nitrogen. After it changes color, gently add the monomer solution. Set the external water bath temperature to 5 °C, introduce nitrogen, and slowly add the initiator solution drop by drop completely within half an hour. Then remove the nitrogen, seal the glass bottle, and increase the external water bath temperature to 35 °C in 3 steps within half an hour, and keep the reaction for 3 hours to obtain a block copolymer macromolecular surfactant gel.

[0149] Granulate the gel, place it in a vacuum oven at 120 °C for drying for 2 hours, and then pulverize it to obtain a block copolymer macromolecular surfactant dry powder.

[0150] The structural formula of the obtained block copolymer macromolecular surfactant is as follows:

[0151]

[0152] In this example, p:q is approximately 1:(18 - 19), and n:(p + q) is approximately 1:(91 - 92).

[0153] Example 9

[0154] Preparation of block copolymer macromolecular surfactant:

[0155] Weigh 120 g of deionized water in a 500 mL beaker, add 100 g of allyl acrylamide, stir evenly, and adjust the pH value to 8.3 with 30 wt% NaOH solution to obtain a monomer solution.

[0156] Weigh 30 g of deionized water in a 200 mL beaker, add 20 g of the macromolecular initiator obtained in Example 3, and dissolve evenly to obtain an initiator solution.

[0157] Add 5 g of FeCl 2 5 g of 2,2'-bipyridine into a 0.5 L glass bottle, and introduce nitrogen. After it changes color, gently add the monomer solution. Set the external water bath temperature to 5 °C, introduce nitrogen, and dropwise add the initiator solution completely within half an hour. Then remove the nitrogen, seal the glass bottle, and increase the external water bath temperature to 45 °C in 3 steps within half an hour, and keep the reaction for 3 hours to obtain a block copolymer macromolecular surfactant gel.

[0158] Granulate the gel, place it in a vacuum oven at 120 °C for drying for 1.5 hours, and then pulverize it to obtain a block copolymer macromolecular surfactant dry powder.

[0159] The structural formula of the obtained block copolymer macromolecular surfactant is as follows:

[0160]

[0161] In this example, p = 0, and n:(p + q) is approximately 1:(39 - 40).

[0162] Example 10

[0163] Preparation of block copolymer macromolecular surfactant:

[0164] Weigh 80 g of deionized water in a 500 mL beaker, add 90 g of N,N-dimethylacrylamide and 10 g of 2-acrylamido-2-methylpropanesulfonic acid sodium salt, stir evenly, and adjust the pH value to 8.1 with 30 wt% NaOH solution to obtain a monomer solution.

[0165] Weigh 40 g of deionized water in a 200 mL beaker, add 10 g of the macroinitiator obtained in Example 4, and dissolve it evenly to obtain an initiator solution.

[0166] Add 5 g of FeBr 2 and 5 g of 4,4'-bipyridine to a 0.5 L glass bottle, and introduce nitrogen gas. After it changes color, gently add the monomer solution. Set the external water bath temperature to 5 °C, introduce nitrogen gas, and slowly add the initiator solution drop by drop completely within half an hour. Then remove the nitrogen gas, seal the glass bottle, and increase the external water bath temperature to 50 °C in 3 steps within half an hour, and maintain the reaction for 2 hours to obtain a block copolymer surfactant gel.

[0167] Granulate the gel, place it in a vacuum oven at 120 °C for drying for 1 hour, and then pulverize it to obtain a dry powder of the block copolymer surfactant.

[0168] The structural formula of the obtained block copolymer surfactant is:

[0169]

[0170] In this example, p:q is approximately 1:(20 - 22), and n:(p + q) is approximately 1:(27 - 28).

[0171] Comparative Example 1

[0172] Weigh 100 g of deionized water in a 500 mL beaker, add 120 g of acrylamide, and then add 20 g of H-(OCH 2 CH 2 ) 12 -CH=CH-C 6 H 12 -C 6 H 5 , stir evenly, and adjust the pH value to 8.2 with 30 wt% NaOH solution to obtain a monomer solution.

[0173] Weigh 50 g of deionized water in a 100 mL beaker, add 0.5 g of potassium persulfate to obtain Initiator 1 solution; weigh 50 g of deionized water in a 100 mL beaker, add 0.5 g of sodium bisulfite to obtain Initiator 2 solution.

[0174] Add the monomer solution to a 0.5 L glass bottle, set the external water bath temperature to 5 °C, introduce nitrogen gas, add 1 g of Initiator 2 solution, and after introducing nitrogen gas for half an hour, slowly add 2 g of Initiator 1 solution drop by drop. Then remove the nitrogen gas after introducing nitrogen gas for another half an hour, seal the glass bottle, and increase the external water bath temperature to 45 °C in 3 steps within half an hour, and maintain the reaction for 3 hours to obtain a polymer gel.

[0175] The gel was granulated, placed in a vacuum oven at 120 °C and dried for 1.5 hours, and then pulverized to obtain a polymer dry powder.

[0176] Comparative Example 2

[0177] Weighed 100 g of deionized water in a 500 mL beaker, added 100 g of acrylamide and 20 g of sodium vinylbenzenesulfonate, and then added H-(OCH 2 CH 2 ) 12 -CH=CH-C 6 H 12 -C 6 H 5 20 g, stirred evenly, adjusted the pH value to 8.2 with 30 wt% NaOH solution to obtain a monomer solution.

[0178] Weighed 50 g of deionized water in a 100 mL beaker, added 0.5 g of potassium persulfate to obtain Initiator 1 solution; weighed 50 g of deionized water in a 100 mL beaker, added 0.5 g of sodium bisulfite to obtain Initiator 2 solution.

[0179] The monomer solution was added to a 0.5 L glass bottle, the external water bath temperature was set at 5 °C, nitrogen was introduced, 1 g of Initiator 2 solution was added, after half an hour of nitrogen introduction, 2 g of Initiator 1 solution was added dropwise, and after another half an hour of nitrogen introduction, nitrogen was removed, the glass bottle was sealed, and the external water bath temperature was raised to 45 °C in 3 steps within half an hour and the reaction was maintained for 3 hours to obtain a polymer gel.

[0180] The gel was granulated, placed in a vacuum oven at 120 °C and dried for 1.5 hours, and then pulverized to obtain a polymer dry powder.

[0181] Performance test:

[0182] Prepared a formulated water containing CaCl 2 11100 mg / L, MgCl 2 3958 mg / L, NaCl 164942 mg / L (total salinity 180000 mg / L, total calcium and magnesium content 5000 mg / L).

[0183] Weighed 198 g of the formulated water in a 600 mL tall beaker, placed it on a mechanical stirrer, started stirring at 500 rpm, slowly added 2 g of the block copolymer macromolecular surfactant dry powder prepared in Examples 5 - 10 and the block copolymer macromolecular surfactant dry powder of Comparative Examples 1 - 2, increased the stirring rate to 700 rpm, and stirred for 2 hours to obtain a 1 wt% block copolymer macromolecular surfactant mother liquor.

[0184] After the mother liquor was left standing for 24 hours, part of the mother liquor was diluted with prepared water to a concentration of 0.1 wt%, obtaining a block polymer macromolecular surfactant test solution, and its viscosity and interfacial tension at 90 °C were measured. The test results are shown in Table 1.

[0185] Table 1 Performance test results of surfactants prepared in Examples 5-10 and Comparative Examples 1-2

[0186]

[0187] As can be seen from Table 1, compared with Example 5, in Comparative Example 1, the monomer raw materials and their dosages used were the same, and the common radical initiator was used to replace the macromolecular initiator in Example 5; the viscosity of Comparative Example 1 was lower, the lowest interfacial tension and the time to reach the lowest interfacial tension were much higher than those of Example 5, and the interfacial tension could not reach <3×10 -2 mN / m.

[0188] Figure 1 For the comparison of the NMR spectra of the surfactants prepared in Example 5 and Comparative Example 1, the monomer raw materials used in Example 5 and Comparative Example 1 were the same. The difference in their structures was that in Example 5, the functional monomers formed a macromolecular initiator, and the block was concentrated in the middle position of the poly-surfactant chain. In Comparative Example 1, all monomers were randomly distributed in the poly-surfactant chain through radical initiation, and the arrangement of the structural units of the poly-surfactant chain was different. Therefore, the main difference between the two in NMR was the splitting of the NMR peaks of C and H on the main chain, while the NMR peak positions of the C atoms connected to N and O on the side chain were basically the same based on the same raw materials. The specific differences between the two have been circled in the figure, and the block polymer macromolecular surfactant can be distinguished from other macromolecular surfactants through NMR testing.

[0189] Compared with Example 6, in Comparative Example 2, the monomer raw materials and their dosages used were the same, and the common radical initiator was used to replace the macromolecular initiator in Example 6; the viscosity of Comparative Example 2 was lower, the lowest interfacial tension and the time to reach the lowest interfacial tension were much higher than those of Example 6, and the interfacial tension could not reach <3×10 -2 mN / m.

[0190] The macromolecular initiators prepared in Examples 1-4, when used to prepare block poly-surfactants, can make the surface-active structural units concentrated in the middle position of the chain, significantly improve the oil-water interfacial activity of the poly-surfactant, and at the same time, the two tail segments of the poly-surfactant long chain are still hydrophilic, and the poly-surfactant still maintains good water solubility and the ability to increase viscosity in aqueous solution.

[0191] Examples 5 to 10 used the macroinitiators prepared in Examples 1 to 4 for the initiation reaction. The obtained block-polymerized macromolecular surfactants had high viscosity, high interfacial activity, and fast interfacial action, solving the problems in the prior art that the viscosity and interfacial activity of macromolecular surfactants for oilfields could not be unified and the interfacial action was slow. At the same time, the dosage of chemical additives was reduced, which was applicable to enhanced oil recovery operations, solving the technical problems that under harsh conditions of high temperature and high salinity, the chemical additives for enhanced oil recovery could increase viscosity and reduce interfacial tension simultaneously, avoid chromatographic separation, improve the effect of chemical additives, and reduce the dosage of chemical additives. Good viscosity and interfacial activity could be provided within a relatively wide range of salinity and temperature.

Claims

1. A macromolecular initiator, calculated based on the total weight of the macromolecular initiator being 100%, is prepared from raw materials including the following components: Functional polymerizable monomer: 10 - 35%; preferably 10 - 30%; Other components: 2 - 15%; preferably 2 - 10%; The balance is solvent; The other components include a functional initiator, catalyst A, and catalyst ligand A; The functional polymerizable monomer is an olefin monomer with oil / water interfacial activity; The molar ratio of catalyst A, functional initiator, and catalyst ligand A is 1:(0.1 - 5):(0.1 - 5), preferably 1:(0.2 - 2):(0.5 - 3).

2. The macromolecular initiator according to claim 1, characterized in that: The structural formula of the functional monomer is Among them, M 1 is -C 4 H 8 -SO 3 Na, -CH 2 -N + -(CH 3 ) 3 Cl or -(CH 2 CH 2 O) m H, and m is an integer between 8 and 24; M 2 is -(C 6 H 4 ) n1 -H, -(OCH(CH 3 )CH 2 ) n2 -H, -(CH 2 ) n3 -H, -(CH 2 ) n4 -(C 6 H 4 ) n5 -H or -(C 6 H 4 ) n6 -(CH 2 ) n7 -H, n1 is an integer between 2 and 4, n2 is an integer between 5 and 10, n3 is an integer between 8 and 20, n4 is an integer between 6 and 12, n5 is an integer between 1 and 3, n6 is an integer between 1 and 3, n7 is an integer between 6 and 12.

3. The macromolecular initiator according to claim 1, characterized in that: The functional initiator is one of polyhalogenated aromatic hydrocarbons and polyhalogenated fatty acid esters, preferably one of p - dibromobenzyl, p - dichlorobenzyl, diethyl 2,5 - dibromohexanedioate, diethyl 2,5 - dichlorohexanedioate, ethyl dibromoacetate, and ethyl dichloroacetate; and / or, The catalyst A is at least one of halides of transition metals, preferably at least one of iron(III) chloride, iron(III) bromide, copper(II) chloride, copper(II) bromide, iron(II) chloride, iron(II) bromide, copper(I) chloride, and copper(I) bromide; and / or, The catalyst ligand A is at least one of polyamines, polybipyridines, and hybrid phenanthrenes, preferably at least one of 1,10 - phenanthroline, o - phenanthroline, 2,2'-bipyridine, and 4,4'-bipyridine; and / or, The solvent is a mixed solvent obtained by mixing an organic solvent and water; the organic solvent is preferably at least one of methanol, ethanol, propanol, isopropanol, toluene, tetrahydrofuran, and N,N - dimethylformamide; the water is preferably deionized water; more preferably, the mass ratio of the organic solvent to water is (0.5 - 3):1, preferably (1 - 2):

1.

4. A method for preparing a macromolecular initiator according to any one of claims 1 - 3, comprising the following steps: (1) Dissolve the functional polymerizable monomer in the solvent to obtain a functional polymerizable monomer solution; (2) First add catalyst A and catalyst ligand A to a reaction vessel, then add the functional initiator and the functional polymerizable monomer solution obtained in step (1), mix and freeze - dry, react under the protection of a protective gas, and obtain the macromolecular initiator after post - treatment.

5. The method for preparing a macromolecular initiator according to claim 4, characterized in that: In step (2), add the functional initiator and the functional polymerizable monomer solution after catalyst A and catalyst ligand A change color; and / or, The freeze - drying step is to introduce frozen nitrogen, evacuate, thaw, and introduce nitrogen, preferably repeat 3 - 5 times; and / or, The protective gas is at least one of nitrogen and inert gases; and / or, The reaction temperature is 40 - 90 °C; and / or, The reaction time is 4 - 10 hours; and / or, The post - treatment is filtration, washing, and drying.

6. A block - polymerized macromolecular surfactant, the structural formula of which is shown in formula (Ⅰ): Wherein, R 1 is one of the groups of the following structures: *-C 4 H 8 -SO 3 Na, *-CH 2 -N + -(CH 3 ) 3 Cl, *-(CH 2 CH 2 O) m1 H, m 1 is an integer between 8 and 24; R 2 is one of the groups of the following structures: *-(C 6 H 4 ) m2 -H, *-(OCH(CH 3 )CH 2 ) m3 -H, *-(CH 2 ) m4 -H, *-(CH 2 ) m5 -(C 6 H 4 ) m6 -H or *-(C 6 H 4 ) m7 -(CH 2 ) m8 -H; m2 is an integer between 2 and 4, m3 is an integer between 5 and 12, m4 is an integer between 8 and 20, m5 is an integer between 6 and 12, m6 is an integer between 1 and 3, m7 is an integer between 1 and 3, m8 is an integer between 6 and 12; The RR segment contains R II , capped with -H; optionally, the RR segment also contains R I ; R I One of the groups having the following structure: R II is one of the groups of the following structures: When both R I and R II are included in the RR segment, the structural units of R I and R II are randomly distributed in RR of formula (I); In formula (I), n:(p + q) = 1:(20 - 100); when p ≠ 0, p:q = 1:(10 - 25).

7. The block polymerized macromolecular surfactant according to claim 6, characterized in that: Based on 100 parts by weight of the polymerization monomer, the block polymerized macromolecular surfactant is prepared from raw materials including the following components: The mass ratio of catalyst B to catalyst ligand B is 1:(0.1 - 5), preferably 1:(0.5 - 3); wherein, the macromolecular initiator is the macromolecular initiator described in any one of claims 1 - 3 or the macromolecular initiator obtained by the preparation method described in claim 4 or 5.

8. The block polymerized macromolecular surfactant according to claim 7, characterized in that: Based on parts by weight, the polymerization monomer includes 80 - 100 parts by weight of non-ionic monomer and 0 - 20 parts by weight of anionic monomer; preferably, the non-ionic monomer is at least one of acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, allyl acrylamide; and / or, the anionic monomer is at least one of sodium acrylate, sodium methacrylate, 2-acrylamido-2-methylpropanesulfonic acid sodium salt, sodium vinyl sulfonate, sodium allyl sulfonate, sodium vinyl benzene sulfonate; and / or, the catalyst B is at least one of halides of transition metals, preferably at least one of ferric chloride, ferric bromide, copper chloride, copper bromide, ferrous chloride, ferrous bromide, cuprous chloride, cuprous bromide; and / or, the catalyst ligand B is at least one of polyamines, polybipyridines, hybrid phenanthrenes, preferably at least one of o-phenanthroline, o-phenanthroline, 2,2'-bipyridine, 4,4'-bipyridine.

9. A preparation method of the block polymerized macromolecular surfactant according to any one of claims 6 - 8, comprising the following steps: (1) Dissolve the polymerization monomer in deionized water to obtain a monomer solution; (2) Dissolve the macromolecular initiator in deionized water to obtain an initiator solution; (3) Add catalyst B and catalyst ligand B into a reaction vessel, add the monomer solution obtained in step (1) under the protection of a protective gas, and then add the initiator solution obtained in step (2), react to obtain a hydrogel containing the block polymerized macromolecular surfactant, and obtain the block polymerized macromolecular surfactant after post-treatment.

10. The preparation method of the block polymerized macromolecular surfactant according to claim 9, characterized in that: In step (1), the concentration of the monomer solution is 40 - 60%; and / or, the pH value of the monomer solution is adjusted to 7.5 - 8.5; and / or, In step (2), the concentration of the macromolecular initiator solution is 20 - 40%; and / or, In step (3), introduce a protective gas into catalyst B and catalyst ligand B, wait until it changes color, and then add the monomer solution; and / or, keep introducing the protective gas and add the initiator solution; and / or, The way of adding the initiator solution into the monomer solution is dropwise addition; preferably, the dropwise addition of the initiator solution is completed within 30 min; and / or, The protective gas is at least one of nitrogen and inert gas; and / or, The temperature during the addition of the initiator solution is 5 to 10 °C; and / or, After the addition of the initiator solution is completed, the reaction vessel is sealed for reaction; and / or, The reaction temperature is 35 to 50 °C; and / or, The reaction time is 2 to 4 hours; and / or, The post-treatment includes granulation, drying, and pulverization.

11. Application of a block polymer macromolecular surfactant as described in any one of claims 6 to 8 or a block polymer macromolecular surfactant obtained by the preparation method as described in claim 9 or 10 in oil recovery, preferably in enhanced oil recovery operations.

12. The application as described in claim 11, characterized in that: The block polymer macromolecular surfactant is dissolved in injection water matching the target formation to obtain a solution with a concentration of the block polymer macromolecular surfactant of 0.05 to 0.15 wt%; preferably, the viscosity of the solution of the block polymer macromolecular surfactant at 90 °C is 15 to 25 mPas; and / or, The interfacial tension between the solution of the block polymer macromolecular surfactant and crude oil reaches below 3×10 -2 mN / m within 2 hours; and / or, The interfacial tension between the solution of the block polymer macromolecular surfactant and crude oil is ultimately less than 1×10 -2 mN / m.

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