Nanoparticles with multiple amino active groups, organic-inorganic composite cross-linking agent, preparation method and application

Abstract

The application discloses a kind of nanoparticles with multi-amino active groups, organic-inorganic composite crosslinking agent and preparation method and application, organic-inorganic composite crosslinking agent is with nano-alumina, nano-zirconia and other nanoparticles as carrier, graft polyamine compound on the surface of nanoparticle by catalytic reaction, and organic-inorganic composite nanometer crosslinking agent with delaying function can be prepared by composite crosslinking control agent.The molecular structure of the synthesized organic-inorganic composite crosslinking agent has rigid benzene ring structure and rich active groups, so it has good temperature resistance and activity.Compared with conventional crosslinking agent, the activity is higher, and it can also react with amide group and carboxyl group on polymer molecule at low temperature;By adjusting the amount of crosslinking control agent, the gelation time and strength of the system can be controlled to meet different construction requirements of oilfield site;Synthetic nanometer crosslinking agent is green and environmentally friendly, and meets the requirements of green medicine, and can be applied to water plugging and profile control in medium-low temperature reservoirs.

Description

TECHNICAL FIELD

[0001] The application relates to a nanoparticle with multiple amino active groups, an organic-inorganic composite crosslinking agent and a preparation method and application, and belongs to the technical field of nanomaterials. BACKGROUND

[0002] For nearly a century since the water injection development was proposed, water injection has been the mainstream oil production method in the world. However, in the water injection development process, due to the difference in the material composition of the rock layer, the rock mineral content and the colloid content, the heterogeneity of the layer and the layer is caused, so the permeability of the oil reservoir and the water injection layer is different. The difference in permeability will form a dominant channel, so that the water injection enters the well too early, and a dominant channel is formed in the oil reservoir, the water injection resistance is reduced, and the water injection process will inevitably have the phenomena of "streaming", "sudden advance" and "straight advance", which seriously affects the oil production rate; the original old channel deblocking also has a negative impact on the water injection effect, and in order to improve the oil production rate, the channels must be blocked and profiled.

[0003] At present, the commonly used profile control and water plugging system mainly uses partially hydrolyzed polyacrylamide crosslinked gel, which has the advantages of high plugging strength and good adaptability, and has been widely used. The molecules of partially hydrolyzed polyacrylamide have various crosslinkable groups, such as amide groups, carboxyl groups and carboxylate ions, which can react with many compounds. Among them, the two commonly used crosslinking systems are: one is a crosslinking agent that can react with the amide groups in the polymer molecular chain segments to form new covalent bonds. The commonly used covalent bond type crosslinking agent is a low molecular aldehyde, and its basic component is phenol and formaldehyde. The second type is a polyvalent metal ion crosslinking agent that can react with the carboxylic acid groups in the polymer molecular chain segments. Its main technology is to use chromium, aluminum and other metal ions, and to add different chelating agents to form water-soluble chelates to control the reaction speed, so as to prolong the crosslinking reaction time.

[0004] At present, the development of deep profile control technology in medium-high temperature reservoirs is relatively mature, while water plugging and profile control in low-temperature reservoirs has always been a technical problem, which leads to the slow development of low-temperature water plugging and profile control system. At present, HPAM / organic acid chromium system and HPAM / phenol formaldehyde system are commonly used in low-temperature environment. Due to the low activity of substances in low-temperature environment, the crosslinking reaction between HPAM and phenol formaldehyde system is slow, the gel strength is poor, and even the gelation phenomenon cannot occur; the HPAM / organic acid chromium system contains heavy metal chromium ions, which has certain toxicity and is limited in the use of low-temperature reservoirs. Therefore, it is of great significance to develop a low-temperature gelation system with controllable gelation time, good gel strength and low pollution. SUMMARY

[0005] In view of the problems of slow low-temperature gelation, poor gelation strength, and non-environmental protection of the crosslinking agent, the present application aims to provide an organic-inorganic composite nano crosslinking agent which is green, controllable in gelation time, good in gelation strength, non-toxic, and applicable to the water plugging and profile control of medium and low temperature reservoirs. The nano crosslinking agent provided by the present application uses nano aluminum oxide, nano zirconium oxide and other nanoparticles as carriers, grafts polyamine compounds on the surface of the nanoparticles through catalytic reaction, and then is compounded with a crosslinking regulator to prepare an organic-inorganic composite nano crosslinking agent with a delaying function. The synthesized nano crosslinking agent has a rigid benzene ring structure and rich active groups on the molecular structure, so that it has good temperature resistance and salt resistance and activity. Compared with conventional crosslinking agents, the nano crosslinking agent has higher activity and can react with amide groups and carboxyl groups on polymer molecules at low temperatures; the gelation time and strength of the system can be controlled by adjusting the amount of the crosslinking regulator, so as to meet different construction requirements of oilfield sites; the synthesized nano crosslinking agent is green and environmentally friendly, meets the requirements of green agents, and can be applied to the water plugging and profile control of medium and low temperature reservoirs.

[0006] According to a first aspect of the present application, a nano particle with a plurality of amino active groups is provided, the nano particle with a plurality of amino active groups has a structure shown in formula I:

[0007]

[0008] In formula I, A is a nano particle;

[0009] R is selected from one of structures shown in formula I-1, formula I-2, formula I-3;

[0010]

[0011]

[0012] Optionally, the nano particle is selected from at least one of nano aluminum oxide, nano zirconium oxide, and nano silicon dioxide.

[0013] Optionally, the particle size of the nano particle is 50-150 nm.

[0014] Optionally, the particle size of the nano particle is selected from any value of 50 nm, 75 nm, 100 nm, 125 nm, 150 nm, or a range value between any two of the above values.

[0015] According to a second aspect of the present application, an organic-inorganic composite crosslinking agent is provided, the organic-inorganic composite crosslinking agent is obtained by compounding a nano particle with a plurality of amino active groups with a crosslinking regulator.

[0016] The nano particle with a plurality of amino active groups is selected from the nano particle with a plurality of amino active groups described above.

[0017] According to the third aspect of the present application, a preparation method of the organic-inorganic composite crosslinking agent is provided, and the preparation method comprises the following steps:

[0018] (1) preparing a nanoparticle dispersion liquid;

[0019] (2) grafting and modifying the nanoparticles in the nanoparticle dispersion liquid by using a coupling agent to obtain grafted and modified nanoparticles;

[0020] (3) reacting the mixture containing the grafted and modified nanoparticles and an amino modifier to obtain nanoparticles with multiple amino active groups;

[0021] (4) compounding the nanoparticles with multiple amino active groups and a crosslinking regulator to obtain the organic-inorganic composite crosslinking agent;

[0022] The nanoparticles with multiple amino active groups have a structure shown in Formula I.

[0023] Optionally, in the step (1), the mixture I containing the nanoparticles, an inorganic base and a dispersant is stirred to obtain the nanoparticle dispersion liquid.

[0024] Optionally, the nanoparticles are selected from at least one of nano-alumina, nano-zirconia and nano-silica.

[0025] Optionally, the inorganic base is selected from sodium hydroxide and / or potassium hydroxide.

[0026] Optionally, the dispersant is polyethylene glycol with a molecular weight of 10,000-20,000.

[0027] Optionally, the dispersant is used in an amount of 0.02wt%-0.04wt% of the nanoparticles.

[0028] Optionally, the dispersant is used in an amount of 0.02wt%, 0.03wt% or 0.04wt% of the nanoparticles, or in an amount within a range between any two of the above values.

[0029] Optionally, the nanoparticle dispersion liquid has a pH value of 8-9.

[0030] Optionally, in the step (2), the mass ratio of the nanoparticles to the coupling agent is 1:1.5-2.5.

[0031] Optionally, in the step (2), the mass ratio of the nanoparticles to the coupling agent is selected from 1:1.5, 1:2 or 1:2.5, or a range between any two of the above values.

[0032] Optionally, the coupling agent is γ-glycidoxypropyltrimethoxysilane.

[0033] Optionally, the grafting modification temperature is 50-70℃, and the grafting modification time is 30-60min.

[0034] Optionally, the grafting modification temperature is selected from any value of 50℃, 55℃, 60℃, 65℃, 70℃ or a range value between any two of the above values.

[0035] Optionally, the grafting modification time is selected from any value of 30min, 35min, 40min, 45min, 50min, 55min, 60min or a range value between any two of the above values.

[0036] Optionally, in the step (3), the mass ratio of the nanoparticles to the amino modifier is 1:3-5.

[0037] Optionally, the amino modifier is selected from at least one of 3-aminophenol, p-aminophenol, and p-methylaminophenol.

[0038] Optionally, in the step (3), the reaction temperature is 90-120℃, and the reaction time is 2-4h.

[0039] Optionally, the reaction temperature is selected from any value of 90℃, 95℃, 100℃, 110℃, 120℃ or a range value between any two of the above values.

[0040] Optionally, the reaction time is selected from any value of 2h, 2.5h, 3h, 3.5h, 4h or a range value between any two of the above values.

[0041] Optionally, in the step (4), the crosslinking regulator is selected from at least two of furfural, glyoxal, malondialdehyde, ammonium chloride, ammonium acetate, and ammonium oxalate.

[0042] Optionally, in the step (4), the mass ratio of the nanoparticles to the crosslinking regulator is 1:1.5-1:5.

[0043] Optionally, in the step (4), the mass ratio of the nanoparticles to the crosslinking regulator is selected from any value of 1:1.5, 1:2, 1:3, 1:4, 1:5 or a range value between any two of the above values.

[0044] According to a fourth aspect of the present application, a crosslinked polymer gel profile control agent is provided, which comprises the organic-inorganic composite crosslinking agent described above.

[0045] According to the fifth aspect of the present application, a preparation method of the cross-linked polymer gel profile control agent is provided, and the preparation method comprises:

[0046] The mixture containing the organic-inorganic composite cross-linking agent and the 0.3-0.5% (mass fraction) polyacrylamide aqueous solution is reacted to obtain the cross-linked polymer gel profile control agent.

[0047] Optionally, the amount of the organic-inorganic composite cross-linking agent is 0.2-0.5% of the mass of the polyacrylamide aqueous solution.

[0048] Optionally, the reaction temperature is 30-50°C, and the reaction time is 2-7 days.

[0049] Optionally, the reaction temperature is selected from any value of 30°C, 35°C, 40°C, 45°C, 50°C or a range between any two of the above values.

[0050] Optionally, the reaction time is any value of 2 days, 3 days, 4 days, 5 days, 6 days, 7 days or a range between any two of the above values.

[0051] The application method of the low-temperature delaying type organic-inorganic composite nano cross-linking agent comprises:

[0052] A 0.3-0.5% (mass fraction) partially hydrolyzed polyacrylamide aqueous solution is prepared; the organic-inorganic composite nano cross-linking agent is added to the partially hydrolyzed polyacrylamide aqueous solution, and stirred to obtain a base solution.

[0053] The amount of the organic-inorganic composite nano cross-linking agent is 0.2-0.5% of the mass of the polyacrylamide aqueous solution.

[0054] The base solution is reacted at a temperature of 30-50°C to obtain a gel with a three-dimensional network structure, and the gel is the cross-linked polymer gel profile control agent.

[0055] According to the sixth aspect of the present application, the organic-inorganic composite cross-linking agent is applied in water plugging and profile control in low-temperature oil reservoirs.

[0056] The low-temperature delayed nano-crosslinking agent provided by the application is prepared by using nano-aluminum oxide, nano-zirconium oxide and other nanoparticles as carriers, grafting polyamine compounds on the surface of the nanoparticles through a catalytic reaction, and then compounding a crosslinking regulator. The organic-inorganic composite nano-crosslinking agent with a delayed function can be prepared. The synthesized nano-crosslinking agent has a rigid benzene ring structure and rich active groups on the molecular structure, and thus has good temperature resistance, salt resistance and activity. Compared with conventional crosslinking agents, the crosslinking agent has higher activity, can react with amide groups and carboxyl groups on polymer molecules at low temperatures, and can control the gelation time and strength of the system by adjusting the amount of the crosslinking regulator, so as to meet different construction requirements on the oilfield site. The nanoparticles in the nano-crosslinking agent are uniformly dispersed in the three-dimensional network of the polymer, and through electrostatic adsorption, the three-dimensional network structure of the polymer is more stable, which is beneficial to improving the long-term stability of the profile control agent in the oil reservoir. In summary, the synthesized nano-crosslinking agent is green and environmentally friendly, meets the requirements of green agents, and can be applied to water plugging and profile control in medium and low temperature reservoirs.

[0057] The beneficial effects that can be produced by the application include:

[0058] 1) The low-temperature delayed organic-inorganic composite nano-crosslinking agent provided by the application has a simple preparation method, mild reaction conditions, does not require a large amount of organic solvent, does not pollute the environment, meets the safety and environmental protection requirements, and is easy to industrialize.

[0059] 2) The low-temperature delayed organic-inorganic composite nano-crosslinking agent provided by the application has a rigid benzene ring structure and rich active groups on the molecular structure, and thus has good temperature resistance, salt resistance and activity. Compared with conventional crosslinking agents, the crosslinking agent has higher activity, can react with amide groups and carboxyl groups on polymer molecules at low temperatures, and can control the gelation time and strength of the system by adjusting the amount of the crosslinking regulator, so as to meet different construction requirements on the oilfield site.

[0060] 3) The nanoparticles in the nano-crosslinking agent provided by the application are uniformly dispersed in the three-dimensional network of the polymer, and through electrostatic adsorption, the three-dimensional network structure of the polymer is more stable, which is beneficial to improving the long-term stability of the profile control agent in the oil reservoir.

[0061] 4) When the low-temperature delayed organic-inorganic composite nano-crosslinking agent provided by the application is added to a polymer to prepare a gel profile control agent, the gelation can be performed at 30-50 DEG C, the gelation time is controllable and is 2-7 days, the formed gel system is stable for 90 days without dehydration, the gel viscosity can be up to 10,000 mPa.s or more, the water plugging rate is 95% or more, and the nano-crosslinking agent can be applied to water plugging and profile control in medium and low temperature reservoirs. BRIEF DESCRIPTION OF DRAWINGS

[0062] Figure 1 Figure 1 is a nano-silicon dioxide particle size test diagram in Example 3 of the application.

[0063] Figure 2 Figure 1 is a graph showing the particle size of the nano-alumina prepared in Example 1 of the present application.

[0064] Figure 3 Figure 2 is a graph showing the particle size of the nano-zirconia prepared in Example 2 of the present application.

[0065] Figure 4 Figure 3 is a graph showing the gelation of the cross-linked polymer gel profile agent prepared in Example 5 of the present application.

[0066] Figure 5 Figure 4 is a graph showing the gelation of the cross-linked polymer gel profile agent prepared in Example 5 of the present application after 90 days of storage.

[0067] Figure 6 Figure 5 is a graph showing the gelation of the cross-linked polymer gel profile agent prepared in Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0068] The present application will be described in detail below with reference to the examples, but the present application is not limited to these examples.

[0069] In the examples of the present application, the raw materials were purchased through commercial channels unless otherwise specified.

[0070] The nano-alumina, nano-silica, γ-glycidoxypropyltrimethoxysilane, 3- aminophenol, p-aminophenol, and p-methylaminophenol were purchased from Shanghai Maikelin Biotechnology Co., Ltd.

[0071] The analysis methods and instruments used in the examples of the present application are as follows:

[0072] A Zetasizer Nano-ZSE Malvern particle size potential instrument was used for particle size testing.

[0073] A HAKKE MARS 40 Thermo Fisher rheometer was used for viscosity testing.

[0074] A DNQP-1 type oil displacement device was used for water plugging rate.

[0075] The method for preparing the delayed organic-inorganic composite nano-crosslinking agent includes the following steps:

[0076] (1) preparing a nano-particle dispersion liquid;

[0077] (2) grafting and modifying the nano-particles through a coupling agent;

[0078] (3) introducing amino active groups on the surface of the nano-particles through a catalytic reaction;

[0079] (4) further compounding a cross-linking control agent to prepare the delayed organic-inorganic composite nano-crosslinking agent.

[0080] The step (1) comprises the following steps: adding nanoparticles into a three-necked flask, adding inorganic alkali, adjusting the pH of the reaction system to 8-9, adding 0.02%-0.04% dispersant, stirring and mixing uniformly, and preparing a stable dispersed nanoparticle dispersion.

[0081] The step (2) comprises the following steps: adding the nanoparticle dispersion obtained in the step (1) into a three-necked flask, dissolving the coupling agent in water, slowly dropping the aqueous coupling agent solution into the nanoparticle dispersion, setting the reaction temperature to 50-70°C, setting the reaction time to 30-60 min, and obtaining surface grafted modified nanoparticles after the reaction is completed.

[0082] The step (3) comprises the following steps: adding an amino active group modifier into the aqueous solution of the surface grafted modified nanoparticles obtained in the step (2), setting the reaction temperature to 90-120°C, setting the reaction time to 2-4 h, and obtaining nanoparticles with a large number of amine groups on the surface after the reaction is completed.

[0083] The step (4) comprises the following steps: adding a crosslinking control agent into the aqueous solution of the surface amino modified nanoparticles obtained in the step (3), stirring and mixing until complete dissolution, and obtaining a delayed type organic-inorganic composite nanocrosslinking agent.

[0084] The chemical reaction flow chart of the nanoparticles with multiple amino active groups is as follows:

[0085]

[0086] A is a nanoparticle;

[0087] R is selected from one of the structures shown in formula I-1, formula I-2, formula I-3;

[0088]

[0089] Example 1

[0090] The step (1) comprises the following steps: adding 1.00 g of nanoparticle alumina into a three-necked flask, adding 99.00 g of ultrapure water, dropping an aqueous sodium hydroxide solution, adjusting the pH of the reaction system to 8, adding 0.02 g of PEG10000, stirring and mixing uniformly, and preparing a stable dispersed nanoparticle dispersion.

[0091] The step (2) comprises the following steps: dissolving 1.50 g of γ-glycidoxypropyltrimethoxysilane in ice water, stirring until complete dissolution, slowly dropping the aqueous coupling agent solution into the nanoparticle dispersion prepared in the step (1), starting stirring at the same time, setting the rotation speed to 400 r / min, setting the reaction temperature to 50°C, setting the reaction time to 60 min, and obtaining surface grafted modified nanoparticles after the reaction is completed.

[0092] Step (3) 4.00 g p-aminophenol is dissolved in ethanol, stirring to completely dissolve, then slowly add the amino-modifier ethanol solution to the solution prepared in step (2), set the reaction temperature to 100°C, condensation reflux is required during the reaction, the reaction time is 3 h, and the surface of the nanoparticles obtained after the reaction is complete has a large number of amine groups.

[0093] Step (4) 3.00 g glyoxal and 0.50 g ammonium acetate are added to the surface amino-modified nanoparticle aqueous solution obtained in step (3), stirring to completely dissolve, to obtain a delayed organic-inorganic composite nanoparticle crosslinking agent.

[0094] Example 2

[0095] Step (1) 1.00 g of nano-zirconium oxide is added to a three-necked flask, 99.00 g of ultrapure water is added, and then a potassium hydroxide aqueous solution is added dropwise to adjust the pH of the reaction system to 9. 0.03 g of PEG15000 is added and stirred to mix uniformly to prepare a stable dispersion of nanoparticle dispersion liquid.

[0096] Step (2) 2.00 g of γ-glycidyl ether propyltrimethoxysilane is dissolved in ice water, stirring to completely dissolve, and then the coupling agent aqueous solution is slowly added dropwise to the nanoparticle dispersion liquid prepared in step (1), while stirring is started at a speed of 500 r / min. The reaction temperature is set to 60°C, and the reaction time is 60 min. After the reaction is complete, the surface of the nanoparticles is grafted and modified.

[0097] Step (3) 4.00 g of p-aminophenol is dissolved in ethanol, stirring to completely dissolve, then slowly add the amino-modifier ethanol solution to the solution prepared in step (2), set the reaction temperature to 100°C, condensation reflux is required during the reaction, the reaction time is 3 h, and the surface of the nanoparticles obtained after the reaction is complete has a large number of amine groups.

[0098] Step (4) 3.00 g of glyoxal and 0.50 g of ammonium acetate are added to the surface amino-modified nanoparticle aqueous solution obtained in step (3), stirring to completely dissolve, to obtain a delayed organic-inorganic composite nanoparticle crosslinking agent.

[0099] Example 3

[0100] Step (1) 1.00 g of nano-silicon dioxide is added to a three-necked flask, 99.00 g of ultrapure water is added, and then a sodium hydroxide aqueous solution is added dropwise to adjust the pH of the reaction system to 9. 0.04 g of PEG20000 is added and stirred to mix uniformly to prepare a stable dispersion of nanoparticle dispersion liquid.

[0101] Step (2) 3.00 g of γ-glycidoxypropyltrimethoxysilane was dissolved in ice water, stirred until completely dissolved, and the coupling agent aqueous solution was slowly added dropwise to the nanoparticle dispersion prepared in step (1), while stirring was started at a speed of 500 r / min, the reaction temperature was set to 70°C, and the reaction time was 30 min. The surface-grafted modified nanoparticles were obtained after the reaction was completed.

[0102] Step (3) 5.00 g of p-methylaminophenol was dissolved in ethanol, stirred until completely dissolved, and then the amino-modifying agent ethanol solution was slowly added dropwise to the solution prepared in step (2). The reaction temperature was set to 120°C, and the reaction was carried out with condensation refluxing. The reaction time was 2 h. The nanoparticles with a large number of amine groups on the surface were obtained after the reaction was completed.

[0103] Step (4) 4.00 g of malondialdehyde and 1.00 g of ammonium oxalate were added to the aqueous solution of the surface-amino-modified nanoparticles obtained in step (3), and stirred until completely dissolved to obtain a delayed organic-inorganic composite nanocrosslinking agent.

[0104] Example 4

[0105] The nanoparticle dispersion obtained in Examples 1-3 was subjected to particle size testing.

[0106] The test method was as follows: nanoparticle diluent was prepared using ultrapure water, with a concentration of 0.01%, and particle size testing was performed using a Zetasizer Nano-ZSE Malvern particle potential instrument. The test results are shown in Table 1. Figure 1

[0107] Results and analysis: it can be seen from Table 1 that the particle size distribution of the nanosilica, nanometer alumina and nanometer zirconia is between 50-150 nm. Figures 1-3

[0108] Example 5

[0109] The organic-inorganic composite nanocrosslinking agent obtained in Examples 1-3 and a partially hydrolyzed polyacrylamide diluent were mixed to prepare a crosslinked polymer gel profile control agent, and the viscosity was tested.

[0110] The preparation method was as follows:

[0111] The preparation of simulated injection water: the formula of simulated saline was 21.67 g of sodium chloride and 3.33 g of calcium chloride per 1 L of solution.

[0112] Preparation of base solution: 300.00 g of simulated injection water was added to a clean beaker, and 3.00 g of polyacrylamide was slowly added under mechanical stirring. The stirring was continued for 2 h until complete dissolution, and the polyacrylamide base solution with a concentration of 10000 mg / L was obtained.

[0113] ​​Polymer crosslinking system preparation: take 1 100 mL beaker, using simulated mineralized water to prepare 5000 mg / L of polyacrylamide diluent, respectively, to the base fluid each add 0.5% of the organic-inorganic composite nanometer crosslinking agent prepared in example 1-3, stirring uniform, after stirring and mixing uniformly pour into 50 mL glass bottle for sealing, each sample preparation two, one for gel time and viscosity test, one for 90 days, observe dehydration and viscosity. Placed in 30 DEG C temperature constant dry box, record the time when put in, every time interval take out the glass bottle, observe the polymer viscosity change in glass bottle, record the time of polymer solution loses fluidity, namely the polymer gel time, using HAKKE MARS 40 rheometer for viscosity test.

[0114] Polymer blank preparation: take 1 100 mL beaker, using simulated mineralized water to prepare 5000 mg / L of polyacrylamide diluent, stirring and mixing uniformly after pouring into 50 mL glass bottle for sealing, placed in 30 DEG C temperature constant dry box for 7 days, after taking out using HAKKE MARS 40 rheometer for viscosity test.

[0115] Experimental results are as follows table 1:

[0116] Table 1 viscosity test results

[0117]

[0118] Experimental results and analysis: from Figure 4 It can be known that the synthesized delayed organic-inorganic composite nanometer crosslinking agent and polyacrylamide have good compatibility, the mixed system is uniform without precipitation, can crosslink with polyacrylamide, and form a stable three-dimensional structure non-flowing gel; from Figure 5 It can be known that after the organic-inorganic composite nanometer crosslinking agent and polyacrylamide form gel, after 90 days, no dehydration phenomenon occurs, from table 1, it can be seen that the gel is placed for 90 days, and the viscosity retention rate is above 90%. From table 1, it can be seen that by adding different amounts of crosslinking control agent, the crosslinking reaction time of the organic-inorganic composite nanometer crosslinking agent and polyacrylamide is different, the higher the amount of crosslinking control agent, the shorter the gel time, and the higher the viscosity of the gel after gelation. Compared with the blank polyacrylamide solubility, the viscosity of the crosslinked system is obviously increased, and the prepared crosslinked polymer gel can be used as a water shutoff profile control agent.

[0119] Comparative example 1

[0120] The phenolic resin crosslinking agent used in oilfield site and partially hydrolyzed polyacrylamide diluent are mixed to prepare a crosslinked polymer gel profile control agent. The preparation method is the same as above.

[0121] Table 2 viscosity test results

[0122]

[0123] Test results and analysis: from Figure 6 and Table 2, the oil field site using phenolic resin added to polyacrylamide base fluid, mixed evenly, the system is white opaque state, 30℃ oven for 7 days, no crosslinking reaction occurs, polyacrylamide still keep flowing state, and the blank polyacrylamide, the viscosity is not significantly increased. It is shown that under the condition of low temperature 30℃, the activity of phenolic resin is low, which can not react with polyacrylamide to form crosslinked polymer gel.

[0124] Example 6

[0125] The organic-inorganic composite nanometer crosslinking agent obtained in examples 1-3 and partially hydrolyzed polyacrylamide dilute solution were mixed to prepare crosslinked polymer gel profile control agent, and DNQP-1 type oil displacement equipment was used to test water plugging rate.

[0126] Test method is:

[0127] (1) Core water saturation: after purchasing the core according to the design, drying in 105℃ oven for 24h, weighing the dry weight of the core, then vacuumizing the core to saturate with simulated water, weighing the mass of the core after saturated with water, and the difference between the mass of the core before and after saturated with water divided by the density of simulated water is the pore volume of the core.

[0128] (2) Measure permeability: the saturated core was loaded into the core holder, water was injected at a speed of 1mL / min, after the injection pressure was stable, the water phase permeability of the core tube was tested.

[0129] (3) Inject polymer crosslinking system: the designed polymer crosslinking system was injected at a speed of 0.3mL / min, the injection amount was 0.5PV, 1mL of simulated mineralized water was further injected, the inlet and outlet valves of the core were closed, and aging was carried out at 50℃ for 72h.

[0130] (4) Breakthrough pressure gradient determination: after aging was completed, simulated mineralized water was injected at a speed of 0.3mL / min, until the first drop of liquid was dropped at the outlet end, after that, liquid was continuously flowed out, the pressure reading at the inlet section was the breakthrough pressure (MPa).

[0131] (5) Water plugging rate determination: after determining the breakthrough pressure gradient, simulated mineralized water was continuously injected at a speed of 0.3mL / min, the plugged permeability was determined, and the water plugging rate calculation formula was as follows:

[0132]

[0133] In the formula:

[0134] D W Water plugging rate

[0135] K1 - water phase permeability before plugging, pm 2

[0136] K2 - water phase permeability after plugging, pm 2

[0137] The experimental results are as follows:

[0138] Table 3 Water plugging rate test

[0139]

[0140] Experimental results and analysis: As shown in Table 3, the crosslinked polymer gel formed by the crosslinking reaction of the organic-inorganic composite nanometer crosslinking agent and the polyacrylamide prepared by the application has a good plugging effect on the core, and the water plugging rate is more than 95%, which can be applied to water plugging and profile control of medium and low temperature reservoirs.

[0141] The above is only a few embodiments of the application, and does not limit the application in any form. Although the application is disclosed as above with preferred embodiments, it is not intended to limit the application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the application, which are equivalent to equivalent embodiments and belong to the scope of the technical solution.

Claims

1. A nanoparticle with multiple amino active groups, characterized in that, The nanoparticles with polyamino active groups have the structure shown in Formula I: Equation I; In Formula I, A represents nanoparticles; R is selected from one of the structures shown in Equation I-1, Equation I-2, and Equation I-3; Formula I-1; Formula I-2; Formula I-3; The nanoparticles are selected from at least one of nano-alumina, nano-zirconia, and nano-silica.

2. The nanoparticles with multiple amino active groups according to claim 1, characterized in that, The nanoparticles have a particle size of 50~150nm.

3. An organic-inorganic composite crosslinking agent, characterized in that, The organic-inorganic composite crosslinking agent is obtained by combining nanoparticles with multiple amino active groups with a crosslinking regulator; The crosslinking regulator is selected from at least two of furfural, glyoxal, malondialdehyde, ammonium chloride, ammonium acetate, and ammonium oxalate. The nanoparticles having multi-amino active groups are selected from the nanoparticles having multi-amino active groups according to any one of claims 1 to 2.

4. The method for preparing the organic-inorganic composite crosslinking agent according to claim 3, characterized in that, The preparation method includes the following steps: (1) Preparation of nanoparticle dispersion; (2) The nanoparticles in the nanoparticle dispersion were grafted and modified using a linker to obtain grafted and modified nanoparticles; (3) React a mixture containing grafted modified nanoparticles and amino modifier to obtain nanoparticles with multiple amino active groups. (4) The nanoparticles with multiple amino active groups are combined with a crosslinking regulator to obtain the organic-inorganic composite crosslinking agent; The nanoparticles with polyamino active groups have the structure shown in Formula I.

5. The preparation method according to claim 4, characterized in that, In step (1), the mixture I containing nanoparticles, inorganic alkali and dispersant is stirred to obtain a nanoparticle dispersion.

6. The preparation method according to claim 5, characterized in that, The nanoparticles are selected from at least one of nano-alumina, nano-zirconia, and nano-silica.

7. The preparation method according to claim 5, characterized in that, The inorganic base is selected from sodium hydroxide and / or potassium hydroxide.

8. The preparation method according to claim 5, characterized in that, The dispersant is polyethylene glycol with a molecular weight of 10,000 to 20,000.

9. The preparation method according to claim 5, characterized in that, The amount of the dispersant is 0.02wt% to 0.04wt% of the nanoparticles.

10. The preparation method according to claim 5, characterized in that, The pH value of the nanoparticle dispersion is 8-9.

11. The preparation method according to claim 4, characterized in that, In step (2), the mass ratio of the nanoparticles to the binder is 1:1.5~2.

5.

12. The preparation method according to claim 4, characterized in that, In step (2), the linker is γ-glycidoxypropyltrimethoxysilane.

13. The preparation method according to claim 4, characterized in that, In step (2), the grafting modification temperature is 50~70 ℃ and the grafting modification time is 30~60 min.

14. The preparation method according to claim 4, characterized in that, In step (3), the mass ratio of nanoparticles to the amino modifier is 1:3~5.

15. The preparation method according to claim 4, characterized in that, In step (3), the amino modifier is selected from at least one of 3-aminophenol, p-aminophenol, and p-methylaminophenol.

16. The preparation method according to claim 4, characterized in that, In step (3), the reaction temperature is 90~120℃ and the reaction time is 2~4h.

17. The preparation method according to claim 4, characterized in that, In step (4), the crosslinking regulator is selected from at least two of furfural, glyoxal, malondialdehyde, ammonium chloride, ammonium acetate, and ammonium oxalate.

18. The preparation method according to claim 4, characterized in that, In step (4), the mass ratio of nanoparticles to the crosslinking regulator is 1:1.5 to 1:

5.

19. A cross-linked polymer gel profile control agent, characterized in that, The crosslinked polymer gel profiler comprises the organic-inorganic composite crosslinking agent as described in claim 3.

20. The method for preparing the crosslinked polymer gel profile control agent according to claim 19, characterized in that, The preparation method includes: A mixture containing an organic-inorganic composite crosslinking agent and an aqueous solution of polyacrylamide with a mass fraction of 0.3% to 0.5% was reacted to obtain the crosslinked polymer gel profile modifier.

21. The preparation method according to claim 20, characterized in that, The amount of the organic-inorganic composite crosslinking agent is 0.2% to 0.5% of the mass of the polyacrylamide aqueous solution.

22. The preparation method according to claim 20, characterized in that, The reaction temperature is 30~50℃, and the reaction time is 2~7 days.

23. The application of the organic-inorganic composite crosslinking agent according to claim 3 in water shut-off and profile control of low-temperature oil reservoirs; The conditions for the low-temperature reservoir are: 30-50℃.

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