Oilfield profile control water plugging agent and synthesis method and application thereof

Abstract

The invention belongs to the technical field of tertiary oil recovery, and particularly relates to an oil field profile control water plugging agent and a synthesis method and application thereof. The synthesis method comprises the following steps: sequentially adding 1-vinyl-2-pyrrolidone, allyl dimethyl (4-methoxyphenyl) silane, 2-acrylamido-2-methylpropanesulfonic acid, allyl malonic acid, bisphenol A glycerol diacrylic acid, TX-10, hydroxypropyl methyl cellulose, sodium dihydrogen phosphate and deionized water into a reactor, and stirring; adding an initiator solution into the reactor, heating to 45-50 DEG C, continuously keeping the temperature and stirring until the solution becomes viscous, continuously heating to 75-80 DEG C, continuously stirring for 2-3 hours, adjusting the pH to 7-8 by using a sodium hydroxide solution, and cooling to below 40 DEG C to obtain viscous liquid; and drying and granulating the viscous liquid until the particle size is 1-4mm to obtain the product water shutoff agent. The profile control and water plugging agent has the characteristics of high breakthrough pressure gradient and high water plugging rate.

Description

Technical Field

[0001] The invention belongs to the technical field of tertiary oil recovery, and in particular relates to an oilfield profile control and water plugging agent, a synthesis method and application thereof. Background Art

[0002] Water injection development technology is an important means to improve oil recovery and is widely used in major oil fields around the world. With the deepening of water injection development, the problem of water production in oil wells has gradually become prominent. Due to the formation heterogeneity and fluid dynamics effects, the injected water often enters the high permeability layer first, resulting in premature flooding of these layers, while the low permeability layer cannot be effectively mobilized, forming a "water flow short circuit" phenomenon, resulting in premature flooding of these layers. The low permeability layer cannot be effectively mobilized, forming a "dead oil zone", which seriously reduces the recovery rate of the oil field, increases the subsequent processing costs, and poses a potential threat to the environment. Therefore, as an effective technical means, the demand for water plugging agents has emerged, aiming to accurately control the water production of oil wells and ensure the sustainable development of oil fields.

[0003] Water plugging agents can accurately block high permeability layers or water-producing layers, allowing the injected fluid to enter medium and low permeability oil layers in turn, increasing the sweep coefficient and thus improving the recovery rate.

[0004] A good water plugging agent has good dispersibility. After absorbing water and swelling, it is adsorbed on the rock surface and blocks large pores. Generally, there is a phenomenon of water plugging and profile control agent retention in the pore structure. Due to the retention effect, the seepage resistance of the high permeability layer increases, the suction pressure difference between the medium and low permeability layers is increased, and the deep liquid flow is forced to turn and enter the low permeability zone, starting the reservoir with high oil saturation, increasing the suction volume and swept volume of the medium and low permeability layers, realizing deep control and expansion, expanding the swept volume of injected water, improving the water drive development effect, and further achieving the purpose of improving the recovery rate.

[0005] CN102876305B discloses an oil well water plugging agent and an oil well water plugging method, wherein the oil well water plugging agent comprises: anionic surfactant, nonionic-anionic surfactant, C1-C8 fatty alcohol, heavy oil and water, and has the characteristics of strong resistance to high-mineralization water, strong temperature resistance, strong stability, low cost and no pollution to the formation. However, the water plugging agent for large pores in the oil layer needs to have a certain strength, and the molecular weight of the components in the invention is relatively small, the strength of the product is limited, and the plugging effect will be greatly affected, so the application range is limited. Summary of the invention

[0006] The present invention aims at the above-mentioned deficiencies of the prior art and provides an oilfield profile control and water plugging agent and its synthesis method and application. The profile control and water plugging agent of the present invention has the characteristics of high breakthrough pressure gradient and high water plugging rate.

[0007] One of the purposes of the present invention is to disclose an oilfield profile control and water plugging agent, the molecular structure of the oilfield profile control and water plugging agent is as follows:

[0008]

[0009] in:

[0010] a=2500-50000;

[0011] b = 50000-500000;

[0012] c = 25000-500000;

[0013] d = 5000-100000;

[0014] e = 5000-100000;

[0015] f = 2500-50000;

[0016] g = 50000-500000;

[0017] h = 25000-500000;

[0018] i = 5000-100000;

[0019] j=5000-100000.

[0020] Preferably, the viscosity-average molecular weight of the profile control and water plugging agent is 30,000,000-40,000,000.

[0021] Another object of the present invention is to disclose a synthesis method of the above-mentioned profile control and water plugging agent, and the specific steps of the synthesis method are as follows:

[0022] (1) Add 1-vinyl-2-pyrrolidone, allyl dimethyl (4-methoxyphenyl) silane, 2-acrylamido-2-methylpropane sulfonic acid, allyl malonic acid, bisphenol A glycerol diacrylate, TX-10, hydroxypropyl methylcellulose, sodium dihydrogen phosphate, and deionized water to the reactor in sequence, stir at a high speed of 800-1000 rpm until all the raw materials are completely formed into a uniform emulsion, and adjust the pH to 7-8 with sodium hydroxide solution;

[0023] (2) Purge the reactor with nitrogen for 5-10 minutes, and slowly introduce nitrogen in the later stage to ensure that oxygen is isolated as much as possible during the synthesis process; add the initiator solution to the reactor, raise the temperature to 45-50° C., and continue to stir until the solution becomes viscous, continue to raise the temperature to 75-80° C., continue to stir for 2-3 hours, adjust the pH to 7-8 with sodium hydroxide solution, and cool to below 40° C. to obtain a viscous liquid;

[0024] (3) The viscous liquid is dried and granulated into particles with a particle size of 1-4 mm to obtain a water plugging agent product.

[0025] In the present invention, preferably, the molar ratio of allyl dimethyl (4-methoxyphenyl) silane, 2-acrylamido-2-methylpropane sulfonic acid, allyl malonic acid, bisphenol A glycerol diacrylate and 1-vinyl-2-pyrrolidone is 0.5-1:0.1-0.2:0.1-0.2:0.05-0.1:1.

[0026] In the present invention, preferably, in step (1), the mass ratio of TX-10, hydroxypropyl methylcellulose, sodium dihydrogen phosphate, deionized water and 1-vinyl-2-pyrrolidone is 0.1-0.2:0.2-0.4:0.05-0.1:10-15:1.

[0027] In the present invention, preferably, in step (2), the initiator is a mixed solution of persulfate and sodium bisulfite, wherein the concentration of persulfate is 8-12wt%, the concentration of sodium bisulfite is 4-6wt%, and the mass ratio of the initiator to 1-vinyl-2-pyrrolidone is 0.2-0.4:1.

[0028] Preferably, the persulfate is one of ammonium persulfate, sodium persulfate and potassium persulfate.

[0029] The synthetic reaction equation of the profile control and water plugging agent of the present invention is as follows:

[0030]

[0031]

[0032] The third object of the present invention is to disclose the application of the water plugging agent in water plugging and profile control in oil fields.

[0033] The oilfield profile control and water plugging agent of the invention is a high molecular water plugging agent with 1-vinyl-2-pyrrolidone, allyl dimethyl (4-methoxyphenyl) silane, 2-acrylamide-2-methylpropane sulfonic acid, allyl malonic acid and bisphenol A glycerol diacrylic acid as polymerization units. 1-vinyl-2-pyrrolidone is a rigid monomer, which can greatly increase the strength of the product; allyl dimethyl (4-methoxyphenyl) silane contains silicon surfactant and is lipophilic, which can be seamlessly bonded to the rock surface, greatly improving the blockage rate of large pores in the formation and improving the water plugging efficiency; 2-acrylamido-2-methylpropanesulfonic acid and allylmalonic acid contain sulfonic acid and carboxyl anions, which are hydrophilic groups, and can make the product molecules adsorb to the surface of large-pore rock formations to improve the water plugging efficiency; allyl dimethyl (4-methoxyphenyl) silane molecules contain silicon surfactant, which can be seamlessly bonded to the rock surface, greatly improving the blockage rate of large pores in the formation and improving the water plugging efficiency; bisphenol A glycerol diacrylate is a cross-linking agent, which can greatly increase the molecular weight of the product and increase the product viscosity; hydroxypropyl methylcellulose is a dispersant, which can prevent the emulsion droplets of the polymerized product from becoming excessively large, enhance stability, and improve the polymerization effect.

[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0035] (1) The oilfield profile control and water plugging agent of the present invention has a relatively high breakthrough pressure gradient, with the highest breakthrough pressure gradient reaching 38.9 MPa / m for low permeability cores and 23.6 MPa / m for high permeability cores;

[0036] (2) The oilfield profile control and water plugging agent of the present invention has a high water plugging rate, which can reach up to 99.8% for low-permeability cores and 99.6% for high-permeability cores;

[0037] (3) The oilfield profile control and water plugging agent of the present invention has a high water plugging rate after 100PV water flushing, with the highest water plugging rate reaching 98.2% for low-permeability cores and 96.3% for high-permeability cores. DETAILED DESCRIPTION

[0038] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0039] The present invention will be further described below in conjunction with specific embodiments:

[0040] Example 1

[0041] (1) 0.2 mol of 1-vinyl-2-pyrrolidone, 0.1 mol of allyldimethyl (4-methoxyphenyl) silane, 0.04 mol of 2-acrylamido-2-methylpropanesulfonic acid, 0.03 mol of allylmalonic acid, 0.01 mol of bisphenol A glycerol diacrylate, 3.2 g of TX-10, 4.44 g of hydroxypropyl methylcellulose, 1.11 g of sodium dihydrogen phosphate, and 222 g of deionized water were added to the reactor in sequence, and stirred at 800 rpm until all the raw materials were completely formed into a uniform emulsion, and the pH was adjusted to 7-8 with sodium hydroxide solution.

[0042] (2) The reactor was purged with nitrogen for 5 min, and nitrogen was slowly introduced in the later stage to ensure that oxygen was isolated as much as possible during the synthesis process. 4.44 g of initiator solution was added to the reactor, the initiator contained 12 wt% of sodium persulfate and 6 wt% of sodium bisulfite, the temperature was raised to 45°C, and the mixture was kept warm and stirred until the solution became viscous, and the temperature was further raised to 75°C, and the stirring was continued for 3 h, the pH was adjusted to 7-8 with sodium hydroxide solution, and the temperature was lowered to below 40°C to obtain a viscous liquid.

[0043] (3) The viscous liquid is dried and granulated into particles with a particle size of 1-4 mm to obtain a water plugging agent product.

[0044] Example 2

[0045] (1) 0.2 mol of 1-vinyl-2-pyrrolidone, 0.12 mol of allyldimethyl (4-methoxyphenyl) silane, 0.036 mol of 2-acrylamido-2-methylpropanesulfonic acid, 0.04 mol of allylmalonic acid, 0.012 mol of bisphenol A glycerol diacrylate, 2.22 g of TX-10, 4.86 g of hydroxypropyl methylcellulose, 1.38 g of sodium dihydrogen phosphate, and 252 g of deionized water were added to the reactor in sequence, and stirred at 800 rpm until all the raw materials were completely formed into a uniform emulsion, and the pH was adjusted to 7-8 with sodium hydroxide solution.

[0046] (2) The reactor was purged with nitrogen for 6 min, and nitrogen was slowly introduced in the later stage to ensure that oxygen was isolated as much as possible during the synthesis process. 4.88 g of initiator solution was added to the reactor, the initiator contained 8 wt % of sodium persulfate and 5 wt % of sodium bisulfite, the temperature was raised to 50° C., and the mixture was kept warm and stirred until the solution became viscous, and the temperature was further raised to 80° C., and the mixture was stirred for 2 h. The pH was adjusted to 7-8 with sodium hydroxide solution, and the temperature was lowered to below 40° C. to obtain a viscous liquid.

[0047] (3) The viscous liquid is dried and granulated into particles with a particle size of 1-4 mm to obtain a water plugging agent product.

[0048] Example 3

[0049] (1) 0.2 mol of 1-vinyl-2-pyrrolidone, 0.14 mol of allyldimethyl (4-methoxyphenyl) silane, 0.033 mol of 2-acrylamido-2-methylpropanesulfonic acid, 0.027 mol of allylmalonic acid, 0.013 mol of bisphenol A glycerol diacrylate, 2.56 g of TX-10, 5.77 g of hydroxypropyl methylcellulose, 1.56 g of sodium dihydrogen phosphate, and 242 g of deionized water were added to the reactor in sequence, and stirred at 900 rpm until all the raw materials were completely formed into a uniform emulsion, and the pH was adjusted to 7-8 with sodium hydroxide solution.

[0050] (2) The reactor was purged with nitrogen for 8 minutes, and nitrogen was slowly introduced in the later stage to ensure that oxygen was isolated as much as possible during the synthesis process. 5.4 g of initiator solution was added to the reactor, the initiator contained 10 wt% of sodium persulfate and 5 wt% of sodium bisulfite, the temperature was raised to 45°C, and the mixture was kept warm and stirred until the solution became viscous, and the temperature was further raised to 78°C, and the stirring was continued for 2.5 hours, the pH was adjusted to 7-8 with sodium hydroxide solution, and the temperature was lowered to below 40°C to obtain a viscous liquid.

[0051] (3) The viscous liquid is dried and granulated into particles with a particle size of 1-4 mm to obtain a water plugging agent product.

[0052] Example 4

[0053] (1) 0.2 mol 1-vinyl-2-pyrrolidone, 0.15 mol allyldimethyl (4-methoxyphenyl) silane, 0.03 mol 2-acrylamido-2-methylpropanesulfonic acid, 0.025 mol allylmalonic acid, 0.015 mol bisphenol A glycerol diacrylate, 3.1 g TX-10, 6.14 g hydroxypropyl methylcellulose, 1.88 g sodium dihydrogen phosphate, and 268 g deionized water were added to the reactor in sequence, and stirred at 900 rpm until all the raw materials were completely formed into a uniform emulsion, and the pH was adjusted to 7-8 with sodium hydroxide solution.

[0054] (2) The reactor was purged with nitrogen for 10 min, and nitrogen was slowly introduced in the later stage to ensure that oxygen was isolated as much as possible during the synthesis process. 6.4 g of initiator solution was added to the reactor, the initiator contained 11 wt% of ammonium persulfate and 5 wt% of sodium bisulfite, the temperature was raised to 48°C, and the mixture was stirred continuously until the solution became viscous, the temperature was further raised to 77°C, and stirring was continued for 2.5 h, the pH was adjusted to 7-8 with sodium hydroxide solution, and the temperature was lowered to below 40°C to obtain a viscous liquid.

[0055] (3) The viscous liquid is dried and granulated into particles with a particle size of 1-4 mm to obtain a water plugging agent product.

[0056] Example 5

[0057] (1) 0.2 mol of 1-vinyl-2-pyrrolidone, 0.16 mol of allyldimethyl (4-methoxyphenyl) silane, 0.028 mol of 2-acrylamido-2-methylpropanesulfonic acid, 0.028 mol of allylmalonic acid, 0.017 mol of bisphenol A glycerol diacrylate, 3.4 g of TX-10, 6.88 g of hydroxypropyl methylcellulose, 2.01 g of sodium dihydrogen phosphate, and 298 g of deionized water were added to the reactor in sequence, and stirred at 1000 rpm until all the raw materials were completely formed into a uniform emulsion, and the pH was adjusted to 7-8 with sodium hydroxide solution.

[0058] (2) The reactor was purged with nitrogen for 8 minutes, and nitrogen was slowly introduced in the later stage to ensure that oxygen was isolated as much as possible during the synthesis process. 7.44 g of initiator solution was added to the reactor, the initiator contained 11 wt% of ammonium persulfate and 4 wt% of sodium bisulfite, the temperature was raised to 50°C, and the solution was continuously stirred until it became viscous, and the temperature was further raised to 80°C, and stirring was continued for 2 hours, and the pH was adjusted to 7-8 with sodium hydroxide solution, and the temperature was lowered to below 40°C to obtain a viscous liquid.

[0059] (3) The viscous liquid is dried and granulated into particles with a particle size of 1-4 mm to obtain a water plugging agent product.

[0060] Example 6

[0061] (1) 0.2 mol of 1-vinyl-2-pyrrolidone, 0.18 mol of allyldimethyl (4-methoxyphenyl) silane, 0.025 mol of 2-acrylamido-2-methylpropanesulfonic acid, 0.033 mol of allylmalonic acid, 0.018 mol of bisphenol A glycerol diacrylate, 4.44 g of TX-10, 7.29 g of hydroxypropyl methylcellulose, 2.22 g of sodium dihydrogen phosphate, and 312 g of deionized water were added to the reactor in sequence, and stirred at 850 rpm until all the raw materials were completely formed into a uniform emulsion, and the pH was adjusted to 7-8 with sodium hydroxide solution.

[0062] (2) The reactor was purged with nitrogen for 5 min, and nitrogen was slowly introduced in the later stage to ensure that oxygen was isolated as much as possible during the synthesis process. 7.98 g of initiator solution was added to the reactor, the initiator contained 8 wt% potassium persulfate and 4 wt% sodium bisulfite, the temperature was raised to 45°C, and the mixture was stirred continuously until the solution became viscous, the temperature was further raised to 75°C, and stirring was continued for 3 h, the pH was adjusted to 7-8 with sodium hydroxide solution, and the temperature was lowered to below 40°C to obtain a viscous liquid.

[0063] (3) The viscous liquid is dried and granulated into particles with a particle size of 1-4 mm to obtain a water plugging agent product.

[0064] Example 7

[0065] (1) 0.2 mol of 1-vinyl-2-pyrrolidone, 0.2 mol of allyldimethyl (4-methoxyphenyl) silane, 0.02 mol of 2-acrylamido-2-methylpropanesulfonic acid, 0.038 mol of allylmalonic acid, 0.02 mol of bisphenol A glycerol diacrylate, 4.2 g of TX-10, 8.88 g of hydroxypropyl methylcellulose, 1.96 g of sodium dihydrogen phosphate, and 333 g of deionized water were added to the reactor in sequence, and stirred at 950 rpm until all the raw materials were completely formed into a uniform emulsion, and the pH was adjusted to 7-8 with sodium hydroxide solution.

[0066] (2) The reactor was purged with nitrogen for 5 min, and nitrogen was slowly introduced in the later stage to ensure that oxygen was isolated as much as possible during the synthesis process. 8.88 g of initiator solution was added to the reactor, the initiator contained 8 wt% potassium persulfate and 6 wt% sodium bisulfite, the temperature was raised to 48°C, and the mixture was kept warm and stirred until the solution became viscous, and the temperature was further raised to 78°C, and the stirring was continued for 2.6 h, the pH was adjusted to 7-8 with sodium hydroxide solution, and the temperature was lowered to below 40°C to obtain a viscous liquid.

[0067] (3) The viscous liquid is dried and granulated into particles with a particle size of 1-4 mm to obtain a water plugging agent product.

[0068] Example 8 Performance Test

[0069] The water plugging agent (Examples 1-7) of the present invention was configured into a product with a concentration of 5000 mg / L. At 80°C, the breakthrough pressure gradient, water plugging rate, and water plugging rate after 100PV water flushing were tested with reference to the method in Q / SH1020 1493-2019 "Performance Indicators and Test Methods of Gel-Based Water Plugging and Profile Control Agents".

[0070] The core used in the test is 0.24μm 2 Low permeability core and 1.16μm 2 The high permeability cores were all 4.6 cm long. The test results are shown in Table 1.

[0071] A comparative experiment was conducted using the water plugging and profile control agent produced by Shengli Oilfield Shengli Chemical Co., Ltd.

[0072] Table 1 Test results of breakthrough pressure gradient, water plugging rate, and water plugging rate after 100PV water flushing

[0073]

[0074] From Table 1 we can see that:

[0075] (1) The oilfield profile control and water plugging agent of the present invention (Examples 1-7) has a relatively high breakthrough pressure gradient. The breakthrough pressure gradient of the low permeability core reaches 37 MPa / m or more, and the highest reaches 38.9 MPa / m (Example 5). The breakthrough pressure gradient of the high permeability core reaches 20 MPa / m or more, and the highest reaches 23.6 MPa / m (Example 1); while the breakthrough pressure gradients of the low permeability core and the high permeability core of the comparative example are 10.6 MPa / m and 6.3 MPa / m, respectively, which are significantly lower than those of the present invention;

[0076] (2) The oilfield profile control and water plugging agent of the present invention (Examples 1-7) has a high water plugging rate. The water plugging rate of the low permeability core is 99.2% or more, and the highest is 99.8% (Example 7). The water plugging rate of the high permeability core is 98% or more, and the highest is 99.6% (Example 7). The water plugging rates of the low permeability core and the high permeability core of the comparative example are 95.9% and 94.2%, respectively, which are significantly lower than those of the present invention.

[0077] (3) The oilfield profile control and water plugging agent of the present invention (Examples 1-7) has a relatively high water plugging rate after 100PV water flushing. The water plugging rate of the low permeability core after 100PV water flushing is greater than 97%, with the highest reaching 98.2% (Example 7), and the water plugging rate of the high permeability core after 100PV water flushing is greater than 95%, with the highest reaching 96.3% (Example 7); while the water plugging rates of the low permeability core and the high permeability core of the comparative example after 100PV water flushing are 90.3% and 88.8%, respectively, which are significantly lower than those of the present invention;

[0078] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for synthesizing an oilfield profile control and water plugging agent, characterized in that: The specific steps of the synthetic method are as follows: (1) Add 1-vinyl-2-pyrrolidone, allyl dimethyl (4-methoxyphenyl) silane, 2-acrylamido-2-methylpropane sulfonic acid, allyl malonic acid, bisphenol A glycerol diacrylate, TX-10, hydroxypropyl methylcellulose, sodium dihydrogen phosphate, and deionized water to the reactor in sequence, stir at a high speed of 800-1000 rpm until all the raw materials are completely formed into a uniform emulsion, and adjust the pH to 7-8 with sodium hydroxide solution; (2) Purge the reactor with nitrogen for 5-10 minutes, and slowly introduce nitrogen in the later stage to ensure that oxygen is isolated as much as possible during the synthesis process; add the initiator solution to the reactor, raise the temperature to 45-50° C., and continue to stir until the solution becomes viscous, continue to raise the temperature to 75-80° C., continue to stir for 2-3 hours, adjust the pH to 7-8 with sodium hydroxide solution, and cool to below 40° C. to obtain a viscous liquid; (3) drying and granulating the viscous liquid to obtain a water plugging agent with a particle size of 1-4 mm; The molar ratio of allyl dimethyl (4-methoxyphenyl) silane, 2-acrylamide-2-methylpropane sulfonic acid, allyl malonic acid, bisphenol A glycerol diacrylate and 1-vinyl-2-pyrrolidone is 0.5-1:0.1-0.2:0.1-0.2:0.05-0.1:

1.

2. The method for synthesizing an oilfield profile control and water plugging agent according to claim 1, characterized in that: In step (1), the mass ratio of TX-10, hydroxypropyl methylcellulose, sodium dihydrogen phosphate, deionized water and 1-vinyl-2-pyrrolidone is 0.1-0.2:0.2-0.4:0.05-0.1:10-15:

1.

3. The method for synthesizing an oilfield profile control and water plugging agent according to claim 1, characterized in that: In step (2), the initiator is a mixed solution of persulfate and sodium bisulfite.

4. The method for synthesizing an oilfield profile control and water plugging agent according to claim 3, characterized in that: The concentration of the persulfate is 8-12 wt %, and the concentration of the sodium bisulfite is 4-6 wt %.

5. A method for synthesizing an oilfield profile control and water plugging agent according to claim 1 or 3, characterized in that: The mass ratio of the initiator to 1-vinyl-2-pyrrolidone is 0.2-0.4:

1.

6. The method for synthesizing an oilfield profile control and water plugging agent according to claim 3, characterized in that: The persulfate is one of ammonium persulfate, sodium persulfate and potassium persulfate.

7. An oilfield profile control and water plugging agent, characterized in that: The molecular structure of the oilfield profile control and water plugging agent is as follows: in: a＝2500-50000； b＝50000-500000； c＝25000-500000； d＝5000-100000； e＝5000-100000； f＝2500-50000； g＝50000-500000； h＝25000-500000； i＝5000-100000； j＝5000-100000。 8. The oilfield profile control and water plugging agent according to claim 7, characterized in that: The viscosity average molecular weight of the profile control and water plugging agent is 30,000,000-40,000,000.

9. Use of the water plugging agent according to claim 7 or 8 in water plugging and profile control in oil fields.

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