CN116640562A - Water shutoff material, preparation method thereof, foam water shutoff agent and application thereof - Google Patents

Abstract

The invention relates to the field of oil exploitation, and discloses a water plugging material, a preparation method thereof, a foam type water plugging agent and application thereof. The water plugging material has excellent selectivity to oil/water, has strong plugging capability, can realize the effect of plugging water and not plugging oil, is suitable for exploitation of water displacement reservoirs in the ultra-high water-containing period, and is particularly suitable for high-temperature and high-salt conditions.

Description

Water blocking material and its preparation method, foam type water blocking agent and their application

technical field

The present invention relates to the field of oil reservoir exploitation, in particular to a water shutoff material, a method for preparing the water shutoff material and the water shutoff material prepared by the method, and the water shutoff material is used in the preparation of a foam-type water shutoff agent The application in the present invention is a foam type water shutoff agent, and the application of the water shutoff material or foam type water shutoff agent in oil reservoir exploitation.

Background technique

Water plugging technology is of great significance to increase the productivity of oil wells in water flooding reservoirs in the ultra-high water cut period, and it is an important measure for inefficient wells to create benefits and increase efficiency under low oil prices. In the ultra-high water cut stage, due to severe water flooding of oil wells and complicated oil-water relationship, traditional plugging agents not only block water, but also greatly reduce the permeability of oil phase, resulting in poor field implementation effect.

Polymer water shutoff agents are widely used water shutoff agents at present, and are mainly divided into polymer phase permeability regulators and polymer gel shutoff agents. The main difference between the two is that the interpenetration modifier is mainly a long-chain polymer molecule, relying on the polymer molecular chain to stretch in the water phase and shrink in the oil phase, forming a dragging effect on the water phase and reducing the water phase penetration rate, the system will not cause physical plugging of the pore volume; the polymer gel water blocking agent relies on the change of the effective movable volume under the action of oil and water to make the oil-water phase permeability decrease unevenly, but this treatment method will The physical blockage of the oil-water channel will result in a decrease in the seepage capacity of the porous medium. The water production of the oil well will be greatly reduced and the oil production capacity will also be reduced. Improper treatment will cause the liquid production rate to be too low and reduce crude oil production.

Several hydrophobically modified polydimethylaminoethyl methacrylate, dimethylaminoethyl methacrylate and isooctyl methacrylate copolymers have been studied abroad as blocking agents, and the results show that: 16-18 carbon Hydrophobic-modified polymers can effectively reduce the permeability of salt water. The polydimethylaminoethyl methacrylate modified with 10 carbon hydrophobic groups has no obvious effect on water blocking, and the permeability decrease rate is up to 25%; the polymethylaminoethyl methacrylate modified with 16 carbon hydrophobic groups Dimethylaminoethyl acrylate reduces the water permeability by at least 80%, has little damage to the oil layer, and has good oil-water selectivity, but is expensive.

At present, domestic and foreign selective water shutoff agents and deep profile control technologies are becoming more and more perfect, and great progress has been made in the research and development of selective water shutoff materials, construction technology and other technologies. Changes, especially in the later stage of development, the long-term use of water shutoff materials makes the contradiction of reservoir development more prominent. According to the characteristics of selective water shutoff materials, the actual development experience of oilfields is summarized, and the current selective water shutoff agents must be overcome. Technical problems, in order to develop new technologies in a targeted manner to adapt to special oil fields and improve the water shutoff effect of selective systems.

The research on selective water shutoff agents is the result of the development of material technology. The understanding of material microstructure and synthetic modification technology based on the molecular level will be the key to the research of selective water shutoff agents; the research on the relationship between plugging agents and rocks under real reservoir conditions The interaction mechanism and deduction of the water shutoff effect from the molecular level are the basis for the research and evaluation of selective plugging agents.

To sum up, most of the selective plugging agents currently used in oil well water plugging are water-soluble polymers such as polyacrylamide and its derivatives to generate gel or jelly in the formation to seal formation water, or use oil The base plugging agent gels or solidifies when it meets water to block water channeling. However, due to its poor selectivity, it will greatly reduce the oil phase permeability while blocking water, resulting in low liquid after plugging, which restricts the application of oil well water plugging technology. . Therefore, it is of great significance to develop a new type of high-selectivity water shutoff material to realize water shutoff but not oil shutoff in the oil layer, which is of great significance to improve the productivity of oil wells in the ultra-high water cut period.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned problems and defects in the prior art, and provide a water blocking material and its preparation method and application. The foam type water blocking agent prepared by the water blocking material has a strong water blocking ability, And basically no oil clogging.

The first aspect of the present invention provides a kind of water shutoff material, and this water shutoff material contains polymer colloid and foaming agent, and described polymer colloid is in complexing agent, accelerator, crosslinking agent, initiator and as solvent In the presence of water, monomer A and monomer B are polymerized and prepared; wherein, the monomer A is acrylamide; the monomer B is selected from isooctyl methacrylate, tert-butyl methacrylate At least one of ester, N,N-dimethylacrylamide and methacrylamide;

Based on 100 parts by weight of the total weight of monomer A and monomer B, the amount of monomer A used is 60-95 parts by weight, and the amount of monomer B used is 5-40 parts by weight.

A second aspect of the present invention provides a method for preparing a water blocking material, wherein the preparation method includes the following steps:

(1) Mix monomer A, monomer B and water to form an aqueous solution;

(2) mixing a complexing agent, an accelerator and a crosslinking agent with the aqueous solution to obtain a mixed solution;

(3) the mixed solution obtained in step (2) is polymerized in the presence of an initiator;

(4) mixing the polymer colloid obtained in step (3) with a foaming agent to obtain a water blocking material;

Wherein, the monomer A is acrylamide; the monomer B is selected from at least one of isooctyl methacrylate, tert-butyl methacrylate, N,N-dimethylacrylamide and methacrylamide kind;

Based on 100 parts by weight of the total weight of monomer A and monomer B, the amount of monomer A used is 60-95 parts by weight, and the amount of monomer B used is 5-40 parts by weight.

The third aspect of the present invention provides a water blocking material prepared by the method described above.

The fourth aspect of the present invention provides the application of the above-mentioned water shutoff material in the preparation of foam water shutoff agent.

The fifth aspect of the present invention provides a foam-type water shutoff agent, which contains the above-mentioned water shutoff material.

The sixth aspect of the present invention provides the application of the above-mentioned water shutoff material or foam water shutoff agent in oil reservoir production.

Through the above technical solution, the water shutoff material with high selectivity provided by the present invention can be mixed with on-site water according to the field demand of the oil field, and then formed into a foam-type water shutoff agent through a foam fluid device. The foam-type water blocking agent has a strong plugging ability in the water phase of the formation, which can greatly reduce the permeability of the water phase, while the foam in the oil phase of the formation will break when it encounters crude oil in the formation, reducing the impact on the oil phase. The influence of permeability, so as to achieve the effect of selective water plugging and not oil plugging, provide measures for inefficient wells to create benefits and increase efficiency under low oil prices, and provide technical support for increasing oil well productivity during ultra-high water cut periods.

The water shutoff material and the corresponding water shutoff agent of the present invention are suitable for the development of water drive reservoirs in the ultra-high water cut period, especially for high temperature (eg 90°C) and high salinity conditions (eg 100,000mg/L).

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

Detailed ways

Neither the endpoints nor any values of the ranges disclosed herein are limited to such precise ranges or values, and these ranges or values are understood to include values approaching these ranges or values. For numerical ranges, between the endpoints of each range, between the endpoints of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, these values Ranges should be considered as specifically disclosed herein.

Most of the selective plugging agents currently used for oil well water plugging are water-soluble polymers such as polyacrylamide and its derivatives to generate gel or jelly in the formation to block formation water, or oil-based plugging agents When it encounters water, it will form gel or solidify to block the channel of water channeling, but due to its poor selectivity, it will greatly reduce the oil phase permeability while blocking water, resulting in the defect of low liquid after blocking. The inventors of the present invention have found through a large number of experiments that the water shutoff material according to the present invention can achieve selective water shutoff after being mixed with on-site water according to the field demand of the oil field, and then formed into a foam-type water shutoff agent through a foam fluid device. The effect of not clogging oil.

The first aspect of the present invention provides a water blocking material, wherein the water blocking material contains a polymer colloid and a foaming agent, wherein the polymer colloid is a complexing agent, an accelerator, a crosslinking agent, an initiator In the presence of water as a solvent, monomer A and monomer B are polymerized and prepared, wherein the monomer A is acrylamide; the monomer B is selected from the group consisting of isooctyl methacrylate, methyl At least one of tert-butyl acrylate, N,N-dimethylacrylamide and methacrylamide;

Based on 100 parts by weight of the total weight of monomer A and monomer B, the amount of monomer A used is 60-95 parts by weight, and the amount of monomer B used is 5-40 parts by weight.

According to the present invention, based on the total weight of 100 parts by weight of the monomer A and the monomer B, the amount of the monomer A is 60-95 parts by weight, such as 60, 65, 70, 75 , 80, 85, 86, 88, 90, 92, 94, 95 parts by weight and any range formed between any two values, the amount of monomer B is 5-40 parts by weight, such as 5, 6 , 8, 10, 12, 14, 15, 20, 25, 30, 35, 40 parts by weight and any range formed between any two values; preferably, with 100 parts by weight of the monomer A and the Based on the total weight of the monomer B, the amount of the monomer A is 75-94 parts by weight, and the amount of the monomer B is 6-25 parts by weight; more preferably, with 100 parts by weight of the monomer Based on the total weight of the monomer A and the monomer B, the amount of the monomer A is 85-92 parts by weight, and the amount of the monomer B is 8-15 parts by weight. In the preferred case, the foam-type water shutoff agent can have a better selective water shutoff but not oil shutoff effect.

In the present invention, the monomer A and the monomer B can be obtained commercially or synthesized by methods of the prior art.

According to the present invention, preferably, based on the total weight of the monomer A and the monomer B, the complexing agent is used in an amount of 0.005-0.5% by weight, such as 0.005, 0.01, 0.02, 0.04, 0.06, 0.08, 0.1, 0.2, 0.5% by weight and any range between any two values, more preferably 0.01-0.1% by weight.

According to the present invention, the complexing agent is preferably ethylenediaminetetraacetic acid salt, such as disodium EDTA or dipotassium EDTA. In the preferred case, the foam-type water shutoff agent can have a better selective water shutoff but not oil shutoff effect.

Preferably, the complexing agent is provided in the form of an aqueous solution. The concentration of the complexing agent in the complexing agent aqueous solution is preferably 0.5-2% by weight.

According to the present invention, preferably, based on the total weight of the monomer A and the monomer B, the amount of the accelerator is 0.005-0.5% by weight, such as 0.005, 0.01, 0.02, 0.04, 0.06 , 0.08, 0.1, 0.2, 0.5% by weight and any range between any two values, more preferably 0.01-0.1% by weight.

According to the present invention, the accelerator is preferably a thiosemicarbazide. In the preferred case, the foam-type water shutoff agent can have a better selective water shutoff but not oil shutoff effect.

According to the present invention, preferably, based on the total weight of the monomer A and the monomer B, the amount of the crosslinking agent is 0.01-0.4% by weight, such as 0.01, 0.02, 0.04, 0.06, 0.08, 0.1, 0.12, 0.15, 0.2, 0.4% by weight and any range composed between any two values, more preferably 0.02-0.15% by weight.

According to the present invention, the crosslinking agent is preferably N,N'-methylenebisacrylamide. In the preferred case, the foam-type water shutoff agent can have a better selective water shutoff but not oil shutoff effect.

According to the present invention, preferably, based on the total weight of the monomer A and the monomer B, the total amount of the initiator is 0.005-0.5% by weight, such as 0.005, 0.01, 0.02, 0.04, 0.06, 0.08, 0.1, 0.2, 0.5% by weight and any range between any two values, more preferably 0.015-0.15% by weight.

According to the present invention, the initiator is preferably a water-soluble initiator; preferably, the water-soluble initiator is a persulfate-sulfite redox initiation system. In the preferred case, the foam-type water shutoff agent can have a better selective water shutoff but not oil shutoff effect.

Preferably, based on the total amount of the monomer A and the monomer B, the amount of the persulfate is 0.01-0.1% by weight, such as 0.01, 0.02, 0.04, 0.06, 0.08, 0.1% by weight % and any range between any two values, the amount of sulfite is 0.005-0.05% by weight, such as 0.005, 0.01, 0.02, 0.04, 0.05% by weight and any two values any range. In the preferred case, the foam-type water shutoff agent can have a better selective water shutoff but not oil shutoff effect.

It should be understood that the amount of the initiator is based on the weight of the active ingredients, such as the total mass of persulfate and sulfite.

Wherein, the persulfate is preferably at least one selected from ammonium persulfate, potassium persulfate and sodium persulfate.

Preferably, the persulfate is provided in the form of an aqueous solution. Wherein, the persulfate concentration in the persulfate aqueous solution is 0.1-0.4% by weight.

Wherein, the sulfite is preferably sodium sulfite or potassium sulfite.

Preferably, the sulfite is provided in the form of an aqueous solution. Wherein, the concentration of sulfite in the sulfite aqueous solution is 0.05-0.2% by weight.

According to the present invention, preferably, based on the total weight of the monomer A and the monomer B, the foaming agent is used in an amount of 10-40% by weight, such as 10, 15, 20, 25, 30, 35, 40% by weight and any range between any two values, more preferably 10-20% by weight.

According to the present invention, the foaming agent is preferably cocamidopropyl betaine (CAB-35) and/or lauramidopropyl betaine (LAB-35). In the preferred case, the foam-type water shutoff agent can have a better selective water shutoff but not oil shutoff effect.

When the foaming agent is cocamidopropyl betaine (CAB-35) and lauryl amidopropyl betaine (LAB-35), the cocoamidopropyl betaine (CAB-35) and The ratio of lauryl amidopropyl betaine (LAB-35) is preferably 1:(1-3); more preferably 1:(1-2).

Each of the above components can be obtained commercially.

According to the present invention, the type of the water is not particularly limited, and may be distilled water, tap water, ultrapure water and water existing in nature.

In a preferred embodiment of the present invention, the monomer A is acrylamide; the monomer B is selected from isooctyl methacrylate, tert-butyl methacrylate, N,N-dimethylpropylene At least one of amide and methacrylamide; the complexing agent is ethylenediamine tetraacetate; the accelerator is thiosemicarbazide; the crosslinking agent is N,N'-methylene Bisacrylamide; The initiator is the redox initiation system of persulfate-sulfite; The foaming agent is cocamidopropyl betaine and/or lauryl amidopropyl betaine; In the specific In the case of the composition, the synergy between the various components can further improve the selective water blocking and not oil blocking effect of the foam type water blocking agent.

The second aspect of the present invention provides a kind of preparation method of water blocking material, and this preparation method comprises the following steps:

(1) Mix monomer A, monomer B and water to form an aqueous solution;

(2) mixing a complexing agent, an accelerator and a crosslinking agent with the aqueous solution to obtain a mixed solution;

(3) the mixed solution obtained in step (2) is polymerized in the presence of an initiator;

(4) mixing the polymer colloid obtained in step (3) with a foaming agent to obtain a water blocking material;

Wherein, the monomer A is acrylamide; the monomer B is 2-acrylamido-2-methylpropanesulfonic acid and/or vinylpyrrolidone;

Based on 100 parts by weight of the total weight of monomer A and monomer B, the amount of monomer A used is 60-95 parts by weight, and the amount of monomer B used is 5-40 parts by weight.

The above mentioned polymerization reaction of the present invention adopts the mode of solution polymerization.

Wherein, the types and amounts of the materials involved have been described in detail in the first aspect, and will not be repeated here.

Wherein, in step (1), preferably, the total content of monomer A and monomer B in the aqueous solution is 20-40% by weight.

According to the preparation method of the present invention, preferably, in step (1), the pH value of the aqueous solution is 6-10 (such as 6, 7, 8, 9, 10 and any composition between any two values). range); more preferably 6-8.

Described pH value can be obtained by adding pH value adjusting agent to aqueous solution or water, and described pH value adjusting agent can be various pH value adjusting agents conventional in this area, for example can be sodium hydroxide, sodium carbonate, potassium carbonate and ammoniacal liquor At least one of them is preferably sodium hydroxide and/or sodium carbonate.

According to the present invention, in step (3), the conditions of the polymerization reaction include: the temperature is 0-25°C (such as 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 , 25°C and any range between any two values), preferably 0-10°C, and the time is 5-10 hours (such as 5, 6, 7, 8, 9, 10 hours and any two values Any range of compositions between), preferably 6-8 hours.

The polymerization reaction can also be carried out in the presence of a protective gas, preferably nitrogen. For example, nitrogen can be introduced before and/or during the polymerization.

The polymerization reaction can be carried out in a reaction vessel commonly used in the art, and the reaction vessel can be a polymerization bottle.

According to the present invention, after the polymer colloid is mixed with the foaming agent, it can also be processed by granulation, drying, crushing and sieving to obtain the water blocking material product.

According to the present invention, the granulation method can be a conventional granulation method in the field, such as granulation by a granulator.

According to the present invention, drying, pulverizing and sieving can all be conventional operations in the field, and those skilled in the art can select according to needs.

According to a preferred embodiment of the present invention, the preparation method of the water blocking material comprises the following steps:

Step 1: Mix monomer A, monomer B and water to form an aqueous solution, and adjust the pH of the aqueous solution to 6-10 with alkali;

Step 2: Add complexing agent, accelerator and crosslinking agent to the aqueous solution obtained in step 1 to obtain a mixed solution;

Step 3: At a temperature of 0-25°C, blow nitrogen into the mixture for 10-30 minutes, add the initiator, and after blowing nitrogen to make it evenly mixed, seal and polymerize for 5-10 hours to obtain a polymer colloid;

Step 4: Mix the polymer colloid and foaming agent evenly, and obtain the water blocking material after granulation, drying and crushing.

The third aspect of the present invention provides a water blocking material prepared by the method described above.

The fourth aspect of the present invention provides the application of the above-mentioned water shutoff material in the preparation of foam water shutoff agent.

The fifth aspect of the present invention provides a foam-type water shutoff agent, which contains the above-mentioned water shutoff material.

According to the present invention, the water shutoff material can be mixed with the oil field water to form a foam water shutoff agent through a foam fluid device.

Wherein, the water may be oilfield on-site water.

Preferably, the content of the water blocking material in the foam type water blocking agent is 0.1-0.5% by weight, preferably 0.1-0.2% by weight.

Wherein, the foam fluid device can be purchased from Suzhou Ansu Fluid Technology Co., Ltd., model LP3310.

The sixth aspect of the present invention provides the application of the above-mentioned water shutoff material or foam water shutoff agent in oil reservoir production.

In the present invention, the environmental conditions of the oil field may include: the temperature is 40-130°C, preferably 70-110°C, more preferably 95-110°C.

The salinity of the oilfield water may be 100-200,000 mg/L, preferably 10,000-150,000 mg/L, more preferably 60,000-150,000 mg/L.

The present invention greatly increases the heat-resistant and salt-resistant properties of the water blocking material by introducing functional monomers into the acrylamide copolymer, and introduces a cross-linking agent to prepare a micro-cross-linked polymer colloid, which is mixed with a foaming agent Finally, the water blocking material is made through granulation, drying, crushing and other operations. After the water blocking material is prepared with on-site water, it is finally prepared by a foam fluid device to form a foam water blocking agent. The foam-type water blocking agent has a strong plugging ability in the water phase of the formation, which can greatly reduce the permeability of the water phase, while the foam in the oil phase of the formation will break when it encounters crude oil in the formation, reducing the impact on the oil phase. The influence of permeability, so as to achieve the effect of selective water plugging and not oil plugging, provide measures for inefficient wells to create benefits and increase efficiency under low oil prices, and provide technical support for increasing oil well productivity during ultra-high water cut periods.

The present invention will be described in detail below by way of examples.

Unless otherwise specified, the reagents and materials involved in the examples were obtained commercially.

In the following examples, the test methods involved are as follows:

The plugging rate is carried out on the core flow test device according to the plugging rate test procedure in the "Laboratory Test Method for Bridging and Plugging Materials for Drilling Fluid" SY/T5840-2007. specifically:

Determination of water shutoff rate: Put the artificial core into the core holder, first saturate it with water, measure its pore volume PV and water phase permeability (K _w1 ), then inject 1.0PV water shutoff agent, and maintain at 95°C for 24h After that, measure the permeability (K _w2 ) after adding the water blocking agent with water, and the ratio of K _w2 to K _w1 (K _w2 /K _w1 ) is the water blocking rate.

Determination of oil plugging rate: put the artificial core into the core holder, first saturate it with oil, measure its pore volume PV and oil phase permeability (K _o1 ), then inject 1.0PV water blocking agent, and maintain it at 95°C After 24 hours, use oil to measure the permeability (K _o2 ) after adding the water shutoff agent, and the (K _o2 /K _o1 ) of K _o2 and K _o1 is the oil shutoff rate.

Determination of erosion resistance multiple: After measuring the water blocking rate, continue to inject water with 50 times the pore volume multiple (PV) into the core, and record the permeability at different PV numbers at the same time, and calculate according to the above-mentioned method for measuring the water blocking rate According to the water blocking rate under different PV numbers, the erosion resistance multiple is the maximum PV number of the injected water when the water blocking rate is ≥ 80%.

Among them, the artificial core is obtained by filling the mold with 40-60 mesh quartz sand.

In the following examples, the concentration of EDTA-2Na in the EDTA-2Na aqueous solution is 1% by weight;

The concentration of potassium persulfate in the potassium persulfate aqueous solution is 0.2% by weight;

The concentration of sodium sulfite in the sodium sulfite aqueous solution was 0.1% by weight.

Example 1

This example is to illustrate the water blocking material prepared by the method provided by the present invention.

Add 19.0g of acrylamide (95% by mass) and 1.0g of isooctyl methacrylate (5% by mass) into an insulated polymerization reaction bottle (ie, a polymerization bottle), add 60.0g of deionized water to dissolve and form aqueous solution, then add sodium hydroxide to adjust the pH to 7.2;

Add 1.0g of EDTA-2Na aqueous solution, 8mg of N,N'-methylenebisacrylamide and 12mg of thiosemicarbazide in sequence, and stir evenly;

Control the temperature of the aqueous solution at 5°C, and blow nitrogen for 20 minutes to drive oxygen, then add 2.5 g of potassium persulfate aqueous solution and 2.5 g of sodium sulfite aqueous solution to initiate the reaction, continue to pass nitrogen for 5 minutes and then stop, and then seal and polymerize for 7 hours;

The colloid and foaming agent CAB-35 2.0g were mixed evenly, and after granulation, drying at 60°C, crushing and sieving, a white granular high-selectivity water blocking material sample was obtained. Using simulated brine with a salinity of 100,000mg/L, the water blocking material is prepared into an aqueous solution with a mass concentration of 0.2%, which is DSJ1.

The water shutoff rate and oil shutoff rate of the foam-type water shutoff agent were tested at high temperature (90°C), and the results are shown in Table 1. Test the erosion resistance performance under high temperature (90°C) conditions, and its erosion resistance multiple is greater than 50PV.

Example 2

This example is to illustrate the water blocking material prepared by the method provided by the present invention.

Add 12.0g of acrylamide (60% in mass ratio) and 8.0g of isooctyl methacrylate (40% in mass ratio) into an insulated polymerization reaction bottle (ie, a polymerization bottle), add 60.0g of deionized water to dissolve and form aqueous solution, then add sodium hydroxide to adjust the pH to 6;

Add 1.0g of EDTA-2Na aqueous solution, 4mg of N,N'-methylenebisacrylamide and 10mg of thiosemicarbazide in sequence, and stir evenly;

Control the temperature of the aqueous solution at 0°C, blow nitrogen to drive oxygen for 20 minutes, then add 3.0 g of potassium persulfate aqueous solution and 3.0 g of sodium sulfite aqueous solution to initiate the reaction, continue to pass nitrogen for 5 minutes, stop, and seal for 8 hours of polymerization;

Mix the colloid and foaming agent LAB-35 4.0g evenly, granulate, dry at 60°C, pulverize and sieve to obtain a white granular high-selectivity water blocking material sample.

According to the method described in Example 1, the foam-type water blocking agent was prepared, namely DSJ2.

The water shutoff rate and oil shutoff rate of the foam-type water shutoff agent were tested at high temperature (90°C), and the results are shown in Table 1. Test the erosion resistance performance under high temperature (90°C) conditions, and its erosion resistance multiple is greater than 50PV.

Example 3

This example is to illustrate the water blocking material prepared by the method provided by the present invention.

Add 18.0g of acrylamide (90% by mass) and 2.0g of isooctyl methacrylate (10% by mass) into an insulated polymerization reaction bottle (ie, a polymerization bottle), add 60.0g of deionized water to dissolve and form aqueous solution, then add sodium hydroxide to adjust the pH to 7.5;

Add 1.2g of EDTA-2Na aqueous solution, 18mg of N,N'-methylenebisacrylamide and 10mg of thiosemicarbazide in sequence, and stir well;

Control the temperature of the aqueous solution at 10°C, and after 20 minutes of blowing nitrogen to drive oxygen, add 3.6 g of potassium persulfate aqueous solution and 3.6 g of sodium sulfite aqueous solution to initiate the reaction, continue to pass nitrogen for 5 minutes, stop, and seal for 8 hours of polymerization;

Mix the colloid and foaming agent CAB-35 and LAB-35 3g (weight ratio 1:1) evenly, granulate, dry at 60°C, pulverize and sieve to obtain a white granular high-selectivity water blocking material sample .

According to the method described in Example 1, the foam-type water blocking agent was prepared, namely DSJ3.

The water shutoff rate and oil shutoff rate of the foam-type water shutoff agent were tested at high temperature (90°C), and the results are shown in Table 1. Test the erosion resistance performance under high temperature (90°C) conditions, and its erosion resistance multiple is greater than 50PV.

Example 4

This example is to illustrate the water blocking material prepared by the method provided by the present invention.

Add 16.0g of acrylamide (mass ratio of 80%) and 4.0g of isooctyl methacrylate (mass ratio of 20%) into an insulated polymerization reaction bottle (ie, a polymerization bottle), add 60.0g of deionized water to dissolve and form aqueous solution, then add sodium hydroxide to adjust the pH to 7;

Add 1.0g of EDTA-2Na aqueous solution, 6mg of N,N'-methylenebisacrylamide and 10mg of thiosemicarbazide in sequence, and stir evenly;

Control the temperature of the aqueous solution at 0°C, blow nitrogen to drive oxygen for 20 minutes, then add 3.0 g of potassium persulfate aqueous solution and 3.0 g of sodium sulfite aqueous solution to initiate the reaction, continue to pass nitrogen for 5 minutes and then stop, and then seal and polymerize for 7 hours;

Mix the colloid and foaming agent CAB-35 and LAB-35 3g (weight ratio: 1:2), and obtain a white granular high-selectivity water blocking material sample after granulation, drying at 60°C, crushing and sieving .

According to the method described in Example 1, the foam-type water blocking agent was prepared, namely DSJ4.

The water shutoff rate and oil shutoff rate of the foam-type water shutoff agent were tested at high temperature (90°C), and the results are shown in Table 1. Test the erosion resistance performance under high temperature (90°C) conditions, and its erosion resistance multiple is greater than 50PV.

Example 5

This example is to illustrate the water blocking material prepared by the method provided by the present invention.

Operate according to the method described in Example 3, except that tert-butyl methacrylate of the same quality is used to replace isooctyl methacrylate.

According to the method described in Example 1, the foam-type water blocking agent was prepared, namely DSJ5.

The water shutoff rate and oil shutoff rate of the foam-type water shutoff agent were tested at high temperature (90°C), and the results are shown in Table 1. Test the erosion resistance performance under high temperature (90°C) conditions, and its erosion resistance multiple is greater than 50PV.

Example 6

This example is to illustrate the water blocking material prepared by the method provided by the present invention.

The operation was carried out according to the method described in Example 3, except that the same mass of N,N-dimethylacrylamide was used to replace isooctyl methacrylate.

According to the method described in Example 1, the foam-type water blocking agent was prepared, namely DSJ6.

The water shutoff rate and oil shutoff rate of the foam-type water shutoff agent were tested at high temperature (90°C), and the results are shown in Table 1. Test the erosion resistance performance under high temperature (90°C) conditions, and its erosion resistance multiple is greater than 50PV.

Example 7

This example is to illustrate the water blocking material prepared by the method provided by the present invention.

Operate according to the method described in Example 3, except that methacrylamide of the same quality is used to replace isooctyl methacrylate.

According to the method described in Example 1, the foam-type water blocking agent was prepared, namely DSJ7.

The water shutoff rate and oil shutoff rate of the foam-type water shutoff agent were tested at high temperature (90°C), and the results are shown in Table 1. Test the erosion resistance performance under high temperature (90°C) conditions, and its erosion resistance multiple is greater than 50PV.

Comparative example 1

This comparative example is to illustrate the reference water blocking material.

The water blocking material was prepared in the same manner as in Example 3, except that the isooctyl methacrylate was replaced by methyl acrylate of equal weight.

According to the method described in Example 1, the foam-type water blocking agent was prepared, namely D-DSJ1.

The water shutoff rate and oil shutoff rate of the foam-type water shutoff agent were tested at high temperature (90°C), and the results are shown in Table 1. Due to the low water blocking rate, the erosion resistance was not measured.

Table 1

serial number Water plugging rate (%) Oil plugging rate (%) DSJ1 93.1 8.9 DSJ2 97.2 5.9 DSJ3 96.7 6.0 DSJ4 95.2 6.1 DSJ5 99.1 4.9 DSJ6 96.2 7.0 DSJ7 99.8 3.9 D-DSJ1 63.3 25.6

According to Table 1, it can be seen that the water blocking material prepared in this example has excellent selective plugging rate and erosion resistance for oil/water, especially under high temperature and high salt conditions, it still has good oil/water Water selective plugging rate.

The preferred embodiments of the present invention have been described in detail above, however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the disclosed content of the present invention. All belong to the protection scope of the present invention.

Claims (13)

1. a water blocking material, it is characterized in that, this water blocking material contains polymer colloid and foaming agent, wherein, described polymer colloid is in complexing agent, promotor, linking agent, initiator and as solvent In the presence of water, monomer A and monomer B are polymerized to prepare; Wherein, the monomer A is acrylamide; the monomer B is selected from at least one of isooctyl methacrylate, tert-butyl methacrylate, N,N-dimethylacrylamide and methacrylamide kind; Based on 100 parts by weight of the total weight of monomer A and monomer B, the amount of monomer A used is 60-95 parts by weight, and the amount of monomer B used is 5-40 parts by weight. 2. The water blocking material according to claim 1, wherein, based on the total weight of 100 parts by weight of the monomer A and the monomer B, the amount of the monomer A is 75-94 parts by weight , the amount of monomer B is 6-25 parts by weight; Preferably, based on the total weight of 100 parts by weight of the monomer A and the monomer B, the amount of the monomer A is 85-92 parts by weight, and the amount of the monomer B is 8-15 parts by weight. parts by weight. 3. The water blocking material according to claim 1 or 2, wherein, based on the total weight of the monomer A and the monomer B, the amount of the complexing agent is 0.005-0.5% by weight, so The amount of the accelerator is 0.005-0.5% by weight, the amount of the crosslinking agent is 0.01-0.4% by weight, the total amount of the initiator is 0.005-0.5% by weight, and the amount of the foaming agent is 10-0.5% by weight. 40% by weight; Preferably, based on the total weight of the monomer A and the monomer B, the amount of the complexing agent is 0.01-0.1% by weight, the amount of the accelerator is 0.01-0.1% by weight, the The amount of the crosslinking agent is 0.02-0.15% by weight, the total amount of the initiator is 0.015-0.15% by weight, and the amount of the foaming agent is 10-20% by weight. 4. The water blocking material according to claim 1 or 2, wherein the complexing agent is ethylenediamine tetraacetate; and/or The accelerator is a thiosemicarbazide; and/or The crosslinking agent is N,N'-methylenebisacrylamide; and/or The initiator is a water-soluble initiator, preferably a persulfate-sulfite redox initiation system; and/or The foaming agent is cocamidopropyl betaine and/or lauryl amidopropyl betaine. 5. A preparation method of water blocking material, characterized in that, the preparation method comprises the following steps: (1) Mix monomer A, monomer B and water to form an aqueous solution; (2) mixing a complexing agent, an accelerator and a crosslinking agent with the aqueous solution to obtain a mixed solution; (3) the mixed solution obtained in step (2) is polymerized in the presence of an initiator; (4) mixing the polymer colloid obtained in step (3) with a foaming agent to obtain a water blocking material; Wherein, the monomer A is acrylamide; the monomer B is selected from at least one of isooctyl methacrylate, tert-butyl methacrylate, N,N-dimethylacrylamide and methacrylamide kind; Based on 100 parts by weight of the total weight of monomer A and monomer B, the amount of monomer A used is 60-95 parts by weight, and the amount of monomer B used is 5-40 parts by weight. 6. The preparation method according to claim 5, wherein, based on the total weight of 100 parts by weight of the monomer A and the monomer B, the amount of the monomer A is 75-94 parts by weight, The amount of monomer B is 6-25 parts by weight; Preferably, based on the total weight of 100 parts by weight of the monomer A and the monomer B, the amount of the monomer A is 85-92 parts by weight, and the amount of the monomer B is 8-15 parts by weight. parts by weight. 7. The preparation method according to claim 5 or 6, wherein, based on the total weight of the monomer A and the monomer B, the amount of the complexing agent is 0.005-0.5% by weight, the The amount of the accelerator is 0.005-0.5% by weight, the amount of the crosslinking agent is 0.01-0.4% by weight, the total amount of the initiator is 0.005-0.5% by weight, the amount of the foaming agent is 10-40% weight%; Preferably, based on the total weight of the monomer A and the monomer B, the amount of the complexing agent is 0.01-0.1% by weight, the amount of the accelerator is 0.01-0.1% by weight, the The amount of the crosslinking agent is 0.02-0.1% by weight, the total amount of the initiator is 0.015-0.15% by weight, and the amount of the foaming agent is 10-20% by weight. 8. The preparation method according to claim 5 or 6, wherein the complexing agent is ethylenediamine tetraacetate; and/or The accelerator is a thiosemicarbazide; and/or The crosslinking agent is N,N'-methylenebisacrylamide; and/or The initiator is a water-soluble initiator; and/or The foaming agent is cocamidopropyl betaine and/or lauryl amidopropyl betaine. 9. The preparation method according to claim 5, wherein, in step (1), the pH value of the aqueous solution is 6-10, preferably 6-8; and/or In step (3), the conditions of the polymerization reaction include: the temperature is 0-25°C, preferably 0-10°C, and the time is 5-10 hours, preferably 6-8 hours. 10. The water blocking material prepared by the method according to any one of claims 5-9. 11. The application of the water shutoff material described in any one of claims 1-4 and 10 in the preparation of foam water shutoff agent. 12. A foam type water blocking agent, characterized in that, the foam type water blocking agent comprises the water blocking material according to any one of claims 1-4 and 10; Preferably, the content of the water blocking material in the foam type water blocking agent is 0.1-0.5% by weight. 13. The application of the water blocking material according to any one of claims 1-4 and 10 or the foam type water blocking agent according to claim 12 in oil reservoir production.