A multi-crosslinking network temperature-resistant and salt-resistant pre-crosslinking gel particle, a preparation method and application thereof

Abstract

The application discloses a kind of multiple crosslinking network temperature-resistant salt-resistant pre-crosslinking gel particles and preparation method and application thereof, belong to oil and gas field development technical field.Preparation raw material of the pre-crosslinking gel particle of the application includes acrylamide, trans-resveratrol, triphenylethyl phenol polyoxyethylene ether methacrylate, aldehyde cellulose nanofibril and initiator.The pre-crosslinking gel particle has higher salt resistance and higher strength, and can withstand at least 130 DEG C high temperature.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field development, and in particular to a multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particle and a preparation method and application thereof. Background Art

[0002] Over 80% of my country's onshore oil fields are developed through waterflooding, but waterflood recovery rates are generally low, typically below 50%. Reservoir heterogeneity is a key factor influencing the recovery rate of waterflood reservoirs. Due to variations in reservoir permeability, injected water easily penetrates through high-permeability layers, fractures, and large pores, resulting in ineffective water circulation and a serious impact on the economic benefits of the oilfield.

[0003] Chemical profile control and water plugging are effective methods for improving oilfield waterflooding and achieving stable reservoir production. Chemical profile control agents are used to plug the dominant channels in water injection wells, reducing water absorption, increasing the water flooding sweep coefficient, and thus enhancing oil recovery. Pre-crosslinked gel particles are widely used due to their simple process, low cost, high plugging strength, and long shelf life.

[0004] For example, Chinese patent CN202311392830.9 discloses a gel particle profile control agent for blocking channeling in oilfield water flooding reservoirs. The agent is made by adding a chromium crosslinker, a reinforcing agent, and a gel promoter to partially hydrolyzed polyacrylamide. This gel particle profile control agent exhibits high plugging strength. However, in the increasingly complex reservoir environment (temperature > 100°C, salinity > 100,000), the aforementioned pre-crosslinked gel particles are difficult to apply. Summary of the Invention

[0005] The purpose of the present invention is to provide a multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles and their preparation method and application. The pre-crosslinked gel particles have high salt resistance and high strength and can withstand high temperatures of at least 130°C.

[0006] The present invention first provides a pre-crosslinked gel particle. The raw materials for preparing the pre-crosslinked gel particle include acrylamide, trans-resveratrol, triphenyl ethylphenol polyoxyethylene ether methacrylate, hydroformylated cellulose nanofibrils and an initiator.

[0007] The pre-crosslinked gel particles described above contain, by weight, 15 to 20 parts of acrylamide, 0.4 to 1.5 parts of trans-resveratrol, 4.3 to 5 parts of triphenyl phenol polyoxyethylene ether methacrylate, and 1.8 to 3.5 parts of aldehyded cellulose nanofibrils;

[0008] The mass of the initiator is 0.01% to 0.05% of the total mass of the monomers, specifically 0.011%, 0.012% or 0.016%; wherein the total mass of the monomers is the sum of the masses of acrylamide, trans-resveratrol, triphenyl ethyl phenol polyoxyethylene ether methacrylate and hydroformylated cellulose nanofibrils.

[0009] In the above-mentioned pre-crosslinked gel particles, the raw materials also include water; based on the total mass of the monomers and water being 100 parts, the remainder is water;

[0010] The monomers are acrylamide, trans-resveratrol, triphenyl ethylphenol polyoxyethylene ether methacrylate and aldehyded cellulose nanofibrils.

[0011] The raw materials for preparing the above-mentioned pre-crosslinked gel particles are any of the following:

[0012] 1) 18 parts of acrylamide, 0.5 parts of trans-resveratrol, 4.5 parts of triphenyl phenol polyoxyethylene ether methacrylate, 2 parts of hydroformylated cellulose nanofibrils, and 75 parts of water; the mass of the initiator is 0.012% of the total mass of the monomers;

[0013] 2) 17 parts of acrylamide, 1 part of trans-resveratrol, 4.5 parts of triphenyl phenol polyoxyethylene ether methacrylate, 2.5 parts of hydroformylated cellulose nanofibrils, and 75 parts of water; the mass of the initiator is 0.012% of the total mass of the monomers;

[0014] 3) 18 parts of acrylamide, 1.5 parts of trans-resveratrol, 5 parts of triphenyl phenol polyoxyethylene ether methacrylate, 3.5 parts of hydroformylated cellulose nanofibrils, and 72 parts of water; the mass of the initiator is 0.011% of the total mass of the monomers;

[0015] 4) 17 parts of acrylamide, 1 part of trans-resveratrol, 4.5 parts of triphenyl phenol polyoxyethylene ether methacrylate, 2.5 parts of hydroformylated cellulose nanofibrils, and 75 parts of water; the mass of the initiator is 0.016% of the total mass of the monomers.

[0016] In the above-mentioned pre-crosslinked gel particles, the initiator is a persulfate, specifically ammonium persulfate.

[0017] In the above-mentioned pre-crosslinked gel particles, the preparation method of the hydroformylated cellulose nanofibrils comprises the following steps: mixing the cellulose nanofibrils, periodate and a solvent to react, and the obtained solid is the hydroformylated cellulose nanofibrils.

[0018] In the above-mentioned pre-crosslinked gel particles, the reaction is carried out under light-proof conditions at a temperature of 40-50° C. for 3-4 hours;

[0019] The pH of the reaction solution was adjusted to 5-6 and the reaction was carried out.

[0020] Specifically, hydrochloric acid can be used to adjust the pH of the reaction solution.

[0021] In the above-mentioned pre-crosslinked gel particles, the periodate is at least one of sodium periodate and potassium periodate;

[0022] The solvent is water;

[0023] The mass ratio of the cellulose nanofibrils to periodate is 10:1.5-2.5;

[0024] The mass of the cellulose nanofibrils is 3-5 wt % of the total mass of the cellulose nanofibrils and the solvent.

[0025] In the above-mentioned pre-crosslinked gel particles, the preparation method of the hydroformylated cellulose nanofibrils further comprises the steps of washing the solid phase with water to neutrality and drying after the reaction.

[0026] Furthermore, the present invention also provides a method for preparing the above-mentioned pre-crosslinked gel particles, comprising the following steps:

[0027] Acrylamide, trans-resveratrol, hydroformylated cellulose nanofibrils and triphenyl phenol polyoxyethylene ether methacrylate are dispersed in water, and an initiator is added to react under deoxygenated conditions to obtain the pre-crosslinked gel particles.

[0028] In the above preparation method, the reaction temperature is 50-60°C; the reaction time is 3-5h;

[0029] Use nitrogen to deoxidize;

[0030] The preparation method further comprises the steps of granulating, drying and crushing the obtained pre-crosslinked gel after the reaction.

[0031] Finally, the present invention provides the use of the pre-crosslinked gel particles as a profile control and water plugging agent in improving the recovery rate of oil and gas fields.

[0032] Specifically, the formation temperature of the oil and gas field is 100-130°C; the formation water salinity is 10×10 4 mg / L~25×10 4 mg / L.

[0033] More specifically, the formation temperature of the oil and gas field is 130°C; the formation water salinity is 25×10 4 mg / L.

[0034] The present invention has the following advantages:

[0035] (1) The pre-crosslinked gel particles of the present invention have high salt resistance and temperature resistance, and can withstand a mineralization degree of at least 25×10 4mg / L, temperature at least 130°C;

[0036] (2) The pre-crosslinked gel particles of the present invention are heated to 130°C and have a mineralization of 25×10 4 mg / L, among which the calcium ion concentration was 5000 mg / L and it still maintained a high turning pressure after aging for 50 days; the toughness coefficient after aging for 50 days was greater than 0.9, indicating that it had good toughness. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The expansion multiples of the multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles prepared in Example 1 at different temperatures.

[0038] Figure 2 The expansion multiples of the multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles prepared in Example 2 at different temperatures.

[0039] Figure 3 The expansion multiples of the multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles prepared in Example 3 at different temperatures.

[0040] Figure 4 The expansion multiples of the multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles prepared in Example 4 at different temperatures.

[0041] Figure 5 The expansion multiples of the multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles prepared in Example 1 at different salinities.

[0042] Figure 6 The expansion multiples of the multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles prepared in Example 2 at different salinities.

[0043] Figure 7 The expansion multiples of the multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles prepared in Example 3 at different salinities.

[0044] Figure 8 The expansion multiples of the multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles prepared in Example 4 at different salinities.

[0045] Figure 9 The turning pressures of the multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles prepared in Examples 1 to 4 are the initial and aging pressures at different times.

[0046] Figure 10 It is the toughness index of the multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles prepared in Examples 1 to 4. Tool Implementation Method

[0047] The present invention will be further described in detail below in conjunction with specific embodiments. The examples given are only for illustrating the present invention, not for limiting the scope of the present invention.

[0048] The experimental methods in the following examples are conventional methods unless otherwise specified.

[0049] The quantitative tests in the following examples were all repeated three times, and the results were averaged.

[0050] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0051] The cellulose nanofibrils used in the following examples were purchased from Northern Century (Jiangsu) Cellulose Materials Co., Ltd.

[0052] Example 1

[0053] The multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles of this embodiment are made from the following raw material components: 18g acrylamide, 0.5g trans-resveratrol, 4.5g triphenyl phenol polyoxyethylene ether methacrylate, 2g hydroformylated cellulose nanofibrils, 0.003g ammonium persulfate and 75g deionized water.

[0054] The specific preparation method is as follows:

[0055] (1) Preparation of hydroformylated cellulose nanofibrils: 4 g of cellulose nanofibrils were added to 96 mL of water, followed by 0.8 g of sodium periodate. The mixture was heated to 45 °C under continuous stirring, and the pH of the reaction solution was adjusted to 5 with hydrochloric acid. The mixture was reacted for 3.5 h in the dark. After the reaction was completed, the solid phase was centrifuged and washed with water until neutral, and then vacuum dried.

[0056] (2) Preparation of pre-crosslinked gel particles: 0.5 g trans-resveratrol and 4.5 g triphenylethylphenol polyoxyethylene ether methacrylate were added to 75 g deionized water and ultrasonicated until the solution was uniform; then 18 g acrylamide and 2 g aldehyded cellulose nanofibrils were added to the above solution and stirred until the solution was uniform; nitrogen was introduced for 30 min to remove oxygen in the solution and air in the flask; 0.003 g ammonium persulfate was added and stirred evenly, and nitrogen was continued to be introduced for 30 min. The system was heated to 50 ° C and kept warm for 3 h to obtain gel particle block products. After granulation, drying, crushing and screening, multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles were obtained.

[0057] Example 2

[0058] The multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles of this embodiment are made from the following raw material components: 17g acrylamide, 1g trans-resveratrol, 4.5g triphenyl phenol polyoxyethylene ether methacrylate, 2.5g formaldehyded cellulose nanofibrils, 0.003g ammonium persulfate, and 75g deionized water.

[0059] The specific preparation method is as follows:

[0060] (1) Preparation of hydroformylated cellulose nanofibrils: 3.8 g of cellulose nanofibrils were added to 96 mL of water, followed by 0.68 g of sodium periodate. The mixture was heated to 45 °C under continuous stirring, and the pH of the reaction solution was adjusted to 5 with hydrochloric acid. The mixture was reacted for 3.5 h in the dark. After the reaction was completed, the solid phase was centrifuged and washed with water until neutral, and then vacuum dried.

[0061] (2) Preparation of pre-crosslinked gel particles: 1 g trans-resveratrol and 4.5 g triphenylethylphenol polyoxyethylene ether methacrylate were added to 75 g deionized water and ultrasonicated until the solution was uniform; then 17 g acrylamide and 2.5 g aldehyded cellulose nanofibrils were added to the above solution and stirred until the solution was uniform; nitrogen was introduced for 30 min to remove oxygen in the solution and air in the flask; 0.003 g ammonium persulfate was added and stirred evenly, and nitrogen was continued to be introduced for 30 min. The system was heated to 50 ° C and kept warm for 3 h to obtain gel particle block products. After granulation, drying, crushing and screening, multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles were obtained.

[0062] Example 3

[0063] The multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles of this embodiment are made from the following raw material components: 18g acrylamide, 1.5g trans-resveratrol, 5g triphenethylphenol polyoxyethylene ether methacrylate, 3.5g hydroformylated cellulose nanofibrils, 0.003g ammonium persulfate, and 72g deionized water.

[0064] The specific preparation method is as follows:

[0065] (1) Preparation of hydroformylated cellulose nanofibrils: 4.2 g of cellulose nanofibrils were added to 96 mL of water, followed by 0.97 g of sodium periodate. The mixture was heated to 45 °C under continuous stirring, and the pH of the reaction solution was adjusted to 6 with hydrochloric acid. The mixture was reacted for 4 h in the dark. After the reaction was completed, the solid phase was centrifuged and washed with water until neutral, and then vacuum dried.

[0066] (2) Preparation of pre-crosslinked gel particles: 1.5 g trans-resveratrol and 5 g triphenylethylphenol polyoxyethylene ether methacrylate were added to 72 g deionized water and ultrasonicated until the solution was uniform; then 18 g acrylamide and 3.5 g aldehyded cellulose nanofibrils were added to the above solution and stirred until the solution was uniform; nitrogen was introduced for 30 min to remove oxygen in the solution and air in the flask; 0.003 g ammonium persulfate was added and stirred evenly, and nitrogen was continued to be introduced for 30 min. The system was heated to 50 ° C and kept warm for 3 h to obtain gel particle block products. After granulation, drying, crushing and screening, multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles were obtained.

[0067] Example 4

[0068] The multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles of this embodiment are made from the following raw material components: 17g acrylamide, 1g trans-resveratrol, 4.5g triphenyl phenol polyoxyethylene ether methacrylate, 2.5g formaldehyded cellulose nanofibrils, 0.004g ammonium persulfate, and 75g deionized water.

[0069] The specific preparation method is as follows:

[0070] (1) Preparation of hydroformylated cellulose nanofibrils: 4 g of cellulose nanofibrils were added to 96 mL of water, followed by 0.8 g of sodium periodate. The mixture was heated to 45 °C under continuous stirring, and the pH of the reaction solution was adjusted to 5 with hydrochloric acid. The mixture was reacted for 3.5 h in the dark. After the reaction was completed, the solid phase was centrifuged and washed with water until neutral, and then vacuum dried.

[0071] (2) Preparation of pre-crosslinked gel particles: 1 g trans-resveratrol and 4.5 g triphenylethylphenol polyoxyethylene ether methacrylate were added to 75 g deionized water and ultrasonicated until the solution was uniform; then 17 g acrylamide and 2.5 g aldehyded cellulose nanofibrils were added to the above solution and stirred until the solution was uniform; nitrogen was introduced for 30 min to remove oxygen in the solution and air in the flask; 0.004 g ammonium persulfate was added and stirred evenly, and nitrogen was continued to be introduced for 30 min. The system was heated to 60 ° C and kept warm for 4 h to obtain gel particle block products. After granulation, drying, crushing and screening, multi-crosslinked network temperature-resistant and salt-resistant pre-crosslinked gel particles were obtained.

[0072] Example 5: Performance Test

[0073] 1. Expansion test

[0074] The multi-crosslinked network heat-resistant and salt-resistant pre-crosslinked gel particles prepared in Examples 1 to 4 were taken and their weight changes at different temperatures and different salinities were tested by weighing method. The mass expansion multiples were then calculated based on the weight changes. The final results are shown in FIG. Figures 1 to 8shown.

[0075] Figures 1 to 4 It is mainly used to test the temperature resistance of pre-crosslinked gel particles: the pre-crosslinked gel particles are placed in a 4 mg / L water, of which the calcium ion concentration is 5000mg / L, and the rest are sodium ions and chloride ions; its temperature resistance under high salt conditions is tested by changing the temperature. Figures 1 to 4 It can be seen that with the increase of temperature, the expansion multiple of the pre-crosslinked gel particles increases, and they are still not dehydrated after aging for 50 days.

[0076] Figures 5 to 8 It is mainly used to test the salt resistance of pre-crosslinked gel particles: the pre-crosslinked gel particles are placed in water at a temperature of 130°C, and the salinity of the water is changed (water of any salinity contains calcium ions at a concentration of 5000 mg / L, and the rest are sodium ions and chloride ions). By changing the salinity, its salt resistance under high temperature conditions is tested. Figures 5 to 8 It can be seen that with the decrease of mineralization, the expansion multiple of gel particles increases rapidly, and they are still not dehydrated after 50 days of aging.

[0077] Depend on Figure 5-Figure 8 It can be seen that the pre-crosslinked gel particles prepared in the embodiment of the present invention can tolerate a mineralization degree of at least 25×10 4 mg / L, and the temperature is at least 130℃, and it has strong heat and salt resistance.

[0078] 2. Pre-crosslinked gel particle strength test

[0079] Steering pressure method: Take the pre-crosslinked gel particles prepared in Examples 1 to 4 and let them pass through a 180-mesh screen at a certain speed. Record the maximum pressure P1 when the pre-crosslinked gel particle system passes through the screen. Collect the pre-crosslinked gel particle system after passing through the screen and let it pass through the screen again at the same speed. Record the maximum pressure P2 when passing through. The toughness index is defined as the ratio of P2 to P1. The closer the toughness index is to 1, the better the toughness. The specific method is as follows: At a temperature of 130°C, use a mineralization degree of 25×10 4 mg / L, wherein the calcium ion concentration is 5000 mg / L of mineral water (the rest are sodium ions and chloride ions). The pre-crosslinked gel particles prepared in Examples 1 to 4 are prepared into a suspension with a mass concentration of 0.5%. The steering pressure at the initial stage and at different aging times is tested. The test results are as follows: Figure 9 and Figure 10 shown.

[0080] Depend on Figure 9 and Figure 10As can be seen, the multi-crosslinked network heat-resistant and salt-resistant pre-crosslinked gel particles prepared in Examples 1-4 still maintained high turning pressure and strength after 50 days of aging. The toughness coefficient after 50 days of aging was greater than 0.9, indicating that the multi-crosslinked network heat-resistant and salt-resistant pre-crosslinked gel particles had good toughness.

Claims

1. A pre-crosslinked gel particle, characterized in that: The raw materials for preparing the pre-crosslinked gel particles include acrylamide, trans-resveratrol, triphenyl ethylphenol polyoxyethylene ether methacrylate, hydroformylated cellulose nanofibrils and an initiator; By weight, 15-20 parts of acrylamide, 0.4-1.5 parts of trans-resveratrol, 4.3-5 parts of triphenyl phenol polyoxyethylene ether methacrylate, and 1.8-3.5 parts of aldehyded cellulose nanofibrils; The mass of the initiator is 0.01% to 0.05% of the total mass of the monomers; wherein the total mass of the monomers is the sum of the masses of acrylamide, trans-resveratrol, triphenyl ethylphenol polyoxyethylene ether methacrylate and aldehyded cellulose nanofibrils.

2. The pre-crosslinked gel particles according to claim 1, characterized in that: The raw materials also include water; Taking the total weight of monomer and water as 100 parts, the balance is water; The monomers are acrylamide, trans-resveratrol, triphenyl ethylphenol polyoxyethylene ether methacrylate and aldehyded cellulose nanofibrils.

3. The pre-crosslinked gel particles according to claim 1 or 2, characterized in that: The initiator is persulfate.

4. The pre-crosslinked gel particles according to claim 1 or 2, characterized in that: The preparation method of the hydroformylated cellulose nanofibrils comprises the following steps: mixing the cellulose nanofibrils, periodate and a solvent to react, and obtaining a solid which is the hydroformylated cellulose nanofibrils.

5. The pre-crosslinked gel particles according to claim 4, characterized in that: The reaction is carried out under light-proof conditions at a temperature of 40-50° C. for 3-4 hours; The pH of the reaction solution was adjusted to 5-6 and the reaction was carried out.

6. The pre-crosslinked gel particles according to claim 4, characterized in that: The periodate is at least one of sodium periodate and potassium periodate; The solvent is water; The mass ratio of the cellulose nanofibrils to periodate is 10:1.5-2.5; The mass of the cellulose nanofibrils is 3-5 wt % of the total mass of the cellulose nanofibrils and the solvent.

7. The method for preparing the pre-crosslinked gel particles according to any one of claims 1 to 6, comprising the following steps: Acrylamide, trans-resveratrol, aldehyded cellulose nanofibrils and triphenyl phenol polyoxyethylene ether methacrylate are dispersed in water, and an initiator is added to react under deoxygenation conditions to obtain a pre-crosslinked gel.

8. The preparation method according to claim 7, characterized in that: The reaction temperature is 50-60°C; the reaction time is 3-5h; Use nitrogen to deoxidize; The preparation method further comprises the steps of granulating, drying and crushing the obtained pre-crosslinked gel after the reaction.

9. Use of the pre-crosslinked gel particles according to any one of claims 1 to 6 as a profile control and water plugging agent in improving oil and gas field recovery.

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