Flexible nylon slow-expansion steering profile control agent and preparation method thereof

Abstract

The invention relates to the technical field of oilfield profile control agents, and discloses a flexible nylon slow-expansion steering profile control agent and a preparation method thereof.The preparation method comprises the steps that nylon 66, sodium sulfonate modified nano titanium dioxide, ethylene-propylene-diene monomer and flexibilizer polybutadiene are added into a high-speed mixer to be mixed for 5-10 min, polyethylene glycol and an alkylbenzene oil-filling agent continue to be added, stirring is conducted for 10-15 min, and a primary material is obtained; transferring the primary material into a double-screw extruder, processing at the temperature of 250-260 DEG C, mixing for 10-15 minutes, and extruding to obtain the flexible nylon slow-expansion steering profile control agent. The profile control agent provided by the invention has good slow expansion and plugging effects.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield profile control agents, in particular to a flexible nylon slow-swelling diverting profile control agent and a preparation method thereof. Background Art

[0002] In the process of oil field development, profile control agents are an important chemical agent that improves the water injection displacement effect by adjusting the permeability distribution of the oil layer, thereby increasing the crude oil recovery rate. Traditional profile control agents often use polymer gels, granular materials or resin-based composite materials, but they still have significant defects in practical applications. For example, the expansion rate of polymer gels is difficult to accurately control, which can easily lead to premature or late expansion, affecting the profile control effect; granular materials are prone to agglomeration or sedimentation under high temperature and high pressure environments, and their stability is insufficient; and although resin-based materials have certain mechanical strength, they have poor flexibility and are prone to fracture and failure under complex geological conditions. Therefore, how to avoid this phenomenon is the key to solving the problem. For example, a profile control agent and its preparation method and application with publication number CN11334267A, the profile control agent provided by the invention can achieve delayed controllable cross-linking, and the gel has a certain strength, but its slow expansion effect is not improved. Summary of the Invention

[0003] (1) Technical problems solved In view of the shortcomings of the existing technology, the present invention provides a flexible nylon slow-swelling diverting profile control agent and a preparation method thereof, which has good slow-swelling and plugging effects.

[0004] (2) Technical solution To achieve the above objectives, the present invention provides the following technical solution: a flexible nylon slow-swelling and diverting profile control agent, comprising the following components by weight: 50-65 parts by weight of nylon 66, 8-10 parts by weight of polyethylene glycol, 1-2 parts by weight of sodium sulfonate-modified nano-titanium dioxide, 2-4 parts by weight of EPDM rubber, 0.1-0.2 parts by weight of toughening agent polybutadiene, and 0.1-0.3 parts by weight of alkylbenzene oil extender.

[0005] Furthermore, the preparation method of the sodium sulfonate modified nano titanium dioxide is: S1. Under a nitrogen atmosphere, 1,3-propylenediamine and 4-vinylbenzoyl chloride were added to N,N-dimethylformamide solvent, stirred and mixed, and pyridine catalyst was added. The reaction was allowed to proceed at room temperature. After completion, the reaction was filtered, washed, and rotary evaporated to obtain an alkenyl intermediate. S2. 25-30 mL of ethanol was added to 30-35 mL of water, ammonia was added dropwise to adjust the pH, and then 10-11 g of nano-titanium dioxide was added, ultrasonically dispersed for 10-15 min, and then heated, 10 mL of an ethanol solution containing 0.25-0.26 g of KH570 was added dropwise, stirred and refluxed for 1-2 h, cooled and allowed to stand for 12 h, filtered, washed with ethanol, and dried to obtain KH570-modified nano-titanium dioxide; S3. Add 1.1-1.2 g of styrene, 0.8-0.84 g of olefin intermediate, 0.5-1 g of KH570 modified nano titanium dioxide, and 0.4-0.8 g of 2-acrylamido-2-methylpropanesulfonate sodium to 65-80 mL of distilled water, stir for 10-15 min, then continue to add 0.02-0.03 g of emulsifier Span-80 and 0.01-0.02 g of OP-10, heat, and then continue to dropwise add 0.012-0.015 g of azobisisobutylamidine hydrochloride, react for 4-6 h, and then add 0.02-0.024 g of N,N'-diphenyl-p-phenylenediamine polymerization inhibitor, react under stirring for 0.5-1 h, cool after completion, add anhydrous ethanol to break the emulsion, evaporate, wash, and dry to obtain sodium sulfonate modified nano titanium dioxide.

[0006] Furthermore, the usage ratio of N,N-dimethylformamide solvent, 1,3-propylenediamine, 4-vinylbenzoyl chloride, and pyridine catalyst in S1 is 50-60 mL: 0.71-0.75 g: 3.1-3.3 g: 0.01-0.02 g.

[0007] Furthermore, the reaction time in S1 is 4-6 hours.

[0008] Furthermore, the pH in S2 is adjusted to 9.

[0009] Furthermore, the heating temperature in S2 is 75-80°C.

[0010] Furthermore, the heating temperature in S3 is 70-80°C.

[0011] Furthermore, the preparation method of the flexible nylon slow-swelling and diverting profile control agent is as follows: nylon 66, sodium sulfonate-modified nano-titanium dioxide, EPDM rubber, and toughening agent polybutadiene are added to a high-speed mixer, mixed for 5-10 minutes, and polyethylene glycol and alkylbenzene oil extender are continuously added, stirred for 10-15 minutes to obtain a preliminary material; the preliminary material is transferred to a twin-screw extruder, the processing temperature is 250-260°C, mixed for 10-15 minutes, and extruded to obtain a flexible nylon slow-swelling and diverting profile control agent.

[0012] (3) Beneficial technical effects By introducing sodium sulfonate-modified nano-titanium dioxide, combined with the molecular structure of nylon 66, a profile control agent achieves controlled and retarded expansion in reservoir environments. The sulfonic acid groups on the nano-titanium dioxide surface enhance the interaction between the material and formation water, slowing the expansion rate. The benzene ring structure within the nano-titanium dioxide enhances the agent's heat resistance and mechanical strength, effectively plugging high-permeability zones. The nylon 66 backbone enhances the compressive strength of the plugging material, maintaining a stable structure in high-temperature formations. The hydrophobic nature of the benzene rings reduces direct contact between the profile control agent and formation water, slowing the expansion rate. The hydrophobic effect of the benzene rings in the sodium sulfonate-modified nano-titanium dioxide synergizes with the hydrophilicity of the sulfonic acid groups to achieve controlled and retarded expansion. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is the NMR spectrum of the alkenyl intermediate in Example 1. DETAILED DESCRIPTION

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0015] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0016] Emulsifiers Span-80 and OP-10, industrial grade, Zibo Haijie Chemical Co., Ltd. Azobisisobutylamidine hydrochloride (AIBA) was of analytical grade and purchased from Tianjin Yongda Chemical Reagent Co., Ltd. The molecular weight of polyethylene glycol is 6000. Example 1

[0017] S1. Under a nitrogen atmosphere, 0.71 g of 1,3-propylenediamine and 3.1 g of 4-vinylbenzoyl chloride were added to 50 mL of N,N-dimethylformamide, stirred and mixed, and 0.01 g of pyridine was added. The reaction was continued at room temperature for 4 h. After the reaction, the mixture was filtered, washed, and rotary evaporated to obtain the alkenyl intermediate; S2. Add 25 mL of ethanol to 30 mL of water, add aqueous ammonia dropwise to adjust the pH to 9, then add 10 g of nano-titanium dioxide, ultrasonically disperse for 10 min, then heat to 75 ° C, add 10 mL of ethanol solution containing 0.25 g of KH570 dropwise, stir and reflux for 1 h, cool and let stand for 12 h, filter, wash with ethanol, and dry to obtain KH570-modified nano-titanium dioxide; S3. To 65 mL of distilled water were added 1.1 g of styrene, 0.8 g of alkenyl intermediate, 0.5 g of KH570 modified nano-titanium dioxide, 0.4 g of 2-acrylamido-2-methylpropanesulfonate sodium, stirred for 10 min, then 0.02 g of emulsifier Span-80 and 0.01 g of OP-10 were added, the temperature was raised to 70 ° C, and then 0.012 g of azobisisobutylamidine hydrochloride was added dropwise, and the reaction was continued for 4 h. After the reaction, 0.02 g of N, N'-diphenyl-p-phenylenediamine polymerization inhibitor was added, and the reaction was stirred for 0.5 h. After the reaction was completed, the mixture was cooled, anhydrous ethanol was added to break the emulsion, evaporated, washed, and dried to obtain sodium sulfonate modified nano-titanium dioxide; S4. Add 50 parts by weight of nylon 66, 1 part by weight of sodium sulfonate modified nano-titanium dioxide, 2 parts by weight of EPDM, and 0.1 part by weight of toughening agent polybutadiene into a high-speed mixer and mix for 5 minutes. Then, add 8 parts by weight of polyethylene glycol and 0.1 part by weight of alkylbenzene oil extender and stir for 10 minutes to obtain a preliminary material. Transfer the preliminary material to a twin-screw extruder with a processing temperature of 250°C, mix for 10 minutes, extrude, and cool to room temperature to obtain a flexible nylon slow-swelling and steering profile control agent. Example 2

[0018] S1. Under a nitrogen atmosphere, 0.75 g of 1,3-propylenediamine and 3.3 g of 4-vinylbenzoyl chloride were added to 60 mL of N,N-dimethylformamide, stirred and mixed, and 0.02 g of pyridine was added. The reaction was continued at room temperature for 6 h. After the reaction, the mixture was filtered, washed, and rotary evaporated to obtain the alkenyl intermediate; S2. 30 mL of ethanol was added to 35 mL of water, and ammonia was added dropwise to adjust the pH to 9. Then 11 g of nano-titanium dioxide was added and ultrasonically dispersed for 15 min. Then, the mixture was heated to 80 ° C and 10 mL of an ethanol solution containing 0.26 g of KH570 was added dropwise. The mixture was stirred and refluxed for 2 h. After cooling, the mixture was allowed to stand for 12 h, filtered, washed with ethanol, and dried to obtain KH570-modified nano-titanium dioxide. S3. To 80 mL of distilled water were added 1.2 g of styrene, 0.84 g of alkenyl intermediate, 1 g of KH570 modified nano-titanium dioxide, 0.8 g of 2-acrylamido-2-methylpropanesulfonate sodium, stirred for 15 min, then 0.03 g of emulsifier Span-80 and 0.02 g of OP-10 were added, the temperature was raised to 80 ° C, and then 0.015 g of azobisisobutylamidine hydrochloride was added dropwise, and the reaction was continued for 6 h. After the reaction, 0.024 g of N, N'-diphenyl-p-phenylenediamine polymerization inhibitor was added, and the reaction was stirred for 1 h. After the reaction was completed, the mixture was cooled, anhydrous ethanol was added to break the emulsion, evaporated, washed, and dried to obtain sodium sulfonate modified nano-titanium dioxide; S4. Add 65 parts by weight of nylon 66, 2 parts by weight of sodium sulfonate modified nano-titanium dioxide, 4 parts by weight of EPDM, and 0.2 parts by weight of toughening agent polybutadiene into a high-speed mixer and mix for 10 minutes. Continue to add 10 parts by weight of polyethylene glycol and 0.3 parts by weight of alkylbenzene oil extender and stir for 15 minutes to obtain a preliminary material; transfer the preliminary material to a twin-screw extruder with a processing temperature of 260°C, mix for 15 minutes, extrude, and cool to room temperature to obtain a flexible nylon slow-swelling and steering profile control agent. Example 3

[0019] S1. Under a nitrogen atmosphere, 0.73 g of 1,3-propylenediamine and 3.2 g of 4-vinylbenzoyl chloride were added to 55 mL of N,N-dimethylformamide, stirred and mixed, and 0.015 g of pyridine was added. The reaction was continued at room temperature for 5 h. After the reaction, the mixture was filtered, washed, and rotary evaporated to obtain the alkenyl intermediate; S2. 27 mL of ethanol was added to 32 mL of water, and ammonia was added dropwise to adjust the pH to 9. Then 10.5 g of nano-titanium dioxide was added and ultrasonically dispersed for 12 min. Then, the mixture was heated to 78 ° C and 10 mL of an ethanol solution containing 0.255 g of KH570 was added dropwise. The mixture was stirred and refluxed for 1.5 h. After cooling, the mixture was allowed to stand for 12 h, filtered, washed with ethanol, and dried to obtain KH570-modified nano-titanium dioxide. S3. To 75 mL of distilled water were added 1.15 g of styrene, 0.82 g of alkenyl intermediate, 0.8 g of KH570 modified nano-titanium dioxide, 0.6 g of 2-acrylamido-2-methylpropanesulfonate sodium, stirred for 12 min, then 0.025 g of emulsifier Span-80 and 0.015 g of OP-10 were added, the temperature was raised to 75 ° C, and then 0.013 g of azobisisobutylamidine hydrochloride was added dropwise, and the reaction was continued for 5 h. After the reaction, 0.022 g of N, N'-diphenyl-p-phenylenediamine polymerization inhibitor was added, and the reaction was stirred for 0.7 h. After the reaction was completed, the mixture was cooled, anhydrous ethanol was added to break the emulsion, evaporated, washed, and dried to obtain sodium sulfonate modified nano-titanium dioxide; S4. Add 60 parts by weight of nylon 66, 1.5 parts by weight of sodium sulfonate modified nano-titanium dioxide, 3 parts by weight of EPDM, and 0.15 parts by weight of toughening agent polybutadiene into a high-speed mixer and mix for 7 minutes. Then, add 9 parts by weight of polyethylene glycol and 0.2 parts by weight of alkylbenzene oil extender and stir for 12 minutes to obtain a preliminary material. Transfer the preliminary material to a twin-screw extruder with a processing temperature of 255°C, mix for 12 minutes, extrude, and cool to room temperature to obtain a flexible nylon slow-swelling and steering profile control agent. Example 4

[0020] S1. Under a nitrogen atmosphere, 0.71 g of 1,3-propylenediamine and 3.1 g of 4-vinylbenzoyl chloride were added to 50 mL of N,N-dimethylformamide, stirred and mixed, and 0.01 g of pyridine was added. The reaction was continued at room temperature for 4 h. After the reaction, the mixture was filtered, washed, and rotary evaporated to obtain the alkenyl intermediate; S2. Add 25 mL of ethanol to 30 mL of water, add aqueous ammonia dropwise to adjust the pH to 9, then add 10 g of nano-titanium dioxide, ultrasonically disperse for 10 min, then heat to 75 ° C, add 10 mL of ethanol solution containing 0.25 g of KH570 dropwise, stir and reflux for 1 h, cool and let stand for 12 h, filter, wash with ethanol, and dry to obtain KH570-modified nano-titanium dioxide; S3. To 80 mL of distilled water were added 1.2 g of styrene, 0.84 g of alkenyl intermediate, 1 g of KH570 modified nano-titanium dioxide, 0.8 g of 2-acrylamido-2-methylpropanesulfonate sodium, stirred for 15 min, then 0.03 g of emulsifier Span-80 and 0.02 g of OP-10 were added, the temperature was raised to 7080 ° C, and then 0.015 g of azobisisobutylamidine hydrochloride was added dropwise, and the reaction was continued for 6 h. After the reaction, 0.024 g of N, N'-diphenyl-p-phenylenediamine polymerization inhibitor was added, and the reaction was stirred for 1 h. After the reaction was completed, the mixture was cooled, anhydrous ethanol was added to break the emulsion, evaporated, washed, and dried to obtain sodium sulfonate modified nano-titanium dioxide; S4. Add 60 parts by weight of nylon 66, 1.5 parts by weight of sodium sulfonate modified nano-titanium dioxide, 3 parts by weight of EPDM, and 0.15 parts by weight of toughening agent polybutadiene into a high-speed mixer and mix for 7 minutes. Then, add 9 parts by weight of polyethylene glycol and 0.2 parts by weight of alkylbenzene oil extender and stir for 12 minutes to obtain a preliminary material. Transfer the preliminary material to a twin-screw extruder with a processing temperature of 255°C, mix for 12 minutes, extrude, and cool to room temperature to obtain a flexible nylon slow-swelling and steering profile control agent.

[0021] Comparative Example 1 This comparative example is different from Example 4 in that no alkenyl intermediate is added.

[0022] Comparative Example 2 Compared with Example 4, this comparative example differs in that KH570 modified nano-titanium dioxide is not added.

[0023] Each profile control agent of the present invention was added into deionized water twice its mass, stirred thoroughly at 50° C., and then allowed to stand for 3 days to obtain an injectable profile control agent solution.

[0024] For the plugging performance test, a simulated sand-filled pipe (a common sample in the field of oil production) was used. First, the permeability of multiple sand-filled pipes was measured at room temperature. Then, different profile control agent solutions were injected at a constant pressure (relative to the per cm of the sand-filled pipe). 2 In terms of cross-sectional area, the injection rate is 0.2 ml / min, the pressure is 0.1 MPa, and the injection time is 2 hours, 4 hours, and 6 hours respectively); after the injection, the permeability of the sand-filled tube is measured again. According to the permeability of the sand-filled tube before and after injection, the plugging rate of each sample can be calculated (plugging rate (%) = (permeability before injection - permeability after injection) / permeability before injection × 100%). The specific results are shown in Table 1 below, where each value is the average value of all samples in the same group.

[0025] Table 1: Plugging rate test.

[0026] project 2h（%） 4h（%） 6h（%） Example 1 88.5 93.7 96.4 Example 2 89.2 95.2 98.2 Example 3 90.1 94.6 98.1 Example 4 88.6 95.9 96.8 Comparative Example 1 80.2 84.6 90.2 Comparative Example 2 81.4 83.9 91.4 As can be seen from Table 1, Examples 1-4 of the present invention have better blocking rates than Comparative Examples 1-2.

[0027] The expansion rate test was carried out using a volume dilatometer in accordance with SY / T5590-2013, and the formation water salinity (5000 mg / L) was measured.

[0028] Table 2: Swelling rate test.

[0029] project 24h expansion rate (%) 48h expansion rate (%) 72h expansion rate (%) Example 1 0.34 0.26 0.18 Example 2 0.36 0.29 0.15 Example 3 0.31 0.25 0.16 Example 4 0.33 0.28 0.15 Comparative Example 1 0.40 0.36 0.24 Comparative Example 2 0.41 0.32 0.26 As can be seen from Table 2, Examples 1-4 of the present invention have better slow expansion effects than Comparative Examples 1-2.

[0030] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0031] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

[0032] Those skilled in the art should understand that the above descriptions are only some specific embodiments of the present invention, rather than all embodiments.

Claims

1. A flexible nylon slow expansion diversion profile control agent, characterized in that: The invention comprises the following components by weight: 50-65 parts by weight of nylon 66, 8-10 parts by weight of polyethylene glycol, 1-2 parts by weight of sodium sulfonate modified nano titanium dioxide, 2-4 parts by weight of EPDM rubber, 0.1-0.2 parts by weight of toughening agent polybutadiene, and 0.1-0.3 parts by weight of alkylbenzene oil extender.

2. The flexible nylon slow expansion diversion profile control agent according to claim 1, characterized in that: The preparation method of the sodium sulfonate modified nano titanium dioxide is: S1. Under a nitrogen atmosphere, 1,3-propylenediamine and 4-vinylbenzoyl chloride were added to N,N-dimethylformamide solvent, stirred and mixed, and pyridine catalyst was added. The reaction was allowed to proceed at room temperature. After completion, the reaction was filtered, washed, and rotary evaporated to obtain an alkenyl intermediate. S2. 25-30 mL of ethanol was added to 30-35 mL of water, ammonia was added dropwise to adjust the pH, and then 10-11 g of nano-titanium dioxide was added, ultrasonically dispersed for 10-15 min, and then heated, 10 mL of an ethanol solution containing 0.25-0.26 g of KH570 was added dropwise, stirred and refluxed for 1-2 h, cooled and allowed to stand for 12 h, filtered, washed with ethanol, and dried to obtain KH570-modified nano-titanium dioxide; S3. Add 1.1-1.2 g of styrene, 0.8-0.84 g of olefin intermediate, 0.5-1 g of KH570 modified nano titanium dioxide, and 0.4-0.8 g of 2-acrylamido-2-methylpropanesulfonate sodium to 65-80 mL of distilled water, stir for 10-15 min, then continue to add 0.02-0.03 g of emulsifier Span-80 and 0.01-0.02 g of OP-10, heat, and then continue to dropwise add 0.012-0.015 g of azobisisobutylamidine hydrochloride, react for 4-6 h, and then add 0.02-0.024 g of N,N'-diphenyl-p-phenylenediamine polymerization inhibitor, react under stirring for 0.5-1 h, cool after completion, add anhydrous ethanol to break the emulsion, evaporate, wash, and dry to obtain sodium sulfonate modified nano titanium dioxide.

3. The flexible nylon slow expansion and diversion profile control agent according to claim 2, characterized in that: The amount ratio of N,N-dimethylformamide solvent, 1,3-propylenediamine, 4-vinylbenzoyl chloride and pyridine catalyst in S1 is 50-60 mL: 0.71-0.75g: 3.1-3.3g: 0.01-0.02g.

4. The flexible nylon slow expansion diversion profile control agent according to claim 2, characterized in that: The reaction time in S1 is 4-6 hours.

5. The flexible nylon slow expansion and diversion profile control agent according to claim 2, characterized in that: The pH of S2 was adjusted to 9.

6. The flexible nylon slow expansion diversion profile control agent according to claim 2, characterized in that: The heating temperature in S2 is 75-80°C.

7. The flexible nylon slow expansion and diversion profile control agent according to claim 2, characterized in that: The heating temperature in S3 is 70-80°C.

8. A method for preparing the flexible nylon slow-swelling and diverting profile control agent according to any one of claims 1 to 7, characterized in that: The preparation method of the flexible nylon slow-swelling and diverting profile control agent comprises the following steps: adding nylon 66, sodium sulfonate-modified nano-titanium dioxide, EPDM rubber, and toughening agent polybutadiene into a high-speed mixer, mixing for 5-10 minutes, continuously adding polyethylene glycol and alkylbenzene oil extender, stirring for 10-15 minutes to obtain a preliminary material; transferring the preliminary material into a twin-screw extruder, processing at a temperature of 250-260° C., mixing for 10-15 minutes, and extruding to obtain the flexible nylon slow-swelling and diverting profile control agent.

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