Nanoscale wicking and expelling particles, methods of making and using the same
By preparing nano-silica frameworks and connecting carboxyl groups to nano-permeation and displacement particles, the problems of poor injection capacity and reservoir damage in low-permeability reservoirs have been solved, achieving high-efficiency oil recovery and low-cost oil extraction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2024-12-04
- Publication Date
- 2026-06-05
AI Technical Summary
Existing tertiary oil recovery methods have poor injection capacity in low-permeability reservoirs, which can easily lead to reservoir damage, affect displacement effect, and are costly.
Nanoparticles are used to prepare a nano-silica framework and attach carboxyl groups to it to form a nanoparticle-based permeation and displacement agent for oil extraction in low-permeability oil fields.
Nanoparticles can be stably dispersed in solution, separating and stripping crude oil, improving crude oil recovery, causing minimal reservoir damage, and are low in cost, thus having high development potential.
Smart Images
Figure CN122146273A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of oil and gas field development, specifically involving a nano-permeation and displacement particle, its preparation method and application. Background Technology
[0002] Along with the growth of the national economy and the rapid development of the domestic industrial system, the average annual growth rate of oil consumption has also increased rapidly, exceeding the average annual growth rate of my country's oil production. Therefore, how to better utilize domestic and foreign oil resources to meet the needs of my country's rapid economic development has become a focus of attention for many scientific researchers.
[0003] Low-permeability oilfields refer to oilfields with low reservoir permeability, low abundance, and low single-well productivity. Low-permeability oil and gas fields are of great significance to my country's oil and gas development. my country's low-permeability oil and gas resources are characterized by abundant oil and gas content, diverse reservoir types, wide distribution areas, and a pattern of "gas above oil, marine gas as the main component, and continental oil and gas as well." Low-permeability oil reservoirs account for a very high proportion of the proven reserves, approximately two-thirds of the national total, indicating enormous development potential.
[0004] Tertiary oil recovery is a technology to enhance the recovery rate of crude oil in low-permeability oilfields. It is implemented after primary and secondary oil recovery and is used when crude oil in a reservoir is difficult to extract through natural or simple methods. Tertiary oil recovery involves injecting chemicals, gases, heat, or microorganisms to alter the viscosity or interfacial tension of the crude oil, thereby effectively displacing discontinuous and difficult-to-extract crude oil from the reservoir. Practice has proven that tertiary oil recovery can increase recovery rates and expand oil reserves. If this potential can be fully realized, it would be equivalent to more than doubling my country's recoverable reserves. Therefore, developing tertiary oil recovery is an essential path for my country's oil extraction.
[0005] Currently, the most commonly used chemical flooding methods in tertiary oil recovery include gel flooding, polymer flooding, microbial flooding, and foam flooding. For example, Chinese invention patent application CN 106150466A discloses a method for heavy oil thermal recovery by inhibiting bottom water coning with gel foam, belonging to the field of oilfield development and oilfield chemical technology. This method includes the following steps: 1) When the overall water cut of the oil well is greater than 90% during the cycle, nitrogen is injected into the oil well to form a pre-nitrogen slug; 2) A mixture of nitrogen and gel foam agent solution is continued to be injected into the oil well to form a nitrogen-gel foam main slug; 3) Nitrogen is injected into the oil well to form a displacement nitrogen slug; 4) Steam is injected. The pre-nitrogen slug can push water from the wellbore and near-wellbore zone to the oil layer, balancing formation pressure. The nitrogen-gel foam main slug can effectively inhibit bottom water intrusion, and the displacement nitrogen slug can displace the gel foam plugging agent from the screen pipe and near-wellbore zone, preventing the plugging agent from solidifying near the wellbore and blocking the steam injection and oil production channels. For example, Chinese invention patent application CN 101493003A discloses a method for microbial enhanced oil recovery, which includes a process of using a bacterial solution for oil displacement after polymer flooding of the oil reservoir. The bacterial solution is a mixture or fermentation broth of Clostridium perfringens 6# CGMCC NO.2439, Bacillus brevis of Potsdamer lanceolata POCGMCC NO.2441, or Bacillus licheniformis U1-3 CGMCC NO.2437 with a culture medium, or a combination thereof. Another example is Chinese invention patent application CN 108316901A, which relates to a method for highly efficient enhanced oil recovery, mainly addressing the problems of low efficiency, high preparation cost, and poor plugging ability in existing fluid flooding technologies. This invention employs a highly efficient enhanced oil recovery method, comprising the following steps: 1) mixing an oil displacement agent with water to obtain an oil displacement fluid; 2) contacting the oil displacement fluid with an oil-bearing formation at an oil displacement temperature of 25–150°C and a total salinity >500 mg / L of formation water to displace crude oil from the oil-bearing formation; wherein, the oil displacement fluid, by mass fraction, comprises the following components: 0–100 parts of polymer profile control or mobility control agent, 1 part of surfactant, and 0–50 parts of alkali; the oil displacement system contains 0.001–1.0 wt% of composite surfactant, 0–1.5 wt% of polymer profile control or mobility control agent, and 0–1.5 wt% of alkali. This technical solution effectively solves the following technical problems: (1) Gels, polymers, microbial fermentation broths and other agents have poor injection capacity in low-permeability reservoirs and cannot penetrate well into the high-permeability zone of low-permeability reservoirs, affecting the displacement effect; (2) They are prone to causing reservoir damage. Summary of the Invention
[0006] Purpose of the invention: The present invention addresses the problems existing in the prior art by disclosing a nano-osmotic displacement particle, its preparation method, and its application.
[0007] Technical solution: A nano-osmotic displacement particle, wherein the nano-osmotic displacement particle comprises a nano-silica framework and carboxyl groups attached to the nano-silica framework.
[0008] The preparation method of the above-mentioned nano-osmotic displacement particles includes the following steps:
[0009] (1) Add sulfuric acid solution to sodium metasilicate solution and react to obtain the first reaction solution;
[0010] (2) Add C-based modifier to the first reaction solution and react to obtain the second reaction solution;
[0011] (3) Heat the second reaction solution to the reaction temperature and carry out the grafting reaction to obtain the third reaction solution;
[0012] (4) The third reaction solution is filtered, washed, and dried to obtain nano-osmotic displacement particles.
[0013] Further, the mass concentration of the sulfuric acid solution in step (1) is at least 9%, preferably 9.5% to 10.5%, and the solvent is water.
[0014] Furthermore, the mass concentration of the sodium metasilicate solution in step (1) is at least 3%, preferably 3% to 5%, and the solvent is water.
[0015] Further, the volume ratio of the sulfuric acid solution to the sodium metasilicate solution in step (1) is at most 1:18, preferably 1:(18-30).
[0016] Further, the reaction conditions for step (1) are as follows: the reaction temperature is at least 40°C, preferably 40-50°C; the reaction time is at least 20 min, preferably 20-60 min.
[0017] Furthermore, the C-based modifier mentioned in step (2) is prepared by the following method:
[0018] An aqueous solution of sodium carboxyethylsilanetriol was slowly added dropwise to an aqueous sulfuric acid solution to carry out the reaction. After the reaction was completed, a C-based modifier was obtained, wherein:
[0019] The aqueous solution of sodium carboxyethylsilane triol has a mass concentration of at least 10 wt%, preferably 10 wt% to 25 wt%.
[0020] The mass concentration of the sulfuric acid aqueous solution is at least 10 wt%, preferably 10 wt% to 30 wt%.
[0021] Furthermore, the C-based modifier is a hydrophobic silane with the following structural formula:
[0022]
[0023] Furthermore, the volume ratio of the above-mentioned sodium carboxyethylsilane triol salt aqueous solution to sulfuric acid aqueous solution is at most 1:3, preferably 1:3 to 8.
[0024] Furthermore, the volume ratio of the C-based modifier to the first reaction solution in step (2) is at most 1:18, preferably 1:18 to 30.
[0025] Further, the reaction conditions for step (2) are: the reaction temperature is at least 55°C, preferably 55-65°C, and the reaction time is at least 80 min, preferably 80-150 min.
[0026] Furthermore, the reaction conditions for the grafting reaction in step (3) are as follows: the reaction temperature is at least 75°C, preferably 75-80°C, and the reaction time is at least 80 min, preferably 80-150 min.
[0027] Further, the specific steps of step (4) are as follows: filter the third reaction solution, take the filter cake, and then wash it at least twice with water, preferably pure water or deionized water, and put it into an oven for drying. The specific drying process control parameters are as follows:
[0028] The drying temperature is at least 100℃, preferably 100-120℃, and the drying time is at least 80 minutes, preferably 80-150 minutes.
[0029] The nanoparticles are prepared by any of the preparation methods described above.
[0030] The above-mentioned nano-permeation and displacement particles are used as oil displacement agents in the oil extraction of low-permeability oil fields.
[0031] The specific steps for the above application are as follows:
[0032] The nano-permeation and displacement particles are thoroughly wetted with anhydrous ethanol, then an alkaline solution is added, and the mixture is stirred to react. After the reaction is complete, the nano-permeation and displacement agent is obtained, which is then directly injected into the target oil layer in the low-permeability oilfield through an injection well.
[0033] Furthermore, the alkaline solution is one of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, or ammonia aqueous solution.
[0034] Furthermore, the mass ratio of the aforementioned nano-permeation and displacement particles to anhydrous ethanol is at most 1:1, preferably (1:1 to 10), and / or
[0035] The concentration of the alkaline solution is at least 0.01 mol / L, preferably 0.01–0.15 mol / L, and / or
[0036] The mass ratio of nano-permeation and displacement particles to alkaline solution is at most 1:10, preferably 1:10 to 200, and / or
[0037] The reaction conditions are as follows: the reaction temperature is at least 60°C, preferably 60-90°C, and the reaction time is at least 60 min, preferably 60-200 min.
[0038] The advantages of the nano-permeation and displacement particles disclosed in this invention are that they cause less reservoir damage and, due to their smaller size, they have certain advantages when injected into low-permeability reservoirs.
[0039] Invention Effects: The nano-osmotic displacement particles, their preparation method, and applications disclosed in this invention have the following beneficial effects:
[0040] (1) The nano-permeation and displacement particles prepared by the present invention have strong controllability and stability, can be stably dispersed in solution, and can separate and strip crude oil and emulsify crude oil. They can be used as nano-permeation and displacement agents for tertiary oil recovery in low-permeability reservoirs to improve crude oil recovery rate.
[0041] (2) The preparation method is simple, environmentally friendly, and low in cost, and has high development potential. Attached Figure Description
[0042] Figure 1 This is an infrared curve of the nanoparticles prepared in Example 4.
[0043] Figure 2 This is a particle size distribution diagram of the nanoparticles prepared in Example 4.
[0044] Figure 3 This is a TEM image of the nanoparticles prepared in Example 4.
[0045] Figure 4 This is a fluid image of the nano-permeation and displacement agent prepared in Example 4. Detailed Implementation
[0046] The specific embodiments of the present invention are described in detail below.
[0047] The "range" disclosed in this invention is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 10–50 is listed for a specific parameter, it is also expected that ranges of 10–40 and 20–50 are also included. Furthermore, if the minimum range values are 1 and 2, and the maximum range values are 3, 4, and 5, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0–5" means that all real numbers between "0–5" have been listed herein; "0–5" is merely a shortened representation of these numerical combinations.
[0048] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.
[0049] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.
[0050] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.
[0051] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.
[0052] Unless otherwise specified, the reaction will proceed under normal temperature and pressure conditions.
[0053] Unless otherwise specified, all parts or percentages are by weight or by weight percentage.
[0054] In this invention, all the substances used are known substances that can be purchased or synthesized by known methods.
[0055] In this invention, all the devices or equipment used are conventional devices or equipment known in the art and are readily available.
[0056] The raw materials used in this invention are as follows:
[0057] Sodium metasilicate is sodium metasilicate nonahydrate.
[0058] The method for preparing sodium metasilicate solution is as follows: weigh sodium metasilicate, add deionized water, stir at high speed until completely dissolved, and set aside; the mass fraction of sodium metasilicate solution can be selected from 3 to 5%.
[0059] The method for preparing sulfuric acid solution is as follows: add concentrated sulfuric acid to deionized water until completely miscible to prepare a sulfuric acid solution for later use; the mass fraction of the sulfuric acid solution can be selected from 9.5% to 10.5%.
[0060] Other materials used in this invention, unless otherwise stated, are commercially available. Other terms used in this invention, unless otherwise specified, generally have the meanings commonly understood by those skilled in the art. The invention is further described in detail below with reference to specific embodiments and data. The following embodiments are merely illustrative and not intended to limit the scope of the invention in any way.
[0061] Example 1
[0062] A nanoparticle for permeation and displacement, the nanoparticle comprising a nano-silica framework and carboxyl groups attached to the nano-silica framework.
[0063] The preparation method of the above-mentioned nano-osmotic displacement particles includes the following steps:
[0064] (1) Add sulfuric acid solution to sodium metasilicate solution and react to obtain the first reaction solution;
[0065] (2) Add C-based modifier to the first reaction solution and react to obtain the second reaction solution;
[0066] (3) Heat the second reaction solution to the reaction temperature and carry out the grafting reaction to obtain the third reaction solution;
[0067] (4) The third reaction solution is filtered, washed, and dried to obtain nano-osmotic displacement particles.
[0068] Further, the sulfuric acid solution in step (1) has a mass concentration of 9% and the solvent is water. In another embodiment, the sulfuric acid solution in step (1) has a mass concentration of 10% and the solvent is water.
[0069] Furthermore, the sodium metasilicate solution in step (1) has a mass concentration of 3% and the solvent is water.
[0070] Further, the volume ratio of the sulfuric acid solution to the sodium metasilicate solution in step (1) is 1:18.
[0071] Furthermore, the reaction conditions for step (1) are as follows: the reaction temperature is 40℃; the reaction time is 60min.
[0072] Furthermore, the C-based modifier mentioned in step (2) is prepared by the following method:
[0073] An aqueous solution of sodium carboxyethylsilanetriol was slowly added dropwise to an aqueous sulfuric acid solution to carry out the reaction. After the reaction was completed, a C-based modifier was obtained, wherein:
[0074] The aqueous solution of sodium carboxyethylsilanetriol has a mass concentration of 10 wt%.
[0075] The mass concentration of the sulfuric acid aqueous solution is 10 wt%.
[0076] Furthermore, the C-based modifier is a hydrophobic silane with the following structural formula:
[0077]
[0078] Furthermore, the volume ratio of the above-mentioned sodium carboxyethylsilane triol salt aqueous solution to the sulfuric acid aqueous solution is 1:3.
[0079] Furthermore, the volume ratio of the C-based modifier to the first reaction solution in step (2) is 1:18.
[0080] Furthermore, the reaction conditions for step (2) are: a reaction temperature of 55°C and a reaction time of 150 min.
[0081] Furthermore, the reaction conditions for the grafting reaction in step (3) are as follows: the reaction temperature is 75℃ and the reaction time is 150min.
[0082] Further, the specific steps of step (4) are as follows: filter the third reaction solution, take the filter cake, wash it twice with water, and put it into an oven for drying. The specific drying process control parameters are as follows:
[0083] The drying temperature is 100℃, and the drying time is 150 minutes.
[0084] The nanoparticles are prepared by any of the preparation methods described above.
[0085] The above-mentioned nano-permeation and displacement particles are used as oil displacement agents in the oil extraction of low-permeability oil fields.
[0086] The specific steps for the above application are as follows:
[0087] The nano-permeation and displacement particles are thoroughly wetted with anhydrous ethanol, then an alkaline solution is added, and the mixture is stirred to react. After the reaction is complete, the nano-permeation and displacement agent is obtained, which is then directly injected into the target oil layer in the low-permeability oilfield through an injection well.
[0088] Furthermore, the alkaline solution is an aqueous solution of sodium hydroxide.
[0089] Furthermore, the mass ratio of the aforementioned nanoparticles to anhydrous ethanol is 1:1, and / or
[0090] The concentration of the alkali solution is 0.01 mol / L, and / or
[0091] The mass ratio of nanoparticles to alkaline solution is 1:10, and / or
[0092] The reaction conditions were: a reaction temperature of 60℃ and a reaction time of 200 min.
[0093] Example 2
[0094] A nanoparticle for permeation and displacement, the nanoparticle comprising a nano-silica framework and carboxyl groups attached to the nano-silica framework.
[0095] The preparation method of the above-mentioned nano-osmotic displacement particles includes the following steps:
[0096] (1) Add sulfuric acid solution to sodium metasilicate solution and react to obtain the first reaction solution;
[0097] (2) Add C-based modifier to the first reaction solution and react to obtain the second reaction solution;
[0098] (3) Heat the second reaction solution to the reaction temperature and carry out the grafting reaction to obtain the third reaction solution;
[0099] (4) The third reaction solution is filtered, washed, and dried to obtain nano-osmotic displacement particles.
[0100] Furthermore, the sulfuric acid solution in step (1) has a mass concentration of 10.5% and the solvent is water.
[0101] Furthermore, the sodium metasilicate solution in step (1) has a mass concentration of at least 5% and the solvent is water.
[0102] Further, the volume ratio of the sulfuric acid solution to the sodium metasilicate solution in step (1) is 1:30.
[0103] Furthermore, the reaction conditions for step (1) are as follows: the reaction temperature is 50℃; the reaction time is 20min.
[0104] Furthermore, the C-based modifier mentioned in step (2) is prepared by the following method:
[0105] An aqueous solution of sodium carboxyethylsilanetriol was slowly added dropwise to an aqueous sulfuric acid solution to carry out the reaction. After the reaction was completed, a C-based modifier was obtained, wherein:
[0106] The aqueous solution of sodium carboxyethylsilanetriol has a mass concentration of 25 wt%.
[0107] The mass concentration of the sulfuric acid aqueous solution is 30 wt%.
[0108] Furthermore, the C-based modifier is a hydrophobic silane with the following structural formula:
[0109]
[0110] Furthermore, the volume ratio of the above-mentioned sodium carboxyethylsilane triol salt aqueous solution to the sulfuric acid aqueous solution is 1:8.
[0111] Furthermore, the volume ratio of the C-based modifier to the first reaction solution in step (2) is 1:30.
[0112] Furthermore, the reaction conditions for step (2) are: a reaction temperature of 65°C and a reaction time of 80 min.
[0113] Furthermore, the reaction conditions for the grafting reaction in step (3) are as follows: the reaction temperature is 80℃ and the reaction time is 80min.
[0114] Further, the specific steps of step (4) are as follows: filter the third reaction solution, take the filter cake, wash it 5 times with pure water, and put it into an oven for drying. The specific drying process control parameters are as follows:
[0115] The drying temperature is 120℃ and the drying time is 80 minutes.
[0116] The nanoparticles are prepared by any of the preparation methods described above.
[0117] The above-mentioned nano-permeation and displacement particles are used as oil displacement agents in the oil extraction of low-permeability oil fields.
[0118] The specific steps for the above application are as follows:
[0119] The nano-permeation and displacement particles are thoroughly wetted with anhydrous ethanol, then an alkaline solution is added, and the mixture is stirred to react. After the reaction is complete, the nano-permeation and displacement agent is obtained, which is then directly injected into the target oil layer in the low-permeability oilfield through an injection well.
[0120] Furthermore, the alkaline solution is an aqueous solution of potassium hydroxide.
[0121] Furthermore, the mass ratio of the aforementioned nanoparticles to anhydrous ethanol is 1:10, and / or
[0122] The concentration of the alkali solution is 0.15 mol / L, and / or
[0123] The mass ratio of nano-permeation and displacement particles to alkaline solution is 1:200, and / or
[0124] The reaction conditions were: a reaction temperature of 90℃ and a reaction time of 60 min.
[0125] Example 3
[0126] A nanoparticle for permeation and displacement, the nanoparticle comprising a nano-silica framework and carboxyl groups attached to the nano-silica framework.
[0127] The preparation method of the above-mentioned nano-osmotic displacement particles includes the following steps:
[0128] (1) Add sulfuric acid solution to sodium metasilicate solution and react to obtain the first reaction solution;
[0129] (2) Add C-based modifier to the first reaction solution and react to obtain the second reaction solution;
[0130] (3) Heat the second reaction solution to the reaction temperature and carry out the grafting reaction to obtain the third reaction solution;
[0131] (4) The third reaction solution is filtered, washed, and dried to obtain nano-osmotic displacement particles.
[0132] Furthermore, the sulfuric acid solution in step (1) has a mass concentration of 9.5% and the solvent is water.
[0133] Furthermore, the mass concentration of the sodium metasilicate solution in step (1) is 4%.
[0134] Further, the volume ratio of the sulfuric acid solution to the sodium metasilicate solution in step (1) is 1:24.
[0135] Furthermore, the reaction conditions for step (1) are as follows: the reaction temperature is 45℃; the reaction time is 30min.
[0136] Furthermore, the C-based modifier mentioned in step (2) is prepared by the following method:
[0137] An aqueous solution of sodium carboxyethylsilanetriol was slowly added dropwise to an aqueous sulfuric acid solution to carry out the reaction. After the reaction was completed, a C-based modifier was obtained, wherein:
[0138] The aqueous solution of sodium carboxyethylsilanetriol has a mass concentration of 20 wt%.
[0139] The mass concentration of the sulfuric acid aqueous solution is 20 wt%.
[0140] Furthermore, the C-based modifier is a hydrophobic silane with the following structural formula:
[0141]
[0142] Furthermore, the volume ratio of the above-mentioned sodium carboxyethylsilane triol salt aqueous solution to the sulfuric acid aqueous solution is 1:7.
[0143] Furthermore, the volume ratio of the C-based modifier to the first reaction solution in step (2) is 1:24.
[0144] Furthermore, the reaction conditions for step (2) are: a reaction temperature of 60°C and a reaction time of 120 min.
[0145] Furthermore, the reaction conditions for the grafting reaction in step (3) are as follows: the reaction temperature is 78℃ and the reaction time is 120min.
[0146] Further, the specific steps of step (4) are as follows: filter the third reaction solution, take the filter cake, wash it three times with deionized water, and put it into an oven for drying. The specific drying process control parameters are as follows:
[0147] The drying temperature is 110℃ and the drying time is 120 minutes.
[0148] The nanoparticles are prepared by any of the preparation methods described above.
[0149] The above-mentioned nano-permeation and displacement particles are used as oil displacement agents in the oil extraction of low-permeability oil fields.
[0150] The specific steps for the above application are as follows:
[0151] The nano-permeation and displacement particles are thoroughly wetted with anhydrous ethanol, then an alkaline solution is added, and the mixture is stirred to react. After the reaction is complete, the nano-permeation and displacement agent is obtained, which is then directly injected into the target oil layer in the low-permeability oilfield through an injection well.
[0152] Furthermore, the alkaline solution is one of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, or ammonia aqueous solution.
[0153] Furthermore, the mass ratio of the aforementioned nano-osmotic displacement particles to anhydrous ethanol is 1:4, and / or
[0154] The concentration of the alkali solution is 0.03 mol / L, and / or
[0155] The mass ratio of nanoparticles to alkaline solution is 1:100, and / or
[0156] The reaction conditions were: a reaction temperature of 75°C and a reaction time of 120 min.
[0157] Example 4
[0158] A nanoparticle for permeation and displacement, the nanoparticle comprising a nano-silica framework and carboxyl groups attached to the nano-silica framework.
[0159] The preparation method of the above-mentioned nano-osmotic displacement particles includes the following steps:
[0160] (1) Add a 10% sulfuric acid solution to a 5% sodium metasilicate solution at a volume ratio of 1:18, control the reaction temperature at 40℃, and react for 30 min to obtain the first reaction solution;
[0161] (2) Add the C-based modifier to the first reaction solution at a volume ratio of 1:18, and raise the temperature to 60°C and react for 2 hours to obtain the second reaction solution;
[0162] (3) Raise the temperature of the second reaction solution to 80°C and carry out the grafting reaction for 1.5 hours. After the reaction is completed, filter the reaction solution, wash it twice with deionized water, and dry it in an oven at 120°C for 120 minutes to obtain nano-osmotic displacement particles.
[0163] The grafting reaction mentioned above refers to the reaction between the Si-OH group of silica nanocrystals and the C-group of the modifier, so that COOH is grafted onto the silica surface, thereby completing the modification of the silica surface.
[0164] In this embodiment, the C-based modifier is prepared by the following method:
[0165] 10 mL of sodium carboxyethylsilanetriol was slowly added dropwise to 32.5 mL of sulfuric acid aqueous solution and reacted for 30 min to obtain the C-based modifier.
[0166] The steps for preparing the nano-osmotic displacement agent are as follows:
[0167] Take 1g of nano-osmotic displacement particles, first wet them with anhydrous ethanol, the mass ratio of nano-osmotic displacement particles to anhydrous ethanol is 1:5; after thorough wetting, add 100mL of 0.02mol / L NaOH alkaline solution, mix thoroughly, and stir at 80℃ for 150min to obtain nano-osmotic displacement agent fluid with a concentration of about 1%.
[0168] A physical image of the nano-permeation and displacement agent fluid is shown below. Figure 4 As shown: From Figure 4 It can be seen that the nano-permeation and displacement agent is evenly dispersed, and its appearance is a uniform semi-transparent liquid.
[0169] Performance testing and characterization
[0170] Test Example 1: Infrared Test
[0171] Infrared detection was performed on silica and the nanoparticles prepared in Example 4, and the infrared detection curves are shown below. Figure 1 As shown. Figure 1 As shown:
[0172] 1556cm -1 The absorption peaks are characteristic of the symmetric and asymmetric stretching vibrations of the carboxylic acid (COO-) group. This demonstrates the successful modification of the silica surface with carboxyl groups. The peak at 1097 cm⁻¹... -1 A strong absorption peak with a broad Si-O-Si bond was also observed at 847 cm⁻¹, indicating that Si-O-Si remains the main chain structure. -1 A vibrational peak of Si-C appeared nearby, indicating that CH3 is bonded to the less electronegative Si. Infrared results confirm that the nanoparticles of permeation and displacement were successfully synthesized.
[0173] Test Example 2
[0174] A certain mass of the nanoparticles prepared in Example 4 were weighed and dispersed in deionized water. The mixture was sonicated for 30 minutes until the nanoparticles were uniformly dispersed. The solution was then diluted to a suitable concentration. The silica nanoparticle dispersion was transferred to a quartz cuvette, and the particle size distribution was measured using a nanoparticle size analyzer (NanoS). Specific results... Figure 2 As shown. From Figure 2 It can be seen that the size of the nanoparticles underwent a slight increase after modification with silane modifier.
[0175] Test Example 3
[0176] A small amount of the aqueous solution of the nano-permeation and displacement particles obtained in Test Example 2 was dropped onto a copper grid. After adsorption for 5 seconds, the sample was dried and observed and analyzed using a Tecnai G2F20 S-TWIN transmission electron microscope. The TEM image is shown below. Figure 3 As shown. From Figure 3 It can be seen that the nanoparticles exhibit a particulate state in the solution.
[0177] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.
Claims
1. A nanoparticle for permeation and displacement, characterized in that, The nanoparticles for permeation and displacement include a nano-silica framework and carboxyl groups attached to the nano-silica framework.
2. A method for preparing the nano-osmotic and expulsive particles according to claim 1, characterized in that, Includes the following steps: (1) Add sulfuric acid solution to sodium metasilicate solution and react to obtain the first reaction solution; (2) Add C-based modifier to the first reaction solution and react to obtain the second reaction solution; (3) Heat the second reaction solution to the reaction temperature and carry out the grafting reaction to obtain the third reaction solution; (4) The third reaction solution is filtered, washed, and dried to obtain nano-osmotic displacement particles.
3. The method for preparing nano-osmotic and expulsive particles as described in claim 2, characterized in that, The sulfuric acid solution in step (1) has a mass concentration of at least 9%, preferably 9.5% to 10.5%, and the solvent is water, and / or The sodium metasilicate solution in step (1) has a mass concentration of at least 3%, preferably 3% to 5%, and the solvent is water, and / or The volume ratio of the sulfuric acid solution to the sodium metasilicate solution in step (1) is at most 1:18, preferably 1:(18-30), and / or The reaction conditions for step (1) are as follows: the reaction temperature is at least 40°C, preferably 40-50°C; the reaction time is at least 20 min, preferably 20-60 min.
4. The method for preparing nano-osmotic and expulsive particles as described in claim 2, characterized in that, The C-based modifier mentioned in step (2) is prepared by the following method: An aqueous solution of sodium carboxyethylsilanetriol was slowly added dropwise to an aqueous sulfuric acid solution to carry out the reaction. After the reaction was completed, a C-based modifier was obtained, wherein: The aqueous solution of sodium carboxyethylsilane triol has a mass concentration of at least 10 wt%, preferably 10 wt% to 25 wt%. The mass concentration of the sulfuric acid aqueous solution is at least 10 wt%, preferably 10 wt% to 30 wt%.
5. The method for preparing nano-osmotic and expulsive particles as described in claim 4, characterized in that, The C-based modifier is a hydrophobic silane, and its structural formula is as follows:
6. The method for preparing nano-osmotic and expulsive particles as described in claim 4, characterized in that, The volume ratio of the above-mentioned sodium carboxyethylsilane triol salt aqueous solution to sulfuric acid aqueous solution is at most 1:3, preferably 1:3 to 8 and / or The volume ratio of the C-based modifier to the first reaction solution in step (2) is at most 1:18, preferably 1:18 to 30 and / or The reaction conditions for step (2) are: the reaction temperature is at least 55°C, preferably 55-65°C, and the reaction time is at least 80 min, preferably 80-150 min.
7. The method for preparing nano-osmotic and expulsive particles as described in claim 4, characterized in that, The reaction conditions for the grafting reaction in step (3) are as follows: reaction temperature at least 75°C, preferably 75–80°C, reaction time at least 80 min, preferably 80–150 min, and / or The specific steps of step (4) are as follows: Filter the third reaction solution, take the filter cake, and then wash it at least twice with water, preferably pure water or deionized water. Place it in an oven to dry. The specific drying process control parameters are as follows: The drying temperature is at least 100℃, preferably 100-120℃, and the drying time is at least 80 minutes, preferably 80-150 minutes.
8. Nanoparticles for permeation and displacement, characterized in that, It is prepared by the preparation method according to any one of claims 2-7.
9. The application of the nano-permeation and displacement particles described in claim 1 or 8 as an oil displacement agent in the extraction of oil in low-permeability oil fields.
10. The application as described in claim 9, characterized in that, The specific steps for the above application are as follows: The nano-permeation and displacement particles are thoroughly wetted with anhydrous ethanol, then an alkaline solution is added, and the mixture is stirred to react. After the reaction is complete, the nano-permeation and displacement agent is obtained, which is then directly injected into the target oil layer in the low-permeability oilfield through an injection well.
11. The application as described in claim 10, characterized in that, The alkaline solution is one of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, or ammonia aqueous solution, and / or The mass ratio of the above-mentioned nano-permeation and displacement particles to anhydrous ethanol is at most 1:1, preferably (1:1 to 10), and / or The concentration of the alkaline solution is at least 0.01 mol / L, preferably 0.01–0.15 mol / L, and / or The mass ratio of nano-permeation and displacement particles to alkaline solution is at most 1:10, preferably 1:10 to 200, and / or The reaction conditions are as follows: the reaction temperature is at least 60°C, preferably 60-90°C, and the reaction time is at least 60 min, preferably 60-200 min.