A nano-bubble displacement agent suitable for various temperature and salinity environments, and a preparation method and application thereof

Abstract

The application provides a nano bubble displacement agent suitable for various temperature and salinity environments and a preparation method and application thereof. The nano bubble displacement agent comprises an anionic surfactant, a nonionic surfactant, a zwitterionic surfactant, a foam stabilizing particle and a solvent; the total mass concentration of the anionic surfactant, the nonionic surfactant and the zwitterionic surfactant in the nano bubble displacement agent is 0.1-1.0 wt%, and the mass concentration of the foam stabilizing particle is 0.1-0.5 wt%; the mass ratio of the anionic surfactant, the nonionic surfactant and the zwitterionic surfactant is 10-30:15-20:15-25. The bubble displacement agent has good foaming, foam stabilizing and liquid carrying capacities in the range of 35-95 DEG C and 10000 mg / L-50000 mg / L salinity, has good salt resistance and calcium and magnesium ion resistance, and can adapt to various temperatures and different salinity environments.

Description

Technical Field

[0001] This invention belongs to the field of foaming agent preparation technology, specifically relating to a nano foaming agent suitable for various temperature and mineralization environments, its preparation method and application. Background Technology

[0002] In the field of natural gas extraction, foam drainage gas production technology is widely used due to its efficient ability to separate gas and liquid. With the development of unconventional natural gas resources such as shale gas, complex mineralization environments place higher demands on the performance of foam drainage agents. Especially under varying temperature and mineralization conditions, traditional foam drainage agents often struggle to simultaneously meet the comprehensive performance requirements of temperature and salt resistance. Therefore, developing novel multi-temperature adaptable nano-foam drainage agents to adapt to drainage gas production operations in complex mineralization environments has become a current research hotspot. Specifically, the foaming performance, foam stabilization performance, and liquid carrying capacity of foam drainage agents are key factors determining the effectiveness of foam drainage gas production.

[0003] Recent research has focused on improving the environmental adaptability of degassing agents through chemical modification and the introduction of nanotechnology. For example, Chinese patent document CN117625165A discloses a high-temperature degassing agent for drainage and gas extraction, whose components are cellulose, dodecylamine, aminosulfonic acid, and methanol, but its salt resistance is poor. Chinese patent document CN115785933A discloses a salt-suppressing foaming agent for use in the development of high-salinity natural gas wells. Its components include the following parts by weight: 30-40 parts sulfonated AEO3, 10-20 parts OP-10, 10-20 parts maleic anhydride (MA) / sodium p-styrene sulfonate (SSS) binary polymer, 5-10 parts polyaspartic acid, 5-10 parts ethylene glycol, and 3-5 parts fatty alcohol polyoxyethylene ether sodium sulfate. Within the salinity range of 200-350 g / L, the foaming power and liquid carrying capacity do not show a significant decreasing trend. However, as the salinity increases, its foaming power and liquid carrying capacity show a significant decreasing trend, or even complete failure.

[0004] Currently, effectively coping with complex and variable temperature and salinity environments has become one of the key challenges in improving oil and gas recovery efficiency. Especially under extreme temperature and high salinity conditions, traditional foaming agents often fail to maintain stability or exert their effects, leading to increased development costs and reduced recovery rates in oil and gas fields. Therefore, it is necessary to develop a nano-foaming agent that can adapt to various temperature and salinity environments, and to achieve effective development of oil and gas fields under complex environments through material innovation and process optimization. This invention is proposed for this purpose. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a nano-foaming agent suitable for various temperature and mineralization environments, along with its preparation method and applications. The foaming agent of this invention exhibits good foaming, foam stabilizing, and liquid-carrying capabilities within a temperature range of 35-95℃ and a mineralization range of 10000mg / L-50000mg / L. It also demonstrates good compatibility with formation water and excellent resistance to salt and calcium / magnesium ions. This allows it to adapt to various temperature and mineralization environments, solving the problem of poor performance of existing foaming agents at different temperatures and mineralization levels.

[0006] The technical solution of the present invention is as follows:

[0007] A nanobubble desiccant suitable for various temperature and mineralization environments, comprising anionic surfactant, nonionic surfactant, amphoteric surfactant, foam-stabilizing particles, and solvent; wherein the total mass concentration of the anionic surfactant, nonionic surfactant, and amphoteric surfactant in the nanobubble desiccant is 0.1-1.0 wt%, and the mass concentration of the foam-stabilizing particles is 0.1-0.5 wt%; wherein the mass ratio of the anionic surfactant, nonionic surfactant, and amphoteric surfactant is 10-30:15-20:15-25.

[0008] According to a preferred embodiment of the present invention, the total mass concentration of anionic surfactant, nonionic surfactant and amphoteric surfactant in the nanobubble desiccant is 0.5-0.9 wt%.

[0009] According to a preferred embodiment of the present invention, the anionic surfactant is alkylphenol polyoxyethylene ether phosphate (APE-4P) and / or sodium cocoyl hydroxyethyl sulfonate (CAS No.: 61789-32-0).

[0010] According to a preferred embodiment of the present invention, the nonionic surfactant is a fatty alcohol polyoxyethylene ether, more preferably one or a combination of two or more of fatty alcohol polyoxyethylene ether 3 (AEO-3), fatty alcohol polyoxyethylene ether 5 (AEO-5), fatty alcohol polyoxyethylene ether 7 (AEO-7), and fatty alcohol polyoxyethylene ether 9 (AEO-9), and more preferably fatty alcohol polyoxyethylene ether 9 (AEO-9).

[0011] According to a preferred embodiment of the present invention, the zwitterionic surfactant is one or a combination of two or more of the following: cocoylpropyl sulfonyl betaine (CHSB, CAS No. 68139-30-0), lauramide propylamine oxide (LAO-30, CAS No. 61792-31-2), cocoamide propyl betaine (LAB-35, CAS No. 61789-40-0), and hexadecyl dimethyl hydroxypropyl sulfonyl betaine (HSB1618), and more preferably lauramide propylamine oxide (LAO-30).

[0012] According to a preferred embodiment of the present invention, the mass ratio of anionic surfactant, nonionic surfactant and amphoteric surfactant in the nanobubble desiccant is 1:1:1.

[0013] According to a preferred embodiment of the present invention, the foam-stabilizing particles are one of nano-silica, carbon nanofibers (CNF), and titanium dioxide nanoparticles, more preferably nano-silica; the particle size of the nano-silica is 80-100 nm; the particle size of the titanium dioxide nanoparticles is 80-100 nm; and the diameter of the carbon nanofibers (CNF) is 10-500 nm and the length is 0.5-100 μm.

[0014] According to a preferred embodiment of the present invention, the solvent is one or a combination of two or more of water, methanol, and ethanol. In the present invention, no special requirements are put forward for the water quality. The water can be deionized water or water containing inorganic minerals. The water containing inorganic minerals can be tap water, gas well formation water, gas well injection water, or mineralized water. The mineralization of the mineralized water is 10,000 mg / L-50,000 mg / L.

[0015] According to the present invention, the preparation method of the above-mentioned nanobubble depletion agent suitable for various temperature and mineralization environments includes the following steps:

[0016] At room temperature, anionic surfactants, nonionic surfactants, and amphoteric surfactants are added to a solvent to obtain a mixed solution. Then, foam-stabilizing particles are added to the mixed solution and ultrasonically dispersed to obtain the final product.

[0017] According to the present invention, the above-mentioned nanobubble drainage agent suitable for various temperature and salinity environments is applied in gas well drainage and gas production. The temperature of the gas well is 35-95℃, such as 35℃, 50℃, 65℃, 80℃, 95℃, etc.; the salinity of the gas well is 10000mg / L-50000mg / L, such as 10000mg / L, 20000mg / L, 30000mg / L, 40000mg / L, 50000mg / L, etc.

[0018] The technical features and beneficial effects of this invention are as follows:

[0019] 1. The foaming agent of this invention is a compound of foam-stabilizing particles, anionic surfactants, nonionic surfactants, and amphoteric surfactants. The foaming agent for temperature-resistant and salt-resistant drainage and gas extraction of this invention uses specific amphoteric surfactants, which have excellent foaming and stabilizing abilities, producing rich, thick, and fine foam. It also has a significant thickening effect when used with an appropriate proportion of anionic surfactants. The anionic surfactants used are readily soluble in water, have good foaming ability, and good salt resistance. They are compatible with amphoteric and nonionic surfactants and are not sensitive to alkalis and hard water. The nonionic surfactants used have uniform foaming properties, good defoaming properties, and excellent low-temperature washing properties. The combination of these three components has an outstanding synergistic effect, which can greatly reduce the consumption of additives, achieving a good cost-performance ratio; at the same time, it enhances the liquid-carrying capacity and foam-stabilizing properties of the foam. The addition of nano-microbubble particles can effectively increase the viscosity of the foam system and form a dense particle film, inhibiting the aggregation and disproportionation of bubbles, thereby enhancing the stability of the foam. If the types of anionic surfactants, nonionic surfactants, and amphoteric surfactants in this invention are changed, especially the types of anionic surfactants, the performance of the resulting foam desiccant is poor.

[0020] 2. The foam-stabilizing particles of this invention significantly improve foam stability. The synergistic effect of the components results in a foaming agent with stronger foaming ability, better foam stabilization effect, and stronger liquid carrying capacity. However, excessively high or low content of foam-stabilizing particles will reduce the performance of the foaming agent. This product can maintain stable foaming within a temperature range of 35-95℃ and has good salt resistance.

[0021] 3. The foaming agent prepared by this invention can adapt to high-salinity formation water, exhibiting strong foaming properties, high liquid carrying capacity, and high salt suppression rate. It can adapt to high-salinity formation water, such as in extended gas wells, effectively solving the technical problems of low foaming and liquid carrying capacity of foaming agents in high-salinity formation water, as well as pipeline blockage caused by salt precipitation. This invention is suitable for wellbore drainage in condensate gas wells, can stably foam within a temperature range of 35-95℃, has excellent salt resistance, and can resist interference from salinity levels of 10000mg / L-50000mg / L. The foaming agent of this invention has a simple composition, low price, strong foaming ability, good foam stability, can resist downhole environments with high salinity and high temperatures, and can meet the foam drainage requirements of natural gas wells. Detailed Implementation

[0022] The technical solutions will now be clearly and completely described in conjunction with embodiments of the present invention. However, this should not be construed as limiting the scope of the subject matter of the present invention to the following embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0023] Meanwhile, the raw materials used in the embodiments are all conventional raw materials that can be purchased commercially; unless otherwise specified, the methods described are all existing technologies.

[0024] The composition of the simulated mineralized water used in the examples, comparative examples, and experimental examples is shown in Tables 1-5 below.

[0025] Table 1 Total mineralization (10000 mg / L)

[0026] Concentration mg / L 0.865g 0.585g 2.635g 5.915g

[0027] Table 2 Total mineralization (20000 mg / L)

[0028] Concentration mg / L 1.73g 1.17g 5.27g 11.83g

[0029] Table 3 Total mineralization 30000 mg / L

[0030] Concentration mg / L 2.595g 1.755g 7.905g 17.745g

[0031] Table 4 Total mineralization 40000 mg / L

[0032] Concentration mg / L 3.46g 2.34g 10.54g 23.66g

[0033] Table 5 Total mineralization (50000 mg / L)

[0034] Concentration mg / L 4.325g 2.925g 13.175g 29.575g

[0035] Example 1

[0036] A method for preparing a nanobubble depletion agent suitable for various temperature and mineralization environments includes the following steps:

[0037] At room temperature, sodium cocoyl hydroxyethyl sulfonate, fatty alcohol polyoxyethylene ether 9 (AEO-9), and lauramide propylamine oxide (LAO-30) were added to water in a mass ratio of 1:1:1 to obtain a mixed solution. Nano-silica (particle size of 80-100 nm) was added to the mixed solution, and the mixture was ultrasonically treated and mixed evenly to obtain a nano-bubble desiccant. The total mass concentration of sodium cocoyl hydroxyethyl sulfonate, fatty alcohol polyoxyethylene ether 9 (AEO-9), and lauramide propylamine oxide (LAO-30) in the nano-bubble desiccant was 0.1 wt%, and the mass concentration of nano-silica was 0.2 wt%. The obtained nano-bubble desiccant was denoted as GL-1.

[0038] Example 2

[0039] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 1, except that the total mass concentration of sodium cocoyl hydroxyethyl sulfonate, fatty alcohol polyoxyethylene ether 9 (AEO-9), and lauramide propylamine oxide (LAO-30) in the nanobubble desiccant is 0.3 wt%, and the resulting nanobubble desiccant is designated as GL-2.

[0040] Example 3

[0041] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 1, except that the total mass concentration of sodium cocoyl hydroxyethyl sulfonate, fatty alcohol polyoxyethylene ether 9 (AEO-9), and lauramide propylamine oxide (LAO-30) in the nanobubble desiccant is 0.5 wt%, and the resulting nanobubble desiccant is designated as GL-3.

[0042] Example 4

[0043] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 1, except that the total mass concentration of sodium cocoyl hydroxyethyl sulfonate, fatty alcohol polyoxyethylene ether 9 (AEO-9), and lauramide propylamine oxide (LAO-30) in the nanobubble desiccant is 0.7 wt%, and the resulting nanobubble desiccant is designated as GL-4.

[0044] Example 5

[0045] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 1, except that the total mass concentration of sodium cocoyl hydroxyethyl sulfonate, fatty alcohol polyoxyethylene ether 9 (AEO-9), and lauramide propylamine oxide (LAO-30) in the nanobubble desiccant is 0.9 wt%, and the resulting nanobubble desiccant is designated as GL-5.

[0046] Example 6

[0047] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 1, except that the total mass concentration of sodium cocoyl hydroxyethyl sulfonate, fatty alcohol polyoxyethylene ether 9 (AEO-9), and lauramide propylamine oxide (LAO-30) in the nanobubble desiccant is 1 wt%, and the resulting nanobubble desiccant is designated as GL-6.

[0048] Example 7

[0049] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 5, except that: an equal mass of alkylphenol polyoxyethylene ether phosphate (APE-4P) is used instead of sodium cocoyl hydroxyethyl sulfonate, and water is replaced with simulated mineralized water with a mineralization of 50,000 mg / L. The resulting nanobubble desiccant is denoted as GL-7.

[0050] Example 8

[0051] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 1, except that water is replaced with simulated mineralized water with mineralization of 10000 mg / L, 20000 mg / L, 30000 mg / L, 40000 mg / L, and 50000 mg / L, respectively. The resulting nanobubble desiccants are denoted as GL-1-10000, GL-1-20000, GL-1-30000, GL-1-40000, and GL-1-50000.

[0052] Example 9

[0053] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 2, except that water is replaced with simulated mineralized water with mineralization of 10000 mg / L, 20000 mg / L, 30000 mg / L, 40000 mg / L, and 50000 mg / L, respectively. The resulting nanobubble desiccants are denoted as GL-2-10000, GL-2-20000, GL-2-30000, GL-2-40000, and GL-2-50000.

[0054] Example 10

[0055] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 3, except that water is replaced with simulated mineralized water with mineralization of 10000 mg / L, 20000 mg / L, 30000 mg / L, 40000 mg / L, and 50000 mg / L, respectively. The resulting nanobubble desiccants are denoted as GL-3-10000, GL-3-20000, GL-3-30000, GL-3-40000, and GL-3-50000.

[0056] Example 11

[0057] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 4, except that water is replaced with simulated mineralized water with mineralization of 10000 mg / L, 20000 mg / L, 30000 mg / L, 40000 mg / L, and 50000 mg / L, respectively. The resulting nanobubble desiccants are denoted as GL-4-10000, GL-4-20000, GL-4-30000, GL-4-40000, and GL-4-50000.

[0058] Example 12

[0059] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 5, except that water is replaced with simulated mineralized water with mineralization of 10000 mg / L, 20000 mg / L, 30000 mg / L, 40000 mg / L, and 50000 mg / L, respectively. The resulting nanobubble desiccants are denoted as GL-5-10000, GL-5-20000, GL-5-30000, GL-5-40000, and GL-5-50000.

[0060] Example 13

[0061] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 6, except that water is replaced with simulated mineralized water with mineralization of 10000 mg / L, 20000 mg / L, 30000 mg / L, 40000 mg / L, and 50000 mg / L, respectively. The resulting nanobubble desiccants are denoted as GL-6-10000, GL-6-20000, GL-6-30000, GL-6-40000, and GL-6-50000.

[0062] Example 14

[0063] A method for preparing a nanobubble dewatering agent suitable for various temperature and mineralization environments is described in Example 7, except that the simulated mineralized water has a mineralization of 10000 mg / L, and the resulting nanobubble dewatering agent is denoted as GL-7-10000.

[0064] Comparative Example 1

[0065] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 1, except that: no anionic surfactant sodium cocoyl hydroxyethyl sulfonate is added; fatty alcohol polyoxyethylene ether 9 (AEO-9) and lauramide propylamine oxide (LAO-30) are added to simulated mineralized water with a mineralization of 50,000 mg / L at a mass ratio of 1:1; and the total mass concentration of fatty alcohol polyoxyethylene ether 9 (AEO-9) and lauramide propylamine oxide (LAO-30) in the nanobubble desiccant is 0.1 wt%.

[0066] Comparative Example 2

[0067] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 2, except that the water used is simulated mineralized water with a mineralization of 50,000 mg / L, and no nano silica is added.

[0068] Comparative Example 3

[0069] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 3, except that: sodium coconut oil-based hydroxyethyl sulfonate, fatty alcohol polyoxyethylene ether 9 (AEO9), and lauramide propylamine oxide (LAO-30) are added to simulated mineralized water with a mineralization of 50000 mg / L in a mass ratio of 1:2:3.

[0070] Comparative Example 4

[0071] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 5, except that sodium lauryl ether sulfate (SLES-2EO) is used instead of sodium cocoyl hydroxyethyl sulfonate.

[0072] Comparative Example 5

[0073] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 5, except that sodium dodecyl sulfonate (SDS) is used instead of sodium coconut oil hydroxyethyl sulfonate.

[0074] Comparative Example 6

[0075] A method for preparing a nanobubble desiccant suitable for various temperature and mineralization environments is described in Example 5, except that sodium secondary alkyl sulfonate (SAS-60) is used instead of sodium cocoyl hydroxyethyl sulfonate.

[0076] Test case

[0077] The evaluation of foaming agents mainly includes two aspects: first, evaluating and measuring the foaming power and foam stabilization ability of the foaming agent; and second, measuring the liquid carrying capacity of the foaming agent. According to SY / T6465-2000 "Evaluation Method for Foaming Agents Used in Foam Drainage and Gas Production", the foaming performance of this foaming agent was tested.

[0078] Evaluation of foaming power and foam stabilization ability: The Waring-Blender method was used. 100 mL of the prepared nano foaming agent was taken and stirred in a high-speed mixer at 7000 r / min for 2 minutes. Then the foam was poured into a graduated cylinder to test the maximum foaming volume and half-life (i.e., the time it takes for 50 mL of solution to precipitate).

[0079] Determination of liquid carrying capacity: The liquid carrying capacity of the foaming agent was tested according to SY / T7494-2020 "Experimental Evaluation Method for Foaming Agents for Oil and Gas Fields". The specific test procedure is as follows: A foam liquid carrying capacity evaluation device was used. Nitrogen gas was dispersed into microbubbles through a glass frit core and introduced into a glass column. The gas flow rate was controlled at 0.4 L / min. The generated foam carried the liquid out of the column. The amount of liquid carried out by the foaming agent with the foam after 9 minutes of nitrogen introduction was used as a measure of the liquid carrying capacity of the foaming agent.

[0080] Test conditions: no condensate oil and temperatures of 35℃, 50℃, 65℃, 80℃, and 95℃ respectively.

[0081] (I) Performance evaluation of foaming agents prepared in a water-based system

[0082] 1. Foaming ability and foam stability

[0083] The foaming and foam stabilization test results of the foaming agents GL-1 to GL-6 prepared in Examples 1-6 of this invention are shown in Table 6.

[0084] Table 6. Performance of foaming and desiccant at different concentrations (room temperature)

[0085] GL-1 355 224 59640 GL-2 364 298 81354 GL-3 410 307 94402.5 GL-4 430 382 123195 GL-5 457 435 149096.25 GL-6 442 400 132600 Comparative Example 4 405 379 115121.25 Comparative Example 5 421 396 123037 Comparative Example 6 400 413 123900

[0086] Table 6 shows that the foaming agents of Examples 1-6 of this invention exhibit good foaming ability and foam stability in a clean water system. Among them, foaming agent GL-5 shows the best foaming performance, indicating that the foaming agent formed by dissolving sodium coconut oil-based hydroxyethyl sulfonate, fatty alcohol polyoxyethylene ether 9 (AEO9), and lauryl ammonium oxide (LAO-30) in water at a mass ratio of 1:1:1 and a total concentration of 0.9 wt% has the best performance. Compared with foaming agent GL-5, the foaming agents of Comparative Examples 4-6 have poorer foaming ability and foam stability. When the solution concentration is the same, the overall foam index of the combined foaming agents increases. This demonstrates that the foaming agents prepared by this invention have good foaming and foam stabilizing properties.

[0087] 2. The effect of temperature on the liquid-carrying capacity of foaming agents

[0088] Table 7. Effect of different temperatures on the liquid-carrying capacity of the foaming agent.

[0089]

[0090]

[0091] Table 7 shows the change in liquid carrying capacity of the foaming agents in the ternary compound system with temperature. As can be seen from Table 7, with the increase of temperature, the liquid carrying capacity of foaming agent GL-1 gradually increased from 15.27% to 61.805%, the liquid carrying capacity of foaming agent GL-2 gradually increased from 15.27% to 75.64%, the liquid carrying capacity of foaming agent GL-3 gradually increased from 25.605% to 90.895%, the liquid carrying capacity of foaming agent GL-4 gradually increased from 29.92% to 92.545%, the liquid carrying capacity of foaming agent GL-5 gradually increased from 37.22% to 93.385%, and the liquid carrying capacity of foaming agent GL-6 gradually increased from 40.32% to 95.33%. This indicates that the potential capacity of the compound system is gradually enhanced with the increase of temperature.

[0092] 3. Temperature resistance of the foaming agent

[0093] Due to the variability of downhole temperatures, the performance evaluation of foaming agents needs to consider their temperature resistance characteristics. Field investigations revealed that the bottom-hole temperature of Changqing gas wells is generally above 60℃, and can even reach 100℃. Therefore, the nano-foaming agents prepared in Examples 1-6 were tested for their 80℃ temperature resistance, and the results are shown in Table 8.

[0094] Table 8. Evaluation data on the temperature resistance of different foaming agents (80℃)

[0095] GL-1 360 240 64800.00 GL-2 375 310 87187.50 GL-3 400 315 94500.00 GL-4 445 395 131831.25 GL-5 463 443 153831.75 GL-6 426 417 133231.5

[0096] As can be seen from Table 8, the foaming agents prepared in Examples 1-6 showed little difference in foam volume before and after the high temperature of 80°C, and still maintained good foam stability, indicating that the foaming agents have good thermal stability and are suitable for use in extended gas wells.

[0097] (II) Performance evaluation of foaming agents prepared using mineralization systems

[0098] 1. Effect of mineralization on the liquid-carrying capacity of foaming agents

[0099] The liquid carrying capacity of the foaming agents prepared in Examples 8-12 at 80°C is shown in Table 9.

[0100] Table 9. Liquid carrying capacity of foaming agents at 80℃ (different mineralization degrees)

[0101]

[0102] Note: GL-1*, GL-2*, GL-3*, GL-4*, and GL-5* indicate that the composition of the foaming agent (except for the solvent used) is the same as that in Examples 1-5.

[0103] Table 9 shows the liquid carrying capacity curves of the nano-composite foaming agent as a function of mineralization. As can be seen from the table, the liquid carrying capacity of the nano-foaming agents in Examples 8-12 gradually increases with increasing mineralization, indicating that the nano-foaming agent of this invention has stable liquid carrying capacity at high temperature (80℃) and high mineralization.

[0104] 2. Foaming ability and foam stability in high-mineralization (50000mg / L) systems

[0105] Table 10 shows the foaming ability and foam stability of the foaming agents prepared in Examples 7, 8-13 under a mineralization of 50000 mg / L and the foaming agents prepared in Comparative Examples 1-3.

[0106] Table 10. Foaming capacity and foam stability (80℃) of the high-mineralization (50000 mg / L) system.

[0107] GL-1-50000 385 273 78828.75 55.99 GL-2-50000 376 385 108570 58.615 GL-3-50000 400 302 90600 67.52 GL-4-50000 445 421 140508.75 71.655 GL-5-50000 478 441 158098.5 73.34 GL-6-50000 453 387 131483.25 67.2 Example 7 370 345 95737.5 63.18 Comparative Example 1 325 185 45093.75 41.2 Comparative Example 2 360 210 56700 51.5 Comparative Example 3 385 275 79406.25 47.5

[0108] As shown in Table 10, at 80℃, all three comparative foaming agents exhibited strong foaming and liquid-carrying capabilities in simulated mineralized water, with liquid-carrying capacities exceeding 40%. Compared to Comparative Example 1, Example 1 showed a higher foam volume and a longer foam half-life, indicating that the anionic surfactant sodium coconut oil-based hydroxyethyl sulfonate in Example 1 had a synergistic effect. Compared to Comparative Example 2, Example 2 showed a slightly higher foam volume and a longer foam half-life, indicating that the performance of the foaming agent decreased after removing the nano-silica foam-stabilizing particles. Compared with Comparative Example 3, Example 3 showed a higher foam volume and a longer foam half-life, indicating that the foaming agent preparation parameters of Example 3 were superior. Furthermore, the foaming ability and foam stability were significantly improved after mixing and compounding sodium coconut oil-based hydroxyethyl sulfonate, fatty alcohol polyoxyethylene ether 9 (AEO9), and lauramide propylamine oxide (LAO-30) in a mass ratio of 1:1:1, demonstrating a significant synergistic effect. Among these, the foaming ability and foam stability were best when the foaming agent concentration was 0.9%. Considering all factors, a total concentration of 0.9% for the three components is considered reasonable.

[0109] 3. On-site application effect

[0110] Generally speaking, the formation water salinity in high-salinity oil reservoirs can reach over 10,000 mg / L (1.0%), and it not only contains high concentrations of monovalent counterions Na, but also... + Furthermore, it will contain a high concentration of divalent counterions Ca. 2+ Mg 2+ The salt resistance properties of different foaming agents were tested, as shown in Table 11.

[0111] Table 11 Salt tolerance evaluation data of different foaming agents (10000 mg / L, 80℃)

[0112] GL-1-10000 310 215 49987.5 GL-2-10000 325 230 56062.5 GL-3-10000 340 260 66300.0 GL-4-10000 385 350 101062.5 GL-5-10000 410 380 116850.0 GL-6-10000 376 325 91650 GL-7-10000 370 365 101287.5

[0113] The above embodiments show that the initial foam volume and foam stability of foaming agents GL-1 to GL-7 decreased after the addition of salt ions. Meanwhile, the salinity of water also had a certain impact on the foaming agents. At 80℃, without oil or methanol, and with a salinity of 10000 mg / L, the foaming agents still exhibited good foaming ability. Field test results showed that no incompatibility issues were found under extended gas well formation conditions, and ideal results were achieved.

[0114] The foaming agent described in this invention has a lower surface tension. It possesses strong foaming ability, producing abundant and stable foam, and exhibits moderate salt resistance and excellent foaming performance. This foaming agent has good compatibility with various corrosion inhibitors and also possesses good corrosion inhibition capabilities itself. It has strong foaming ability, good stability, and strong liquid carrying capacity, making it suitable for gas wells with various temperatures and salinity levels. It performs exceptionally well in extending the service life of gas wells, which is beneficial for large-scale application in field gas wells.

[0115] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between the embodiments can be referred to mutually, and each embodiment focuses on describing its differences from other embodiments.

[0116] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations, or equivalent methods that can be easily replaced by those skilled in the art without creative effort, without departing from the core of the present invention, are all within the scope of protection of the present invention.

Claims

1. A nanobubble depletion agent suitable for environments with various temperatures and mineralization levels, characterized in that, The nanobubble desiccant comprises anionic surfactant, nonionic surfactant, amphoteric surfactant, foam-stabilizing particles, and solvent; the total mass concentration of the anionic surfactant, nonionic surfactant, and amphoteric surfactant in the nanobubble desiccant is 0.1-1.0 wt%, and the mass concentration of the foam-stabilizing particles is 0.1-0.5 wt%; the mass ratio of the anionic surfactant, nonionic surfactant, and amphoteric surfactant is 1:1:

1. The anionic surfactant is alkylphenol polyoxyethylene ether phosphate APE-4P or sodium cocoyl hydroxyethyl sulfonate; the nonionic surfactant is fatty alcohol polyoxyethylene ether AEO-9; the amphoteric surfactant is lauramide propylamine oxide; the foam-stabilizing particles are nano-silica; and the solvent is one or a combination of two or more of water, methanol, and ethanol.

2. The nanobubble draining agent suitable for various temperature and mineralization environments according to claim 1, characterized in that, The total mass concentration of anionic surfactants, nonionic surfactants, and amphoteric surfactants in the nanobubble desiccant is 0.5-0.9 wt%.

3. The nanobubble draining agent suitable for various temperature and mineralization environments according to claim 1, characterized in that, The particle size of the nano-silica is 80-100 nm.

4. The nanobubble draining agent suitable for various temperature and mineralization environments according to claim 1, characterized in that, The water is deionized water or water containing inorganic minerals. The water containing inorganic minerals is tap water, gas well formation water, gas well injection water, or mineralized water. The mineralization of the mineralized water is 10,000 mg / L to 50,000 mg / L.

5. The preparation method of the nanobubble depletion agent suitable for various temperature and mineralization environments as described in claim 1, comprising the following steps: At room temperature, anionic surfactants, nonionic surfactants, and amphoteric surfactants are added to a solvent to obtain a mixed solution. Then, foam-stabilizing particles are added to the mixed solution and ultrasonically dispersed to obtain the final product.

6. The application of the nanobubble drainage agent of claim 1, which is suitable for various temperature and mineralization environments, in gas well drainage and gas production, wherein the temperature of the gas well is 35-95℃ and the mineralization of the gas well is 10000mg / L-50000mg / L.

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