Nano air drive deoxidizing foaming agent, its preparation method and application

Abstract

This invention discloses a nano-air-driven oxygen-scavenging foaming agent, composed of the following components: 0.1%-2% surfactant, 0.1%-0.5% polymeric foam stabilizer, 0.1%-2% nanoparticle material, 0.2%-5% oxygen scavenger, and the balance being water. The invention also discloses a method for preparing the nano-air-driven oxygen-scavenging foaming agent, comprising the following steps: adding the prescribed amounts of nanoparticle material, polymeric foam stabilizer, and oxygen scavenger sequentially to the prescribed amounts of water, and finally adding the surfactant, stirring until homogeneous, and allowing to stand. This invention has the following beneficial effects: 1. The foaming volume of the oxygen-scavenging foaming agent is greater than 600 mL, the semi-foam lifespan is greater than 20 days (480 h), and the foaming performance and salt resistance are less than 100,000 mineralization; 2. Low oil-water interfacial tension and surface tension; 3. After being placed at 70°C for 10 hours, the dissolved oxygen concentration decreases from 5.345 mg / L to 0.042 mg / L.

Description

Technical Field

[0001] This invention relates to a deoxygenating foaming agent for nano-air drive, its preparation method and application, belonging to the field of petroleum exploration and development. Background Technology

[0002] The method of using surfactants to formulate oil displacement agents for oil recovery is called foam flooding. The emergence of foam flooding technology has, to some extent, solved problems associated with current enhanced oil recovery methods, such as severe pollutant emissions, severe downhole pipeline corrosion, high costs, and low recovery rates. On the one hand, the high resistance coefficient of foam facilitates flow control and increases the volume of oil swept; on the other hand, the foam system can effectively reduce the oil-water interfacial tension and has a strong dilution capacity; furthermore, the characteristics of foam allow for a larger controlled area, saving on chemical reagents and reducing costs compared to other chemical flooding methods.

[0003] Research on foam flooding began abroad in the 1950s, while my country started its own research in the 1960s. Extensive research has been conducted on foam stability and the mechanism of foam flooding, with applications in the field yielding considerable experience. Currently, the development of foaming agents mainly focuses on the synthesis or formulation of surfactants; however, due to the inherent properties of surfactants, their stability is relatively poor.

[0004] To improve foam stability, foam stabilizers need to be added to the foaming agent. Foam stabilizers can be categorized into liquid stabilizers and solid particulate stabilizers. Liquid foam stabilizers mainly include polymers such as polyacrylamide, proteins, and peptides. The addition of these substances increases the viscosity of the base liquid, slowing down drainage. Simultaneously, it reduces the osmotic pressure of the liquid film, slowing down gas diffusion between bubbles, thus achieving a stable foam effect. However, the foam volume is smaller after adding polymers. Current research suggests that solid nanoparticles can also improve foam stability. Surface-modified, hydrophobic nanoparticles adsorb onto the liquid film in the foam system, forming a shell-like structure that hinders foam drainage, thereby stabilizing the foam.

[0005] Chinese authorized patent CN 104059625 B discloses a method for preparing a highly stable, temperature-resistant, and salt-resistant air foam oil displacement agent. The method uses nano-lithium saponite as a foam stabilizer and high-temperature stabilizer. The process steps are as follows: Lithium saponite is added to deionized water at 50-90℃, stirred and dispersed evenly, cooled to room temperature, and allowed to stand for a period of time to obtain a lithium saponite aqueous dispersion. Then, a quantitative amount of cationic surfactant is added, stirred evenly, and allowed to stand for aging. Finally, a foaming agent is added, and the mixture is stirred at high speed on a high-speed emulsifier to obtain the highly stable, temperature-resistant, and salt-resistant air foam oil displacement agent. The foam half-life is as high as 768 hours, exhibiting excellent foam stability. Under NaCl mineralization of 30000 mg / L, the foam half-life is as high as 70 hours, demonstrating good salt resistance. The apparent viscosity is as high as 2000 mPa·s, and the temperature resistance reaches 90℃. It also exhibits high foam strength and temperature resistance, with a shear rate of 170 s⁻¹. -1 The apparent viscosity of the foam after 60 minutes of shearing reaches 800 mPa·s, exhibiting good shear resistance and making it suitable for exploration and development in both conventional and unconventional oilfields.

[0006] Chinese patent CN 107603582 B discloses a high-efficiency foaming agent for air foam flooding and its preparation method. The high-efficiency foaming agent for air foam flooding is composed of the following components by mass percentage: 20%–30% betaine amphoteric surfactant containing polyether segments, 4%–10% alkylamidopropyl dimethylamine oxide, 1%–3% cationic alkyl polysaccharide glycoside, 0.005%–0.01% thickening and foam stabilizing agent, 6%–12% sodium chloride, 2%–5% sodium alkyl sulfate, 10%–15% N-(2-pyridyl) alcohol ether methylene amide, and the balance being water. The foaming agent of this invention exhibits strong comprehensive foaming performance, corrosion resistance, resistance to high salinity, and oil resistance. In the oilfield production field, it can meet the performance requirements of foam flooding in low-permeability reservoirs.

[0007] However, the above technical solutions still have the following shortcomings:

[0008] 1. Foaming agents have good foam stabilizing ability, but their composition is relatively complex or their price is relatively high (currently, lithium-containing compounds are expensive).

[0009] 2. The foam drive mentioned above uses air foam drive. Due to the presence of oxygen in the air, foam drive is prone to some safety issues and corrosion of oil extraction equipment. Summary of the Invention

[0010] The technical problem this invention aims to solve is as follows: Currently, foam flooding mainly uses air foam flooding. Due to the presence of oxygen in the air, foam flooding can easily cause some safety issues and corrosion of oil extraction equipment. Although current foam stabilizers have good foam stabilizing capabilities, they are relatively complex in composition or expensive.

[0011] Technical solution: Nano air-driven deoxygenating foaming agent, by mass percentage, consists of the following components: 0.1wt%-2wt% surfactant, 0.1wt%-0.5wt% polymer foam stabilizer, 0.1wt%-2wt% nanoparticle material, 0.2wt%-5wt% deoxygenating agent, and the balance being water.

[0012] The preparation method of the above-mentioned nano-air-driven oxygen-scavenging foaming agent includes the following steps:

[0013] Add the prescribed amount of nanoparticle material, polymer foam stabilizer, and oxygen scavenger to the prescribed amount of water in sequence, and finally add the prescribed amount of surfactant. Stir well and let stand for a period of time to obtain the nano air-driven oxygen scavenging foaming agent.

[0014] The nano-air drive oxygen-removing foaming agent is prepared by the method described above.

[0015] The above-mentioned nano-air drive deoxygenating foaming agent is used as a foaming agent in foam flooding oil reservoir development.

[0016] This invention provides a relatively inexpensive nanoparticle-stabilized foam that achieves good stability while effectively controlling costs. This invention utilizes an oxygen scavenger to remove oxygen from the air driven by the air foam.

[0017] Effects of the Invention: The nano-air-driven oxygen-removing foaming agent, its preparation method, and its application disclosed in this invention have the following beneficial effects:

[0018] 1. The deoxygenating foaming agent of the present invention has a foaming volume greater than 600 mL, a semi-foaming life greater than 20 days (480 h), and a foaming performance salt resistance of less than 100,000 mineralization.

[0019] 2. After using the deoxygenating foaming agent of the present invention, the oil-water interfacial tension and surface tension are small;

[0020] 3. After the oxygen-scavenging foaming agent of the present invention is used, the dissolved oxygen concentration decreases from 5.345 mg / L to 0.042 mg / L after being placed at a temperature of 70°C for 10 hours. Detailed Implementation

[0021] The specific embodiments of the present invention are described in detail below.

[0022] 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.

[0023] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0024] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0025] 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.

[0026] 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.

[0027] Unless otherwise specified, the reaction will proceed under normal temperature and pressure conditions.

[0028] Unless otherwise specified, all parts or percentages are by weight or by weight percentage.

[0029] In this invention, all the substances used are known substances that can be purchased or synthesized by known methods.

[0030] In this invention, all the devices or equipment used are conventional devices or equipment known in the art and are readily available.

[0031] The performance evaluation method used in this application is:

[0032] 1. Specific steps for evaluating foam volume and half-life:

[0033] (1) Take 200.0 mL of the prepared solution and place it in the sample container of the foam scanner. Inject 100 mL of the sample into the sample chamber, set the temperature to the required temperature, keep the temperature constant for 30 min, and heat to the required temperature.

[0034] (2) Adjust the gas mass flow meter controller to 200cm 3 Inject air at a rate of / min. When the foam volume reaches its maximum value and tends to stabilize, inject air and record the maximum foam volume as the initial value. Then record the time corresponding to when the foam volume drops to half of the initial value, which is the foam half-life.

[0035] 2. The steps for evaluating the deoxygenation effect are as follows:

[0036] (1) Transfer the water sample to the sample bottle and let it stand at room temperature for 15 minutes.

[0037] (2) Transfer 300 mL of water sample from the sample bottle into the test bottle and determine the dissolved oxygen concentration of the water sample according to the operating procedure of GB / T 7489.

[0038] (3) Inorganic product reagent concentration: calculated according to the ratio of dissolved oxygen to oxygen scavenger concentration of 1:45; add a certain amount of oxygen scavenger to the sample bottle according to the corresponding ratio and mix thoroughly.

[0039] (4) Every 10 minutes, the dissolved oxygen concentration of the water sample shall be determined according to the operating procedure of GB / T7489.

[0040] (5) When the dissolved oxygen concentration no longer changes with time, the dissolved oxygen concentration at this time is the remaining dissolved oxygen concentration.

[0041] (6) Conduct parallel tests. The difference between the results of the parallel tests shall not exceed 0.01 mg / L, and the average value shall be taken.

[0042] The nano air-driven deoxygenating foaming agent, by mass percentage, consists of the following components: 0.1wt%-2wt% surfactant, 0.1wt%-0.5wt% polymeric foam stabilizer, 0.1wt%-2wt% nanoparticle material, 0.2wt%-5wt% deoxygenating agent, and the balance being water.

[0043] Further, the surfactant is a mixture of sodium dodecyl sulfate, hexadecyltrimethylammonium chloride, OP-10 (the active ingredient of which is dodecylphenol polyoxyethylene ether), and / or

[0044] The mass ratio of sodium dodecyl sulfate, hexadecyltrimethylammonium chloride, and OP-10 is (8-9.5):(0.5-2):(1-3), preferably (8.5-9.5):(0.5-1.5):(1.5-2.5).

[0045] Furthermore, the polymeric foam stabilizer is an anionic and cationic amphoteric polyacrylamide polymer, the molecular weight of which is 15-25 million, and the general formula of which is as follows:

[0046] in:

[0047] m, p, and q are all integers, and the range of m is 140,000 ≤ m ≤ 300,000, the range of p is 2,000 ≤ p ≤ 5,000, and the range of q is 30,000 ≤ q ≤ 50,000.

[0048] Y is a tertiary amine and acrylic acid forming a cationic quaternary ammonium salt, preferably hexadecyl dimethyl tertiary amine or octadecyl dimethyl tertiary amine.

[0049] Furthermore, the nanoparticle material is one or more of nano-silica, nano-graphite, and nano-iron powder, preferably nano-silica, and / or

[0050] The particle size of the nanoparticle material is between 1 nm and 200 nm, preferably between 2 nm and 100 nm.

[0051] Furthermore, the oxygen scavenger is one or more of sodium sulfite, sodium thiosulfate, sodium dithionite, and sodium nitrite.

[0052] The preparation method of the above-mentioned oxygen-scavenging foaming agent for nano-air drive includes the following steps:

[0053] Add the prescribed amount of nanoparticle material, polymer foam stabilizer, and oxygen scavenger to the prescribed amount of water in sequence, and finally add the prescribed amount of surfactant. Stir well and let stand for a period of time to obtain the nano air-driven oxygen scavenging foaming agent.

[0054] Furthermore, after adding the nanoparticle material to the water, stir for at least 10 minutes, preferably 10-20 minutes, before adding the polymeric foam stabilizer, and / or

[0055] After adding the polymer foam stabilizer to the water, stir for at least 60 minutes, preferably 60-90 minutes, then add the oxygen scavenger, and / or

[0056] After adding the oxygen scavenger, stir for at least 10 minutes, preferably 10-20 minutes, and then let it stand.

[0057] Furthermore, after adding the polymer foam stabilizer to the water, the stirring speed should be controlled at at least 100 rpm, preferably 100-300 rpm, and / or

[0058] After adding the polymer foam stabilizer, the temperature of the entire system should be controlled at RT-60℃ during stirring.

[0059] Furthermore, the settling time should be at least 15 minutes, preferably 15-20 minutes.

[0060] The nano-air drive oxygen-removing foaming agent is prepared by the method described above.

[0061] The above-mentioned nano-air drive deoxygenating foaming agent is used as a foaming agent in foam flooding oil reservoir development.

[0062] In one embodiment

[0063] The nano air-driven deoxygenating foaming agent, by mass percentage, consists of the following components: 0.1 wt% surfactant, 0.5 wt% polymeric foam stabilizer, 0.1 wt% nanoparticle material, 0.2 wt% deoxygenating agent, and the balance being water.

[0064] Further, the surfactant is a mixture of sodium dodecyl sulfate, hexadecyltrimethylammonium chloride, and OP-10, and / or

[0065] The mass ratio of sodium dodecyl sulfate, hexadecyltrimethylammonium chloride, and OP-10 is 8:0.5:1. In another embodiment, the mass ratio of sodium dodecyl sulfate, hexadecyltrimethylammonium chloride, and OP-10 is preferably 8.5:0.5:1.5.

[0066] Furthermore, the polymeric foam stabilizer is an anionic and cationic amphoteric polyacrylamide polymer with a molecular weight of 15 million. The general formula of the anionic and cationic amphoteric polyacrylamide polymer is as follows:

[0067] in:

[0068] m, p, and q are all integers, and m = 161,600, p = 2,000, and q = 30,000;

[0069] Y is a tertiary amine and acrylic acid forming a cationic quaternary ammonium salt, preferably octadecyl dimethyl tertiary amine.

[0070] Furthermore, the nanoparticle material is nano-silica, and / or

[0071] The nanoparticle material has a particle size of 1 nm, and in another embodiment, the nanoparticle material has a particle size of 2 nm.

[0072] Furthermore, the oxygen scavenger is sodium sulfite.

[0073] The preparation method of the above-mentioned nano-air-driven oxygen-scavenging foaming agent includes the following steps:

[0074] Add the prescribed amount of nanoparticle material, polymer foam stabilizer, and oxygen scavenger to the prescribed amount of water in sequence, and finally add the prescribed amount of surfactant. Stir well and let stand for a period of time to obtain the nano air-driven oxygen scavenging foaming agent.

[0075] Furthermore, after adding nanoparticle materials to the water, stir for 10 minutes before adding a polymeric foam stabilizer, and / or

[0076] After adding the polymer foam stabilizer to the water, stir for 60 minutes, then add the oxygen scavenger, and / or

[0077] After adding the oxygen scavenger, stir for 10 minutes and then let stand.

[0078] Furthermore, after adding the polymer foam stabilizer to the water, the stirring speed is controlled at 100 rpm, and / or

[0079] After adding the polymer foam stabilizer, the temperature of the entire system is controlled at RT during stirring.

[0080] Furthermore, the settling time is 15 minutes.

[0081] The nano-air drive oxygen-removing foaming agent is prepared by the method described above.

[0082] The above-mentioned nano-air drive deoxygenating foaming agent is used as a foaming agent in foam flooding oil reservoir development.

[0083] In another embodiment, the nano air-driven deoxygenating foaming agent comprises, by mass percentage: 0.2 wt% surfactant, 0.5 wt% polymeric foam stabilizer, 2 wt% nanoparticle material, 5 wt% deoxygenating agent, and the balance being water.

[0084] Further, the surfactant is a mixture of sodium dodecyl sulfate, hexadecyltrimethylammonium chloride, OP-10 (the active ingredient of which is dodecylphenol polyoxyethylene ether), and / or

[0085] The mass ratio of sodium dodecyl sulfate, hexadecyltrimethylammonium chloride, and OP-10 is 9.5:2:3, preferably 9.5:1.5:2.5.

[0086] Furthermore, the polymeric foam stabilizer is an anionic and cationic amphoteric polyacrylamide polymer with a molecular weight of 25 million. The general formula of the anionic and cationic amphoteric polyacrylamide polymer is as follows:

[0087] in:

[0088] m, p, and q are all integers, and m = 300,000, p = 2227, and q = 31,000;

[0089] Y is a tertiary amine and acrylic acid forming a cationic quaternary ammonium salt, preferably octadecyl dimethyl tertiary amine.

[0090] Furthermore, the nanoparticle material is nanographite, and / or

[0091] The nanoparticle material has a particle size of 200 nm. In another embodiment, the nanoparticle material has a particle size of 100 nm.

[0092] Furthermore, the oxygen scavenger is sodium thiosulfate.

[0093] The preparation method of the above-mentioned oxygen-scavenging foaming agent for nano-air drive includes the following steps:

[0094] Add the prescribed amount of nanoparticle material, polymer foam stabilizer, and oxygen scavenger to the prescribed amount of water in sequence, and finally add the prescribed amount of surfactant. Stir well and let stand for a period of time to obtain the nano air-driven oxygen scavenging foaming agent.

[0095] Furthermore, after adding nanoparticle materials to the water, stir for 20 minutes before adding a polymeric foam stabilizer, and / or

[0096] After adding the polymer foam stabilizer to the water, stir for 90 minutes, then add the oxygen scavenger, and / or

[0097] After adding the oxygen scavenger, stir for 20 minutes and then let it stand.

[0098] Furthermore, after adding the polymer foam stabilizer to the water, the stirring speed is controlled at 300 rpm, and / or

[0099] After adding the polymer foam stabilizer, the temperature of the entire system should be controlled at 60℃ during stirring.

[0100] Furthermore, the settling time is 20 minutes.

[0101] The nano-air drive oxygen-removing foaming agent is prepared by the method described above.

[0102] The above-mentioned nano-air drive deoxygenating foaming agent is used as a foaming agent in foam flooding oil reservoir development.

[0103] In yet another embodiment

[0104] The nano air-driven deoxygenating foaming agent, by mass percentage, consists of the following components: 0.15 wt% surfactant, 0.3 wt% polymeric foam stabilizer, 0.15 wt% nanoparticle material, 3 wt% deoxygenating agent, and the balance being water.

[0105] Further, the surfactant is a mixture of sodium dodecyl sulfate, hexadecyltrimethylammonium chloride, OP-10 (the active ingredient of which is dodecylphenol polyoxyethylene ether), and / or

[0106] The mass ratio of sodium dodecyl sulfate, hexadecyltrimethylammonium chloride, and OP-10 is 9:1:2.

[0107] Furthermore, the polymeric foam stabilizer is an anionic and cationic amphoteric polyacrylamide polymer with a molecular weight of 25 million. The general formula of the anionic and cationic amphoteric polyacrylamide polymer is as follows:

[0108] in:

[0109] m, p, and q are all integers, where m = 195,700, p = 5,000, and q = 50,000.

[0110] Y is a tertiary amine and acrylic acid forming a cationic quaternary ammonium salt, preferably hexadecyl dimethyl tertiary amine.

[0111] Furthermore, the nanoparticle material is nano-iron powder, and / or

[0112] The particle size of the nanoparticle material is 10 nm.

[0113] Further, the oxygen scavenger is sodium dithionite. In other embodiments, the oxygen scavenger is sodium nitrite. In other embodiments, the oxygen scavenger is a mixture of sodium sulfite, sodium thiosulfate, sodium dithionite, and sodium nitrite in equal mass ratios.

[0114] The preparation method of the above-mentioned oxygen-scavenging foaming agent for nano-air drive includes the following steps:

[0115] Add the prescribed amount of nanoparticle material, polymer foam stabilizer, and oxygen scavenger to the prescribed amount of water in sequence, and finally add the prescribed amount of surfactant. Stir well and let stand for a period of time to obtain the nano air-driven oxygen scavenging foaming agent.

[0116] Furthermore, after adding the nanoparticle material to the water, stir for 15 minutes before adding the polymer foam stabilizer, and / or

[0117] After adding the polymer foam stabilizer to the water, stir for 75 minutes, then add the oxygen scavenger, and / or

[0118] After adding the oxygen scavenger, stir for 15 minutes and then let it stand.

[0119] Furthermore, after adding the polymer foam stabilizer to the water, the stirring speed is controlled at 200 rpm, and / or

[0120] After adding the polymer foam stabilizer, the temperature of the entire system should be controlled at 40℃ during stirring.

[0121] Furthermore, the settling time is 60 minutes.

[0122] The nano-air drive oxygen-removing foaming agent is prepared by the method described above.

[0123] The above-mentioned nano-air drive deoxygenating foaming agent is used as a foaming agent in foam flooding oil reservoir development.

[0124] Example 1

[0125] The preparation method of the oxygen-scavenging foaming agent for nano-air drive is as follows:

[0126] 1. Dissolve 0.2g of nano-silica and 0.3g of sodium sulfite completely, then add 100g of formation water. While stirring, add 0.5g of polymer and stir for 80 minutes to prepare the base solution.

[0127] 2. While stirring, add 0.02g of 1631, 0.16g of sodium dodecyl sulfate, and 0.05g of OP-10 to the base solution, and stir until homogeneous to form an oxygen-removing foaming agent solution.

[0128] The properties of the foaming agent solution were tested at 70℃ and a mineralization of 1×10⁻⁶. 5 mg / L; using a nano-foam generator and a foam measuring instrument, the foaming volume was measured to be 620 mL, the half-life reached 29 days, and the cost of the foaming agent was 61 yuan / cubic meter. It exhibits good foaming performance and salt resistance; the oil-water interfacial tension is 0.034 mN / m, the surface tension is 27.23 mN / m, and the oxygen removal capacity is demonstrated by reducing dissolved oxygen concentration from 5.345 mg / L to 0.042 mg / L after 10 hours at 70°C.

[0129] Example 2

[0130] The preparation method of the oxygen-scavenging foaming agent for nano-air drive is as follows:

[0131] 1. Dissolve 0.2g of nano-silica and 0.2g of sodium sulfite completely, then add 50g of formation water. While stirring, add 0.3g of polymer and stir for 80 minutes to prepare the base solution.

[0132] 2. While stirring, add 0.015g of 1631, 0.185g of sodium dodecyl sulfate, and 0.03g of OP-10 to the base solution, and stir until homogeneous to form an oxygen-removing foaming agent solution.

[0133] The properties of the foaming agent solution were tested at 70℃ and a mineralization of 1×10⁻⁶. 5 mg / L; using a nano-foam generator and a foam measuring instrument, the foaming volume was measured to be 610 mL, with a half-life of 31 days, and the cost of the foaming agent was 42 yuan / cubic meter. It exhibits good foaming performance and salt resistance; the oil-water interfacial tension is 0.022 mN / m, and the surface tension is 27.54 mN / m. Its oxygen removal capacity decreased from 5.345 mg / L to 0.047 mg / L after 10 hours at 70°C.

[0134] Example 3

[0135] The preparation method of the oxygen-scavenging foaming agent for nano-air drive is as follows:

[0136] 1. Dissolve 0.4g of nano-silica and 0.4g of sodium sulfite completely, then add 50g of formation water. While stirring, add 0.2g of polymer and stir for 90 minutes to prepare the base solution.

[0137] 2. While stirring, add 0.04g of 1631, 0.2g of sodium dodecyl sulfate, and 0.06g of OP-10 to the base solution, and stir until homogeneous to form an oxygen-removing foaming agent solution.

[0138] The properties of the foaming agent solution were tested at 70℃ and a mineralization of 1×10⁻⁶. 5 mg / L; using a nano-foam generator and a foam measuring instrument, the foaming volume was measured to be 650 mL, with a half-life of 33 days, and the cost of the foaming agent was 33 yuan / cubic meter. It exhibits good foaming performance and salt resistance; the oil-water interfacial tension is 0.019 mN / m, and the surface tension is 27.02 mN / m. Its oxygen removal capacity decreased the dissolved oxygen concentration from 5.345 mg / L to 0.038 mg / L after 10 hours at 70°C.

[0139] On-site effect:

[0140] Analysis of the dynamic and static data of the XLA 8-61 well reservoir and its production history revealed that water channeling was primarily caused by the formation of high-permeability channels in the Sha-2 7-3 and 7-4 layers, leading to severe water channeling in these layers. The 7-1 and 7-2 layers had relatively lower permeability and fewer high-permeability bands. The nano-aerobic foaming agent formulated in Example 1 was used to tap the remaining oil potential at the reservoir top and between wells.

[0141] The injection pressure of the profile-adjusting plug was increased from 4 MPa to 7.5 MPa.

[0142] XLA 8-61 corresponds to 13 oil wells. The well was started on May 13, 2021. It showed significant results on May 20, 2021, with a daily oil increase of 2 tons. The highest daily oil increase for a single well was 15.2 tons. All wells with a water cut of 12% showed results. By May 2022, the cumulative oil increase exceeded 2,700 tons.

[0143] Analysis of the XLA-8-54 well group's reservoir dynamics, static data, and production history revealed that water channeling was primarily caused by the formation of high-permeability channels in the Sha-2 6-3 and 6-4 layers, leading to severe water channeling in this section. The 6-1 and 6-2 layers had relatively lower permeability and fewer high-permeability bands. The foam-driven oil displacement technology formulated in Example 2 was used to tap the remaining oil potential at the reservoir top and between wells.

[0144] As can be seen from the foaming agent injection process, as the foaming agent injection pressure steadily increases, the oil pressure rises from 11MPa to 13.5MPa.

[0145] XLA 8-54 corresponds to 11 oil wells. The well was started on September 7, 2021. The oil production increase gradually became apparent on September 27, 2021, with a maximum daily oil production increase of 10 tons. By September 2021, the cumulative oil production increase was 1,100 tons.

[0146] Cost Analysis

[0147] The existing foaming agent 1 is Haimings' water-based defoamer DAPRO AP 7010S, which contains mineral oil and wax. The existing foaming agent 2 is BASF's mineral oil defoamer Foamaster MO NXZ, a general-purpose surfactant.

[0148]

[0149] As can be seen from the trademark, the nano air-driven oxygen-removing foaming agent prepared by this invention not only has a long half-life, but also has a cost advantage.

[0150] 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 nano-air-driven oxygen-scavenging foaming agent, characterized in that, It consists of the following components by mass percentage: 0.1wt%-2wt% surfactant, 0.1wt%-0.5wt% polymeric foam stabilizer, 0.1wt%-2wt% nanoparticle material, 0.2wt%-5wt% oxygen scavenger, and the balance being water.

2. The nano-air-driven oxygen-removing foaming agent as described in claim 1, characterized in that, The surfactant is a mixture of sodium dodecyl sulfate, hexadecyltrimethylammonium chloride, and OP-10, and / or The mass ratio of sodium dodecyl sulfate, hexadecyltrimethylammonium chloride, and OP-10 is (8-9.5):(0.5-2):(1-3), preferably (8.5-9.5):(0.5-1.5):(1.5-2.5).

3. The nano-air-driven oxygen-removing foaming agent as described in claim 1, characterized in that, The polymeric foam stabilizer is an anionic and cationic amphoteric polyacrylamide polymer with a molecular weight of 15-25 million. The general formula of the anionic and cationic amphoteric polyacrylamide polymer is as follows: in: m, p, and q are all integers, and the range of m is 140,000 ≤ m ≤ 300,000, the range of p is 2,000 ≤ p ≤ 5,000, and the range of q is 30,000 ≤ q ≤ 50,000. Y is a tertiary amine and acrylic acid forming a cationic quaternary ammonium salt, preferably hexadecyl dimethyl tertiary amine or octadecyl dimethyl tertiary amine.

4. The nano-air-driven oxygen-removing foaming agent as described in claim 1, characterized in that, The nanoparticle material is one or more of nano-silica, nano-graphite, and nano-iron powder, preferably nano-silica, and / or The nanoparticle material has a particle size between 1 nm and 200 nm, preferably between 2 nm and 100 nm, and / or The oxygen scavenger is one or more of sodium sulfite, sodium thiosulfate, sodium dithionite, and sodium nitrite.

5. The method for preparing the nano-air-driven oxygen-scavenging foaming agent according to any one of claims 1-4, characterized in that, The steps are as follows: Add the prescribed amount of nanoparticle material, polymer foam stabilizer, and oxygen scavenger to the prescribed amount of water in sequence, and finally add the prescribed amount of surfactant. Stir well and let stand for a period of time to obtain the nano air-driven oxygen scavenging foaming agent.

6. The preparation method of the nano-air-driven oxygen-scavenging foaming agent as described in claim 5, characterized in that, After adding the nanoparticle material to the water, stir for at least 10 minutes, preferably 10-20 minutes, before adding the polymer foam stabilizer, and / or After adding the polymer foam stabilizer to the water, stir for at least 60 minutes, preferably 60-90 minutes, then add the oxygen scavenger, and / or After adding the oxygen scavenger, stir for at least 10 minutes, preferably 10-20 minutes, and then let it stand.

7. The preparation method of the nano-air-driven oxygen-scavenging foaming agent as described in claim 6, characterized in that, After adding the polymer foam stabilizer to the water, the stirring speed should be controlled at at least 100 rpm, preferably 100-300 rpm, and / or After adding the polymer foam stabilizer, the temperature of the entire system should be controlled at RT-60℃ during stirring.

8. The preparation method of the nano-air-driven oxygen-scavenging foaming agent as described in claim 6, characterized in that, The settling time should be at least 15 minutes, preferably 15-20 minutes.

9. A nano-air-driven oxygen-scavenging foaming agent, characterized in that, Prepared by the method described in any one of claims 5-7.

10. The application of the nano-air-drive deoxygenating foaming agent according to any one of claims 1-5 and 9 as a foaming agent in foam-driven oil reservoir development.

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