A foaming agent and its synthesis method and application

Abstract

The present invention belongs to the technical field of oil and gas field development, and specifically relates to a foaming agent and its synthesis method and application. The synthesis method is as follows: 1-amino-3,6,9,12,15,18-hexaoxahexane-21-acid and ethanol are added to an autoclave, stirred and dissolved, 4-(2-bromoethyl) benzenesulfonate sodium is added, stirring is continued, pH is adjusted to 8-9 with sodium hydroxide, heated and heat-insulated, and pH is adjusted to 8-9 with sodium hydroxide during the period; bromotetradecane is added to the above solution, heated to reflux, pH is adjusted to 8-9 with sodium hydroxide during the period, and a viscous solid is obtained by vacuum distillation, and a product, i.e., a foaming agent, is obtained by recrystallization with n-hexane. The foaming agent of the present invention has the advantages of strong foaming power, good stability and low interfacial tension.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field development, and specifically relates to a foaming agent and a synthesis method and application thereof. Background Art

[0002] Foam fluids are widely used in oilfield exploitation due to their low density, high viscosity and unique rheological properties, such as foam drilling, foam cement cementing, foam acidizing, foam fracturing, foam sand washing, foam profile control, foam flooding, etc. The necessary component for forming foam is the foaming agent, and its most important performance is the foaming performance. The quality of foam performance is one of the most important factors for whether it can be used in a foam system, which also includes its foaming ability and the stability of the generated foam.

[0003] A foaming agent is a surface active substance that mainly reduces the interfacial tension at the air-water interface, prompts the air to form small bubbles in the slurry, expands the separation interface, and ensures that the bubbles rise to form a foam layer. The stability of the foam system is affected by many factors, but the structure and composition of the foaming agent are important influencing factors. According to the molecular structure, the foaming agent can be divided into: anionic, cationic, nonionic and zwitterionic types. The foaming agent for air foam flooding is mainly anionic and nonionic. In addition to being able to greatly reduce the surface tension of the gas-liquid interface, it must also have strong foaming ability, good foam stability, good compatibility with the formation rock fluid, and certain salt resistance, oil resistance and temperature resistance.

[0004] Patent CN102020981A discloses a heat-resistant, salt-resistant, low-tension foam flooding agent and its preparation method, which is prepared by continuously stirring alkanolamide, bipolar surfactant and water at 40-60°C until they are completely dissolved. The heat-resistant, salt-resistant, low-tension foaming agent of the invention is suitable for tertiary oil recovery under conditions of a temperature of 50-120°C and a mineralization of 0-100,000ppm. Compared with other commonly used foaming agents in the prior art, the oil-water interfacial tension is increased from 10 -2 mN.m -1 Down to 10 -3 mN.m -1 Compared with the commonly used surfactants in the prior art, the foam half-life at 50°C is increased from 15 minutes to more than 40 minutes, and the indoor model increases the recovery rate by more than 15%. However, the main agent of the foaming agent is alkanolamide and bipolar surfactant. Alkanolamide is easy to hydrolyze, has poor high temperature stability, is easy to fail in the formation, and its application is limited.

[0005] Patent CN111961451A discloses a slow-release foaming agent for oil and gas wells and a preparation method thereof, comprising the following raw materials: a novel fluorocarbon surfactant, a nonionic surfactant, a foam stabilizer, alcohol, and water; the foam stabilizer is a polymer foam stabilizer or nano dust; the alcohol is selected from one or more of methanol, ethanol, propanol, isopropanol, ethylene glycol, glycerol, 1,3-propylene glycol, and 1,2-propylene glycol. The slow-release foaming agent for oil and gas wells prepared by the present invention has good high temperature resistance, high salt resistance, high pressure resistance, and oil resistance, and exhibits excellent stability under high temperature, high pressure, and high mineralization. Therefore, it is suitable for the effective development of difficult-to-use oil reservoirs such as high-temperature, high-salt oil reservoirs and heavy oil reservoirs in China, and has broad application prospects. However, the product contains a large amount of fluorine element, is not easy to biodegrade, and is easy to cause environmental pollution. Summary of the invention

[0006] The present invention aims at the deficiencies of the prior art and provides a foaming agent and a synthesis method and application thereof. The foaming agent of the present invention has the advantages of strong foaming power, good stability and low interfacial tension.

[0007] One of the purposes of the present invention is to disclose a method for synthesizing a foaming agent, and the specific steps of the synthetic method are as follows:

[0008] (1) Add 1-amino-3,6,9,12,15,18-hexaoxaheneicosane-21-oic acid and ethanol to a high-pressure reactor, stir to dissolve, add sodium 4-(2-bromoethyl)benzenesulfonate, continue stirring, adjust the pH to 8-9 with sodium hydroxide, heat and keep warm, and adjust the pH to 8-9 with sodium hydroxide during the process;

[0009] (2) Add tetradecane bromide to the above solution, heat under reflux, adjust the pH to 8-9 with sodium hydroxide, and distill under reduced pressure to obtain a viscous solid, which is recrystallized from n-hexane to obtain the product, i.e., the foaming agent.

[0010] In the present invention, preferably, based on 1 mol part of 1-amino-3,6,9,12,15,18-hexaoxaheneicosane-21-oic acid, the amounts of sodium 4-(2-bromoethyl)benzenesulfonate and tetradecane bromide are 0.8-1.2 mol parts and 0.8-1.2 mol parts, respectively.

[0011] In the present invention, preferably, the weight ratio of ethanol to 1-amino-3,6,9,12,15,18-hexaoxaheneicosane-21-oic acid in step (1) is 40-60:1.

[0012] In the present invention, preferably, the stirring time in step (1) is 1-2 h.

[0013] In the present invention, preferably, the heating and heat preservation temperature in step (1) is 40-50° C. and the time is 30-60 min.

[0014] In the present invention, preferably, the reflux time in step (2) is 12-24 hours.

[0015] The reaction equation for the synthesis of the foaming agent of the present invention is as follows:

[0016]

[0017]

[0018]

[0019] Another object of the present invention is to disclose a foaming agent, the molecular structure of the foaming agent is as follows:

[0020] .

[0021] The third object of the present invention is to disclose the application of the above foaming agent in the development of oil and gas fields.

[0022] The foaming agent of the present invention belongs to a composite surfactant, a long linear molecule, has strong flexibility and good stability. The active groups include two anionic groups (one benzenesulfonic acid group and one carboxyl group) and one nonionic group (polyether), which is more active than conventional surfactants with a single active group, can greatly reduce surface tension, and increase foaming volume and capacity.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] (1) The foaming agent of the present invention has the characteristics of strong foaming power. At a concentration of 0.1wt%, the foaming volume can reach 700ml;

[0025] (2) The foaming agent of the present invention has the characteristic of a long half-life. At a concentration of 0.1wt%, the half-life can reach 5100s;

[0026] (3) The foaming agent of the present invention has the characteristic of low interfacial tension. At a concentration of 0.1wt%, the interfacial tension can reach 0.056×10 -3 mN / m. DETAILED DESCRIPTION

[0027] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0028] The technical solution of the present invention is further described below in conjunction with specific embodiments:

[0029] Example 1

[0030] (1) Add 10 mmol 1-amino-3,6,9,12,15,18-hexaoxaheneicosane-21-oic acid and 141 g ethanol to a high-pressure reactor, stir to dissolve, add 8 mmol sodium 4-(2-bromoethyl)benzenesulfonate, continue stirring for 1 hour, adjust the pH to 8-9 with sodium hydroxide, heat to 40°C, keep warm for 30 minutes, during which time adjust the pH to 8-9 with sodium hydroxide;

[0031] (2) Add 8 mmol of tetradecane bromide to the above solution, heat and reflux for 12 h, adjust the pH to 8-9 with sodium hydroxide, and distill under reduced pressure to obtain a viscous solid, which is recrystallized from n-hexane to obtain the product, i.e., the foaming agent.

[0032] Example 2

[0033] (1) Add 10 mmol 1-amino-3,6,9,12,15,18-hexaoxaheneicosane-21-oic acid and 162 g ethanol to a high pressure reactor, stir to dissolve, add 12 mmol sodium 4-(2-bromoethyl)benzenesulfonate, continue stirring for 2 h, adjust the pH to 8-9 with sodium hydroxide, heat to 42 ° C, keep warm for 40 min, during which time adjust the pH to 8-9 with sodium hydroxide;

[0034] (2) Add 8.5 mmol of tetradecane bromide to the above solution, heat and reflux for 16 h, adjust the pH to 8-9 with sodium hydroxide, and distill under reduced pressure to obtain a viscous solid, which is recrystallized from n-hexane to obtain the product, i.e., the foaming agent.

[0035] Example 3

[0036] (1) Add 10 mmol 1-amino-3,6,9,12,15,18-hexaoxahene-21-oic acid and 171 g ethanol to a high pressure reactor, stir to dissolve, add 9 mmol sodium 4-(2-bromoethyl)benzenesulfonate, continue stirring for 1.5 h, adjust the pH to 8-9 with sodium hydroxide, heat to 45°C, keep warm for 50 min, during which time adjust the pH to 8-9 with sodium hydroxide;

[0037] (2) Add 12 mmol of tetradecane bromide to the above solution, heat and reflux for 20 h, adjust the pH to 8-9 with sodium hydroxide, and distill under reduced pressure to obtain a viscous solid, which is recrystallized from n-hexane to obtain the product, i.e., the foaming agent.

[0038] Example 4

[0039] (1) Add 10 mmol 1-amino-3,6,9,12,15,18-hexaoxahene-21-oic acid and 188 g ethanol to a high pressure reactor, stir to dissolve, add 11 mmol sodium 4-(2-bromoethyl)benzenesulfonate, continue stirring for 1.2 h, adjust the pH to 8-9 with sodium hydroxide, heat to 50°C, keep warm for 60 min, during which time adjust the pH to 8-9 with sodium hydroxide;

[0040] (2) Add 9 mmol of tetradecane bromide to the above solution, heat and reflux for 24 h, adjust the pH to 8-9 with sodium hydroxide, and distill under reduced pressure to obtain a viscous solid, which is recrystallized from n-hexane to obtain the product, i.e., the foaming agent.

[0041] Example 5

[0042] (1) Add 10 mmol 1-amino-3,6,9,12,15,18-hexaoxaheneicosane-21-oic acid and 194 g ethanol to a high pressure reactor, stir to dissolve, add 9.3 mmol sodium 4-(2-bromoethyl)benzenesulfonate, continue stirring for 1.8 h, adjust the pH to 8-9 with sodium hydroxide, heat to 50°C, keep warm for 45 min, during which time adjust the pH to 8-9 with sodium hydroxide;

[0043] (2) Add 9.8 mmol of tetradecane bromide to the above solution, heat and reflux for 24 h, adjust the pH to 8-9 with sodium hydroxide, and distill under reduced pressure to obtain a viscous solid, which is recrystallized from n-hexane to obtain the product, i.e., the foaming agent.

[0044] Example 6

[0045] (1) Add 10 mmol 1-amino-3,6,9,12,15,18-hexaoxaheneicosane-21-oic acid and 212 g ethanol to a high pressure reactor, stir to dissolve, add 10.2 mmol sodium 4-(2-bromoethyl)benzenesulfonate, continue stirring for 2 h, adjust the pH to 8-9 with sodium hydroxide, heat to 50 ° C, keep warm for 50 min, during which time adjust the pH to 8-9 with sodium hydroxide;

[0046] (2) Add 10.4 mmol of tetradecane bromide to the above solution, heat and reflux for 24 h, adjust the pH to 8-9 with sodium hydroxide, and distill under reduced pressure to obtain a viscous solid, which is recrystallized from n-hexane to obtain the product, i.e., the foaming agent.

[0047] Example 7 Test of Foaming Power

[0048] Refer to GB / T 13173-2021 "Test Methods for Surfactant Detergents" and test the foaming power according to the Ross-Miles method. The test concentration is 0.1wt%.

[0049] A comparative experiment was conducted using the foam stabilizer SM-WP from Shaoxing Shangyu Simo Organic Chemistry Research Institute. The test results are shown in Table 1.

[0050] It can be seen from Table 1 that the foaming agent of the present invention (Examples 1-6) has good foaming performance, and the foaming volume is greater than 500 mL, and the highest is 700 mL (Example 6); while the foaming volume of the foam stabilizer SM-WP of the comparative example Shaoxing Shangyu Simo Organic Chemistry Research Institute is 300 mL, which is significantly lower than that of the present invention.

[0051] Example 8 Testing of Foam Half-Life

[0052] Refer to SY / T 7494-2020 "Experimental Evaluation Method for Foaming Agents for Oil and Gas Fields" and the test concentration is 0.1wt%.

[0053] A comparative experiment was conducted using the foam stabilizer SM-WP from Shaoxing Shangyu Simo Organic Chemistry Research Institute. The test results are shown in Table 1.

[0054] It can be seen from Table 1 that the foaming agent of the present invention (Examples 1-6) has the characteristic of a long half-life, which is not less than 4500s and reaches a maximum of 5100s; while the half-life of the foam stabilizer SM-WP of the comparative example Shaoxing Shangyu Simo Organic Chemistry Research Institute is as short as 2100s, which is significantly lower than that of the present invention.

[0055] Example 9 Test of interfacial tension

[0056] The interfacial tension γ was tested with reference to SY / T 5370-2018 "Determination of surface and interfacial tension", and the test concentration was 0.1wt%. The oil phase was dehydrated crude oil from a joint station of Shengli Oilfield, with a viscosity of 850 mPa•s.

[0057] A comparative experiment was conducted using the foam stabilizer SM-WP from Shaoxing Shangyu Simo Organic Chemistry Research Institute. The test results are shown in Table 1.

[0058] Table 1 Foaming power, half-life, and interfacial tension test results

[0059]

[0060] It can be seen from Table 1 that the interfacial tension of the oilfield foaming agent (Examples 1-6) of the present invention is lower than 0.1×10 -3 mN / m, the lowest is 0.056×10 -3 mN / m; while the interfacial tension of the foam stabilizer SM-WP from Shaoxing Shangyu Simo Organic Chemistry Research Institute is 1.2×10 -3 mN / m, which is significantly higher than that of the present invention.

[0061] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for synthesizing a foaming agent, characterized in that: The specific steps of the synthetic method are as follows: (1) Add 1-amino-3,6,9,12,15,18-hexaoxaheneicosane-21-oic acid and ethanol to a high-pressure reactor, stir to dissolve, add sodium 4-(2-bromoethyl)benzenesulfonate, continue stirring, adjust the pH to 8-9 with sodium hydroxide, heat and keep warm, and adjust the pH to 8-9 with sodium hydroxide during the process; (2) adding tetradecane bromide to the above solution, heating under reflux, adjusting the pH to 8-9 with sodium hydroxide, distilling under reduced pressure to obtain a viscous solid, and recrystallizing with n-hexane to obtain the product, i.e., the foaming agent; Based on 1 mole of 1-amino-3,6,9,12,15,18-hexaoxaheneicosane-21-oic acid, the amounts of sodium 4-(2-bromoethyl)benzenesulfonate and tetradecane bromide are 0.8-1.2 mole parts and 0.8-1.2 mole parts, respectively; The molecular structural formula of the foaming agent is as follows: 。 2. A method for synthesizing a foaming agent as claimed in claim 1, characterized in that: The weight ratio of ethanol to 1-amino-3,6,9,12,15,18-hexaoxaheneicosane-21-oic acid in step (1) is 40-60:

1.

3. A method for synthesizing a foaming agent as claimed in claim 1, characterized in that: The stirring time in step (1) is 1-2h.

4. A method for synthesizing a foaming agent as claimed in claim 1, characterized in that: The heating and insulation temperature in step (1) is 40-50°C and the time is 30-60 minutes.

5. A method for synthesizing a foaming agent as claimed in claim 1, characterized in that: The reflux time in step (2) is 12-24 hours.

6. The foaming agent prepared by the synthesis method according to claim 1-5, characterized in that: The molecular structural formula of the foaming agent is as follows: 。 7. Use of the foaming agent as claimed in claim 6 in oil and gas field development.

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