Efficient deep penetration acid liquor as well as preparation method and application thereof

Abstract

The invention discloses efficient deep penetration acid liquor as well as a preparation method and application thereof. The efficient deep penetration acid liquor comprises the following components in parts by mass: 20-35 parts of a main acid agent, 5-15 parts of a penetration enhancer, 2-6 parts of a corrosion inhibitor, 2-5 parts of a stabilizer and 40-70 parts of deionized water, wherein the main acid agent is a compound of main acid and auxiliary acid, and the penetration enhancer is a compound of fatty alcohol-polyoxyethylene ether and sodium lauroyl sarcosinate. Main body acid (one or two of sulfamic acid and chloroacetic acid) and auxiliary acid (one or two of formic acid and acetic acid) are compounded to serve as a main acid agent, and the main acid agent is combined with a penetration enhancer compounded by fatty alcohol-polyoxyethylene ether and sodium lauroyl sarcosinate, a corrosion inhibitor and a stabilizer. The core goals of deep penetration and low corrosion are jointly achieved, and the method can be applied to various scenes such as soil improvement, oil and gas exploitation and industrial equipment cleaning in a cross-field mode.

Description

Technical Field

[0001] This invention relates to the field of chemical preparation technology. Specifically, it relates to a highly efficient deep-penetrating acid solution, its preparation method, and its application. Background Technology

[0002] Existing acid-based agents (such as hydrochloric acid and citric acid) generally suffer from limited penetration depth in practical applications: in soil improvement scenarios, they can only act on the surface soil and cannot penetrate deep into the acidified and compacted state of the soil; in oil and gas reservoir stimulation, they tend to react rapidly in the near-wellbore area of ​​the reservoir to form filter cake, which hinders the acid from advancing into the deeper reservoir and reduces the stimulation effect; in industrial equipment pipeline descaling, they are difficult to penetrate into the deep scale on the inner wall of the pipeline, resulting in incomplete descaling and repeated scaling.

[0003] Meanwhile, traditional acid-based agents suffer from strong corrosiveness, easily damaging microorganisms in the soil, metal components of oil and gas extraction equipment, and industrial pipelines. This necessitates the addition of large amounts of corrosion inhibitors, increasing costs and potentially introducing impurities that affect application effectiveness. Therefore, developing a deep-penetrating acid with deep penetration, low corrosiveness, and adaptability to various scenarios has become an urgent technical challenge. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide a highly efficient deep-penetrating acid solution, its preparation method and application, which has a deep penetration depth and low corrosivity.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A highly efficient deep-penetrating acid solution comprises the following components in parts by weight: 20-35 parts of main acid agent, 5-15 parts of penetration enhancer, 2-6 parts of corrosion inhibitor, 2-5 parts of stabilizer, and 40-70 parts of deionized water;

[0007] The primary acid agent is a compound of a main acid and an auxiliary acid, wherein the main acid is one or both of aminosulfonic acid and chloroacetic acid; the auxiliary acid is one or both of formic acid and acetic acid; and the penetration enhancer is a compound of fatty alcohol polyoxyethylene ether and sodium lauroyl sarcosinate.

[0008] This application uses a compound of main acids (sulfamic acid and chloroacetic acid) and auxiliary acids (formic acid and acetic acid) as the main acid agent, combined with a penetration enhancer, corrosion inhibitor, and stabilizer compounded from fatty alcohol polyoxyethylene ether and sodium lauroyl sarcosinate. Sulfamic acid and chloroacetic acid are relatively mild acids with strong solubility for calcium and magnesium scale, while formic acid and acetic acid have good slow-release and corrosion-inhibiting properties. The compound constructs a relatively weakly acidic slow-release reaction system, which significantly reduces the overall reaction rate of the acid solution while maintaining effective dissolving capacity and stability. This characteristic fundamentally avoids the rapid and violent reaction of strong acids on the surface of the target material, forming an isolation layer that prevents penetration into the interior, thus laying the foundation for deep penetration. Furthermore, the slow-release reaction environment created by this relatively weakly acidic environment ensures specific... The permeation effect of the permeation enhancer: Fatty alcohol polyoxyethylene ether is a nonionic surfactant, which has high stability in relatively weak acid environments. Under strong acid conditions, it may cause ether bond breakage, affecting its surface activity. Sodium lauroyl sarcosinate, on the other hand, is an anionic surfactant. Although it may undergo hydrolysis in relatively weak acid environments, this application also adds a stabilizer to prevent the precipitation of metal ions in the acid, thus avoiding the formation of precipitates with the hydrolysis products of sodium lauroyl sarcosinate, which would affect its permeation capacity. In addition, acidizing operations are mainly for removing blockages in oil-bearing sections. Downhole rocks blocked or contaminated by oil or polymers are prone to changing from hydrophilic to hydrophobic, while acids are mostly aqueous, making the reaction difficult. The mild reaction kinetics of this application also provide a valuable time window for the permeation process, allowing the permeation enhancer to fully exert its effect. Under these conditions, fatty alcohol polyoxyethylene ether greatly reduces the surface tension of the acid, reduces flow resistance, and significantly improves its fluidity and spreadability; sodium lauroyl sarcosinate further enhances deep permeation capacity through adsorption and wetting. The two work together to promote the wetting and penetration of the acid into the target material, achieving deep permeation.

[0009] This effect is not a simple superposition of the functions of each component, but rather the result of the mutual promotion between a specific relatively weak acid system and a specific combination of surfactants, corrosion inhibitors, and stabilizers. Ultimately, they work together to achieve the core goals of deep penetration and low corrosion, enabling it to be applied across various fields such as soil improvement, oil and gas extraction, and industrial equipment cleaning.

[0010] The above-mentioned high-efficiency deep-penetrating acid solution has a mass ratio of (3-5):1 between the main acid and the auxiliary acid.

[0011] The mass ratio of the fatty alcohol polyoxyethylene ether and sodium lauroyl sarcosinate in the above-mentioned high-efficiency deep-penetrating acid solution is (2-3):1.

[0012] The aforementioned high-efficiency deep-penetrating acid solution uses a corrosion inhibitor that is a compound of benzotriazole and hexamethylenetetramine. The corrosion inhibitor forms a protective film on the metal surface, protecting the composite metal from acid corrosion, reducing the corrosion rate, and acting as an acid buffer.

[0013] The aforementioned high-efficiency deep-penetrating acid solution has a benzotriazole to hexamethylenetetramine mass ratio of 1:(1-3).

[0014] The aforementioned high-efficiency deep-penetrating acid solution uses disodium ethylenediaminetetraacetate as a stabilizer to prevent the precipitation of metal ions in the acid solution from affecting the penetration effect.

[0015] The aforementioned high-efficiency deep-penetrating acid solution has a pH value of 2.5–3.5.

[0016] A method for preparing a highly efficient deep-penetrating acid solution includes the following steps:

[0017] Step 1: Weigh each component according to the above-mentioned raw material composition of high-efficiency deep-penetrating acid solution, and set aside for later use;

[0018] Step 2: Add deionized water to the reaction vessel, and under stirring conditions, add the main acid agent and stir until completely dissolved to obtain the acid matrix;

[0019] Step 3: While maintaining stirring, add the penetration enhancer and corrosion inhibitor to the acid matrix in sequence, ensuring that each component is fully dispersed after addition;

[0020] Step 4: Finally, add the stabilizer, continue stirring, and check the pH value to be 2.5–3.5 to obtain the above-mentioned high-efficiency deep-penetrating acid solution.

[0021] In the preparation method of the present invention, firstly, a main acid agent is added to fully dissolve it and construct the basic system of acid solution; secondly, a penetration promoter as a surfactant is introduced to effectively reduce surface tension and establish the acid solution action system; then, a corrosion inhibitor is added to reduce the corrosion of metal by the acid solution; finally, a stabilizer with chelating effect is added to form the final high-efficiency deep-penetrating acid solution.

[0022] In step two, the stirring speed is 200~300 r / min.

[0023] The application of a highly efficient deep-penetrating acid in soil improvement, oil and gas extraction reservoir modification, or industrial equipment pipeline descaling utilizes the aforementioned highly efficient deep-penetrating acid.

[0024] The above-mentioned high-efficiency deep-penetrating acid solution is used in soil improvement, oil and gas extraction reservoir modification, or industrial equipment pipeline descaling. Its characteristic is that when applied to soil improvement, the high-efficiency deep-penetrating acid solution is diluted with water at a mass ratio of 1:(10-20) and applied to the soil by drip irrigation or deep injection.

[0025] When applied to reservoir stimulation in oil and gas extraction: high-efficiency deep-penetrating acid and soil acid are mixed at a mass ratio of 1:(8-10) and directly injected into the oil and gas reservoir; the soil acid is prepared from 15% hydrochloric acid and 5% hydrofluoric acid; the formation temperature for oil and gas extraction is 30-100℃, and the construction pressure is determined according to the formation pressure.

[0026] When used for descaling industrial equipment pipelines: dilute the high-efficiency deep-penetrating acid solution and water at a mass ratio of 1:(5-8), and treat the pipeline by circulating soaking.

[0027] The technical solution of the present invention achieves the following beneficial technical effects:

[0028] (1) This application uses a combination of a main acid (aminosulfonic acid or chloroacetic acid) and an auxiliary acid (formic acid or acetic acid) as the main acid agent, and combines it with a penetration promoter, corrosion inhibitor and stabilizer composed of fatty alcohol polyoxyethylene ether and sodium lauroyl sarcosinate. Among them, aminosulfonic acid and chloroacetic acid are relatively mild and have strong solubility for calcium and magnesium scale, while formic acid and acetic acid have good slowing and corrosion inhibition properties. After the two are combined, while maintaining effective corrosion resistance and stability, the overall reaction rate of the acid solution is significantly reduced. This property fundamentally avoids the strong acid from reacting rapidly and violently on the surface of the target material to form an isolation layer that prevents it from penetrating into the interior, thus laying the foundation for achieving deep penetration.

[0029] (2) The weakly acidic environment and the specific permeation promoter produced a synergistic effect. Acidizing operations are mainly for removing blockages in oil-bearing sections. After the downhole rock is blocked or contaminated by oil or polymers, it is very easy to change from hydrophilic to hydrophobic. However, the acid is mostly water-based, so the reaction is difficult. The mild reaction kinetics provide a valuable time window for the permeation process, allowing the permeation promoter to play its full role. Under these conditions, fatty alcohol polyoxyethylene ether greatly reduces the surface tension of the acid, reduces flow resistance, and significantly improves its fluidity and spreadability. Sodium lauroyl sarcosinate further enhances the deep permeation capacity through adsorption and wetting. The two work together to promote the wetting and penetration of the acid into the target material, achieving deep permeation. This effect is not a simple superposition of the functions of each component, but the result of the mutual promotion between the specific weak acid system and the specific surfactant and corrosion inhibitor combination, ultimately achieving the core goals of deep permeation and low corrosion.

[0030] (3) This application can be flexibly applied to three different fields: soil improvement, oil and gas reservoir transformation and industrial equipment pipeline descaling by simply adjusting the dilution ratio. It solves the drawback of the single function of traditional acid. Moreover, the preparation process is simple, the cost is controllable, and it is easy to industrialize. The penetration depth is significantly improved. The penetration depth in soil is 1.2-1.8 meters, the penetration radius in oil and gas reservoirs is 2-4 meters, and in the field of industrial equipment pipeline descaling, it can penetrate to the inner wall of the pipeline to a depth of 3-5 mm of scale. Compared with traditional hydrochloric acid, the penetration depth is increased by 2-3 times under the same application conditions. The descaling rate is over 95%, and the corrosion rate of metal pipelines such as carbon steel and cast iron is less than 0.05 mm / a, protecting the safety of equipment and the environment. It is far below the national industry standard (≤0.1 mm / a) and does not require additional anti-corrosion measures, saving costs. Detailed Implementation

[0031] Example 1

[0032] 1. This embodiment describes a highly efficient deep-penetrating acid solution for soil improvement, which consists of a main acid agent, a penetration enhancer, a corrosion inhibitor, and a stabilizer. The main acid agent is a mixture of aminosulfonic acid and formic acid; the penetration enhancer is a mixture of fatty alcohol polyoxyethylene ether and sodium lauroyl sarcosinate; the corrosion inhibitor is a compound of benzotriazole and hexamethylenetetraacetate; and the stabilizer is disodium ethylenediaminetetraacetate. Each substance is weighed according to the following component ratio (mass percentage).

[0033] 18% aminosulfonic acid, 6% formic acid, 4% fatty alcohol polyoxyethylene ether, 2% sodium lauroyl sarcosinate, 1.5% benzotriazole, 1.5% hexamethylenetetraacetic acid disodium salt, 2% deionized water.

[0034] 2. Preparation process

[0035] (1) Add 65 kg of deionized water to the reactor, stir at 250 r / min, add 18 kg of aminosulfonic acid and 6 kg of formic acid at room temperature, stir for 20 min until dissolved, and obtain acid matrix;

[0036] (2) Add 4 kg of fatty alcohol polyoxyethylene ether and 2 kg of sodium lauroyl sarcosinate to the acid matrix and stir for 18 min; then add 1.5 kg of benzotriazole and 1.5 kg of hexamethylenetetramine and stir for 18 min.

[0037] (3) Add 2kg of disodium ethylenediaminetetraacetate, stir for 30min, and test the pH=3.0 to obtain the finished high-efficiency deep penetration acid solution.

[0038] 3. Application Effects

[0039] The prepared high-efficiency deep-penetrating acid solution was diluted with water at a mass ratio of 1:15 and injected into the deep saline-alkali soil. After 7 days, the penetration depth was 1.6m, the pH of the deep soil decreased from 8.5 to 7.2, the soil bulk density decreased by 12%, and the air permeability was significantly improved.

[0040] Example 2

[0041] 1. This embodiment describes a high-efficiency deep-penetrating acid solution suitable for reservoir stimulation in oil and gas extraction. The solution consists of a main acid agent, a penetration enhancer, a corrosion inhibitor, and a stabilizer. Specifically: the main acid agent is a mixture of chloroacetic acid, formic acid, and acetic acid; the penetration enhancer is a mixture of fatty alcohol polyoxyethylene ether and sodium lauroyl sarcosinate; the corrosion inhibitor is a compound of benzotriazole and hexamethylenetetraacetate; and the stabilizer is disodium ethylenediaminetetraacetate. The following components (mass percentage) are weighed out.

[0042] 24% chloroacetic acid, 5% formic acid, 3% acetic acid, 8% fatty alcohol polyoxyethylene ether, 4% sodium lauroyl sarcosinate, 3% benzotriazole, 3% hexamethylenetetraacetic acid disodium salt, 5% deionized water.

[0043] 2. Preparation process

[0044] (1) Add 45 kg of deionized water to the reactor, stir at 250 r / min, add 24 kg of chloroacetic acid, 5 kg of formic acid and 3 kg of acetic acid at room temperature, stir for 20 min until dissolved, and obtain acid matrix;

[0045] (2) Add 8 kg of fatty alcohol polyoxyethylene ether and 4 kg of sodium lauroyl sarcosinate to the acid matrix and stir for 18 min; then add 3 kg of benzotriazole and 3 kg of hexamethylenetetramine and stir for 18 min.

[0046] (3) Add 5 kg of disodium ethylenediaminetetraacetate, stir for 30 min, and test the pH to be 3.5 to obtain the finished high-efficiency deep-penetrating acid solution.

[0047] 3. Application Effects

[0048] The prepared high-efficiency deep-penetrating acid solution and argillaceous acid were mixed at a mass ratio of 1:8 and directly pumped into the target oil and gas reservoir. The argillaceous acid solution was prepared by mixing 15% hydrochloric acid and 5% hydrofluoric acid. After 48 hours of operation under construction conditions of 90℃ and 12MPa, the effect was evaluated: the effective penetration radius of the high-efficiency deep-penetrating acid solution in the reservoir reached 3.5m, effectively dissolving the deep carbonate rocks in the reservoir and expanding the oil and gas channels, thus achieving safe and efficient deep reservoir stimulation.

[0049] Example 3

[0050] 1. This embodiment describes a highly efficient deep-penetrating acid solution for descaling industrial equipment pipelines. The solution comprises a main acid agent, a penetration enhancer, a corrosion inhibitor, and a stabilizer. Specifically: the main acid agent is a mixture of aminosulfonic acid and formic acid; the penetration enhancer is a mixture of fatty alcohol polyoxyethylene ether and sodium lauroyl sarcosinate; the corrosion inhibitor is a compound of benzotriazole and hexamethylenetetraacetate; and the stabilizer is disodium ethylenediaminetetraacetate. Each substance is weighed according to the following component ratio (mass percentage).

[0051] The ingredients are: 16% aminosulfonic acid, 4% formic acid, 3% fatty alcohol polyoxyethylene ether, 3% sodium lauroyl sarcosinate, 1.2% benzotriazole, 1.8% hexamethylenetetraacetic acid disodium salt, 3% deionized water, and 68% thiocyanate.

[0052] 2. Preparation process

[0053] (1) Add 68 kg of deionized water to the reactor, stir at 250 r / min, add 16 kg of aminosulfonic acid and 4 kg of formic acid at room temperature, stir for 20 min until dissolved, and obtain acid matrix;

[0054] (2) Add 3 kg of fatty alcohol polyoxyethylene ether and 3 kg of sodium lauroyl sarcosinate to the acid matrix and stir for 18 min; then add 1.2 kg of benzotriazole and 1.8 kg of hexamethylenetetramine and stir for 18 min.

[0055] (3) Add 3 kg of disodium ethylenediaminetetraacetate, stir for 30 min, and test the pH to be 2.8 to obtain the finished high-efficiency deep-penetrating acid solution.

[0056] 3. Application Effects

[0057] The prepared high-efficiency deep-penetrating acid solution was diluted with water at a mass ratio of 1:6 and used to treat carbon steel industrial pipes with 3mm thick calcium carbonate scale on the inner wall by circulating immersion. After 6 hours of treatment, the scale removal rate reached 97%. The high-efficiency deep-penetrating acid solution can penetrate to the bottom of the scale layer and protect the substrate. The corrosion rate of carbon steel pipes is less than 0.05mm / a, which is far better than the industrial cleaning standard requirements.

[0058] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A high-efficiency deep-penetrating acidizing fluid, characterized in that, Components comprising the following mass parts: main acid agent 20-35 parts, penetration promoter 5-15 parts, corrosion inhibitor 2-6 parts, stabilizer 2-5 parts and deionized water 40-70 parts; Wherein, the main acid agent is a compound of main acid and auxiliary acid, the main acid is one or both of sulfamic acid and chloroacetic acid; the auxiliary acid is one or both of formic acid and acetic acid; the penetration promoter is a compound of fatty alcohol polyoxyethylene ether and sodium lauroyl sarcosinate.

2. The high-efficiency deep-penetration acidizing fluid of claim 1, wherein, The mass ratio of the main acid and auxiliary acid is (3-5):

1.

3. The high-efficiency deep-penetration acidizing fluid of claim 1, wherein, The mass ratio of the fatty alcohol polyoxyethylene ether and sodium lauroyl sarcosinate is (2-3):

1.

4. The high-efficiency deep-penetrating acidizing fluid of claim 1, wherein, The corrosion inhibitor is a compound of benzotriazole and urotropine.

5. The high-efficiency deep-penetrating acidizing fluid of claim 4, wherein, The mass ratio of the benzotriazole and urotropine is 1:(1-3).

6. The high-efficiency deep-penetrating acidizing fluid of claim 1, wherein, The stabilizer is disodium ethylenediaminetetraacetate.

7. The high-efficiency deep-penetrating acidizing fluid of claim 1, wherein, The pH value of the high-efficiency deep-penetration acidizing fluid is 2.5-3.

5.

8. A preparation method of a high-efficiency deep-penetration acid acidizing fluid, characterized in that, Comprising the following steps: Step one, the raw material composition of the high-efficiency deep-penetration acidizing fluid according to any one of claims 1-7 is weighed, and is ready for use; Step two, deionized water is added to the reaction container, and the main acid agent is added under stirring until it is completely dissolved to obtain an acid liquid matrix; Step three, under stirring, the penetration promoter and the corrosion inhibitor are added to the acid liquid matrix in sequence, and each component is ensured to be fully dispersed after being added; Step four, finally, the stabilizer is added, and the stirring is continued, and when the pH value is 2.5-3.5, the high-efficiency deep-penetration acidizing fluid according to any one of claims 1-7 is obtained.

9. The use of high-efficiency deep-penetration acid acidizing fluid in soil improvement or reservoir reconstruction for oil and gas production or pipeline descaling for industrial equipment, characterized in that, The high-efficiency deep-penetration acidizing fluid according to any one of claims 1-7 is used.

10. A highly efficient deep-penetrating acid acidizing fluid according to claim 9 for use in soil improvement or reservoir modification for oil and gas production or descaling of industrial equipment pipes, characterized in that, When applied to soil improvement, the high-efficiency deep-penetration acidizing fluid and water are diluted at a mass ratio of 1:(10-20), and are applied to the soil by drip irrigation or deep injection; When applied to oil and gas reservoir reconstruction, the high-efficiency deep-penetration acidizing fluid and soil acid are mixed at a mass ratio of 1:(8-10) and are directly injected into the oil and gas reservoir; wherein the soil acid is prepared from 15% hydrochloric acid and 5% hydrofluoric acid; When applied to industrial equipment pipeline descaling, the high-efficiency deep-penetration acidizing fluid and water are diluted at a mass ratio of 1:(5-8), and are used for pipeline treatment by circulating immersion.