Biochemical composite paraffin remover and inhibitor and application thereof

Abstract

The invention relates to a biochemical composite paraffin removal and inhibition agent and application, and belongs to the technical field of paraffin removal and inhibition of oil wells, the biochemical composite paraffin removal and inhibition agent is prepared from the following components by weight: 20-30 parts of a lipopeptide biosurfactant, 8-15 parts of alkyl dimethyl carboxyl betaine, 3-5 parts of a demulsifier, 2-5 parts of cocoanut fatty acid diethanolamide, and 45-67 parts of water. The wax-proof viscosity-reducing agent has good wax-proof viscosity-reducing effects on high-wax-content crude oil; the paraffin inhibition rate is more than 80%, and the viscosity reduction rate is more than 65%; the interfacial tension and the wetting reversal effect can be effectively reduced, and the permeation and dispersion properties are relatively strong; the system is wide in application range, is suitable for the formation temperature range of 30-120 DEG C, is suitable for the surface crude oil viscosity of below 1000 mPa.s, is suitable for the produced liquid water content of more than 20%, and is suitable for the formation working fluid level of more than 300 m; the average alternating load can be reduced to a greater extent, and the average alternating load of the biochemical composite paraffin remover and inhibitor can be reduced by more than 60% at most in site construction; the components of the system are biodegradable products and have the characteristics of being green, non-toxic, pollution-free, free of organic chlorine, safe, environment-friendly and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of biochemical complex paraffin remover, belong to oil well paraffin removal technology field, specifically related to a kind of biochemical complex paraffin remover and application, especially suitable for solving the problem of serious wax deposition in the process of high-wax, high-viscosity crude oil exploitation oil well shaft, pumping equipment and gathering pipeline. BACKGROUND

[0002] In the process of crude oil exploitation and gathering, wax deposition is one of the core problems that restrict production efficiency. When the temperature of crude oil is lower than the wax precipitation temperature, wax components are precipitated in the form of crystals, which gradually adhere to the inner wall of the wellbore, pumping rod and gathering pipeline, resulting in a decrease in flow area and an increase in flow resistance. This may cause a decrease in crude oil production, or even lead to wellbore blockage, equipment wear and other serious accidents, increasing the cost of exploitation.

[0003] Currently, the widely used paraffin removal technology in industry is mainly chemical paraffin removal. Chemical paraffin remover mainly includes chemical surfactant type, polymer type and solvent type. Among them, chemical surfactant type paraffin remover can prevent paraffin by reducing the surface tension of wax crystal and destroying the aggregation structure of wax crystal. However, it has poor salt tolerance and is easily ineffective in high salinity formation water. Polymer type paraffin remover can change the growth form of wax crystal by adsorbing on the surface of wax crystal. However, it has poor low-temperature fluidity and uneven dispersion. Solvent type paraffin remover has fast paraffin removal speed, but it is highly toxic and causes serious environmental pollution, which does not meet the requirements of green exploitation.

[0004] Biological surfactant, as a green and environmentally friendly surfactant, has the advantages of strong emulsifying property, excellent salt and temperature resistance, and biodegradability, and has gradually attracted attention in the field of oilfield chemistry. However, the paraffin removal efficiency of single biological surfactant is limited, and it has slow effect time and insufficient ability to remove stubborn wax deposits. It is difficult to meet the needs of complex oilfield conditions. If biological surfactant and chemical paraffin remover are scientifically compounded, the defects of each other can be compensated by the synergistic effect, and a new type of paraffin remover with high efficiency, stability and environmental protection can be developed.

[0005] Therefore, it is of great significance to develop a composite system with biological surfactant and chemical paraffin remover as the core to realize the organic unity of green environmental protection and high-efficiency paraffin removal, and to promote the green exploitation of high-wax crude oil. SUMMARY

[0006] The present application aims to overcome the defects of low efficiency, poor stability or insufficient environmental protection of single paraffin remover, and provides a biological and chemical complex paraffin remover and application. The composite paraffin remover realizes the multiple advantages of high efficiency, long-acting and environmental friendliness of paraffin removal through the synergistic effect of biological surfactant and chemical paraffin remover, combined with synergist and stabilizer.

[0007] The biochemical complex wax removal and prevention agent is prepared from the following components in parts by weight: 20-30 parts of lipopeptide biological surfactant, 8-15 parts of alkyl dimethyl carboxy betaine, 3-5 parts of demulsifier, 2-5 parts of coconut oil fatty acid diethanolamide, and 45-67 parts of water.

[0008] As a further improvement of the present application, the lipopeptide biological surfactant is a natural compound with amphiphilic property produced by Bacillus subtilis ACCC01430, which has a hydrophilic cyclic heptapeptide head group and a hydrophobic β-hydroxy fatty acid tail chain, and has both the hydrophobicity of lipids and the hydrophilicity of peptides.

[0009] As a further improvement of the present application, the lipopeptide biological surfactant is prepared by the following method: (1) inoculating the activated Bacillus subtilis ACCC01430 into a seed culture medium to obtain a seed liquid; (2) preparing a fermentation culture medium, which is sterilized at high temperature after preparation and ready for use; (3) inoculating the seed liquid prepared in step (1) into the fermentation culture medium for 72 h of expansion culture to obtain a biological surfactant lipopeptide fermentation liquor containing the biological surfactant lipopeptide; wherein the content of the lipopeptide in the lipopeptide fermentation liquor is 2000-3500 mg / L; The components of the seed culture medium are: 20-25 g / L of sucrose, 2-3 g / L of sodium nitrate, 1-3 g / L of ammonium chloride, 0.8-3 g / L of potassium phosphate dibasic, 7-10 g / L of sodium phosphate monobasic, 0.3-0.5 g / L of magnesium sulfate, 0.1-0.3 g / L of yeast, 0.2-0.3 mL / L (0.05 mol / L) of manganese chloride, and the balance is pure water; the pH of the seed culture medium is 7.0-7.2, and it is sterilized at 121°C for 30 min for standby use; The components of the fermentation culture medium are specifically as follows: 20-25 g / L of sucrose, 2-3 g / L of sodium nitrate, 1-3 g / L of ammonium chloride, 0.8-3 g / L of potassium phosphate dibasic, 7-10 g / L of sodium phosphate monobasic, 0.3-0.5 g / L of magnesium sulfate, 0.1-0.3 g / L of yeast, 0.2-0.3 mL / L of manganese chloride, and the balance is pure water; the pH of the fermentation culture medium is 7.0-7.2, and it is sterilized at 121°C for 30 min for standby use; The inoculation amount of the seed liquid is 2-5 wt%.

[0010] As a further improvement of the present application, the demulsifier is one or both of SP-169 type or AE-1910 type of non-ionic polyether surfactant.

[0011] The application of the biochemical composite wax cleaning and preventing agent has the following beneficial effects compared with the prior art:

[0012] The biochemical composite wax cleaning and preventing agent has the following beneficial effects compared with the prior art: (1) The biochemical composite wax cleaning and preventing agent, wherein the lipopeptide biological surfactant is produced by fermentation of Bacillus subtilis, and the lipopeptide biological surfactant has good wax preventing and viscosity reducing effects on high-wax crude oil in the wax cleaning and preventing agent; (2) The biochemical composite wax cleaning and preventing agent has good wax preventing and viscosity reducing effects on waxy crude oil in different regions, with a wax preventing rate of more than 80% and a viscosity reducing rate of more than 65%. The biological surfactant produced by microbial metabolism plays a key role in the wax preventing system, and the main modes of action include: 1) effectively reducing the interfacial tension: enhancing the hydrophilicity of the crude oil, promoting the dispersion of wax crystals in the water phase, and reducing the deposition of wax crystals on the pipe wall; 2) wetting reversal: relying on the wetting reversal of the biological surfactant, the oil-wet surface of the pipe wall is reversed to a water-wet surface, reducing the adhesion of wax crystals and preventing the deposition of wax on the pipe wall; 3) strong penetration and dispersion performance: the biological surfactant penetrates into the wax crystal gap, weakens the bonding force between wax molecules, and disperses the wax crystal molecules in the oil flow; (3) The biochemical composite wax cleaning and preventing agent, wherein the alkyl dimethyl carboxy betaine is an amphoteric surfactant. When the betaine molecules form a directional adsorption film on the surface, the originally oil-wet surface becomes a water-wet surface, which is not conducive to the adhesion and deposition of wax molecules, thereby preventing the precipitation and growth of wax from the source, and changing the wettability of the formed wax deposition, greatly reducing the adhesion of the wax to the metal pipe wall, and making it easier to fall off under the flow of fluid; (4) The biochemical composite wax cleaning and preventing agent, wherein the demulsifier changes the precipitation and deposition environment of wax by destroying the stability of oil-water emulsion, and cooperates with other components to effectively enhance the overall effect of wax cleaning and preventing; (5) The biochemical composite wax cleaning and preventing agent, wherein the coconut oil fatty acid diethanolamide utilizes its strong penetration to loosen and destroy the deposits from the root, and has a synergistic effect with other components; (6) The biochemical composite wax cleaning and preventing agent has a wide system use range, is suitable for a formation temperature range of 30-120 DEG C, is suitable for a ground crude oil viscosity of below 1000 mPa.s, a produced liquid water content of above 20%, and a formation dynamic liquid level of above 300 m. (7) The biochemical composite wax cleaning and preventing agent can greatly reduce the average alternating load, and the average alternating load of the biochemical composite wax cleaning and preventing agent on site can be reduced by above 60%. (8) The biochemical composite wax cleaning and preventing agent has a biochemical degradable product as a system component, and has the characteristics of green, non-toxic, non-pollution, no organic chlorine, safety and environmental protection. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 The indicator diagram changes before and after the biochemical composite wax cleaning and preventing agent prepared in Example 1 is taken; Figure 2 The indicator diagram changes before and after the biochemical composite wax cleaning and preventing agent prepared in Example 5 is taken; Figure 3 The indicator diagram changes before and after the biochemical composite wax cleaning and preventing agent prepared in Example 6 is taken. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical scheme and advantages of the application more clear and understandable, the application is further described in detail below in combination with examples, and the illustrative embodiments of the application and the description thereof are only used to explain the application, and do not limit the application.

[0015] The reagents used in the following examples are described as follows: Alkyl dimethyl carboxy betaine, demulsifier and coconut oil fatty acid diethanolamide are respectively products produced by Hubei Xingyan New Material Technology Co., Ltd., Jiangsu Haian Petroleum Chemical Factory and Shanghai Haibo Oilfield Chemical Co., Ltd., and are obtained by purchase; Water is on-site injection water.

[0016] The lipopeptide biological surfactant is obtained by fermentation of Daqing Huali Biotechnology Co., Ltd., and the specific preparation method is as follows: (1) The activated Bacillus subtilis ACCC01430 is inoculated into a seed culture medium to obtain a seed liquid after culture; (2) A fermentation culture medium is prepared, and the culture medium is sterilized at high temperature after preparation and is ready for use; (3) The seed liquid prepared in step (1) is inoculated into the fermentation culture medium, and is cultured for 72 h to obtain a biological surfactant lipopeptide fermentation liquid, wherein the lipopeptide fermentation liquid contains the biological surfactant lipopeptide; the content of the lipopeptide in the lipopeptide fermentation liquid is 2000-3500 mg / L. The components of the seed culture medium are: sucrose 20-25 g / L, sodium nitrate 2-3 g / L, ammonium chloride 1-3 g / L, dipotassium hydrogen phosphate 0.8-3 g / L, sodium dihydrogen phosphate 7-10 g / L, magnesium sulfate 0.3-0.5 g / L, yeast 0.1-0.3 g / L, manganese chloride 0.2-0.3 mL / L (0.05 mol / L), and the balance is pure water; the pH of the seed culture medium is 7.0-7.2, and it is sterilized at 121°C for 30 min for standby; The components of the fermentation medium are specifically as follows: sucrose 20-25 g / L, sodium nitrate 2-3 g / L, ammonium chloride 1-3 g / L, dipotassium hydrogen phosphate 0.8-3 g / L, sodium dihydrogen phosphate 7-10 g / L, magnesium sulfate 0.3-0.5 g / L, yeast 0.1-0.3 g / L, manganese chloride 0.2-0.3 mL / L, and the balance is pure water; the pH of the fermentation medium is 7.0-7.2, and it is sterilized at 121°C for 30 min for standby; The inoculation amount of the seed liquid is 2-5 wt%.

[0017] The natural compound with amphiphilicity (both hydrophilic and hydrophobic structure) produced by Bacillus subtilis ACCC01430 through the above method is composed of a hydrophilic cyclic heptapeptide head group and a hydrophobic beta-hydroxy fatty acid tail chain, as shown below, and has both the hydrophobicity of lipids and the hydrophilicity of peptides;

[0018] Example 1

[0019] The main components and mass fraction composition of the biochemical composite wax cleaning and preventing agent of the application are as follows: Surfactant: 20 parts, which is a lipopeptide biological surfactant; Alkyl dimethyl carboxy betaine: 8 parts; Demulsifier: 3 parts, which is SP-169 type; Coconut oil fatty acid diethanolamide: 2 parts; Injection water: 67 parts; The biochemical composite wax cleaning and preventing agent prepared in Example 1 was applied in a certain oilfield in Qinghai from 2022 to 2024, and the implementation block had a mineralization of 9.4×10 4 -18.22×10 4 mg / L, a crude oil freezing point of 34.5°C, and a wax content of about 26.38%. The underground crude oil viscosity of a certain well 1 was 27.96 mPa.s, and the crude oil freezing point was 34.5°C. The daily liquid production was 11.3 t, and the daily oil production was 8.9 t. The maximum load decreased from 61.3 kN to 52.7 kN on the third day after adding the agent, a decrease of 14.0%. As Figure 1 shown.

[0020] Example 2

[0021] The biochemical composite paraffin cleaning and preventing agent of the present application has the following main components and mass fraction composition: Surfactant: 27 parts, which is a lipopeptide biological surfactant; Alkyl dimethyl carboxy betaine: 13 parts; Demulsifier: 5 parts, which is AE-1910 type; Coconut oil fatty acid diethanol amide: 5 parts; Injection water: 50 parts.

[0022] Example 3

[0023] The biochemical composite paraffin cleaning and preventing agent of the present application has the following main components and mass fraction composition: Surfactant: 30 parts, which is a lipopeptide biological surfactant; Alkyl dimethyl carboxy betaine: 15 parts; Demulsifier: 5 parts, which is AE-1910 type; Coconut oil fatty acid diethanol amide: 5 parts; Injection water: 45 parts.

[0024] Example 4

[0025] The biochemical composite paraffin cleaning and preventing agent of the present application has the following main components and mass fraction composition: Surfactant: 28 parts, which is a lipopeptide biological surfactant; Alkyl dimethyl carboxy betaine: 12 parts; Demulsifier: 4 parts, which is SP-169 type; Coconut oil fatty acid diethanol amide: 4 parts; Injection water: 52 parts.

[0026] Example 5

[0027] The biochemical composite paraffin cleaning and preventing agent of the present application has the following main components and mass fraction composition: Surfactant: 23 parts, which is a lipopeptide biological surfactant; Alkyl dimethyl carboxy betaine: 9 parts; Demulsifier: 4 parts; Coconut oil fatty acid diethanol amide: 3 parts; Injection water: 61 parts; The biochemical composite paraffin removal agent prepared in Example 5 is used in a well (Well 2) in Daqing Oilfield in 2025 for test, the average crude oil viscosity of the block where the well is located is 36.4 mPa.s, the average freezing point is 37.0℃, and the average wax content is 25.8%. The average alternating load of the well before treatment is 64.88 KN, and the average alternating load after adding the biochemical composite paraffin removal agent is 25.92 KN, which is decreased by 60.05% on average. The maximum alternating load is decreased by 74.56% before and after treatment, and the dynamometer card change of the well before and after treatment is shown in Figure 2 .

[0028] Example 6

[0029] The main components and mass fraction composition of the biochemical composite paraffin removal agent of the present application are as follows: Surfactant: 21 parts, which is a lipopeptide biological surfactant; Alkyl dimethyl carboxy betaine: 9 parts; Demulsifier: 4 parts; Coconut oil fatty acid diethanolamide: 3 parts; Injection water: 63 parts; The biochemical composite paraffin removal agent prepared in Example 6 is used in a well (Well 3) in Daqing Oilfield in 2025 for pilot test, the average crude oil viscosity of the block where the well is located is 36.4 mPa.s, the average freezing point is 37.0℃, and the average wax content is 25.8%. The average alternating load of the well before treatment is 27.68 KN, and the average alternating load after adding the biochemical composite paraffin removal agent is 24.27 KN, which is decreased by 12.32%. The maximum alternating load is decreased by 27.84% before and after treatment, and the dynamometer card change of the well before and after treatment is shown in Figure 3 .

[0030] Comparative Example 1

[0031] The main components and mass fraction composition of the petroleum sulfonate paraffin removal agent system are as follows: Petroleum sulfonate paraffin removal agent: 50 parts; Injection water: 50 parts.

[0032] The paraffin removal rates of Examples 1-6 and Comparative Example 1 above are tested as follows.

[0033] Test instrument: 120 ml triangular bottle, 250 ml wide-mouth bottle, water bath, drying oven, electronic balance.

[0034] Wax control rate test method: 1) Prepare a water-containing crude oil sample with a water content of about 50%. 2) Take several 120ml triangular bottles, wash and dry them, cool them, and then remove the plug and weigh them m1 (accurate to 0.0001g). Add 50g (accurate to 0.01g) of water-containing crude oil to the 120ml triangular bottle, and then add 1g (accurate to 0.01g) of the wax control agent, cover the plug, and place it in a water bath (or dry box) with a constant temperature of 5~7℃ above the wax precipitation point for 30min. Take it out and shake it 100 times (or 10min), mix it evenly. Keep it constant temperature for 60min. 3) Adjust the temperature of the dryer to 1~3℃ above the freezing point, and place the triangular bottle in the constant temperature for 10min. 4) Place an empty 250ml wide-mouth bottle without a plug in the dry box. Quickly remove the plug from the 120ml oil bottle, and place it upside down on the 250ml wide-mouth bottle, allowing the emulsion to flow into the wide-mouth bottle, and continue to keep it constant temperature for a period of time until the oil bottle does not drip. 5) Take out the oil bottle and weigh m2 (without plug, accurate to 0.0001g).

[0035] At the same time, do not add the blank test according to the above operation steps, and the parallel test should not be less than 3; .....................(1) In the formula: E Wax control rate, unit: percentage (%); m0— The average value of the oil bottle wall mass of the blank test (m2 0 - m1 0 ), g m — The average value of the oil bottle wall mass of the drug test (m2- m1), g The data is shown in Table 1 Table 1 Indoor wax control effect evaluation of biochemical composite wax control agent for different block crude oils

[0036] As can be seen from Table 1, the biochemical composite wax control agent of the present application can achieve a wax control rate of more than 90% for Qinghai crude oil; for Daqing crude oil, the indoor evaluation of the wax control rate is more than 80%, and the effect is better than that of the comparative example.

[0037] The viscosity reduction rate of the crude oil of the above examples 1-6 and comparative example 1 is tested as follows.

[0038] Test instrument: 100ml beaker, water bath, Brookfield rotational viscometer, electronic balance.

[0039] The crude oil viscosity reduction rate test method is as follows: 1) taking the dewatered and degassed oil sample; 2) using the produced water to prepare 1% wax inhibitor; 3) after the crude oil is kept at 50 DEG C for 30 minutes, the viscosity of the crude oil is measured by a rotary viscometer; 4) after the crude oil in 1) and the prepared solution in 2) are mixed at a ratio of 5:5 and kept at 50 DEG C for 30 minutes, the viscosity of the crude oil emulsion is measured by a rotary viscometer; 5) calculating the viscosity reduction rate of the agent on the crude oil; .....................(2) M --- viscosity reduction rate, unit: percentage (%); η1 --- viscosity of the dewatered and degassed crude oil at 50 DEG C, unit: millipascal second (mPa s); η2 --- viscosity of the dewatered and degassed crude oil after adding the agent at 50 DEG C, unit: millipascal second (mPa s).

[0040] The data is shown in Table 2; Table 2: indoor crude oil viscosity reduction effect evaluation of the biochemical composite wax inhibitor for different blocks

[0041] As shown in Table 2, the indoor evaluation of the viscosity reduction rate of the biochemical composite wax inhibitor of the present application for Qinghai crude oil and Daqing crude oil can reach more than 65%, and the effect is obviously better than that of the comparative examples.

[0042] As shown in the above examples, the present application discloses a biochemical composite wax inhibitor and its application. The biochemical composite wax inhibitor has good wax inhibition and viscosity reduction effect on high-wax-content crude oil. After the oil well wax inhibition in Qinghai and Daqing oilfields, the average alternating load is reduced by 14.0% to 74.56%, which prevents the precipitation and growth of wax from the root, and changes the wettability of the formed wax deposition, so that the adhesion of the wax deposition to the metal pipe wall is greatly reduced, and the wax deposition is more easily removed under the fluid scouring.

[0043] The above description of the examples is for the convenience of the ordinary skilled in the art to understand and use the present application. It should be noted that, within the scope of knowledge possessed by the ordinary skilled in the art, the present application can be improved and modified in several ways, and these improvements and modifications made without departing from the scope of the present application should be within the protection scope of the present application.

Claims

1. A biochemical complex paraffin control agent, characterized in that, It is made from the following components in parts by weight: 20-30 parts of lipopeptide biosurfactant, 8-15 parts of alkyl dimethyl carboxylic betaine, 3-5 parts of demulsifier, 2-5 parts of coconut oil fatty acid diethanolamide, and 45-67 parts of water.

2. The biochemical complex paraffin inhibitor according to claim 1, characterized in that, The lipopeptide biosurfactant is an amphiphilic natural compound produced by Bacillus subtilis ACCC01430. Its structure consists of a hydrophilic cyclic heptapeptide head group and a hydrophobic β-hydroxy fatty acid tail chain, combining the hydrophobicity of lipids and the hydrophilicity of peptides.

3. The biochemical complex paraffin inhibitor according to claim 2, characterized in that, Lipopeptide biosurfactants are prepared by the following methods: (1) The activated Bacillus subtilis ACCC01430 was inoculated into the seed culture medium and cultured to obtain the seed liquid; (2) Prepare the fermentation culture medium. After preparation, the culture medium is sterilized at high temperature and then set aside. (3) The seed liquid prepared in step (1) is inoculated into the fermentation medium and cultured for 72 h to obtain the biosurfactant lipopeptide fermentation broth, wherein the lipopeptide fermentation broth contains the biosurfactant lipopeptide; wherein the lipopeptide content in the lipopeptide fermentation broth is 2000-3500 mg / L. The seed culture medium comprises: 20-25 g / L sucrose, 2-3 g / L sodium nitrate, 1-3 g / L ammonium chloride, 0.8-3 g / L dipotassium hydrogen phosphate, 7-10 g / L sodium dihydrogen phosphate, 0.3-0.5 g / L magnesium sulfate, 0.1-0.3 g / L yeast, 0.2-0.3 mL / L manganese chloride (0.05 mol / L), with the remainder being purified water; the pH of the seed culture medium is 7.0-7.2, and it is sterilized at 121℃ for 30 min before use. The specific components of the fermentation medium are as follows: sucrose 20-25 g / L, sodium nitrate 2-3 g / L, ammonium chloride 1-3 g / L, dipotassium hydrogen phosphate 0.8-3 g / L, sodium dihydrogen phosphate 7-10 g / L, magnesium sulfate 0.3-0.5 g / L, yeast 0.1-0.3 g / L, manganese chloride 0.2-0.3 mL / L, and the balance being purified water; the pH of the fermentation medium is 7.0-7.2, and it is sterilized at 121℃ for 30 min before use; The inoculation amount of the seed solution is 2-5 wt%.

4. The biochemical complex paraffin inhibitor according to claim 1, characterized in that, The demulsifier is one or both of the SP-169 or AE-1910 types of nonionic polyether surfactants.

5. The use of a biochemical complex paraffin inhibitor according to any one of claims 1 to 5, characterized in that, The applicable conditions for the biochemical composite dewaxing agent are: (1) Formation temperature: between 30 and 120°C; (2) Surface crude oil viscosity: below 1000 mPa.s; (3) Produced fluid water content > 20%; (4) Formation dynamic fluid level > 300 m.

Images