Bactericide for oil field as well as preparation method and application of bactericide

Abstract

The invention belongs to the technical field of oil exploitation, and relates to a bactericide for an oil field and a preparation method and application thereof. The preparation method comprises the following steps: adding terephthalaldehyde, methanol, 4-morpholine piperidine and sodium cyanoborohydride into a reactor, stirring and dissolving, adding hydrochloric acid to adjust the pH value to 3-4, heating to 60-65 DEG C, carrying out heat preservation reaction to obtain an intermediate mixed solution, and cooling to room temperature; adding distilled water, fully stirring, extracting twice with chloroform, combining extract liquor, and performing reduced pressure distillation to obtain a high-viscosity solid; transferring into a four-neck flask by using isopropanol, adding bromoalkane, adjusting the pH value to 9-10, and heating and refluxing to obtain a mixed solution; and carrying out reduced pressure distillation to obtain a high-viscosity solid, recrystallizing with ethyl acetate, and drying overnight to obtain the product bactericide. The bactericide disclosed by the invention has the characteristic of broad-spectrum sterilization, and has a relatively good sterilization effect on SRB, TGB and FB.

Description

Technical Field

[0001] The invention belongs to the technical field of oil extraction and relates to a fungicide for oil fields and a preparation method and application thereof. Background Art

[0002] Both secondary and tertiary oil recovery require the injection of large amounts of water into the formation to replenish the formation's energy deficit. Since the injected water is recycled, the composition of the water becomes increasingly complex, making it easy for various bacteria to grow. Coupled with the application of polymer flooding, favorable conditions have been created for the reproduction of bacteria in the system, making the harm of bacteria increasingly serious. The growth, metabolism and reproduction of these bacteria can cause corrosion and damage to drilling and production equipment, water injection pipelines and other metal materials, blockage of pipelines and formations, reduce the pore permeability of the oil layer, and reduce the oil field recovery rate, all of which cause huge economic losses to the production and operation of the oil field.

[0003] Therefore, produced water must be sterilized before reinjection. There are many kinds of chemical agents used to kill or inhibit the growth of microorganisms. The extent of the killing effect on microorganisms varies depending on the toxicity of the chemical agent, the permeability into the cell and the type of microorganism. A chemical agent is toxic to a certain microorganism, but may have no effect on another microorganism. Some agents have a bactericidal effect at a slightly higher concentration, but at a certain low concentration, they have a stimulating effect on growth. Only by correctly selecting and using bactericides can the reproduction of harmful bacteria be effectively inhibited.

[0004] However, the current fungicide types used in oilfield produced water are limited. Long-term use will cause bacteria to develop a certain degree of drug resistance, resulting in a significant decrease in the effectiveness of the agents.

[0005] Invention patent CN104488874A is a compound fungicide for oilfield water injection system. The invention belongs to the technical field of oilfield wastewater treatment. A compound fungicide for oilfield water injection system, characterized in that: the weight percentage composition of the compound fungicide for oilfield water injection system is 70-80% of an aqueous solution with a mass fraction of benzalkonium chloride of 45-55%, 10-20% of an ethanol solution with a mass fraction of cetylpyridinium bromide of 25-35%, and 10-15% of a xylene solution with a mass fraction of tetrachloroisophthalonitrile of 18-22%. The compound fungicide for oilfield water injection system of the invention has a strong bactericidal effect, can effectively remove sulfate-reducing bacteria, iron bacteria, and saprophytic bacteria in sewage, and avoid bacterial corrosion and blockage of pipeline equipment. It has the advantages of simple components, convenient preparation, fast and efficient, low cost, high bactericidal rate, low usage, and small side effects. However, the compound ingredients of the invention contain a large amount of cetylpyridinium bromide, which has increased toxicity and will cause secondary pollution and environmental damage after use.

[0006] Invention patent CN107593703B discloses a fungicide for oilfield water treatment system, its preparation method and application, the fungicide comprises 5wt.% to 60wt.% of dodecyl dimethyl benzyl ammonium halide, 0.5wt.% to 5wt.% of D-amino acid, 10wt.% to 30wt.% of surfactant, 3wt.% to 10wt.% of buffer and the balance of water. The fungicide of the invention has high bactericidal efficiency, has high bactericidal effect on sulfate reducing bacteria (SRB) and saprophytic bacteria (TGB), has long duration of efficacy, simple production process and low cost. However, the invention has the problem that the amount of fungicide used is large and the bactericidal effect is not satisfactory. Summary of the invention

[0007] The present invention aims at the deficiencies of the above-mentioned prior art and provides a fungicide for oil field and its preparation method and application. The fungicide of the present invention has the characteristics of broad-spectrum bactericidal and has good bactericidal effect on SRB, TGB and FB.

[0008] One of the purposes of the present invention is to disclose a method for preparing an oilfield fungicide, the specific steps of which are as follows: (1) Add terephthalaldehyde, methanol, 4-morpholinopiperidine and sodium cyanoborohydride into a reactor, stir and dissolve, add hydrochloric acid to adjust the pH to 3-4, heat to 60-65°C, keep warm for reaction, obtain an intermediate mixed solution, and cool to room temperature; (2) Add distilled water to the intermediate mixture, stir thoroughly, extract twice with chloroform, combine the extracts, and distill under reduced pressure to obtain a high-viscosity solid; (3) The high-viscosity solid was transferred into a four-necked flask with isopropanol, bromoalkane was added, the pH was adjusted to 9-10, and the mixture was heated under reflux to obtain a mixed solution; (4) The mixed solution in (3) is distilled under reduced pressure to obtain a high-viscosity solid, which is recrystallized from ethyl acetate and dried overnight to obtain a fungicide product.

[0009] In the present invention, preferably, based on 1 mole of terephthalaldehyde, the 4-morpholinopiperidine and the bromoalkane are 1.8-2.2 moles and 3.5-5 moles, respectively.

[0010] In the present invention, preferably, the weight ratio of methanol, sodium cyanoborohydride and terephthalaldehyde in step (1) is 30-40:0.3-0.5:1 respectively.

[0011] In the present invention, preferably, the insulation time in step (1) is 4-6 hours.

[0012] In the present invention, preferably, the weight ratio of distilled water, chloroform and terephthalaldehyde in step (2) is 30-40:60-80:1.

[0013] In the present invention, preferably, the weight ratio of isopropanol to terephthalaldehyde in step (3) is 60-80:1.

[0014] In the present invention, preferably, the reflux reaction time in step (3) is 24-48 hours.

[0015] The reaction equation for the synthesis of the oilfield bactericide of the present invention is as follows: Another object of the present invention is to disclose a fungicide for oil fields, the molecular structure of the fungicide is as follows: .

[0016] Where R is C 6 -C 22 Preferably, R is C 12 -C 18 of normal alkanes.

[0017] The third object of the present invention is to disclose the application of the above-mentioned bactericide in oilfield wastewater treatment.

[0018] The oil field bactericide of the present invention is a Gemini cationic and nonionic composite surfactant. Four quaternary ammonium salts are positively charged, and bacteria have negative charges. Quaternary ammonium salt molecules can be adsorbed on the surface of the bacteria, form hydrogen bonds with deoxyribonucleic acid in bacterial proteins, and be adsorbed on bacterial cells to destroy the DNA structure of the bacteria, causing them to lose replication ability and die. The morpholine structure affects the rearrangement of the molecular structure of the bacterial cell wall, interferes with the assembly of the cell wall polymer, produces a chamber barrier effect, and causes the bacterial growth to be inhibited and die. The alkyl R has a lipophilic property, and the molecule can enter the crude oil and kill the bacteria hidden in the crude oil.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) The oilfield fungicide of the present invention has a broad spectrum and can kill SRB, TGB and FB in oily wastewater; (2) The oilfield fungicide of the present invention has the advantages of low concentration and high efficiency. When the concentration is 3 mg / L, the bactericidal rates of SRB, TGB and FB are all above 90%; when the concentration is 8 mg / L, the bactericidal rates of SRB, TGB and FB are all 100%. DETAILED DESCRIPTION

[0020] 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.

[0021] The present invention will be further described below in conjunction with specific embodiments: Example 1 (1) Add 0.05 mol of terephthalaldehyde, 201 g of methanol, 0.09 mol of 4-morpholinopiperidine, and 2.01 g of sodium cyanoborohydride into a reactor, stir and dissolve, add 5 mol / L hydrochloric acid to adjust the pH to 3-4, heat to 60°C, keep the temperature for 4 hours to obtain an intermediate mixed solution, and cool to room temperature; (2) Add 201 g of distilled water to the intermediate mixture, stir thoroughly, extract twice with 402 g of chloroform, combine the extracts, and distill under reduced pressure to obtain a high-viscosity solid; (3) The high-viscosity solid was transferred to a four-necked flask with 402 g of isopropanol, 0.25 mol of bromohexane was added, the pH was adjusted to 9-10, and the mixture was heated under reflux for 24 h to obtain a mixed solution; (4) The mixed solution in (3) is distilled under reduced pressure to obtain a high-viscosity solid, which is recrystallized from ethyl acetate and dried overnight to obtain a fungicide product.

[0022] Example 2 (1) Add 0.05 mol of terephthalaldehyde, 224 g of methanol, 0.11 mol of 4-morpholinopiperidine, and 3.35 g of sodium cyanoborohydride into a reactor, stir to dissolve, add 5 mol / L hydrochloric acid to adjust the pH to 3-4, heat to 62°C, keep the temperature for 4 hours to obtain an intermediate mixed solution, and cool to room temperature; (2) Add 224 g of distilled water to the intermediate mixture, stir thoroughly, extract twice with 448 g of chloroform, combine the extracts, and distill under reduced pressure to obtain a high-viscosity solid; (3) The high-viscosity solid was transferred to a four-necked flask with 430 g of isopropanol, 0.23 mol of bromooctane was added, the pH was adjusted to 9-10, and the mixture was heated under reflux for 36 h to obtain a mixed solution; (4) The mixed solution in (3) is distilled under reduced pressure to obtain a high-viscosity solid, which is recrystallized from ethyl acetate and dried overnight to obtain a fungicide product.

[0023] Example 3 (1) Add 0.05 mol of terephthalaldehyde, 238 g of methanol, 0.095 mol of 4-morpholinopiperidine, and 2.47 g of sodium cyanoborohydride into a reactor, stir and dissolve, add 5 mol / L of hydrochloric acid to adjust the pH to 3-4, heat to 60°C, keep the temperature for 5 hours to react, obtain an intermediate mixed solution, and cool to room temperature; (2) Add 238 g of distilled water to the intermediate mixture, stir thoroughly, extract twice with 482 g of chloroform, combine the extracts, and distill under reduced pressure to obtain a high-viscosity solid; (3) The high-viscosity solid was transferred to a four-necked flask with 536 g of isopropanol, 0.175 mol of bromodocosane was added, the pH was adjusted to 9-10, and the mixture was heated under reflux for 36 h to obtain a mixed solution; (4) The mixed solution in (3) is distilled under reduced pressure to obtain a high-viscosity solid, which is recrystallized from ethyl acetate and dried overnight to obtain a fungicide product.

[0024] Example 4 (1) Add 0.05 mol of terephthalaldehyde, 246 g of methanol, 0.105 mol of 4-morpholinopiperidine, and 2.98 g of sodium cyanoborohydride into a reactor, stir and dissolve, add 5 mol / L hydrochloric acid to adjust the pH to 3-4, heat to 62°C, keep the temperature for 5 hours to react, obtain an intermediate mixed solution, and cool to room temperature; (2) Add 246 g of distilled water to the intermediate mixture, stir thoroughly, extract twice with 490 g of chloroform, combine the extracts, and distill under reduced pressure to obtain a high-viscosity solid; (3) The high-viscosity solid was transferred to a four-necked flask with 520 g of isopropanol, 0.19 mol of bromooctadecane was added, the pH was adjusted to 9-10, and the mixture was heated under reflux for 40 h to obtain a mixed solution; (4) The mixed solution in (3) is distilled under reduced pressure to obtain a high-viscosity solid, which is recrystallized from ethyl acetate and dried overnight to obtain a fungicide product.

[0025] Example 5 (1) Add 0.05 mol of terephthalaldehyde, 251 g of methanol, 0.1 mol of 4-morpholinopiperidine, and 2.84 g of sodium cyanoborohydride into a reactor, stir to dissolve, add 5 mol / L hydrochloric acid to adjust the pH to 3-4, heat to 63°C, keep the temperature for 6 hours to obtain an intermediate mixed solution, and cool to room temperature; (2) Add 251 g of distilled water to the intermediate mixture, stir thoroughly, extract twice with 500 g of chloroform, combine the extracts, and distill under reduced pressure to obtain a high-viscosity solid; (3) The high-viscosity solid was transferred to a four-necked flask with 480 g of isopropanol, 0.21 mol of hexadecane bromide was added, the pH was adjusted to 9-10, and the mixture was heated under reflux for 44 h to obtain a mixed solution; (4) The mixed solution in (3) is distilled under reduced pressure to obtain a high-viscosity solid, which is recrystallized from ethyl acetate and dried overnight to obtain a fungicide product.

[0026] Example 6 (1) Add 0.05 mol of terephthalaldehyde, 268 g of methanol, 0.1 mol of 4-morpholinopiperidine, and 3.13 g of sodium cyanoborohydride into a reactor, stir and dissolve, add 5 mol / L hydrochloric acid to adjust the pH to 3-4, heat to 65°C, keep the temperature for 6 hours to obtain an intermediate mixed solution, and cool to room temperature; (2) Add 268 g of distilled water to the intermediate mixture, stir thoroughly, extract twice with 536 g of chloroform, combine the extracts, and distill under reduced pressure to obtain a high-viscosity solid; (3) The high-viscosity solid was transferred to a four-necked flask with 499 g of isopropanol, 0.22 mol of dodecane bromide was added, the pH was adjusted to 9-10, and the mixture was heated under reflux for 48 h to obtain a mixed solution; (4) The mixed solution in (3) is distilled under reduced pressure to obtain a high-viscosity solid, which is recrystallized from ethyl acetate and dried overnight to obtain a fungicide product.

[0027] Example 7: Evaluation of sterilization rate The water sample after oil-water separation from a joint station of an oil production plant in Shengli Oilfield was taken and divided into several 250 mL narrow-necked bottles, and different concentrations of the bactericide of the present invention (Examples 1-6) were added, shaken well, placed in a 65°C oven, and sampled after 1 hour. The three-tube MPN method was used to detect the bacterial content of SRB (sulfate-reducing bacteria), TGB (saprophytic bacteria), and FB (iron bacteria), and the bactericidal rate was calculated.

[0028] Dodecyl dimethyl benzyl ammonium chloride (1227) was used for comparative experiments. The experimental results are shown in Tables 1, 2 and 3.

[0029] Table 1 SRB sterilization results (sterilization rate, %) Concentration, mg / L 3 5 8 Example 1 91.1 98.2 100 Example 2 91.1 99.3 100 Example 3 93.3 99.3 100 Example 4 95.1 100 100 Example 5 96.7 100 100 Example 6 98.7 100 100 Comparative Example 33.3 44.4 64.4 From Table 1 we can see that: (1) When the fungicide of the present invention (Examples 1-6) was used at a concentration of 3%, the bactericidal rate against SRB was greater than 91%, with the highest reaching 98.7% (Example 6); while the bactericidal rate of the comparative example dodecyl dimethyl benzyl ammonium chloride (1227) was 33.3%, which was significantly lower than that of the present invention; (2) When the fungicide of the present invention (Examples 1-6) was used at a concentration of 5%, the bactericidal rate against SRB was greater than 98%, with the highest reaching 100% (Examples 4, 5 and 6); while the bactericidal rate of the comparative example dodecyl dimethyl benzyl ammonium chloride (1227) was 44.4%, which was significantly lower than that of the present invention; (3) When the fungicide of the present invention (Examples 1-6) was used at a concentration of 8%, the bactericidal rate against SRB reached 100%; while the bactericidal rate of the comparative example dodecyl dimethyl benzyl ammonium chloride (1227) was 64.4%, which was significantly lower than that of the present invention.

[0030] Table 2 TGB sterilization results (sterilization rate, %) Concentration, mg / L 3 5 8 Example 1 91.1 98.2 100 Example 2 93.3 99.3 100 Example 3 95.4 100 100 Example 4 95.1 100 100 Example 5 96.7 100 100 Example 6 99.3 100 100 Comparative Example 59.1 81.8 86.4 From Table 2 we can see that: (1) When the fungicide of the present invention (Examples 1-6) was used at a concentration of 3%, the bactericidal rate against TGB was greater than 91%, with the highest reaching 99.3% (Example 6); while the bactericidal rate of the comparative example dodecyl dimethyl benzyl ammonium chloride (1227) was 59.1%, which was significantly lower than that of the present invention; (2) When the fungicide of the present invention (Examples 1-6) was used at a concentration of 5%, the bactericidal rate against TGB was greater than 98%, with the highest reaching 100%; while the bactericidal rate of the comparative example dodecyl dimethyl benzyl ammonium chloride (1227) was 81.8%, which was significantly lower than that of the present invention; (3) When the fungicide of the present invention (Examples 1-6) was used at a concentration of 8%, the fungicide rate against TGB reached 100%; while the fungicide rate of the comparative example dodecyl dimethyl benzyl ammonium chloride (1227) was 86.4%, which was significantly lower than that of the present invention.

[0031] Table 3 FB sterilization results (sterilization rate, %) Concentration, mg / L 3 5 8 Example 1 96.7 100 100 Example 2 99.3 100 100 Example 3 100 100 100 Example 4 100 100 100 Example 5 100 100 100 Example 6 100 100 100 Comparative Example 64.4 81.8 91.1 From Table 3 we can see that: (1) When the fungicide of the present invention (Examples 1-6) was used at a concentration of 3%, the bactericidal rate against FB was greater than 96%, with the highest reaching 100%; while the bactericidal rate of the comparative example dodecyl dimethyl benzyl ammonium chloride (1227) was 64.4%, which was significantly lower than that of the present invention; (2) When the fungicide of the present invention (Examples 1-6) was used at a concentration of 5%, the bactericidal rate against FB reached 100%; while the bactericidal rate of the comparative example dodecyl dimethyl benzyl ammonium chloride (1227) was 81.8%, which was significantly lower than that of the present invention; (3) When the fungicide of the present invention (Examples 1-6) was used at a concentration of 8%, the bactericidal rate against FB reached 100%; while the bactericidal rate of the comparative example dodecyl dimethyl benzyl ammonium chloride (1227) was 91.1%, which was significantly lower than that of the present invention.

[0032] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0033] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0034] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing an oilfield bactericide, characterized in that: The specific steps of the preparation method are as follows: (1) Add terephthalaldehyde, methanol, 4-morpholinopiperidine and sodium cyanoborohydride into a reactor, stir and dissolve, add hydrochloric acid to adjust the pH to 3-4, heat to 60-65°C, keep warm for reaction, obtain an intermediate mixed solution, and cool to room temperature; (2) Add distilled water to the intermediate mixture, stir thoroughly, extract twice with chloroform, combine the extracts, and distill under reduced pressure to obtain a high-viscosity solid; (3) The high-viscosity solid was transferred into a four-necked flask with isopropanol, bromoalkane was added, the pH was adjusted to 9-10, and the mixture was heated under reflux to obtain a mixed solution; (4) distilling the mixed solution in (3) under reduced pressure to obtain a high-viscosity solid, recrystallizing it with ethyl acetate, and drying it overnight to obtain a fungicide product; Based on 1 mole of terephthalaldehyde, the 4-morpholinopiperidine and the bromoalkane are 1.8-2.2 moles and 3.5-5 moles, respectively.

2. The method for preparing an oilfield bactericide according to claim 1, characterized in that: The weight ratio of methanol, sodium cyanoborohydride and terephthalaldehyde in step (1) is 30-40:0.3-0.5:1 respectively.

3. The method for preparing an oilfield bactericide according to claim 1, characterized in that: The insulation time in step (1) is 4-6 hours.

4. The method for preparing an oilfield bactericide according to claim 1, characterized in that: The weight ratio of distilled water, chloroform and terephthalaldehyde in step (2) is 30-40:60-80:

1.

5. The method for preparing an oilfield bactericide according to claim 1, characterized in that: The weight ratio of isopropanol to terephthalaldehyde in step (3) is 60-80:

1.

6. The method for preparing an oilfield bactericide according to claim 1, characterized in that: The reflux reaction time in step (3) is 24-48 hours.

7. The fungicide prepared by the preparation method according to any one of claims 1 to 6, characterized in that: The molecular structure of the bactericide is as follows: ， Where R is C6-C 22 of normal alkanes.

8. The bactericide according to claim 7, characterized in that: The R is C 12 -C 18 of normal alkanes.

9. Use of the fungicide according to claim 7 or 8 in oilfield wastewater treatment.

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