Corrosion and scale inhibition bactericide for oilfield produced water and preparation method thereof

Abstract

The invention discloses a corrosion and scale inhibition bactericide for oilfield produced water and a preparation method thereof.The preparation method comprises the following steps that an allyl polyoxyethylene ether solution is prepared, allyloxy hydroxypropyl sulfonic acid and 2-vinyl imidazole are added and stirred, and the allyloxy hydroxypropyl sulfonic acid and the 2-vinyl imidazole serve as reaction substrates after being evenly dissolved; preparing an initiator solution; and dropwise adding an initiator solution into the reaction substrate, heating, and reacting under a protective atmosphere to obtain the corrosion and scale inhibition bactericide for oilfield produced water. The preparation method has the characteristics of simple process, convenience in operation and the like. The corrosion / scale inhibition effect on the metal surface can be effectively relieved, bacterial corrosion is inhibited, and various corrosive bacteria in the service environment are effectively killed. And in the filling process, only one medicament is filled to realize three effects of corrosion inhibition, scale inhibition and sterilization, so that frequent medicament filling by workers can be reduced, the investment of filling equipment is reduced, and the protection cost and the labor cost are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and natural gas exploitation, and relates to a corrosion and scale inhibition bactericide for oil field produced water and a preparation method thereof. Background Art

[0002] As the development of oil fields enters the middle and late stages, water injection becomes the main method of exploitation. Polymers, surfactants and microbial flooding are used to inject produced water back into the formation to achieve the purpose of oil production, but at the same time, the water content in the produced fluid of the oil well increases rapidly. The produced fluid contains dissolved gases such as H2S, CO2, O2, as well as oil, suspended matter, inorganic ions, bacterial sulfate-reducing bacteria, saprophytes, etc. These corrosive media are highly corrosive to equipment and pipelines, causing serious corrosion to the oil field system. At the same time, produced water must be treated before reinjection or discharge. If it is not treated, the soil and water sources are easily contaminated. During the reinjection of produced water, calcium and magnesium ions in the water combine with sulfate and carbonate to produce precipitation, causing sediments to form on the metal surface, leading to problems such as stagnation and blockage of the oil pipeline. Therefore, it is necessary to carry out corrosion inhibition, scale prevention and sterilization treatment to ensure the safe and stable operation of equipment and pipelines. At present, the common treatment method is to add corrosion inhibitors, scale inhibitors and bactericides, but there are problems such as complex agent addition, mutual influence of agent effects, and poor compatibility of agents with oilfield water.

[0003] Chinese invention patent CN110273157B discloses a corrosion inhibitor with bactericidal and scale-inhibiting functions and its preparation method, including 0.5-20% corrosion inhibitor, 5-20% bactericide, 5-10% solvent, 1-10% scale inhibitor, 1-5% synergist, and 35-70% water. The scale inhibitor is one or more of sodium gluconate, hydroxyethylidene diphosphonic acid, sodium hydroxyethylidene diphosphonic acid, and potassium hydroxyethylidene diphosphonic acid. The agent is compounded. In actual application, due to the variety of additives, it is easy to be incompatible with the produced water of oil and gas fields. In addition, the formula contains phosphorus, which is easy to cause eutrophication of water quality and poor environmental protection.

[0004] Chinese invention patent CN105254039B discloses a solid corrosion inhibitor and scale inhibitor for oil fields and its preparation method. The agent also adopts a compounding method, using Echinacea extract, Perilla, arsanilic acid, artemisinin, tartaric acid, 2-hydroxytetradecanoic acid, sorbitol, hydroxystearin, sodium acryloyldimethyltaurate, sulfosuccinate, ethanol, water, etc. The preparation process of the agent is relatively complicated, and there is also a problem that in actual application, due to the large variety of additives, it is easy to be incompatible with oil and gas field produced water.

[0005] Chinese invention patent CN111252914B discloses a phosphorus-free corrosion and scale inhibitor and its preparation device and method, which specifically includes 10-15 parts of zinc salt, 25-30 parts of polymaleic anhydride, 6-10 parts of L-ascorbic acid, 30-35 parts of polyaspartic acid, and the balance of water constitutes 100 parts by weight. The agent is also compounded and only has corrosion and scale inhibition properties, but not bactericidal properties. Summary of the invention

[0006] The purpose of the present invention is to solve the problems in the prior art and provide a corrosion and scale inhibition bactericide for oilfield produced water and a preparation method thereof, so as to solve the problems of complex agent addition, mutual influence of agent effects, and poor compatibility of agents with oilfield water.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A corrosion and scale inhibition bactericide for oilfield produced water is prepared by heating reaction with allyl polyoxyethylene ether solution, allyloxy hydroxypropyl sulfonic acid and 2-vinyl imidazole as reaction substrates under the action of an initiator.

[0009] Furthermore, the mass ratio of the allyl polyoxyethylene ether solution, allyloxy hydroxypropyl sulfonic acid and 2-vinylimidazole is 3:(1-2):(1-3).

[0010] Furthermore, the initiator is AIBN or persulfate.

[0011] Furthermore, the persulfate is K2S2O8, Na2S2O8 or (NH4)2S2O8.

[0012] Furthermore, the mass of the initiator is 1-20% of the mass of the reaction substrate.

[0013] A method for preparing the corrosion and scale inhibition bactericide for oilfield produced water comprises the following steps:

[0014] Prepare an allyl polyoxyethylene ether solution, add allyloxy hydroxypropyl sulfonic acid and 2-vinyl imidazole, stir, and dissolve evenly as a reaction substrate;

[0015] preparing an initiator solution;

[0016] The initiator solution is added dropwise to the reaction substrate, heated, and reacted under a protective atmosphere to obtain a corrosion and scale inhibitor bactericide for oilfield produced water.

[0017] Furthermore, the preparation process of the allyl polyoxyethylene ether solution is: adding a solvent to the allyl polyoxyethylene ether, dissolving it at 40 to 50° C., and cooling it;

[0018] The solvent is deionized water and C1-C6 straight-chain or branched alcohol, and the mass fraction of the allyl polyoxyethylene ether solution is 20%-22%.

[0019] Furthermore, in the preparation process of the initiator solution, the solvent is deionized water and a C1-C6 straight-chain or branched alcohol, and the mass fraction of the initiator solution is 1-3%.

[0020] Furthermore, the C1-C6 straight-chain or branched alcohol is methanol, ethanol, propanol, isopropanol, butanol or isobutanol.

[0021] Furthermore, the heating temperature is 50-150° C., and the reaction time is 1-24 hours.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention provides a method for preparing a corrosion inhibitor, scale inhibitor and bactericide for oilfield produced water. By introducing 2-vinyl imidazole with corrosion inhibition function and allyloxy hydroxypropyl sulfonic acid with scale inhibition and bactericidal function into the allyl polyoxyethyl segment, the target product has multiple functions of corrosion inhibition, scale inhibition and bactericidal. In the corrosion protection process of metals, the chemical adsorption force is stronger than the physical adsorption. In order to form a strong chemical adsorption effect, it is necessary to form a coordination bond between the corrosion inhibitor and the atoms on the metal surface. There are empty d orbitals on the surface of iron atoms. The lone pair electrons of atoms such as N, O, and S contained in the corrosion inhibitor structure will form coordination bonds with the empty d orbitals of iron atoms, so that the corrosion inhibitor molecules or ions are firmly adsorbed on the metal surface. At the same time, the imidazoline functional fragments have high reactivity to metal materials and can form a dense compound film on the metal surface, giving the metal good antioxidant and corrosion resistance. The sulfonic acid fragments also have excellent bactericidal function. The present invention combines multiple functional fragments on a single agent through multifunctional molecular design and polymerization, so that the agent has the properties of corrosion inhibition, scale inhibition and bactericidal.

[0024] The preparation method of the present invention has the characteristics of simple process and convenient operation. It can effectively alleviate the corrosion / scale inhibition of metal surfaces, inhibit bacterial corrosion, and effectively kill various types of corrosive bacteria in the service environment. During the filling process, only one agent can be added to achieve the three effects of corrosion inhibition, scale inhibition and sterilization, which can reduce the frequent filling of agents by staff, reduce the investment in filling equipment, and reduce the protection cost and labor cost. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0026] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0027] Herein, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0028] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0029] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0030] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0031] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0032] The present invention is described in further detail below:

[0033] The present invention provides a method for preparing a corrosion and scale inhibition bactericide for oilfield produced water, comprising the following steps:

[0034] S1, preparing an allyl polyoxyethylene ether solution, adding allyloxy hydroxypropyl sulfonic acid and 2-vinyl imidazole, stirring, and dissolving them uniformly as a reaction substrate.

[0035] In S1, the preparation process of the allyl polyoxyethylene ether solution is: adding a solvent to the allyl polyoxyethylene ether, dissolving it at 40-50° C., and cooling it.

[0036] The solvent is deionized water, a C1-C6 straight-chain or branched alcohol, preferably water, methanol, ethanol, propanol, isopropanol, butanol, isobutanol; the most preferred solvent is water.

[0037] The mass fraction of the prepared allyl polyoxyethylene ether solution is 20-22%.

[0038] The mass ratio of allyl polyoxyethylene ether, allyloxy hydroxypropyl sulfonic acid and 2-vinylimidazole added is 3:1-2:1-3, preferably 3:1:3.

[0039] S2, prepare an initiator solution.

[0040] In S2, the solvent is water, a C1-C6 straight-chain or branched alcohol; preferably water, methanol, ethanol, propanol, isopropanol, butanol, isobutanol; most preferably water.

[0041] The mass fraction of the prepared initiator solution is 1-3%.

[0042] The initiator is AIBN or persulfate, preferably K2S2O8, Na2S2O8 or (NH4)2S2O8; the most preferred is (NH4)2S2O8.

[0043] S3, adding the initiator solution dropwise to the reaction substrate, heating, and reacting under a nitrogen protective atmosphere to obtain a corrosion and scale inhibitor bactericide for oilfield produced water.

[0044] In S3, the mass of the initiator added is 1-20% of the mass of the reaction substrate, preferably 1-10%, and most preferably 5%.

[0045] The reaction temperature is 50 to 150° C., preferably 60 to 90° C., and most preferably 70° C. The reaction time is 1 to 24 h, preferably 2 to 12 h, and most preferably 5 h.

[0046] Embodiment 1:

[0047] Take 150g of allyl polyoxyethylene ether, add 200g of deionized water, and dissolve in a water bath at 50°C. After the solution is cooled, pour it into a three-mouth reactor equipped with an electric stirrer, a condensation reflux device, a dropping funnel and a thermometer, then add 50g of allyloxy hydroxypropyl sulfonic acid, 150g of 2-vinyl imidazole and turn on the electric stirring to make it dissolve evenly. Then dissolve 17.5g of ammonium persulfate in 150g of deionized water and place it in a dropping funnel, and tidy up the reaction device. Heat slowly and pass nitrogen for 15min. The temperature rises to 70°C and remains stable. Add an aqueous solution of ammonium persulfate dropwise, and pay attention to controlling the dropwise addition speed. The time for adding ammonium persulfate is controlled to 1h. After the dropwise addition is completed, continue the reaction for 4h to obtain a yellow transparent viscous liquid, which is the final product, a corrosion and scale inhibitor for oilfield produced water.

[0048] Embodiment 2:

[0049] Take 160g of allyl polyoxyethylene ether, add 210g of deionized water, and dissolve in a water bath at 60°C. After the solution is cooled, pour it into a three-mouth reactor equipped with an electric stirrer, a condensation reflux device, a dropping funnel and a thermometer, then add 60g of allyloxyhydroxypropyl sulfonic acid, 160g of 2-vinyl imidazole and turn on the electric stirring to make it dissolve evenly. Then dissolve 15g of ammonium persulfate in 160g of deionized water and place it in a dropping funnel, and tidy up the reaction device. Heat slowly and pass nitrogen for 15min. The temperature rises to 80°C and remains stable. Add an aqueous solution of ammonium persulfate dropwise, and pay attention to controlling the dropwise addition speed. The time for adding ammonium persulfate is controlled to 1.5h. After the dropwise addition is completed, continue the reaction for 4h to obtain a yellow transparent viscous liquid, which is the final product, a corrosion and scale inhibitor for oilfield produced water.

[0050] Embodiment 3:

[0051] Take 170g of allyl polyoxyethylene ether, add 200g of deionized water, and dissolve in a water bath at 70°C. After the solution is cooled, pour it into a three-mouth reactor equipped with an electric stirrer, a condensation reflux device, a dropping funnel and a thermometer, then add 70g of allyloxy hydroxypropyl sulfonic acid, 170g of 2-vinyl imidazole and turn on the electric stirring to make it dissolve evenly. Then dissolve 18g of ammonium persulfate in 180g of deionized water and place it in a dropping funnel, and tidy up the reaction device. Heat slowly and pass nitrogen for 15min. The temperature rises to 90°C and remains stable. Add an aqueous solution of ammonium persulfate dropwise, and pay attention to controlling the dropwise addition speed. The time for adding ammonium persulfate is controlled to 1h. After the dropwise addition is completed, continue the reaction for 4h to obtain a yellow transparent viscous liquid, which is the final product, a corrosion and scale inhibitor for oilfield produced water.

[0052] Embodiment 4:

[0053] Take 180g of allyl polyoxyethylene ether, add 200g of deionized water, and dissolve in a water bath at 80°C. After the solution is cooled, pour it into a three-mouth reactor equipped with an electric stirrer, a condensation reflux device, a dropping funnel and a thermometer, then add 75g of allyloxyhydroxypropyl sulfonic acid, 175g of 2-vinyl imidazole and turn on the electric stirring to make it dissolve evenly. Then dissolve 19g of ammonium persulfate in 190g of deionized water and place it in a dropping funnel, and tidy up the reaction device. Heat slowly and pass nitrogen for 15min. The temperature rises to 90°C and remains stable. Add an aqueous solution of ammonium persulfate dropwise, and pay attention to controlling the dropwise addition speed. The time for adding ammonium persulfate is controlled to 1.5h. After the dropwise addition is completed, continue the reaction for 4h to obtain a yellow transparent viscous liquid, which is the final product, a corrosion and scale inhibitor for oilfield produced water.

[0054] Embodiment 5:

[0055] Take 190g of allyl polyoxyethylene ether, add 200g of deionized water, and dissolve in a 90°C water bath. After the solution is cooled, pour it into a three-mouth reactor equipped with an electric stirrer, a condensation reflux device, a dropping funnel and a thermometer, then add 80g of allyloxy hydroxypropyl sulfonic acid, 180g of 2-vinyl imidazole and turn on the electric stirring to make it dissolve evenly. Then dissolve 20g of ammonium persulfate in 190g of deionized water and place it in a dropping funnel, and tidy up the reaction device. Heat slowly and pass nitrogen for 15min. The temperature rises to 90°C and remains stable. Add an aqueous solution of ammonium persulfate dropwise, and pay attention to controlling the dropwise addition speed. The time for adding ammonium persulfate is controlled at 2.5h. After the dropwise addition is completed, continue the reaction for 4h to obtain a yellow transparent viscous liquid, which is the final product, a corrosion and scale inhibitor for oilfield produced water.

[0056] Performance test of the corrosion and scale inhibitor bactericide for oilfield produced water prepared in Examples 1 to 5 of the present invention:

[0057] 1. Corrosion inhibition performance

[0058] The corrosion inhibition performance evaluation was carried out in a simulated carbon dioxide flooding oil well environment in accordance with SY / T5273-204 "Performance Indicators and Evaluation Methods of Corrosion Inhibitors for Oilfield Produced Water Treatment".

[0059] When the experimental conditions were simulated aqueous solution, CO2 content of 300 mg / L, 60°C, and material L245N, the corrosion and scale inhibitor and fungicide for oilfield produced water prepared in Examples 1 to 5 was added at a concentration of 100 mg / L. The experimental results are shown in Table 1.

[0060] Table 1 Corrosion inhibition performance

[0061]

[0062]

[0063] 2. Bactericidal properties

[0064] According to SY / T 0532-2012 "Oilfield Injection Water Bacteria Analysis Method Extinction Dilution Method", the SRB bacteria cultured on site were taken, and the corrosion and scale inhibitor bactericide for oilfield produced water prepared in Example 1 was added at a concentration of 100 mg / L. The water sample containing SRB bacteria was added with the corrosion and scale inhibitor bactericide for oilfield produced water prepared in Examples 1 to 5, and then cultured at 60°C for 24 hours, and the bacterial content was determined and the bactericidal rate was calculated. The results are shown in Table 2.

[0065] Table 2 Bactericidal performance

[0066] Serial number Drug concentration / ppm Sterilization rate / / % Blank Group - - Example 1 100 99.8 Example 2 100 99.5 Example 3 100 99.1 Example 4 100 98.5 Example 5 100 98.7

[0067] 3. Scale inhibition performance

[0068] According to SY-T 5673-93 “Method for evaluating the performance of scale inhibitors for oil fields”, the corrosion inhibitor and scale inhibitor for oil field produced water prepared in Example 1 was added at a concentration of 100 mg / L. The results are shown in Table 3.

[0069] Table 3 Antiscaling performance

[0070]

[0071]

[0072] It can be seen from the test results that the corrosion inhibition, scale inhibition and bactericidal agent of the present invention shows excellent effects in corrosion inhibition, scale inhibition and sterilization. When the experimental conditions are simulated aqueous solution, CO2 content is 300 mg / L, temperature is 60°C, and the material is L245N, when the corrosion inhibitor is added at 100 mg / L, the corrosion inhibition rate is between 91.7% and 93.3%, the SRB bacterial sterilization rate is greater than 98.7%, and the maximum scale prevention rate is 90.7%, which proves that the corrosion inhibition, scale inhibition and bactericidal agent has excellent material corrosion protection, bacteria killing and scale inhibition effects.

[0073] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A corrosion and scale inhibitor bactericide for oilfield produced water, characterized in that: The product is prepared by heating reaction with allyl polyoxyethylene ether solution, allyloxy hydroxypropyl sulfonic acid and 2-vinyl imidazole as reaction substrates under the action of an initiator.

2. The corrosion and scale inhibition bactericide for oilfield produced water according to claim 1, characterized in that: The mass ratio of the allyl polyoxyethylene ether solution, allyloxy hydroxypropyl sulfonic acid and 2-vinylimidazole is 3:(1-2):(1-3).

3. The corrosion and scale inhibition bactericide for oilfield produced water according to claim 1, characterized in that: The initiator is AIBN or persulfate.

4. The corrosion and scale inhibition bactericide for oilfield produced water according to claim 3, characterized in that: The persulfate is K2S2O8, Na2S2O8 or (NH4)2S2O8.

5. The corrosion and scale inhibition bactericide for oilfield produced water according to claim 1, characterized in that: The mass of the initiator is 1-20% of the mass of the reaction substrate.

6. A method for preparing the corrosion and scale inhibitor bactericide for oilfield produced water according to any one of claims 1 to 5, characterized in that: The following steps are involved: Prepare an allyl polyoxyethylene ether solution, add allyloxy hydroxypropyl sulfonic acid and 2-vinyl imidazole, stir, and dissolve evenly as a reaction substrate; preparing an initiator solution; The initiator solution is added dropwise to the reaction substrate, heated, and reacted under a protective atmosphere to obtain a corrosion and scale inhibitor bactericide for oilfield produced water.

7. The method for preparing the corrosion and scale inhibition bactericide for oilfield produced water according to claim 6, characterized in that: The preparation process of the allyl polyoxyethylene ether solution is as follows: adding a solvent to the allyl polyoxyethylene ether, dissolving it at 40-50° C., and cooling it; The solvent is deionized water and C1-C6 straight-chain or branched alcohol, and the mass fraction of the allyl polyoxyethylene ether solution is 20%-22%.

8. The method for preparing the corrosion and scale inhibition bactericide for oilfield produced water according to claim 6, characterized in that: During the preparation of the initiator solution, the solvent is deionized water and a C1-C6 straight-chain or branched alcohol, and the mass fraction of the initiator solution is 1-3%.

9. The method for preparing the corrosion and scale inhibition bactericide for oilfield produced water according to claim 7 or 8, characterized in that: The C1-C6 straight-chain or branched alcohol is methanol, ethanol, propanol, isopropanol, butanol or isobutanol.

10. The method for preparing the corrosion and scale inhibition bactericide for oilfield produced water according to claim 6, characterized in that: The heating temperature is 50-150° C., and the reaction time is 1-24 hours.

Images