CN115818849A - Oilfield sewage purifying agent and preparation method thereof - Google Patents

Abstract

The invention relates to an oilfield sewage purifying agent and a preparation method thereof, belonging to the technical field of oilfield sewage treatment. The preparation method of the oilfield sewage purifying agent comprises the following steps: reacting the compound shown in the formula I, the thiol compound shown in the formula II and the particle material to obtain the compound; wherein R is ₁ 、R ₂ And R ₃ Is hydrogen or alkyl; r ₄ And R ₇ Is an alkylene group; r ₅ 、R ₆ And R ₈ Is an alkyl group. Oil field of the inventionThe preparation method of the sewage purifying agent is simple to operate, and the sewage purifying agent is prepared by taking the compound shown in the formula I and alkyl mercaptan as raw materials, taking a particle material as a catalyst and a catalytic reaction carrier and carrying out a mixing reaction. The prepared oil field sewage purifying agent has better desulfurization and corrosion inhibition effects on high-sulfur-content sewage, has flocculation and sterilization effects of a conventional sewage treating agent, and can be suitable for sewage treatment of high-sulfur-content and common oil and gas fields.

Description

A kind of oil field sewage purification agent and preparation method thereof

technical field

The invention relates to an oilfield sewage purifying agent and a preparation method thereof, belonging to the technical field of oilfield sewage treatment.

Background technique

Sewage produced from high-sulfur oil and gas fields is generally re-injected into the formation after treatment. The sewage components usually include divalent sulfide salts, dissolved hydrogen sulfide, formation minerals, oil phase, inorganic salt ions, etc. Experiments show that conventional polyaluminum mixed The coagulant has poor effect on the adsorption and net capture of divalent sulfide, and it is difficult to achieve the purpose of sewage flocculation. The currently used auxiliary technologies such as alkali neutralization and negative pressure air stripping can only reduce the content of divalent sulfides, but cannot fundamentally solve the problem of sewage purification.

In recent years, oilfield sewage purifiers have been gradually applied in the field of oilfield chemical industry, and their application in the field of oilfield sewage treatment has also deepened. Combining oilfield sewage purifiers with traditional sewage treatment agents, taking advantage of the strong dispersibility and adsorption of oilfield sewage purifiers , can significantly improve the use of sewage treatment agent effect. Chinese patent document CN106745367B discloses an iron-based nano-scale sewage treatment agent, which is composed of surface-modified attapulgite clay, organic silicon rubber waste, iron-based nano-composite agent, green vitriol, solubilizer, regenerative composite agent and nano-mesoporous molecular sieve. It can be used for advanced treatment of low-phosphorus sewage after biochemical treatment. Attapulgite clay, iron-based nano-composite agent, and green vitriol have strong adsorption to phosphorus, but attapulgite clay suspension is not easy to flocculate and precipitate. Iron-based nano-composite agent mainly removes heavy metals and halogenated organic substances, and has an adsorption effect on divalent sulfide Poor, and the high activity of the iron-based nano-composite agent makes it easy to be oxidized, and the removal rate of pollutants is reduced. It is not suitable for the treatment of divalent sulfide and suspended solids in high-sulfur sewage.

Chinese patent document CN106673265B discloses a treatment method for high-sulfur sewage in oil and gas fields. First, adjust the pH of the sewage to 7-8, then add an oxidant to remove sulfur, and then add a corrosion inhibitor and a bactericide to completely oxidize hydrogen sulfide. While not generating sulfate ions, it can reduce the corrosion of sewage to equipment. However, this treatment method only has a high sulfur removal rate, without flocculation, and cannot effectively remove suspended solids in sulfur-containing sewage. Moreover, corrosion inhibition and sterilization are not carried out simultaneously, and the operation process is complicated.

Contents of the invention

The purpose of the present invention is to provide a preparation method of oilfield sewage purifying agent, which is used to solve the problem of complicated operation process caused by desulfurization, flocculation, corrosion inhibition and sterilization cannot be carried out simultaneously in the process of treating high sulfur sewage in oil and gas fields.

Another object of the present invention is to provide a cleaning agent for oilfield sewage.

In order to achieve the above object, the technical scheme adopted in the preparation method of the oilfield sewage cleaning agent of the present invention is:

A preparation method of an oilfield sewage purifying agent, comprising the following steps: reacting a compound shown in formula I, a mercaptan compound shown in formula II, and a granular material; wherein, R ₁ , R ₂ and R ₃ are hydrogen or Alkyl; R ₄ and R ₇ are alkylene; R ₅ , R ₆ and R ₈ are alkyl; the particulate material is β-Al ₂ O ₃ and/or γ-Al ₂ O ₃ .

The preparation method of the oilfield sewage purifying agent of the present invention is simple to operate, and the compound shown in formula I and alkyl mercaptan are used as raw materials, and the granular material is used as a catalyst and a catalytic reaction carrier, and is prepared through a mixed reaction. The prepared oilfield sewage purifier has good desulfurization and corrosion inhibition effects on high-sulfur sewage, and also has the flocculation and bactericidal effects of conventional sewage treatment agents, and can be applied to high-sulfur and general oil and gas field sewage treatment. The positive charge in the molecular chain of the organic material formed after the reaction of the compound shown in formula I with the thiol has a strong adsorption neutralization effect, and the contained hydroxyl group has an adsorption bridging effect, and the organic material can be further adsorbed on the particles. The surface of the material or the inside of its pores, or the S in the molecular chain is bonded to it, and the molecular chain of the organic material combined on the granular material can play a role in sediment netting. Long-chain organic amines have corrosion inhibition and bactericidal effects. The oilfield sewage purification agent prepared by the invention has good effects of desulfurization, removal of suspended solids, sterilization and corrosion inhibition.

Preferably, each of R ₁ , R ₂ and R ₃ is independently selected from hydrogen or C ₁ -C ₆ alkyl. Preferably, each of R ₅ , R ₆ and R ₈ is independently selected from C ₁ -C ₆ alkyl groups. Preferably, each of R ₄ and R ₇ is independently selected from C ₁ -C ₅ alkylene.

Preferably, said R ₁ is hydrogen. Preferably, said R ₂ is hydrogen. Preferably, said R ₃ is methyl. Preferably, said R ₄ is ethylene. Preferably, said R ₇ is methylene. Preferably, said R ₅ is methyl. Preferably, said R ₆ is methyl. Preferably, the R ₈ is a C ₂ -C ₆ alkyl group. Preferably, said R ₈ is C ₂ -C ₄ alkyl. Further preferably, said R ₈ is ethyl, n-propyl or n-butyl.

Preferably, the compound represented by the formula I is (2,3-epoxypropyl)[2-(methacryloyloxy)ethyl]dimethylammonium chloride, and its structural formula is as follows:

β-Al ₂ O ₃ and γ-Al ₂ O ₃ have higher surface activity, which can adsorb or chemically bond more organic materials, thus exerting a better purification effect.

Preferably, the particle size of the particulate material is 30-100 nm.

Preferably, the molar ratio of the compound represented by formula I to the thiol compound represented by formula II is 1:0.95-2.3.

Preferably, the mass ratio of the compound represented by formula I to the thiol compound represented by formula II is 100:30-60.

Preferably, the mass of the granular material is 1%-2% of the mass of the thiol compound represented by formula II.

Preferably, the solvent used for the reaction is water.

Preferably, the reaction is performed under ultrasonic conditions. Further, the temperature of the reaction system is raised to 50-70° C. under the action of ultrasound. The role of ultrasound is to provide the energy required for the reaction, that is, the thermal energy and kinetic energy required for the reaction.

Preferably, the reaction time is 60-90min.

Preferably, the ultrasonic conditions include: ultrasonic power of 50-150 W·cm ^-2 ; frequency of 20-30 kHz.

Preferably, the preparation method of the oilfield sewage purifying agent further includes the following step: performing drying treatment after the reaction.

Preferably, the drying treatment is carried out at 50-70° C.; the drying treatment time is 3 hours. After drying, it is naturally cooled to room temperature. The purpose of drying is to remove the moisture in the oilfield sewage purifier.

Preferably, the particle size of the oilfield sewage purification agent is 50-150nm.

The technical scheme adopted by the oilfield sewage purifying agent of the present invention is:

An oilfield sewage purifying agent prepared by the above preparation method of the oilfield sewage purifying agent.

The oilfield sewage purifying agent of the invention has better desulfurization and corrosion inhibition effects on high-sulfur sewage, and simultaneously has the flocculation and bactericidal effects of conventional sewage treatment agents.

Preferably, the particle size of the oilfield sewage purification agent is 50-150nm.

When the oilfield sewage purifying agent of the present invention purifies sewage, the addition amount of the oilfield sewage purifying agent in the sewage can be determined as required, preferably, the addition amount of the oilfield sewage purifying agent in the sewage is 100 ppm. The added amount is the ratio of the quality of the oilfield sewage purifying agent to the quality of sewage.

Description of drawings

Fig. 1 is the relation of the addition of the oilfield sewage cleaning agent prepared in embodiment 1, embodiment 2 and embodiment 3 in the sewage and the suspended solids content in the sewage after purification treatment;

Fig. 2 is the relationship between the addition amount of the oilfield sewage purifying agent prepared in Example 1 in the sewage and the sulfate reducing bacteria (SRB) content, saprophytic bacteria (TGB) content and iron bacteria (FB) content in the sewage after purification treatment .

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with specific embodiments.

One, the specific embodiment of the preparation method of oilfield sewage cleaning agent of the present invention is as follows:

Example 1

The preparation method of the oilfield sewage cleaning agent of the present embodiment may further comprise the steps:

Add 100g (2,3-epoxypropyl)[2-(methacryloyloxy)ethyl]dimethylammonium chloride, 30g ethanethiol and 1.5g beta -Al ₂ O ₃ , then add water until the volume of the reaction system is 600mL, and then react under ultrasonic conditions for 60 minutes (ultrasonic power 50W·cm ^-2 , frequency 20kHz), at this time the temperature of the reaction system is 70°C, and the reaction is complete Finally, the product was dried at 50° C. for 3 hours, and then cooled to room temperature to obtain granular materials. The particle size of the oilfield sewage purification agent prepared in this example was 50-150 nm.

Example 2

The preparation method of the oilfield sewage cleaning agent of the present embodiment may further comprise the steps:

Add 100g (2,3-epoxypropyl)[2-(methacryloyloxy)ethyl]dimethylammonium chloride, 50g propanethiol and 2.5g gamma -Al ₂ O ₃ , then add water until the volume of the reaction system is 600mL, and then react under ultrasonic conditions for 80 minutes (ultrasonic power 100W·cm ^-2 , frequency 20kHz), at this time the temperature of the reaction system is 65°C, and the reaction is complete Finally, the product was dried at 60° C. for 3 hours, and then cooled to room temperature to obtain granular materials. The particle size of the oilfield sewage purifying agent prepared in this example was 50-150 nm.

Example 3

The preparation method of the oilfield sewage cleaning agent of the present embodiment may further comprise the steps:

Add 100g (2,3-epoxypropyl) [2-(methacryloyloxy) ethyl] dimethyl ammonium chloride, 60g butanethiol and 3g of β- Al ₂ O ₃ , then add water until the volume of the reaction system is 600mL, then react under ultrasonic conditions for 90 minutes (ultrasonic power 150W·cm ^-2 , frequency 30kHz), the temperature of the reaction system at this time is 60°C, after the reaction is completed The product was dried at 70° C. for 3 hours, and then cooled to room temperature to obtain granular materials. The particle size of the oilfield sewage purifying agent prepared in this example was 50-150 nm.

Example 4

The preparation method of the oilfield sewage cleaning agent of the present embodiment may further comprise the steps:

Add 100g (2,3-epoxypropyl)[2-(methacryloyloxy)ethyl]dimethylammonium chloride, 35g ethanethiol and 2g β- Al ₂ O ₃ , then add water until the volume of the reaction system is 600mL, and then react under ultrasonic conditions for 70 minutes (ultrasonic power 60W·cm ^-2 , frequency 20kHz), at this time the temperature of the reaction system is 70°C, after the reaction is completed The product was dried at 55° C. for 3 hours, and then cooled to room temperature to obtain granular material. The particle size of the oilfield sewage purifying agent prepared in this example was 50-150 nm.

Example 5

The preparation method of the oilfield sewage cleaning agent of the present embodiment may further comprise the steps:

Add 100g (2,3-epoxypropyl)[2-(methacryloyloxy)ethyl]dimethylammonium chloride, 40g propanethiol and 2g β- Al ₂ O ₃ , then add water until the volume of the reaction system is 600mL, and then react under ultrasonic conditions for 80 minutes (ultrasonic power 70W·cm ^-2 , frequency 25kHz), at this time the temperature of the reaction system is 60°C, after the reaction The product was dried at 65° C. for 3 hours, and then cooled to room temperature to obtain granular material. The particle size of the oilfield sewage purifying agent prepared in this example was 50-150 nm.

Example 6

The preparation method of the oilfield sewage cleaning agent of the present embodiment may further comprise the steps:

Add 100g (2,3-epoxypropyl)[2-(methacryloyloxy)ethyl]dimethylammonium chloride, 50g butanethiol and 2g of β- Al ₂ O ₃ , then add water until the volume of the reaction system is 600mL, and then react under ultrasonic conditions for 90 minutes (ultrasonic power 90W·cm ^-2 , frequency 30kHz), at this time the temperature of the reaction system is 55°C, after the reaction The product was dried at 50° C. for 3 hours, and then cooled to room temperature to obtain granular material. The particle size of the oilfield sewage purifying agent prepared in this example was 50-150 nm.

Example 7

The preparation method of the oilfield sewage cleaning agent of the present embodiment may further comprise the steps:

Add 100g (2,3-epoxypropyl) [2-(methacryloyloxy) ethyl] dimethyl ammonium chloride, 55g ethanethiol and 3g β- Al ₂ O ₃ , then add water until the volume of the reaction system is 600mL, and then react under ultrasonic conditions for 70 minutes (ultrasonic power 120W·cm ^-2 , frequency 25kHz), at this time the temperature of the reaction system is 70°C, after the reaction is completed The product was dried at 60° C. for 3 hours, and then cooled to room temperature to obtain granules.

Example 8

The preparation method of the oilfield sewage cleaning agent of the present embodiment may further comprise the steps:

Add 100g (2,3-epoxypropyl)[2-(methacryloyloxy)ethyl]dimethylammonium chloride, 45g propanethiol and 3g β- Al ₂ O ₃ , then add water until the volume of the reaction system is 600mL, and then react under ultrasonic conditions for 80 minutes (ultrasonic power 150W·cm ^-2 , frequency 30kHz), at this time the temperature of the reaction system is 65°C, after the reaction The product was dried at 55° C. for 3 hours, and then cooled to room temperature to obtain granular material. The particle size of the oilfield sewage purifying agent prepared in this example was 50-150 nm.

Example 9

The preparation method of the oilfield sewage cleaning agent of the present embodiment may further comprise the steps:

Add 100g (2,3-epoxypropyl)[2-(methacryloyloxy)ethyl]dimethylammonium chloride, 35g butanethiol and 2g of γ- Al ₂ O ₃ , then add water until the volume of the reaction system is 600mL, and then react under ultrasonic conditions for 90 minutes (ultrasonic power 80W·cm ^-2 , frequency 20kHz), at this time the temperature of the reaction system is 70°C, after the reaction The product was dried at 65° C. for 3 hours, and then cooled to room temperature to obtain granular material. The particle size of the oilfield sewage purifying agent prepared in this example was 50-150 nm.

Example 10

The preparation method of the oilfield sewage cleaning agent of the present embodiment may further comprise the steps:

Add 100g (2,3-epoxypropyl)[2-(methacryloyloxy)ethyl]dimethylammonium chloride, 40g ethanethiol and 2g γ- Al ₂ O ₃ , then add water until the volume of the reaction system is 600mL, and then react under ultrasonic conditions for 70 minutes (ultrasonic power 100W·cm ^-2 , frequency 25kHz), at this time the temperature of the reaction system is 50°C, after the reaction The product was dried at 70° C. for 3 hours, and then cooled to room temperature to obtain granular materials. The particle size of the oilfield sewage purifying agent prepared in this example was 50-150 nm.

Example 11

The preparation method of the oilfield sewage cleaning agent of the present embodiment may further comprise the steps:

Add 100g (2,3-epoxypropyl)[2-(methacryloyloxy)ethyl]dimethylammonium chloride, 50g propanethiol and 3g γ- Al ₂ O ₃ , then add water until the volume of the reaction system is 600mL, and then react under ultrasonic conditions for 80 minutes (ultrasonic power 120W·cm ^-2 , frequency 30kHz), at this time the temperature of the reaction system is 70°C, after the reaction The product was dried at 50° C. for 3 hours, and then cooled to room temperature to obtain granular material. The particle size of the oilfield sewage purifying agent prepared in this example was 50-150 nm.

Example 12

The preparation method of the oilfield sewage cleaning agent of the present embodiment may further comprise the steps:

Add 100g (2,3-epoxypropyl)[2-(methacryloyloxy)ethyl]dimethylammonium chloride, 45g butanethiol and 3g of γ- Al ₂ O ₃ , then add water until the volume of the reaction system is 600mL, and then react under ultrasonic conditions for 90 minutes (ultrasonic power 140W·cm ^-2 , frequency 30kHz), at this time the temperature of the reaction system is 60°C, after the reaction is completed The product was dried at 60° C. for 3 hours, and then cooled to room temperature to obtain granular material. The particle size of the oilfield sewage purifying agent prepared in this example was 50-150 nm.

Two, the specific embodiment of oilfield sewage cleaning agent of the present invention is as follows:

The oilfield sewage purifying agent of this embodiment can be obtained by preparing any one of the oilfield sewage purifying agent in embodiment 1 to embodiment 12. When using the oilfield sewage purifying agent of this embodiment to purify sewage, the addition amount of the oilfield sewage purifying agent in the sewage is 100 ppm, and the addition amount is the ratio of the quality of the oilfield sewage purifying agent to the quality of sewage.

Experimental example

The oilfield sewage purifying agent prepared in embodiment 1, embodiment 2 and embodiment 3 is applied to the purification treatment process of certain gas field high sulfur sewage (sulfur content is about 3000mg/L) (the oilfield sewage purifying agent is added in the water sample , just stir it), the addition amount of different oilfield sewage purifiers in the gas field high sulfur sewage is 0ppm, 30ppm, 50ppm, 80ppm, 100ppm, 120ppm, 150ppm, 180ppm and 200ppm, and the addition amount is oil field The ratio of the quality of the sewage purifying agent to the quality of the sewage was tested in accordance with the provisions of SY/T 5329-2012 "Water Quality Indicators and Analysis Methods for Clastic Reservoir Injection" to test the sulfur content, suspended solids content, and Bacterial content and corrosion rate. The experimental results show that when the content of different oilfield sewage purifiers is added to the high sulfur sewage of the gas field at 100ppm, the sulfur removal rate can reach more than 99%. The content of suspended solids in the purified sewage is shown in Figure 1. It can be seen from Figure 1 that when the addition of different oilfield sewage purifiers in the sewage is greater than 100ppm, the suspended solids content of the purified sewage is all the same. Less than 2mg/L. The relationship between the sulfate reducing bacteria (SRB) content, saprophytic bacteria (TGB) content and iron bacteria (FB) content and the amount of addition of the oilfield sewage purifying agent prepared in embodiment 1 in the purified sewage is as shown in Figure 2, It can be seen from Fig. 2 that when the amount of the oilfield sewage purifying agent prepared in Example 1 in the sewage is greater than 60 ppm, the content of different bacteria in the purified sewage is less than 10/mL. The relationship between the corrosion rate and the amount of different oilfield sewage purifiers added to the sewage is shown in Table 1. It can be seen from Table 1 that when the content of different oilfield sewage purifiers added to the sewage is greater than 100ppm, the corrosion rate is less than 0.076mm /a. The above experiment was repeated with the oilfield sewage purification agent prepared in other embodiments of the present invention, and the sulfur content, suspended solid content, bacteria content and corrosion rate in the purified sewage were tested, and the same conclusion was obtained.

Table 1 The relationship between the addition amount of different oilfield sewage purifiers in sewage and the corrosion rate

From the experimental results, it can be seen that when the addition amount of different oilfield sewage purifiers in the gas field high-sulfur sewage is 100ppm, the suspended solids removal, sterilization and corrosion inhibition effects of the oilfield sewage purifiers all meet the requirements of SY/T 5329- 2012 "Water Quality Indicators and Analysis Methods for Injection in Clastic Reservoirs" requires water quality indicators, that is, the content of suspended solids is less than 3mg/L, the content of sulfate-reducing bacteria (SRB) is less than or equal to 25/mL, and the content of saprophytic bacteria (TGB) is less than or equal to 100 per mL, iron bacteria (FB) content ≤ 100/mL, corrosion rate < 0.076mm/a. When the amount of oilfield sewage purifier added to the high-sulfur sewage in the gas field is higher than 100ppm, the effect of removing suspended solids, sterilization and corrosion inhibition will not increase significantly, but the cost will increase significantly. Therefore, when the oilfield sewage purifying agent of the present invention is applied to gas field high-sulfur sewage, the addition amount of the oilfield sewage purifying agent in the sewage is 100ppm.

Claims (10)

1. The preparation method of the oilfield sewage purifying agent is characterized by comprising the following steps: reacting a compound shown in a formula I, a thiol compound shown in a formula II and a particle material; wherein R is ₁ 、R ₂ And R ₃ Is hydrogen or alkyl; r ₄ And R ₇ Is an alkylene group; r is ₅ 、R ₆ And R ₈ Is an alkyl group; the particle material is beta-Al ₂ O ₃ And/or gamma-Al ₂ O ₃ 。

2. The method for preparing the oilfield sewage purifying agent according to claim 1, wherein R is R ₁ 、R ₂ And R ₃ Each independently selected from hydrogen or C ₁ -C ₆ An alkyl group; said R is ₅ 、R ₆ And R ₈ Each independently selected from C ₁ -C ₆ An alkyl group; the R is ₄ And R ₇ Each independently selected from C ₁ -C ₅ An alkylene group.

3. The method for preparing the oilfield sewage purifying agent according to claim 2, wherein R is R ₁ Is hydrogen; the R is ₂ Is hydrogen; said R is ₃ Is methyl; said R is ₅ Is methyl; the R is ₆ Is methyl; the R is ₈ Is ethyl, n-propyl or n-butyl; the R is ₄ Is an ethylene group; the R is ₇ Is methylene.

4. The method for preparing the oilfield sewage purifying agent according to claim 1, wherein the reaction is performed under ultrasonic conditions; the conditions of the ultrasound include: the ultrasonic power is 50-150W cm ^-2 (ii) a The frequency is 20-30kHz.

5. The method for preparing the oilfield sewage purifying agent according to claim 1, further comprising the steps of: after the reaction is finished, the reaction system is dried.

6. The method for preparing the oilfield sewage purifying agent according to claim 1, wherein the particle size of the particulate material is 30-100nm.

7. The method for preparing the oilfield sewage purifying agent according to claim 1, wherein the molar ratio of the compound represented by the formula I to the thiol compound represented by the formula II is 1.95-2.3.

8. The method for preparing the oilfield sewage purifying agent according to claim 1, wherein the mass of the particulate material is 1% to 2% of the mass of the thiol compound represented by formula II.

9. An oilfield sewage purifying agent prepared by the method for preparing an oilfield sewage purifying agent according to any one of claims 1 to 8.

10. The oilfield sewage purifying agent of claim 9, wherein the oilfield sewage purifying agent has a particle size of 50-150nm.

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