CN106565007A - Ternary compound flooding produced water deoiling agent and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of oilfield sewage treatment, and in particular relates to a degreasing agent for produced water produced by three-element compound flooding. Sodium diacid reacts to generate zwitterionic degreasing agent, and the mol ratio of described 2,5 pyridinediamine, formaldehyde, formic acid and sodium chlorododecanoate is 1: 2.5～6: 2.5～5.5: 0.8～2.5, Preferably it is 1:3:3:1.5. The oil removal agent of the present invention has the characteristics of simple preparation, strong adaptability, low cost, strong salt resistance and good oil removal effect ^. The oil rate is above 97%. And the recovered oil produced by the separation does not affect the subsequent dehydration of crude oil, therefore, the present invention can be widely applied in the oil removal process of the ASP flooding produced water.

Description

A kind of degreasing agent for ASP flooding produced water and preparation method thereof

technical field

The invention relates to a degreasing agent for oil field sewage treatment, in particular to a degreasing agent for three-element compound flooding produced water and a preparation method thereof.

Background technique

In recent years, my country has accelerated the promotion of tertiary oil recovery technology to maintain and increase crude oil production. Alkali-surfactant-polymer ASP flooding is a chemical flooding technology developed on the basis of surfactant flooding, alkaline water flooding and polymer flooding. Relevant studies have shown that ASP flooding can significantly increase recovery and has broad application prospects.

However, due to the complex water quality of the wastewater produced by ASP flooding, which contains a large amount of residual alkali, surfactants and polymers (such as polyacrylamide PAM), the viscosity of the wastewater becomes larger, and the particle size of the sewage oil droplets becomes smaller, resulting in emulsification of the wastewater. Seriously, it increases the difficulty of demulsification and purification of produced fluid. At the same time, the "secondary sedimentation + secondary filtration" treatment method commonly used in oilfields can no longer meet environmental protection requirements, and problems such as reduced equipment processing capacity, long sedimentation time, and unqualified effluent quality have emerged.

The measures commonly used at present mainly include: ① physical means to treat the sewage containing aggregates. At present, the electrochemical method is the main physical treatment method. Among them, the electrocoagulation technology is gradually widely used in sewage treatment because of its relatively mature mechanism research, easy access to electrode materials, low investment, and ease of automation; sewage. This type of technology first carries out demulsification treatment, and then selects suitable degreasing agents and other agents for purification process. At present, the commonly used agents mainly include quaternary ammonium salt type, polymer modified clay type, polyacrylamide organic polymer type and modified starch, etc., and have achieved good flocculation and oil removal effects.

Patent ZL201410455664.7 "A degreasing agent for oilfield binary compound flooding produced sewage" uses acryloyloxyethyl dimethylamine, chloroalkane, acrylamide, N,N'-methylenebis Acrylamide, ammonium persulfate and sodium sulfite reacted. The degreasing agent has the characteristics of less dosage, low cost, high degreasing rate, high degreasing efficiency, simple preparation and low cost. However, the degreasing agent belongs to The reverse demulsifier has a poor demulsification effect on oil-in-water emulsions, and at the same time, this degreaser is not suitable for deoiling treatment of complex ASP flooding wastewater.

Contents of the invention

The present invention aims at the deficiencies of the current prior art and provides an oil remover for ASP flooding produced water and a preparation method thereof. The oil remover has the advantages of simple process, low cost, strong adaptability, strong salt resistance and The oil removal effect is good, the salt tolerance reaches 2.3×10 ⁴ mg/L, and the oil removal rate of the ASP flooding produced water reaches more than 97%.

The object of the present invention is to provide a kind of deoiling agent of three-element compound flooding produced water, described deoiling agent is to generate intermediate by 2,5-pyridinediamine and formaldehyde, formic acid reaction, then with sodium chlorododecanoate The reaction generates a zwitterionic degreasing agent with the following molecular formula:

The molar ratio of the 2,5-pyridinediamine, formaldehyde, formic acid and sodium chlorododecanoate is 1:2.5-6:2.5-5.5:0.8-2.5, preferably 1:3:3:1.5.

Another object of the present invention is to provide a kind of preparation method of the deoiling agent of ASP flooding produced water, the preparation method of this deoiling agent specifically comprises the following steps:

(1) Add 2,5-pyridinediamine and solvent in the above molar ratio into a three-necked flask, install a reflux condenser with a water separator, stir at a rate of 200-300rpm, heat up to 30-40°C, and Pour the above molar ratio of formic acid into the constant pressure dropping funnel, and control the titration speed so that the formic acid is dripped within 20-30 minutes. Pour the formaldehyde in the above ratio into the constant pressure dropping funnel, control the titration speed, so that the formaldehyde will be dripped within 40-60 minutes, after the formaldehyde titration is completed, heat up to 80-85°C, react for 10-24 hours and then cool down naturally to obtain solution A ;

(2) Alkalinizing the above solution A with potassium hydroxide with a mass concentration of 20% to a pH value of 12 to 13, extracting the upper liquid state with n-hexane, removing the solvent, and obtaining the crude product B;

(3) Pour the above-mentioned crude product B into a four-necked flask, add absolute ethanol, install a condenser, and dissolve the sodium chlorododecanoate in the above ratio in water at a stirring rate of 100 to 300 rpm, and then use Slowly add the funnel into the four-necked flask, then heat up to 70-75°C, stir at 350-400rpm, alkalinize with 25% sodium bicarbonate to pH 8-9, react for 10-14 hours and then naturally Cool down to obtain solution C;

(4) Use 6mol/L HCl to adjust the pH of solution C to 2-3, let it stand for 24-36 hours, then spin evaporate ethanol and water in a vacuum environment, and dry it in vacuum; finally wash with ether 3-5 times to obtain the final Products Degreasers according to the invention.

The solvent is cyclohexanol or benzene in an amount of 10 to 25 times the mass of 2,5-pyridinediamine; the amount of n-hexane is 2 to 3 times the mass of 2,5-pyridinediamine; The amount of absolute ethanol used is 5-10 times the mass of 2,5-pyridinediamine; the amount of diethyl ether used is 0.5-1 times the mass of 2,5-pyridinediamine.

Described reaction equation is as follows:

A degreaser for ASP flooding produced water, the process of using it is as follows:

According to the oil content in the water produced by the three-element compound flooding in the oil field, the degreasing agent of the present invention is added to the sewage to realize demulsification and oil-water separation, and the petroleum substances are recovered for further processing in subsequent processes. The specific addition amount of degreasing agent is as follows:

(1) When the oil content α is greater than or equal to 500 mg/L, add a degreasing agent so that the mass concentration of the degreasing agent in the sewage is 50-150 mg/L;

(2) When 500>oil content α≥300mg/L, add a degreasing agent to make the mass concentration of the degreasing agent in the sewage 30-50mg/L;

(3) When 300>oil content α≥100mg/L, add a degreasing agent to make the mass concentration of the degreasing agent in the sewage 10-30mg/L;

(4) When the oil content α<100mg/L, add a degreasing agent to make the mass concentration of the degreasing agent in the sewage 0.1~10mg/L.

The degreasing agent for produced water by three-element compound flooding provided by the present invention belongs to betaine (zwitterion) type surfactant, and the molecule has cationic and anionic zwitterionic groups, and its positive ions and negative ions can attract each other, and it is easy to form A relatively stable surface film, after being adsorbed to the oily surface, can strip off the surfactant in the wastewater produced by ASP flooding, and has strong interfacial activity. The N-containing heterocyclic group in the molecule and the hydrophobic group connected to it have a similar structure to the oil stain, which is easy to adsorb with the oil stain and promotes the flocculation of the degreasing agent and the oil stain in the sewage; since the molecule has both anion and cation , the external ions are difficult to get close to the degreasing agent, so its salt resistance is strong; in addition, the molecular ions can also entangle with the polyacrylamide molecules, which makes the extensibility of polyacrylamide in sewage worse, thereby reducing the The viscosity of sewage accelerates the speed of oil-water separation.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

(1) The degreasing agent of the present invention has a wide range of raw material sources, simple synthesis process, strong adaptability, and can meet the needs of environmental protection and oil field development;

(2) The degreasing agent of the present invention can reduce the viscosity of sewage, and has good salt resistance, the salt resistance reaches 2.3×10 ⁴ mg/L and does not contain inorganic flocculation components;

(3) The oil removal agent of the present invention has the characteristics of high oil removal efficiency, and the oil removal rate of the produced water of ASP flooding reaches more than 97%, which is more than 50% higher than that of the existing agents, and meets the requirements of the produced water of ASP flooding. Requirements for degreasing pretreatment.

detailed description

The present invention will be further described in detail below in conjunction with specific examples and with reference to data. It should be understood that these examples are only for illustration of the present invention, but not to limit the scope of the present invention in any way.

Embodiment 1: degreasing agent H ₁ and preparation method thereof

(1) The composition, components and molecular formula of degreaser H ₁ are as follows:

Degreaser H ₁ reacts 2,5-pyridinediamine with formaldehyde and formic acid to form an intermediate, and then reacts with sodium chlorododecanoate to generate a zwitterionic degreaser, wherein 2,5-pyridinediamine, formaldehyde, The molar ratio of formic acid and sodium chlorododecanoate is 1:2.5:2.5:0.8. _The molecular formula of degreaser H1 is as follows:

( ₂ ) The preparation method of degreasing agent H1 is as follows:

① Add 1mol of 2,5-pyridinediamine and 1091.5g of cyclohexanol into a three-necked flask, install a reflux condenser with a water separator, stir at 230rpm, heat up to 30°C, and add 2.5mol of formic acid Pour into the constant pressure dropping funnel, control the titration speed, so that the formic acid is dropped within 20 minutes, after the formic acid is dropped, adjust the stirring rate to 530rpm, raise the temperature to 50°C, and pour 2.5mol of formaldehyde into the constant pressure dropping funnel In the process, control the titration speed so that the formaldehyde is dripped within 40 minutes. After the formaldehyde titration is completed, the temperature is raised to 82 ° C, and after 10 hours of reaction, the temperature is naturally cooled to obtain solution A;

②Alkalinize the above-mentioned solution A with potassium hydroxide with a mass concentration of 20% until the pH value is 12, extract the upper liquid state with n-hexane, the amount of n-hexane is 218.3g, remove the solvent, and obtain the crude product B;

③ Pour the above crude product B into a four-necked flask, add 545.8g of absolute ethanol, install a condenser, and dissolve 0.8mol of sodium chlorododecanoate in water at a stirring rate of 100rpm, and then use a funnel to slowly Add it into a four-neck flask, then raise the temperature to 72°C, stir at a rate of 350rpm, alkalinize it with sodium bicarbonate with a mass concentration of 25% to a pH value of 8, react for 10 hours and naturally cool down to obtain solution C;

④Use 6mol/L HCl to adjust the pH of solution C to 2, let it stand for 24h, and then evaporate ethanol and water in a vacuum environment, and dry it in vacuum; finally, wash with ether 3 times, and the amount of ether is 54.6g to obtain the final product Degreaser H ₁ of the present invention.

Embodiment 2: degreasing agent H ₂ and preparation method thereof

(1) The composition, components and molecular formula of degreasing agent _H2 are as follows:

Degreaser H ₂ is formed by reacting 2,5-pyridinediamine with formaldehyde and formic acid to form an intermediate, and then reacts with sodium chlorododecanoate to generate a zwitterionic degreaser, wherein 2,5-pyridinediamine, formaldehyde, The molar ratio of formic acid and sodium chlorododecanoate is 1:3:3:1.5. _The molecular formula of degreaser H1 is as follows:

( ₂ ) Degreaser H The preparation method is as follows:

①Put 1mol of 2,5-pyridinediamine and 1637.3g of benzene into a three-necked flask, install a reflux condenser with a water separator, stir at 200rpm, heat up to 32°C, pour 3mol of formic acid into a constant In the pressure dropping funnel, control the titration speed so that the formic acid is dropped within 28 minutes. After the formic acid is dropped, adjust the stirring rate to 500rpm, raise the temperature to 52°C, pour 3mol of formaldehyde into the constant pressure dropping funnel, and control the titration. The speed is such that the formaldehyde is dripped within 50 minutes. After the formaldehyde titration is completed, the temperature is raised to 80°C, and the temperature is naturally cooled after 16 hours of reaction to obtain solution A;

②Alkalinize the above-mentioned solution A with potassium hydroxide with a mass concentration of 20% to a pH value of 12, extract the upper liquid state with n-hexane, the amount of n-hexane is 265.2g, and remove the solvent to obtain the crude product B;

③ Pour the above-mentioned crude product B into a four-necked flask, add 756.3g of absolute ethanol, install a condenser, and dissolve 1.5mol of sodium chlorododecanoate in water at a stirring rate of 150rpm, and then use a funnel to slowly Add it into a four-necked flask, then raise the temperature to 70°C, stir at a rate of 360rpm, alkalinize it with sodium bicarbonate with a mass concentration of 25% to a pH value of 9, react for 12 hours and cool down naturally to obtain solution C;

④Use 6mol/L HCl to adjust the pH of solution C to 2, let it stand for 28h, and then evaporate ethanol and water in a vacuum environment, and dry it in vacuum; finally, wash with ether 3 times, and the amount of ether is 64.3g to obtain the final product The degreasing agent H ₂ of the present invention.

Embodiment 3: degreasing agent H ₃ and preparation method thereof

( ₁ ) The composition, components and molecular formula of degreasing agent H3 are as follows:

Degreaser H3 is formed by reacting 2,5 _- pyridinediamine with formaldehyde and formic acid to form an intermediate, and then reacts with sodium chlorododecanoate to generate a zwitterionic degreaser, wherein 2,5-pyridinediamine, formaldehyde, The molar ratio of formic acid and sodium chlorododecanoate is 1:5:4:2. The molecular _formula of degreasing agent H3 is as follows:

( ₂ ) The preparation method of degreasing agent H3 is as follows:

①Put 1mol of 2,5-pyridinediamine and 2183g of cyclohexanol into a three-necked flask, install a reflux condenser with a water separator, stir at 270rpm, heat up to 35°C, pour 4mol of formic acid into In the constant pressure dropping funnel, control the titration speed so that the formic acid is dripped within 24 minutes. After the formic acid is dripped, adjust the stirring rate to 580rpm, raise the temperature to 53°C, and pour 5mol of formaldehyde into the constant pressure dropping funnel. Control the titration speed so that the formaldehyde is dripped within 45 minutes. After the formaldehyde titration is completed, the temperature is raised to 84°C, and after 20 hours of reaction, the temperature is naturally cooled to obtain solution A;

②Alkalinize the above-mentioned solution A with potassium hydroxide with a mass concentration of 20% until the pH value is 13, extract the upper liquid state with n-hexane, the amount of n-hexane is 301.5g, remove the solvent, and obtain the crude product B;

③ Pour the above-mentioned crude product B into a four-necked flask, add 865.2g of absolute ethanol, install a condenser, and dissolve 2.0mol of sodium chlorododecanoate in water at a stirring rate of 250rpm, and then use a funnel to slowly Add it into a four-neck flask, then raise the temperature to 73°C, stir at a rate of 380rpm, alkalinize it with sodium bicarbonate with a mass concentration of 25% to a pH value of 8, react for 13 hours and naturally cool down to obtain solution C;

④Use 6mol/L HCl to adjust the pH of solution C to 3, let it stand for 32h, and then spin evaporate ethanol and water in a vacuum environment, and dry it in vacuum; finally wash 4 times with ether, the amount of ether is 85.3g, to obtain the final product Degreasing agent H ₃ of the present invention.

Embodiment 4: degreasing agent H ₄ and preparation method thereof

( ₁ ) The composition, components and molecular formula of degreasing agent H4 are as follows:

Degreaser H ₄ reacts 2,5-pyridinediamine with formaldehyde and formic acid to form an intermediate, and then reacts with sodium chlorododecanoate to generate a zwitterionic degreaser, wherein 2,5-pyridinediamine, formaldehyde, The molar ratio of formic acid and sodium chlorododecanoate is 1:6:5.5:2.5. _The molecular formula of degreaser H1 is as follows:

( ₂ ) The preparation method of degreaser H4 is as follows:

①Put 1mol of 2,5-pyridinediamine and 2728.7g of benzene into a three-necked flask, install a reflux condenser with a water separator, stir at 300rpm, heat up to 40°C, pour 5.5mol of formic acid into In the constant pressure dropping funnel, control the titration speed so that the formic acid is dropped within 30 minutes. After the formic acid is dropped, adjust the stirring rate to 600rpm, raise the temperature to 55°C, pour 6mol of formaldehyde into the constant pressure dropping funnel, and control The titration speed is such that the formaldehyde is dripped within 60 minutes. After the formaldehyde titration is completed, the temperature is raised to 85°C, and after 24 hours of reaction, the temperature is naturally cooled to obtain solution A;

②Alkalinize the above-mentioned solution A with potassium hydroxide with a mass concentration of 20% to a pH value of 13, extract the upper liquid state with n-hexane, the amount of n-hexane is 327.4g, remove the solvent, and obtain the crude product B;

③ Pour the above crude product B into a four-necked flask, add 1091.5g of absolute ethanol, install a condenser tube, and dissolve 2.5mol of sodium chlorododecanoate in water at a stirring rate of 300rpm, and then use a funnel to slowly Add it into a four-neck flask, then raise the temperature to 75°C, stir at 400rpm, alkalinize it with sodium bicarbonate with a mass concentration of 25% to a pH value of 9, react for 14 hours and naturally cool down to obtain solution C;

④Use 6mol/L HCl to adjust the pH of solution C to 3, let it stand for 36h, and then spin evaporate ethanol and water in a vacuum environment, and dry it in vacuum; finally wash it with ether 5 times, and the amount of ether is 109.15g to obtain the final product Degreaser H ₄ according to the invention.

Embodiment 5 Field application of degreasing agent H ₁

The incoming water of the combined station M ₂ is the produced water of ASP flooding, the test treatment scale is 90m ³ /d, the oil content of the incoming water is 765mg/L, and the salinity of the sewage is 22560mg/L. Using the oil removal agent H ₁ of the present invention Degreasing treatment is carried out on the sewage of the combined station _M2 . The dosage _of the degreasing agent H1 is 6.3kg/d. 19.1mg/L, the oil content is reduced by 97.5%, meeting the technical requirements.

Embodiment 6 Field application of degreaser H ₂

The incoming water of L ₂ of the combined station is the produced water of ASP flooding, the test treatment scale is 60m ³ /d, the oil content of incoming water is 586mg/L, and the salinity of sewage is 20253mg/L. Using the deoiling agent H ₂ of the present invention Degreasing treatment is carried out on the sewage of the combined station L2. The dosage of degreasing agent _H2 is _3.3kg /d. 8.2mg/L, the oil content is reduced by 98.6%, meeting the technical requirements.

Example 7 Field application of degreasing agent H ₃

The incoming water of L ₅ of the joint station is the produced water of ASP flooding, the test treatment scale is 50m ³ /d, the oil content of incoming water is 823mg/L, and the salinity of sewage is 18256mg/L. Using the deoiling agent H ₃ of the present invention Degreasing treatment is carried out _on the sewage of the combined station L5, the dosage of the degreasing agent H3 is _4.0kg /d, the concentration of the degreasing agent in the sewage after adding the degreasing agent is 80mg/L, and the oil content after treatment is reduced to 16.5mg/L, the oil content is reduced by 98.0%, meeting the technical requirements.

Example 8 Field application of degreasing agent H ₄

The incoming water of L ₆ of the combined station is the produced water of ASP flooding, the test treatment scale is 100m ³ /d, the oil content of the incoming water is 752mg/L, and the salinity of sewage is 17650mg/L. Using the oil removal agent H ₄ of the present invention Degreasing treatment is carried out on the sewage of the joint station L ₆ , the dosage of the degreasing agent H ₄ is 7.0kg/d, the concentration of the degreasing agent in the sewage after adding the degreasing agent is 70mg/L, and the oil content after treatment is reduced to 20.3mg/L, the oil content is reduced by 97.3%, meeting the technical requirements.

Claims (8)

1. a kind of degreasing agent of triple compound flooding produced water, it is characterized in that, described degreasing agent is to generate intermediate by 2,5-pyridinediamine and formaldehyde, formic acid reaction, then with sodium chlorododecanoate The reaction generates a zwitterionic degreasing agent with the following molecular formula: 2. the deoiling agent of the three-element compound flooding produced water according to claim 1, is characterized in that, described 2, the mol ratio of 5-pyridinediamine, formaldehyde, formic acid and sodium chlorododecanoate is 1: 2.5-6: 2.5-5.5: 0.8-2.5. 3. according to claim 1 and 2 described three-element compound flooding produced water degreasers, it is characterized in that, described 2, the mol ratio of 5-pyridinediamine, formaldehyde, formic acid and sodium chlorododecanoate is 1:3:3:1.5. 4. a preparation method of an oil removal agent for ASP flooding produced water, characterized in that, the preparation method specifically comprises the following steps: (1) Add 2,5-pyridinediamine and solvent in the above molar ratio into a three-necked flask, install a reflux condenser with a water separator, stir at a rate of 200-300rpm, heat up to 30-40°C, and Pour the above molar ratio of formic acid into the constant pressure dropping funnel, and control the titration speed so that the formic acid is dripped within 20-30 minutes. Pour the formaldehyde in the above ratio into the constant pressure dropping funnel, control the titration speed, so that the formaldehyde will be dripped within 40-60 minutes, after the formaldehyde titration is completed, heat up to 80-85°C, react for 10-24 hours and then cool down naturally to obtain solution A ; (2) Alkalinizing the above solution A with potassium hydroxide with a mass concentration of 20% to a pH value of 12 to 13, extracting the upper liquid state with n-hexane, removing the solvent, and obtaining the crude product B; (3) Pour the above-mentioned crude product B into a four-necked flask, add absolute ethanol, install a condenser, and dissolve the sodium chlorododecanoate in the above ratio in water at a stirring rate of 100 to 300 rpm, and then use Slowly add the funnel into the four-necked flask, then heat up to 70-75°C, stir at 350-400rpm, alkalinize with 25% sodium bicarbonate to pH 8-9, react for 10-14 hours and then naturally Cool down to obtain solution C; (4) Use 6mol/L HCl to adjust the pH of solution C to 2-3, let it stand for 24-36 hours, then spin evaporate ethanol and water in a vacuum environment, and dry it in vacuum; finally wash with ether 3-5 times to obtain the final Products Degreasers according to the invention. 5. the preparation method of the deoiling agent of the triple compound flooding produced water according to claim 4, is characterized in that, described solvent is cyclohexanol or benzene, and consumption is 10% of 2,5-pyridine diamine quality ~25 times. 6. according to claim 4 or the preparation method of the degreasing agent of the ASP flooding produced water described in claim 5, it is characterized in that, the consumption of described n-hexane is 2～3 times of 2,5-pyridine diamine quality . 7. The preparation method of the deoiling agent for ASP flooding produced water according to claim 6, characterized in that the amount of the dehydrated ethanol is 5 to 10 times the mass of 2,5-pyridinediamine. 8 . The preparation method of the degreasing agent for ASP flooding produced water according to claim 7 , wherein the amount of ether is 0.5 to 1 times the mass of 2,5-pyridinediamine.