DEMULSIFICATION ENHANCER, PREPARATION METHOD AND APPLICATION THEREOF

Abstract

The present disclosure relates to an emulsification enhancer, wherein the emulsification enhancer is made from the following components by weight: 3.8-18 parts of melamine, 0.1-2.7 parts of urea, 2-9.6 parts of monoaldehyde, 0.2-8.4 parts of dialdehyde, 0.9-4.8 parts of hydrochloric acid (HCl) and 56.5-93 parts of water. The present disclosure provides a preparation method of the demulsification enhancer and the application of the demulsification enhancer as an auxiliary agent in the improvement of oil demulsification. The demulsification enhancer of the present disclosure can assist a traditional demulsifier to accelerate the three-phase separation of oil, water and sludge in the oilfield produced-fluid, which is helpful to efficiently extract crude oil from oil sludge emulsion layer and water, reduce oil footprint of the oilfield flowing to the environment, reduce energy consumption of crude oil dehydration and carbon emission of the oilfield, and achieve good three-phase separation effect of oil, water and sludge.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to and takes the benefit of Chinese Patent Application No. 202211466239.9 filed on Nov. 22, 2022, the contents of which are herein incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to the technical field of oilfield chemicals, in particular to an emulsification enhancer, a preparation method and an application thereof.

BACKGROUND

In the process of oil exploitation and refining, due to surfactants naturally existing in the downhole formation and chemical additives artificially added in the oil production process, these chemicals cause serious emulsification of crude oil and water. The crude oil emulsion carries a lot of water and salts. If these brine mixtures cannot be completely removed, it will bring corrosion and environmental safety hazards to process equipment of the refinery and petrochemical plant, and demulsifiers need to be used for treatment. Generally, the demulsifier includes traditional demulsifiers, reverse demulsifiers and water clarifiers. As a surfactant, the traditional demulsifiers have been widely used in oilfield produced liquid, oil sand mine produced liquid, crude oil dehydration, refinery electric desalting emulsion, oilfield drilling mud emulsion, ethylene plant quench water treatment, fuel oil emulsion dehydration, sludge treatment, waste oil recovery and other fields, playing a role in breaking the oil-water emulsion state and separating oil and water.

In the prior art, the traditional demulsifiers, reverse demulsifiers and water clarifiers have been used for oil-water separation of these emulsions. However, with the application of new oil recovery technologies, such as oil sands steam drive produced fluid, heavy oil thermal recovery, chemical flooding, shale oil fracturing produced fluid and other new technologies, the oil and water emulsion of oilfield produced fluid is serious, and the emulsion is also mixed with oil sludge. The conventional demulsifiers in the oilfield can no longer meet the requirements of the oilfield and refinery for crude oil dehydration due to the slow dehydration speed, incomplete crude oil dehydration and other reasons. In addition, environmental protection policies are increasingly strict on oil pollution control. Since crude oil emulsions contain oil sludge of different concentrations, the current oilfield agents cannot completely separate oil, water and sludge. These emulsions will cause serious water pollution and soil oil sludge pollution. Environmental hazards also put forward higher requirements for traditional demulsifiers. Therefore, it is urgent to develop new demulsifier combination agents to assist traditional demulsifiers to separate oil, water and sludge more effectively, especially to reduce oil sludge pollution in the oilfield.

The Chinese patent document CN112048335B (Application No.: CN202010664944.4) discloses a synchronous demulsification water clarifier for petroleum production liquid, the molecular structure of the synchronous demulsification water clarifier contains hyper-branched polyether and polyethylene imine, and hyper-branched polyether and polyethylene imine are combined through allyl acyl chloride. The preparation method of the demulsification water clarifier comprises the following steps: (1) enabling the hyper-branched polyether to react with allyl acyl chloride, and replacing part of terminal hydroxyl groups of the hyper-branched polyether with allyl groups, so as to prepare hyper-branched polyether allyl ester; and (2) carrying out addition reaction on the hyper-branched polyether allyl ester and polyethylene imine to prepare the synchronous demulsification water clarifier for the petroleum production liquid. The agent has the functions of synchronously realizing crude oil dehydration and sewage oil removal, and polymer-containing produced liquid does not react with polymers in sewage, so that the polymers can be retained in-situ in the sewage. However, the demulsification water clarifier has some deficiencies in the separation speed of oil and water and the reduction of oil sludge pollution.

The Chinese patent document CN101024153 (Application No.: CN200710010069.2) discloses a mixed mode demulsifier of multi-loop polyether amine demulsifier phenol A and polyene amine more sticks demulsifier B for oil field dense oil liquid dewatering with a complex proportion A:B=3:7-8:2 and an effective concentration 30%-50%; crude oil dehydration ratio one section is 80-85%, two section is 99.0-99.5%, the multi-loop polyether amine structure of the multi-loop polyether amine demulsifier phenol A is very similar with the structure of gum and asphaltene, and has a good wetting and penetrating ability to help high-temperature dehydration, rapid demulsification performance, multi-thinning polyamines demulsifier B rinsing effective. The disclosure first composed the multi-loop polyether amine demulsifier phenol A; multi-loop polyether amine resin, demulsifier A oil head, polyether and demulsifier A composition, and then composed the polyene amine more sticks demulsifier B, demulsifier B oil head and demulsifier B composition. It solves the existing technology in large dosage, dehydration long time, dehydration poor results, which can be widely used in heavy oil production in the mining dehydration. However, there are also shortcomings of high demulsification temperature and large sludge output.

In view of this, in order to improve the demulsification effect of the demulsifier on oilfield produced crude oil, it is necessary to provide a demulsification enhancer, a preparation method and application thereof to solve the above shortcomings.

SUMMARY

To solve the problems existing in the prior art, the present disclosure provides a demulsification enhancer, a preparation method and an application thereof. The demulsification enhancer of the present disclosure solves the problems of the existing demulsifier, such as slow oil-water separation, high demulsification temperature, high water content of the dehydrated crude oil, high oil content of the dehydrated water, and large output of hazardous sludge wastes, and can assist the traditional demulsifier to accelerate the three-phase separation of oil, water and sludge in the oilfield produced-fluid, which is helpful to efficiently extract crude oil from oil sludge emulsion layer and water, reduce oil footprint of the oilfield flowing to the environment, and reduce energy consumption of crude oil dehydration and carbon emission of the oilfield. Therefore, the emulsification enhancer is applicable to oil and water separation environments such as oilfield drilling mud emulsion treatment, ethylene plant quench water treatment, fuel oil emulsion dehydration treatment, oilfield sludge treatment, oilfield sludge recovery treatment, etc..

An object of the present disclosure is to provide a demulsification enhancer.

The demulsification enhancer provided according to the specific examples of the present disclosure is made from the following components by weight:

• • 3.8-18 parts of melamine, 0.1-2.7 parts of urea, 2-9.6 parts of monoaldehyde, 0.2-8.4 parts of dialdehyde, 0.9-4.8 parts of hydrochloric acid (HCl) and 56.5-93 parts of water.

The demulsification enhancer is provided according to the specific examples of the present disclosure, wherein the dialdehyde is selected from any one or several of glyoxal, malondialdehyde, succinaldehyde and glutaric dialdehyde.

The demulsification enhancer is provided according to the specific embodiments of the present disclosure, wherein the monoaldehyde is selected from any one or several of formaldehyde, acetaldehyde, propionaldehyde and butyraldehyde.

Another object of the present disclosure is to provide a preparation method of the demulsification enhancer.

The preparation method of the demulsification enhancer is provided according to the specific examples of the present disclosure, comprising the following steps:

• • S1: taking 2-9.6 parts by weight of monoaldehyde and 0.2-8.4 parts by weight of dialdehyde, adding them to 56.5-92.93 parts by weight of water, and mixing to form an aldehyde liquid;
  • S2: adding 3.8-18 parts by weight of melamine into the aldehyde liquid formed in the step S1 and mixing them to form a mixed solution;
  • S3: adding 0.9-4.8 parts by weight of HCl into the mixed solution formed in the step S2 to form an acid liquor;
  • S4: subjecting the acid liquor formed in the step S3 to an aldehyde-amine condensation reaction to form an aldehyde-amine solution; and
  • S5: adding 0.1-2.7 parts by weight of urea into the aldehyde-amine solution formed in the step S4 to conduct a polymerization reaction to form the demulsification enhancer.

The preparation method of the demulsification enhancer is provided according to the specific examples of the present disclosure, in the step S3, the formed acid liquor has a pH value of 1-3.

The preparation method of the demulsification enhancer is provided according to the specific examples of the present disclosure, wherein in the step S4, the aldehyde-mine condensation reaction of the acid liquor comprises:

• • adjusting the acid liquor to conduct a first heat preservation reaction at a first temperature; and
  • adjusting the acid liquor to conduct a second heat preservation reaction at a second temperature after the first heat preservation reaction.

The preparation method of the demulsification enhancer is provided according to the specific examples of the present disclosure, wherein the first temperature is 85-90° C., and the first heat preservation reaction is conducted for 0.2-1 h.

The preparation method of the demulsification enhancer is provided according to the specific examples of the present disclosure, wherein the second temperature is 92-96° C., and the second heat preservation reaction is conducted for 0.1-0.3 h.

The preparation method of the demulsification enhancer is provided according to the specific examples of the present disclosure, wherein the polymerization reaction is conducted at 60-70° C. for 0.1-0.5 h.

Another object of the present disclosure is to further provide an application of the demulsification enhancer as an auxiliary agent in the improvement of oil demulsification.

Principles of raw materials of the present disclosure:

HCl: HCl can react with melamine to generate melamine hydrochloride. In addition, HCl regulates the pH of the mixed solution to provide acidic reaction conditions. Hydrochloric acid can be used as a catalyst for the aldehyde-amine condensation reaction.

Water: as the monoaldehyde will deoxygenate and generate water after condensation reaction with urea and melamine aldehyde amine, the polymerization reaction needs to be conducted in a water environment. In addition, water can be HCl ionized, which is convenient for HCl to adjust the acidity and alkalinity.

Monoaldehyde: the monoaldehyde reacts with the amino group of melamine and the amino group of urea to form methylene on the main chain of the polymer generated by the reaction and generate water.

Dialdehyde: the dialdehyde reacts with the amino group of melamine and the amino group of urea to form ethylidene with two hydroxyl groups on the main chain of the polymer generated by the reaction.

Melamine melamine reacts with hydrochloric acid to form melamine hydrochloride, which protects one amino group of melamine, and allows the other two amino groups of melamine to participate in the polymerization reaction that will cause the aldehyde-amine condensation reaction with aldehyde.

Compared with the prior art, the beneficial effects of the present disclosure lie in that:

The demulsification enhancer of the present disclosure can assist the traditional demulsifier to accelerate the three-phase separation of oil, water and sludge in the oilfield produced-fluid, which is helpful to efficiently extract crude oil from oil sludge emulsion layer and water, reduce the oil footprint of the oilfield flowing to the environment, and reduce energy consumption of crude oil dehydration and carbon emission of the oilfield. Therefore, the emulsification enhancer is applicable to oil and water separation environments such as oilfield drilling mud emulsion treatment, ethylene plant quench water treatment, fuel oil emulsion dehydration treatment, oilfield sludge treatment, oilfield sludge recovery treatment, etc..

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the effect of a demulsifier added with an demulsification enhancer on crude oil produced in the oilfield.

In FIG. 1, the left-hand measuring cup shows the demulsification effect of the commercially available demulsifier added separately, and the right-hand measuring cup shows the demulsification effect of the demulsifier added with the demulsification enhancer of Example 1.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In order to make the object, technical solution and advantages of the present disclosure more clear, the technical solution of the present disclosure will be further described in detail. Obviously, the examples described are only a part of examples of the present disclosure, and are not all of examples thereof. All other embodiments that persons of ordinary skill in the art obtain without creative efforts based on the embodiments of the present disclosure also fall within the scope of the present disclosure.

Example 1

This example provided a demulsification enhancer, which was made by the following steps:

• • 1. taking 325 g of formaldehyde and 50 g of glyoxal, adding into a reaction flask with 3000 g of water, and mixing them to form an aldehyde liquid;
  • 2. adding 215 g of melamine into the aldehyde liquid and mixing them to form a mixed solution;
  • 3. adding 60 g of HCl into the mixed solution to form an acid liquor with pH=1.8;
  • 4. heating the acid solution to 90° C. to conduct the reaction for 0.5 h, and then heating to 94° C. to conduct the reaction for 0.1 h to form an aldehyde-amine solution; and
  • 5. reducing the temperature to 65° C., adding 5 g of urea into the aldehyde-amine solution to conduct the reaction for 10 min to form a demulsification enhancer.

Example 2

This example provided a demulsification enhancer, which was made by the following steps:

• • 1. taking 300 g of formaldehyde and 10 g of glyoxal, adding into a reaction flask with 3300 g of water, and mixing them to form an aldehyde liquid;
  • 2. adding 200 g of melamine into the aldehyde liquid and mixing them to form a mixed solution;
  • 3. adding 50 g of HCl into the mixed solution to form an acid liquor with pH=2.2;
  • 4. heating the acid solution to 90° C. to conduct the reaction for 0.5 h, and then heating to 94° C. to conduct the reaction for 0.1 h to form an aldehyde-amine solution; and
  • 5. reducing the temperature to 65° C., adding 6 g of urea to the aldehyde-amine solution to conduct the reaction for 10 min to form a demulsification enhancer.

Example 3

This example provided a demulsification enhancer, which was made by the following steps:

• • 1. taking 330 g of formaldehyde and 100 g of glyoxal, adding into a reaction flask with 2700 g of water, and mixing them to form an aldehyde liquid;
  • 2. adding 220 g of melamine into the aldehyde liquid and mixing them to form a mixed solution;
  • 3. adding 60 g of HCl into the mixed solution to form an acid liquor with pH=2.6; 4. heating the acid solution to 90° C. to conduct the reaction for 0.5 h, and then heating to 94° C. to conduct the reaction for 0.1 h to form an aldehyde-amine solution; and
  • 5. reducing the temperature to 65° C., adding 10 g of urea into the aldehyde-amine solution to conduct the reaction for 10 min to form a demulsification enhancer.

Example 4

This example provides a demulsification enhancer, which is made by the following steps:

• • 1. taking 305 g of formaldehyde and 20 g of glyoxal, adding into a reaction flask with 2700 g of water, and mixing them to for an aldehyde liquid;
  • 2. adding 200 g of melamine into the aldehyde liquid and mixing them to form a mixed solution;
  • 3. adding 60 g of HCl into the mixed solution to form an acid liquor with pH=2.3;
  • 4. heating the acid solution to 90° C. to conduct the reaction for 0.5 h, and then heating to 94° C. to conduct the reaction for 0.1 h to form an aldehyde-amine solution; and
  • 5. reducing the temperature to 65° C., adding 5 g of urea to the aldehyde-amine solution to conduct the reaction for 10 min to form a demulsification enhancer.

Comparative Example 1

This comparative example provided a demulsification enhancer, which is made by the following steps:

• • 1. taking 330 g of formaldehyde and 100 g of glyoxal, adding into a reaction flask with 2700 g of water, and mixing them to form an aldehyde liquid;
  • 2. adding 220 g of melamine into the aldehyde liquid and mixing them to form a mixed solution;
  • 3. adding 10 wt % sodium hydroxide solution to the mixed solution to form an alkaline solution with pH=9;
  • 4. heating the alkaline solution to 90° C. to conduct the reaction for 0.5 h, and then heating to 94° C. to conduct the reaction for 0.1 h to form an aldehyde-amine solution; and
  • 5. reducing the temperature to 65° C., adding 10 g of urea into the aldehyde-amine solution to conduct the reaction for 10 min to form a demulsification enhancer.

Compared with Example 3, this comparative example provided alkaline conditions for preparing the demulsification enhancer, indicating that the pH value affected the polymerization of the demulsification enhancer.

This comparative example provided a demulsification enhancer, which is made by the following steps:

• • 1. taking 325 g of formaldehyde and 50 g of glyoxal, adding into a reaction flask with 3000 g of water, and mixing them to form an aldehyde liquid;
  • 2. adding 215 g of melamine into the aldehyde liquid and mixing them to form a mixed solution;
  • 3. adding 10 wt % sodium hydroxide solution to the mixed solution to form an alkaline solution with pH=9; and
  • 4. heating the alkaline solution to 90° C. to conduct the reaction for 0.5 h, and then heating to 94° C. to conduct the reaction for 0.1 h to form a demulsification enhancer.

Compared with Example 1, the demulsification enhancer was formed without urea in this comparative example, indicating that urea participated in the polymerization reaction and the formed demulsification enhancer had good effects.

Comparative Example 3

This comparative example provided a demulsification enhancer, which is made by the following steps:

• • 1. taking 325 g of formaldehyde, adding into a reaction flask with 3000 g of water, and mixing them to form an aldehyde liquid;
  • 2. adding 215 g of melamine into the aldehyde liquid and mixing them to form a mixed solution;
  • 3. adding 60 g of HCl into the mixed solution to form an acid liquor with pH=1.8;
  • 4. heating the acid solution to 90° C. to conduct the reaction for 0.5 h, and then heating to 94° C. to conduct the reaction for 0.1 h to form an aldehyde-amine solution; and
  • 5. reducing the temperature to 65° C., adding 5 g of urea to the aldehyde-amine solution to conduct the reaction for 10 min to form a demulsification enhancer.

This comparative example differs from Example 1 in that the demulsification enhancer was formed without glyoxal, indicating that glyoxal participated in the polymerization reaction and the formed demulsification enhancer had good effects.

Experimental Example

This experimental example was to study the influence of the demulsification enhancer of the present disclosure on the demulsification effect of the demulsifier. The demulsification enhancer and the traditional demulsifiers were added to the crude oil produced in the oilfield in turn. Based on the effect of three-phase demulsification separation of oil, water and sludge from the crude oil produced in the oilfield, the enhancement effect of the demulsification enhancer on the demulsification effect of the demulsifier as an auxiliary agent of the demulsifier was determined.

Reagent Preparation:

The control solution was the Commercially available demulsifier X1 of Xi'an Juli, and the addition amount of the control solution demulsifier X1 is 50 mg/L.

There were 7 test solutions in total, which were respectively the demulsification enhancer formed from Examples 1-4 and Comparative Examples 1-3. The addition amount of the demulsification enhancer of the test solution was 200 mg/L. Each test solution was used for demulsification test with the control solution X1.

Effect test: the above test solution and control solution were added to 1 L oilfield produced crude oil (oil phase 15%, water phase 84.8%, sludge 0.2%) respectively, and the dehydration rate and oil sludge amount were tested at different times according to SY-T5281-2000 Testing Method for Use Performance of Crude Oil Demulsifier (bottle test). The test results were shown in Table 1, and the visual effect after demulsification of the combination of the demulsification enhancer of Example 1 and the demulsifier was shown in FIG. 1.

	Demulsification		Dehydration rate at		Sludge
	Temperature	amount	different time (%)		volume
	(° C.)	(mg/L)	2 min	5 min	20 min	Water color	(g)
X1 + Example 1	20	50 +	75	90	97	clear	0.4
		200
X1 + Example 2	20	50 +	69	88	98	clear	0.5
		200
X1 + Example 3	30	50 +	65	91	98	clear	0.3
		200
X1 + Example 4	50	50 +	68	77	99	clear	0.3
		200
X1 + Comparative	50	50 +	26	45	73	Translucent	1.8
Example 1		200
X1 + Comparative	50	50 +	30	42	71	Translucent	1.6
Example 2		200
X1 + Comparative	50	50 +	27	39	85	Translucent	1.9
Example 3		200
Demulsifier X1	20	50	13	35	66	Turbid	2.0

As shown in FIG. 1, the left-hand measuring cup showed the demulsification effect of the commercially available demulsifier used separately, and the right-hand measuring cup showed the demulsification effect of the combination of the commercially available demulsifier and the demulsification enhancer. The three-phase separation effect of the combination of the commercially available demulsifier and the demulsification enhancer in the examples of the present disclosure in treating crude oil produced in the oilfield was obviously better than that of using commercially available demulsifiers separately, and the bottom oil sludge was significantly reduced.

The test results showed that the combination of the demulsification enhancers of Examples 1-4 and the demulsifier had a good three-phase separation effect for treating oil, water and sludge from crude oil produced in the oilfield, which was better than Comparative Examples 1-3. The treated water was more clear, and the amount of oil sludge generated was reduced by 50-80%, indicating that the demulsification enhancer in the present disclosure can significantly improve the demulsification effect of the demulsifier in treating crude oil produced in the oilfield.

What are described above are merely preferred examples of the present disclosure, and are not to limit the present disclosure, and any modification, equivalent and improvement made within the spirit and principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. An emulsification enhancer made from the following components by weight: 3.8-18 parts of melamine, 0.1-2.7 parts of urea, 2-9.6 parts of monoaldehyde, 0.2-8.4 parts of dialdehyde, 0.9-4.8 parts of hydrochloric acid (HCl) and 56.5-93 parts of water.

2. The emulsification enhancer according to claim 1, wherein the dialdehyde is selected from any one or several of glyoxal, malondialdehyde, succinaldehyde and glutaric dialdehyde.

3. The emulsification enhancer according to claim 1, wherein the monoaldehyde is selected from any one or several of formaldehyde, acetaldehyde, propionaldehyde and butyraldehyde.

4. A preparation method of the emulsification enhancer according to claim 1, comprising the following steps: S1: taking 2-9.6 parts by weight of monoaldehyde and 0.2-8.4 parts by weight of dialdehyde, adding them to 56.5-92.93 parts by weight of water, and mixing to form an aldehyde liquid;S2: adding 3.8-18 parts by weight of melamine into the aldehyde liquid formed in the step S1 and mixing them to form a mixed solution;S3: adding 0.9-4.8 parts by weight of HCl into the mixed solution formed in the step S2 to form an acid liquor;S4: subjecting the acid liquor formed in the step S3 to an aldehyde-amine condensation reaction to form an aldehyde-amine solution; andS5: adding 0.1-2.7 parts by weight of urea into the aldehyde-amine solution formed in the step S4 to conduct a polymerization reaction to form the demulsification enhancer.

5. The preparation method according to claim 3, wherein in the step S3, the formed acid liquor has a pH value of 1-3.

6. The preparation method according to claim 3, wherein in the step S4, the aldehyde-mine condensation reaction of the acid liquor comprises: adjusting the acid liquor to conduct a first heat preservation reaction at a first temperature; andadjusting the acid liquor to conduct a second heat preservation reaction at a second temperature after the first heat preservation reaction.

7. The preparation method according to claim 6, wherein the first temperature is 85-90° C., and the first heat preservation reaction is conducted for 0.2-1 h.

8. The preparation method according to claim 6, wherein the second temperature is 92-96° C., and the second heat preservation reaction is conducted for 0.1-0.3 h.

9. The preparation method according to claim 4, wherein the polymerization reaction is conducted at 60-70° C. for 0.1-0.5 h.

10. An application of the demulsification enhancer according to claim 1 as an auxiliary agent in the improvement of oil demulsification.