A demulsifier for treating crude oil emulsion layer

Abstract

The present invention discloses a demulsifier for treating crude oil emulsion layers, comprising: component A, component B, component C, and component D; component A is a toluene diisocyanate-modified phenolic resin-based polyether solution; component B is an acrylic acid-modified phenolic resin-based polyether solution; component C is a high-carbon alcohol polyether solution; and component D is a long-chain alkyl dimethyl benzyl ammonium chloride solution. The mass ratio of components A, B, C, and D is 30:30 to 50:1 to 10:5 to 15. The present invention has the beneficial effects of providing a demulsifier for treating crude oil emulsion layers with a fast dehydration rate and low water content in the purified oil.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical industry, in particular to a demulsifier for treating a crude oil emulsion layer. Background Art

[0002] Currently, most of my country's offshore oilfields have entered the middle and late stages of development and production. The trend toward heavier crude oil is becoming more pronounced, and the composition of the produced fluid's oil-water interface is becoming more complex, further increasing the difficulty of oil-water separation. This has led to the emergence of the so-called "emulsion" problem in many oilfields. This is because during the oil-water separation process, a certain amount of "emulsion" (also known as the "intermediate layer") forms at the oil-water interface at each stage of the separator, which is inaccessible to conventional demulsifiers. If this intermediary layer is not treated, it will become "aged oil" upon entering the cargo tanks. This emulsion, which cannot be eliminated during the process, gradually accumulates, affecting the normal operation of equipment and ultimately the oil-water separation efficiency, disrupting normal oilfield production and, in severe cases, forcing production restrictions. Furthermore, when this emulsion accumulates to a certain level, it will enter the water treatment system or cargo tanks. If it enters the wastewater treatment system, it will significantly reduce the system's efficiency, leading to a significant increase in the use of water treatment chemicals and substandard quality of the reinjected wastewater. If it enters the cargo tanks, it will cause the water content of the exported crude oil to exceed the standard, causing a drop in crude oil prices and even making the crude oil unsalable.

[0003] Generally, there are two main approaches to treating emulsions in a process. One is a process-based approach, which involves reducing the amount of emulsions by adjusting on-site production processes, thereby minimizing their impact on the overall process. The other is a chemical approach, which involves optimizing suitable demulsifiers and / or reverse demulsifiers, water purifiers, etc. to thermodynamically reduce the stability of the emulsion, thereby fundamentally reducing the amount of emulsions, achieving a reduction or even complete elimination of emulsions. However, due to the limited space in offshore oilfields and the short residence time of produced fluids in processing equipment, these conventional demulsifier optimization methods are not fully adapted to the operating conditions of offshore oilfields.

[0004] Therefore, a demulsifier with fast dehydration rate and low water content in purified oil for treating crude oil emulsion layer becomes the key to solving the problem. Summary of the Invention

[0005] The present invention compounds a modified polyether having excellent dehydration performance for water-in-oil emulsions, a polyether having excellent dehydration performance for oil-in-water emulsions, and a small molecule cationic additive to obtain a four-component crude oil demulsifier. The compounded demulsifier has the characteristics of fast dehydration rate, low water content in purified oil, and small emulsion layer content for crude oil production containing emulsion in offshore oil fields.

[0006] The object of the present invention is to provide a demulsifier for treating crude oil emulsion layers, which has a fast dehydration rate and low water content in the purified oil and can be used for treating the emulsion layer in the crude oil treatment process.

[0007] To achieve the above objectives, the present invention adopts the following technical solutions.

[0008] A demulsifier for treating a crude oil emulsion layer, characterized by being composed of a mixture of component A, component B, component C, and component D; component A being a toluene diisocyanate-modified phenolic resin-based polyether solution; component B being an acrylic acid-modified phenolic resin-based polyether solution; component C being a high-carbon alcohol polyether solution; and component D being a long-chain alkyl dimethyl benzyl ammonium chloride solution; and the mass ratio of component A, component B, component C, and component D being 30:30-50:1-10:5-15.

[0009] The toluene diisocyanate-modified phenolic resin-based polyether solution is one of a xylene solution of toluene diisocyanate-modified bisphenol A phenolic resin polyoxypropylene polyoxyethylene ether, a xylene solution of toluene diisocyanate-modified tert-butyl phenolic resin polyoxypropylene polyoxyethylene ether, and a xylene solution of toluene diisocyanate-modified nonyl phenolic resin polyoxypropylene polyoxyethylene ether, with a cross-linking degree of 0.5% to 1.5% and an effective matter content of 50%;

[0010] The acrylic acid modified phenolic resin-based polyether solution is one of a xylene solution of acrylic acid modified bisphenol A phenolic resin polyoxypropylene polyoxyethylene ether, a xylene solution of acrylic acid modified tert-butyl phenolic resin polyoxypropylene polyoxyethylene ether, and a xylene solution of acrylic acid modified nonyl phenolic resin polyoxypropylene polyoxyethylene ether, with a crosslinking degree of 5% to 10% and an effective matter content of 50%;

[0011] The high-carbon alcohol polyether solution is a solution obtained by dissolving octadecyl polyoxypropylene polyoxyethylene polyoxypropylene ether in a mixture of methanol and deionized water in a mass ratio of 8:2, with an effective matter content of 50%;

[0012] The long-chain alkyl dimethyl benzyl ammonium chloride solution is a solution obtained by dissolving octyl dimethyl benzyl ammonium chloride, decyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride, and tetradecyl dimethyl benzyl ammonium chloride in a mixture of methanol and deionized water in a mass ratio of 1:1, and the effective matter content is 40%.

[0013] Preferably, the mass ratio of component A, component B, component C and component D is 30:40:5:10.

[0014] Preferably, the toluene diisocyanate-modified phenolic resin-based polyether solution is a xylene solution of toluene diisocyanate-modified bisphenol A phenolic resin polyoxypropylene polyoxyethylene ether, and the cross-linking degree is 1%.

[0015] Preferably, the acrylic acid modified phenolic resin-based polyether solution is a xylene solution of acrylic acid modified nonylphenolic resin polyoxypropylene polyoxyethylene ether, with a cross-linking degree of 10%.

[0016] Preferably, the long-chain alkyl dimethyl benzyl ammonium chloride solution is a solution obtained by dissolving dodecyl dimethyl benzyl ammonium chloride in a mixture of methanol and deionized water in a mass ratio of 1:1.

[0017] The beneficial effects of the present invention are: it has the advantages of fast dehydration rate and low water content in purified oil, and can be used for emulsion layer treatment in crude oil treatment processes. DETAILED DESCRIPTION

[0018] The invention is described in further detail so that those skilled in the art can implement it according to the description.

[0019] Example 1

[0020] A demulsifier for treating a crude oil emulsion layer is prepared by mixing components A, B, C, and D; component A is a xylene solution of toluene diisocyanate-modified bisphenol A novolac resin polyoxypropylene polyoxyethylene ether; component B is a xylene solution of acrylic acid-modified nonylphenol-formaldehyde resin polyoxypropylene polyoxyethylene ether; component C is a solution obtained by dissolving octadecyl polyoxypropylene polyoxyethylene polyoxypropylene ether in a mixture of methanol and deionized water in a mass ratio of 8:2; and component D is a solution obtained by dissolving dodecyl dimethyl benzyl ammonium chloride in a mixture of methanol and deionized water in a mass ratio of 1:1. The mass ratio of components A, B, C, and D is 30:40:5:10.

[0021] Component A is polymerized from bisphenol A-based phenolic resin, propylene oxide, and ethylene oxide in a mass ratio of 1:49:17. The crosslinker, toluene diisocyanate, accounts for 1% of the polyether mass and has an active ingredient content of 50%. Component B is polymerized from nonylphenolic resin, propylene oxide, and ethylene oxide in a mass ratio of 1:49:17. The crosslinker, acrylic acid, accounts for 7% of the polyether mass and has an active ingredient content of 50%. Component C has an active ingredient content of 50%. Component D has an active ingredient content of 40%.

[0022] First, add component B into a three-necked flask equipped with an electric stirrer and a thermometer, start stirring, turn on water bath heating, and when the temperature in the flask reaches 30°C, add components A, C and D in sequence. After 10 minutes, stop stirring and discharge the materials to obtain the demulsifier for treating crude oil emulsion layer according to the present invention.

[0023] Example 2

[0024] A demulsifier for treating a crude oil emulsion layer is prepared by mixing components A, B, C, and D; component A is a xylene solution of toluene diisocyanate-modified bisphenol A novolac resin polyoxypropylene polyoxyethylene ether; component B is a xylene solution of acrylic acid-modified tert-butyl novolac resin polyoxypropylene polyoxyethylene ether; component C is a solution obtained by dissolving octadecyl alcohol polyoxypropylene polyoxyethylene polyoxypropylene ether in a mixture of methanol and deionized water in a mass ratio of 8:2; and component D is a solution obtained by dissolving octyldimethylbenzyl ammonium chloride in a mixture of methanol and deionized water in a mass ratio of 1:1. The mass ratio of components A, B, C, and D is 30:50:10:10.

[0025] Component A is a polymerized mixture of bisphenol A-based phenolic resin, propylene oxide, and ethylene oxide in a mass ratio of 1:49:17. The crosslinker, toluene diisocyanate, accounts for 1.5% of the polyether mass, and the active ingredient content is 50%. Component B comprises tert-butylphenolic resin, propylene oxide, and ethylene oxide in a mass ratio of 1:39:13. The crosslinker, acrylic acid, accounts for 8% of the polyether mass, and the active ingredient content is 50%. Component C has an active ingredient content of 50%. Component D has an active ingredient content of 40%.

[0026] First, add component B into a three-necked flask equipped with an electric stirrer and a thermometer, start stirring, turn on water bath heating, and when the temperature in the flask reaches 30°C, add components A, C and D in sequence. After 10 minutes, stop stirring and discharge the materials to obtain the demulsifier for treating crude oil emulsion layer according to the present invention.

[0027] Example 3

[0028] A demulsifier for treating a crude oil emulsion layer is prepared by mixing components A, B, C, and D; component A is a xylene solution of toluene diisocyanate-modified nonylphenolic resin polyoxypropylene polyoxyethylene ether; component B is a xylene solution of acrylic acid-modified tert-butylphenolic resin polyoxypropylene polyoxyethylene ether; component C is a solution obtained by dissolving octadecyl alcohol polyoxypropylene polyoxyethylene polyoxypropylene ether in a mixture of methanol and deionized water in a mass ratio of 8:2; and component D is a solution obtained by dissolving tetradecyl dimethyl benzyl ammonium chloride in a mixture of methanol and deionized water in a mass ratio of 1:1. The mass ratio of components A, B, C, and D is 30:30:1:5.

[0029] Component A consists of nonylphenolic resin, propylene oxide, and ethylene oxide in a mass ratio of 1:49:17, with a crosslinker of toluene diisocyanate accounting for 0.5% of the polyether mass, and an active ingredient content of 50%. Component B consists of tert-butylphenolic resin, propylene oxide, and ethylene oxide in a mass ratio of 1:59:20, with a crosslinker of acrylic acid accounting for 5% of the polyether mass, and an active ingredient content of 50%. Component C has an active ingredient content of 50%, and Component D has an active ingredient content of 40%.

[0030] First, add component B into a three-necked flask equipped with an electric stirrer and a thermometer, start stirring, turn on water bath heating, and when the temperature in the flask reaches 30°C, add components A, C and D in sequence. After 10 minutes, stop stirring and discharge the materials to obtain the demulsifier for treating crude oil emulsion layer according to the present invention.

[0031] Example 4

[0032] A demulsifier for treating a crude oil emulsion layer is prepared by mixing components A, B, C, and D; component A is a xylene solution of toluene diisocyanate-modified tert-butylphenolic resin polyoxypropylene polyoxyethylene ether; component B is a xylene solution of acrylic acid-modified bisphenol A phenolic resin polyoxypropylene polyoxyethylene ether; component C is a solution obtained by dissolving octadecyl polyoxypropylene polyoxyethylene polyoxypropylene ether in a mixture of methanol and deionized water in a mass ratio of 8:2; and component D is a solution obtained by dissolving decyldimethylbenzyl ammonium chloride in a mixture of methanol and deionized water in a mass ratio of 1:1. The mass ratio of components A, B, C, and D is 30:30:3:15.

[0033] Component A is composed of tert-butylphenol-formaldehyde resin, propylene oxide, and ethylene oxide in a mass ratio of 1:39:13, with a crosslinker of toluene diisocyanate accounting for 1.5% of the polyether weight, and an active ingredient content of 50%. Component B is composed of bisphenol A phenol-formaldehyde resin, propylene oxide, and ethylene oxide in a mass ratio of 1:59:20, with a crosslinker of acrylic acid accounting for 10% of the polyether weight, and an active ingredient content of 50%. Component C has an active ingredient content of 50%, and Component D has an active ingredient content of 40%.

[0034] First, add component B into a three-necked flask equipped with an electric stirrer and a thermometer, start stirring, turn on water bath heating, and when the temperature in the flask reaches 30°C, add components A, C and D in sequence. After 10 minutes, stop stirring and discharge the materials to obtain the demulsifier for treating crude oil emulsion layer according to the present invention.

[0035] Data Analysis

[0036] The demulsifier prepared by the present invention is compared with the demulsifier commonly used in oil fields at the same effective concentration. The crude oil produced for the comparative experiment was obtained from different offshore oil fields in my country.

[0037] 1. The demulsifier prepared by the present invention and the demulsifier commonly used in oil fields were subjected to a dehydration experiment on heavy oil emulsion at the same effective concentration, and the results were shown in Table 1.

[0038] Table 1 Dehydration effect of different agents on heavy oil emulsion

[0039] Oil sample source: Chengbei Oilfield primary separator inlet Sample volume: 80mL Mixing method: Manual shaking 100 times Experimental temperature: 80℃

[0040]

[0041] 2. The demulsifier prepared by the present invention and the demulsifier commonly used in oil fields were subjected to dehydration experiments on medium crude oil emulsions at the same effective concentrations, and the results were shown in Table 2.

[0042] Table 2 Dehydration effect of different agents on medium crude oil emulsion

[0043] Sample source: BZ34-2 / 4 oilfield primary separator inlet Sample volume: 80mL Mixing method: Manual shaking 100 times Experimental temperature: 65℃

[0044]

[0045] It can be seen that the demulsifier for crude oil emulsion layer treatment prepared by this method has the advantages of fast dehydration rate and low water content in purified oil, and can be used for emulsion layer treatment in crude oil treatment processes.

[0046] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. A demulsifier for treating a crude oil emulsion layer, characterized in that: The invention is prepared by mixing component A, component B, component C and component D; component A is a toluene diisocyanate modified phenolic resin-based polyether solution; component B is an acrylic acid modified phenolic resin-based polyether solution; component C is a high-carbon alcohol polyether solution; component D is a long-chain alkyl dimethyl benzyl ammonium chloride solution; the mass ratio of component A, component B, component C and component D is 30:30-50:1-10:5-15; The toluene diisocyanate-modified phenolic resin-based polyether solution is one of a xylene solution of toluene diisocyanate-modified bisphenol A phenolic resin polyoxypropylene polyoxyethylene ether, a xylene solution of toluene diisocyanate-modified tert-butyl phenolic resin polyoxypropylene polyoxyethylene ether, and a xylene solution of toluene diisocyanate-modified nonyl phenolic resin polyoxypropylene polyoxyethylene ether, with a crosslinking degree of 0.5% to 1.5% and an effective matter content of 50%; component A is prepared by polymerizing toluene diisocyanate-modified phenolic resin, propylene oxide, and ethylene oxide in a mass ratio of 1:39-49:13-17; The acrylic acid-modified phenolic resin-based polyether solution is one of a xylene solution of acrylic acid-modified bisphenol A phenolic resin polyoxypropylene polyoxyethylene ether, a xylene solution of acrylic acid-modified tert-butyl phenolic resin polyoxypropylene polyoxyethylene ether, and a xylene solution of acrylic acid-modified nonyl phenolic resin polyoxypropylene polyoxyethylene ether, with a crosslinking degree of 5% to 10% and an effective matter content of 50%; component B is prepared by polymerizing acrylic acid-modified phenolic resin, propylene oxide, and ethylene oxide in a mass ratio of 1:39-59:13-20; The high-carbon alcohol polyether solution is a solution obtained by dissolving octadecyl polyoxypropylene polyoxyethylene polyoxypropylene ether in a mixture of methanol and deionized water in a mass ratio of 8:2, with an effective matter content of 50%; The long-chain alkyl dimethyl benzyl ammonium chloride solution is a solution obtained by dissolving octyl dimethyl benzyl ammonium chloride, decyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride or tetradecyl dimethyl benzyl ammonium chloride in a mixture of methanol and deionized water in a mass ratio of 1:1, and the effective matter content is 40%.

2. The demulsifier for treating a crude oil emulsion layer according to claim 1, wherein: The mass ratio of component A, component B, component C and component D is 30:40:5:

10.

3. The demulsifier for treating a crude oil emulsion layer according to claim 1, wherein: The toluene diisocyanate modified phenolic resin-based polyether solution is a xylene solution of toluene diisocyanate modified bisphenol A phenolic resin polyoxypropylene polyoxyethylene ether, and the crosslinking degree is 1%.

4. The demulsifier for treating a crude oil emulsion layer according to claim 1, wherein: The acrylic acid modified phenolic resin-based polyether solution is a xylene solution of acrylic acid modified nonylphenolic resin polyoxypropylene polyoxyethylene ether, and has a cross-linking degree of 10%.

5. The demulsifier for treating a crude oil emulsion layer according to claim 1, wherein: The long-chain alkyl dimethyl benzyl ammonium chloride solution is a solution obtained by dissolving dodecyl dimethyl benzyl ammonium chloride in a mixture of methanol and deionized water in a mass ratio of 1:1.

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