Offshore oilfield environment-friendly oil spill dispersant and preparation method thereof

Abstract

The invention discloses an offshore oilfield environment-friendly oil spill dispersant and a preparation method thereof. The oil spill dispersant comprises the following components in parts by weight: 45-50 parts of a base solution which is a mixed solution of low-toxicity rhamnose ester, polyol polyoxyethylene ether and a penetrant in a mass ratio of 4: 6: 9; 1 part of sodium dihydrogen phosphate; 10 parts of glycerol; 39 to 44 parts of distilled water; according to the food-grade defoaming agent, less than 100 mg of the defoaming agent is added into each liter of the oil spill dispersing agent. The oil spill emulsifying agent contains rhamnose ester serving as a biological surfactant, polyhydric alcohol polyoxyethylene ether serving as a green cosolvent, octadecenol polyether amine serving as a penetrating agent, polydimethylsiloxane serving as a food-grade defoaming agent, sodium dihydrogen phosphate serving as a pH regulator and glycerin serving as a wetting agent according to an accurate proportion, can efficiently emulsify oil spill, has excellent biodegradability, and can be applied to oil spill processing. And no secondary pollution is caused to the environment.

Description

Technical Field

[0001] This invention relates to the field of oil spill emergency technology, and in particular to an environmentally friendly oil spill dispersant for offshore oil fields and its preparation method. Background Technology

[0002] Oil spill dispersants, also known as oil removers, connect oil and water through lipophilic and hydrophilic groups. Through mechanical stirring and wave action, they disperse the oil spill into water-in-oil emulsion particles, which then diffuse into the water body with natural movement. This significantly increases the contact area between oil and water, making the oil easier for microorganisms to degrade and accelerating the natural purification of the oil spill. The main components of oil spill dispersants are surfactants, solvents, and small amounts of additives (wetting agents, stabilizers, etc.). The surfactant, composed of both lipophilic and hydrophilic groups, is the primary component. Because surfactants have an affinity for both oil and water, they alter the interaction between the oil and water interfaces and greatly reduce the surface tension of the oil film. The solvent dilutes the oil and lowers its freezing point, and also reduces the viscosity of both the surfactant and the oil to facilitate emulsification. Additives adjust the pH value, increase solution stability, and improve the oil-dispersing effect.

[0003] Currently, there are many types of oil spill dispersants available, such as Guangming GM-2, JFT, Fuken-2, Haihuan, and Shuangxiang, but all of them are products from before 2021. Their emulsifiers are mainly composed of chemically synthesized products such as esters and polyethers, resulting in low emulsifying properties. The solvents are mainly PEG, ethylene glycol monobutyl ether, and ethylene glycol. Although these have high closed-cup flash points and good miscibility, their biodegradability is poor. For example, the biodegradability of ethylene glycol monobutyl ether with different contents is less than 10%, far below the target of 40%.

[0004] With increasingly stringent national requirements for marine ecology, the biodegradability requirement in the GB / T18188.1-2021 standard has been raised from 30% to 40%. While there are many types of oil spill dispersants currently available, most suffer from poor biodegradability and water solubility, failing to meet environmental protection requirements. To overcome these shortcomings, a green, water-soluble, and environmentally friendly product has been developed that combines high emulsification rate, low toxicity, and high biodegradability. Its performance indicators simultaneously meet the requirements of the new national standard GB / T18188.1-2021, which is of significant importance. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an environmentally friendly oil spill dispersant for offshore oil fields and its preparation method. This oil spill dispersant exhibits excellent emulsification and dispersion effects on both low- and medium-viscosity crude oil and heavy oil spills at sea, without impacting the marine ecological environment.

[0006] In a first aspect, the present invention provides an environmentally friendly oil spill dispersant for offshore oil fields, which is achieved by the following technical solution.

[0007] An environmentally friendly oil spill dispersant for offshore oil fields, comprising the following components in parts by weight: Base liquid: 45-50 parts, wherein the base liquid is a mixture of low-toxicity rhamnosine ester, polyol polyoxyethylene ether, and penetrant, and the mass ratio of low-toxicity rhamnosine ester, polyol polyoxyethylene ether, and penetrant is 4:6:9; Sodium dihydrogen phosphate: 1 part; Glycerin: 10 parts; Distilled water: 39-44 parts; Food-grade defoamer: Add less than 100mg of defoamer per liter of oil spill dispersant.

[0008] Furthermore, the rhamnose ester is low in toxicity, and its toxic components have been removed through multi-step concentration. Furthermore, the polyol polyoxyethylene ether is selected from pentaerythritol polyoxyethylene ether, and the mass ratio of ethylene oxide to propylene oxide in the polyether is 8:2 to 9:1.

[0009] Furthermore, the food-grade defoamer is food-grade polydimethylsiloxane.

[0010] Furthermore, the penetrant is octadecenol polyetheramine.

[0011] By adopting the above technical solution, this application selects low-toxicity and well-emulsifying biosurfactant rhamnosyl ester, green cosolvent polyol polyoxyethylene ether, penetrating non-toxic octadecenol polyetheramine, food-grade polydimethylsiloxane defoamer, sodium dihydrogen phosphate, and glycerin in appropriate proportions to prepare an environmentally friendly oil spill dispersant with good emulsifying and dispersing ability and good biodegradability. Among them, the biosurfactant rhamnosyl ester disrupts and alters the polarity of oil / hydrocarbons, separating covalent bonds from ionic bonds and accelerating oil emulsification. Its production process incorporates a four-step purification process to strictly remove toxic components, resulting in low interfacial tension and good biodegradability. The cosolvent uses polyol polyoxyethylene ether, a biodegradable component found in infant cosmetics, with numerous hydrophilic and lipophilic adsorption sites, good miscibility, and enhanced safety. Its long chain contains multiple hydroxyl groups, strengthening its binding force with water and sugar esters. The highly permeable octadecenol polyetheramine component, combined with its linear structure, improves biodegradability and contains active groups with strong adsorption capacity for polar groups such as asphaltenes and gums, resulting in strong dispersing ability and a certain viscosity-reducing effect on crude oil. Polydimethylsiloxane primarily uses food-grade defoamers, significantly reducing foam while being non-toxic to zebrafish.

[0012] Secondly, the present invention provides a method for preparing an environmentally friendly oil spill dispersant for offshore oil fields, which is achieved by the following technical solution.

[0013] A method for preparing the above-mentioned environmentally friendly oil spill dispersant for offshore oil fields includes the following steps: S1. Mix low-toxicity rhamnosine ester, polyol polyoxyethylene ether, and penetrant in a mass ratio of 4:6:9; S2. Add distilled water to the system, add food-grade defoamer according to the size of the foam, and stir evenly at low speed at room temperature; S3. Add the specified amount of glycerol and sodium dihydrogen phosphate, and continue stirring at low speed until clear and transparent, thus obtaining a light yellow transparent oil spill dispersant product.

[0014] Furthermore, in step S2, the temperature is controlled at 25-35℃ and the stirring speed is controlled at 100-150rpm.

[0015] Furthermore, after mixing low-toxicity rhamnose ester, polyol polyoxyethylene ether, and penetrant, the mixture is added to a stainless steel reactor using a circulating pump such as a hose pump to avoid excessive foaming. The reactor is made of 304 stainless steel to ensure the environmental friendliness of the biological reagent. The dosing port in the reactor is positioned close to the bottom to prevent splashing and foaming. A propeller-type or paddle-type agitator is used in the reactor, with blades placed near the bottom and in the middle of the reactor to prevent foaming and ensure uniform mixing of the reagent at low speed.

[0016] Furthermore, in step S3, to ensure the convenience and accuracy of drug addition, sodium dihydrogen phosphate and glycerin can be prepared into a solution with water before use, but the total amount of drug added remains unchanged.

[0017] This application has the following beneficial effects.

[0018] (1) The bio-surfactant rhamnolipid of the present invention differs from conventional rhamnolipids on the market. It adopts a multi-step purification process to gradually remove toxic components without affecting interfacial tension, thus ensuring the environmental friendliness of the product. This product can be used in microbial enhanced oil recovery technology, which belongs to a new type of biological cold recovery technology. It is a green and environmentally friendly agent that does not produce secondary precipitation, has no negative effects on the reservoir after use, and has no environmental pollution problems during the use of the technology. It has multiple functions and strong compatibility. Moreover, the produced liquid is easy to separate into oil and water, easy to demulsify, and the wastewater does not require special treatment and can effectively inhibit and kill bacteria.

[0019] (2) The present invention introduces a highly active penetrant component with good biodegradability, which has a good dilution and viscosity reduction effect on asphaltene, is non-corrosive, has a good cleaning effect on crude oil, has a low HLB value and is soluble in water, and has good compatibility with rhamnose esters.

[0020] (3) The green cosolvent of this invention mainly uses infant-grade polyol polyoxyethylene ether, which has mild wetting properties and low toxicity and side effects. It effectively solves the problem of compatibility between biosurfactants and penetrants. It has many hydrophilic and lipophilic adsorption sites, and has good adsorption properties for oxygen heterocycles and double bonds respectively. It is safer and does not harm the skin.

[0021] (4) The oil spill dispersant system of the present invention can also be used in environmentally friendly deck cleaning agents, wax depressants, and oil film removers on the sea surface. Detailed Implementation

[0022] The following examples, illustrating the production of 1 ton of product, further illustrate this patent application. Unless otherwise specified, all materials used in the preparation process in the following examples were obtained commercially and were not subject to further processing.

[0023] The preparation method of low-toxicity rhamnosyl ester used in the following embodiments of this application is described in Chinese Invention Patent Publication No. CN112279879A, which discloses a method for extracting and purifying rhamnosyl ester. The octadecene alcohol polyetheramine used in the following embodiments of this application was purchased from Jiangsu Nimeda Technology Co., Ltd., NDS-301; The polydimethylsiloxane used in the following embodiments of this application was purchased from Dongguan Defeng Defoamer Co., Ltd., DF-201; The pentaerythritol polyoxyethylene ether used in the following embodiments of this application was purchased from Tianjin Longxinshengyuan Technology Development Co., Ltd., LEB-900.

[0024] Example 1 A method for preparing an environmentally friendly oil spill dispersant for offshore oil fields, comprising the following steps: 1. Add 94.7 kg of bio-type surfactant rhamnosyl ester, 142.1 kg of green co-solvent pentaerythritol polyoxyethylene ether (ethylene oxide: propylene oxide mass ratio = 8:2), and 213.2 kg of penetrant octadecenol polyetheramine to a stainless steel reactor using a hose pump. 2. Add 440 kg of distilled water to the system to prepare an aqueous solution. According to the size of the foam, add 0.08 kg of polydimethylsiloxane defoamer and stir evenly at 150 rpm at 25°C. 3. Add 100 kg of glycerol and 10 kg of sodium dihydrogen phosphate to the reaction vessel, and continue stirring at low speed until clear and transparent, thus obtaining a light yellow transparent oil spill dispersant product.

[0025] Example 2 A method for preparing an environmentally friendly oil spill dispersant for offshore oil fields, comprising the following steps: 1. Add 101.1 kg of bio-type surfactant rhamnosyl ester, 151.6 kg of green co-solvent pentaerythritol polyoxyethylene ether (ethylene oxide: propylene oxide mass ratio = 8:2), and 227.4 kg of penetrant octadecenol polyetheramine to a stainless steel reactor using a hose pump. 2. Add 410 kg of distilled water to the system to prepare an aqueous solution. According to the size of the foam, add 0.08 kg of polydimethylsiloxane defoamer and stir evenly at 150 rpm at 25°C. 3. Add 100 kg of glycerol and 10 kg of sodium dihydrogen phosphate to the reaction vessel, and continue stirring at low speed until clear and transparent, thus obtaining a light yellow transparent oil spill dispersant product.

[0026] Example 3 A method for preparing an environmentally friendly oil spill dispersant for offshore oil fields, comprising the following steps: 1. Add 105.3 kg of bio-type surfactant rhamnosyl ester, 157.9 kg of green co-solvent pentaerythritol polyoxyethylene ether (ethylene oxide: propylene oxide mass ratio = 8:2), and 236.8 kg of penetrant octadecenol polyetheramine to a stainless steel reactor using a hose pump. 2. Add 390 kg of distilled water to the system to prepare an aqueous solution. According to the size of the foam, add 0.08 kg of polydimethylsiloxane defoamer and stir evenly at 150 rpm at 25°C. 3. Add 100 kg of glycerol and 10 kg of sodium dihydrogen phosphate to the reaction vessel, and continue stirring at low speed until clear and transparent, thus obtaining a light yellow transparent oil spill dispersant product.

[0027] Experimental Example 1 A certain light oil field has a wax content of 17.30%–24.50%, a sulfur content of 0.1%–0.23%, and a main oil layer density of 0.812–0.843 g / cm³. 3 Viscosity 41.60–62.30 mPa·s, asphaltene content 6.70–9.30%, freezing point 10–20℃, thin oil. Formation water type (NaHCO3), water content 80–90%.

[0028] Using the crude oil from this oilfield as the standard oil, and the product prepared in Example 1 as the oil spill dispersant, the indicators were measured at 20-25℃ in accordance with GB / T18188.1-2021 Oil Spill Dispersants Part 1: Technical Conditions.

[0029] Table 1. Performance characteristics of the oil spill dispersant in Example 1 for this crude oil. Experiment Example 2 A certain medium-quality oilfield has a wax content of 8.51–12.47%, a sulfur content of 0.12–0.21%, and a main oil layer density of 0.864–0.883 g / cm³. 3 Viscosity 71.37–82.54 mPa·s, asphaltene content 10.70–13.42%, pour point 3–12℃, medium-quality oil. Formation water type (NaHCO3), water content 80–90%.

[0030] Using the crude oil from this oilfield as the standard oil, and the product prepared in Example 2 as the oil spill dispersant, the indicators were measured at 20-25℃ in accordance with GB / T18188.1-2021 Oil Spill Dispersants Part 1: Technical Conditions.

[0031] Table 2 Performance characteristics of the oil spill dispersant in Example 2 for this crude oil Experimental Example 3 A heavy oil field in the Bohai Sea has a wax content of 2.40–4.70%, a sulfur content of 0.15–0.25%, and a main oil layer density of 0.93–0.95 g / cm³. 3 Viscosity 273.40–494.80 mPa·s, asphaltene content 15.80–20.60%, freezing point -10 to -2℃, heavy oil. Formation water type (NaHCO3), water content approximately 80%.

[0032] Using crude oil from this oilfield as the standard oil, and the product prepared in Example 3 as the oil spill dispersant, the indicators were measured at 20-25℃ in accordance with GB / T18188.1-2021 Oil Spill Dispersants Part 1: Technical Conditions.

[0033] Table 3 Performance characteristics of the oil spill dispersant in Example 3 for this crude oil The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. An environmentally friendly oil spill dispersant for offshore oil fields, characterized in that: The components include the following parts by weight: Base liquid: 45-50 parts, wherein the base liquid is a mixture of low-toxicity rhamnosine ester, polyol polyoxyethylene ether, and penetrant, and the mass ratio of low-toxicity rhamnosine ester, polyol polyoxyethylene ether, and penetrant is 4:6:9; Sodium dihydrogen phosphate: 1 part; Glycerin: 10 parts; Distilled water: 39-44 parts; Food-grade defoamer: Add less than 100mg of defoamer per liter of oil spill dispersant.

2. The environmentally friendly oil spill dispersant for offshore oil fields according to claim 1, characterized in that: The polyol polyoxyethylene ether is selected from pentaerythritol polyoxyethylene ether, and the mass ratio of ethylene oxide to propylene oxide in the polyether is 8:2 to 9:

1.

3. The environmentally friendly oil spill dispersant for offshore oil fields according to claim 1, characterized in that: The food-grade defoamer is food-grade polydimethylsiloxane.

4. The environmentally friendly oil spill dispersant for offshore oil fields according to claim 1, characterized in that: The penetrant is octadecenol polyetheramine.

5. A method for preparing an environmentally friendly oil spill dispersant for offshore oil fields according to any one of claims 1-4, characterized in that: Includes the following steps: S1. Mix low-toxicity rhamnosine ester, polyol polyoxyethylene ether, and penetrant in a mass ratio of 4:6:9; S2. Add distilled water to the system, add food-grade defoamer according to the size of the foam, and stir evenly at low speed at room temperature; S3. Add the specified amount of glycerol and sodium dihydrogen phosphate, and continue stirring at low speed until clear and transparent to obtain the oil spill dispersant product.

6. The method for preparing an environmentally friendly oil spill dispersant for offshore oil fields according to claim 5, characterized in that: In step S2, the temperature is controlled at 25-35℃ and the stirring speed is controlled at 100-150rpm.

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