阅读说明：本技术 一种自破乳型抗盐稠油冷采驱油剂及其制备方法和应用 (Self-demulsification type salt-resistant heavy oil cold recovery oil-displacing agent and preparation method and application thereof ) 是由 崔仕章 宋新旺 崔学章 郭鑫 徐丽君 刘小芳 于 2020-03-11 设计创作，主要内容包括：本发明提供了一种自破乳型抗盐稠油冷采驱油剂,按质量百分比计,包括：40-50wt％活性组分,15-20wt％添加剂,5-8wt％渗透剂,余量为去离子水；所述活性组分包括：质量比为(8-10):(1-3):(4-6)的脂肪醇聚氧乙烯醚羧酸盐、聚氧乙烯蓖麻油和脂肪酸-胺复合物。本申请提供的自破乳型抗盐稠油冷采驱油剂,其各组分之间具有很好的复配性,在应用于高粘度、高地层水矿化度的稠油时,能够表现出显著的降粘性能,并且在降粘后还能表现出较好的自破乳效果,各组分之间还表现出了很好的协同作用。特别是当活性组分中A<Sub>21</Sub>EO<Sub>11</Sub>C-Na、EL-20和棕榈酸-乙醇胺复合物的质量比为8：3：5时,其破乳性能达到最优。(The invention provides a self-breaking type salt-resistant heavy oil cold recovery oil displacement agent, which comprises the following components in percentage by mass: 40-50 wt% of active component, 15-20 wt% of additive, 5-8 wt% of penetrating agent and the balance of deionized water; the active components comprise: fatty alcohol polyoxyethylene ether carboxylate, polyoxyethylene castor oil and fatty acid-amine compound in the mass ratio of (8-10) to (1-3) to (4-6). The application provides a from anti salt heavy oil cold recovery oil-displacing agent of demulsification type has fine complex nature between its each component, when being applied to the heavy oil of high viscosity, high stratum water mineralization degree, can demonstrate apparent viscosity reduction performance to can also demonstrate better from breaking emulsion effect after the viscosity reduction, still demonstrate fine synergism between each component. Especially when A is the active ingredient 21 EO 11 When the mass ratio of the C-Na, the E L-20 and the palmitic acid-ethanolamine compound is 8:3:5, the demulsification performance of the composite emulsion reaches the optimum.)

1. The self-breaking type salt-resistant heavy oil cold recovery oil displacement agent is characterized by comprising the following components in percentage by mass:

40-50 wt% of active component, 15-20 wt% of additive, 5-8 wt% of penetrating agent and the balance of deionized water; the active components comprise: fatty alcohol polyoxyethylene ether carboxylate, polyoxyethylene castor oil and fatty acid-amine compound in the mass ratio of (8-10) to (1-3) to (4-6).

2. The cold recovery oil-displacing agent according to claim 1, wherein the mass ratio of the fatty alcohol-polyoxyethylene ether carboxylate, the polyoxyethylene castor oil and the fatty acid-amine compound is 8:3: 5.

3. The cold recovery oil-displacing agent according to claim 1, wherein the fatty alcohol-polyoxyethylene ether carboxylate has a structural formula: RO (CH)₂CH₂O)₁₁CH₂COOM, wherein M is a metal ion selected from sodium, potassium and lithium, and R is an alkyl group with 20-22 carbon atoms.

4. The cold recovery oil-displacing agent according to claim 1, wherein the degree of polymerization of polyoxyethylene in the polyoxyethylene castor oil is 20 to 40.

5. The cold recovery oil-displacing agent according to claim 1, wherein the fatty acid-amine complex is formed by compounding and mixing fatty acid and amine in a molar ratio of 1: 1.

6. The cold recovery oil-displacing agent according to claim 5, wherein the fatty acid is selected from one or more of lauric acid, palmitic acid, stearic acid, oleic acid, abietic acid, preferably palmitic acid; the amine is selected from one or more of dodecylamine, hexadecylamine, octadecylamine, ethanolamine and triethanolamine, and is preferably ethanolamine.

7. Cold recovery oil-displacing agent according to claim 1, wherein the additive is selected from one or more of methanol, ethanol, isopropanol, n-butanol, preferably isopropanol; the penetrating agent is octyl phenol polyoxyethylene ether phosphate.

8. A method for preparing the self-breaking type anti-salt heavy oil cold recovery oil-displacing agent according to any one of claims 1 to 7, which comprises: adding the raw materials into a reaction kettle according to the proportion, stirring for 1 hour at the temperature of 50-70 ℃, and cooling to normal temperature to obtain the catalyst.

9. The use of the self-breaking type anti-salt heavy oil cold recovery oil displacement agent in heavy oil recovery as claimed in any one of claims 1 to 7, characterized in that the self-breaking type anti-salt heavy oil cold recovery oil displacement agent is used for heavy oil with the viscosity of 150000-20000 mPa-s and the formation water mineralization degree of more than 250000 mg/L at 75 ℃.

10. The use of claim 9, wherein the use in heavy oil recovery comprises use in wellbore viscosity reduction, reservoir conditions, or during pipeline transportation.

Technical Field

The invention relates to the technical field of oil field chemicals, in particular to a self-demulsification type salt-resistant heavy oil cold recovery oil displacement agent and a preparation method and application thereof.

Background

Heavy crude oil is generally referred to as heavy crude oil with high viscosity, high density and high content of colloids and asphaltenes. In the world, the reserves of the thick oil are equivalent to those of the common crude oil, and the thick oil accounts for about 30 percent of the reserves of the crude oil in China, so that the method is an important strategic resource. Because the thick oil has high content of colloid and asphaltene, high viscosity and poor fluidity, the exploitation difficulty is high and the recovery ratio is low.

The surfactant for efficient salt-resistant oil displacement is an important support for improving the recovery ratio of chemical flooding. The surfactant is an important auxiliary agent for chemical flooding, and the crude oil recovery rate is greatly improved by improving the oil displacement efficiency. In the implemented high-quality resource chemical flooding, heavy alkylbenzene sulfonate and petroleum sulfonate are developed aiming at the oil reservoir properties, and a batch of daily chemical surfactants are introduced for synergism, so that a remarkable oil-increasing effect is achieved. However, with the continuous expansion of the implementation scale, chemical flooding enters a new stage, high-quality resources are basically used up, most of eastern oil reservoirs and western oil reservoirs belong to high-temperature and high-salt oil reservoirs with harsh conditions, and the performance of the existing flooding material is greatly limited and cannot be popularized. Therefore, the surfactant for efficient oil displacement is an important measure for popularizing the chemical flooding technology and ensuring national energy safety in terms of oil reservoir development with high salinity and mineralization.

In addition, one of the current research and development situations of the thick oil emulsifying viscosity reducer is mainly focused on pursuing the emulsifying viscosity reducing effect, but lack of consideration on the later demulsification treatment, so that the existing thick oil emulsifying viscosity reducer can achieve high thick oil viscosity reducing rate, but faces the problem of difficult demulsification in the post-treatment process. The post-treatment demulsification and the thick oil emulsification and viscosity reduction are important links in the utilization of thick oil resources, the post-treatment demulsification and the emulsification and viscosity reduction are inseparable organic integers immediately after the emulsification and viscosity reduction, and the post-treatment demulsification and the emulsification and viscosity reduction are both fully considered in the research and development process of the thick oil emulsification and viscosity reducer, otherwise, the research and development cost of the demulsifier is inevitably increased, a large amount of unnecessary energy consumption is brought, and the utilization cost of the thick oil resources is further improved.

Disclosure of Invention

In order to solve the problems, the invention aims to provide a self-demulsification type anti-salt heavy oil cold recovery oil-displacing agent which can show a remarkable viscosity reduction effect in heavy oil with high viscosity and high formation water mineralization degree and has a better self-demulsification effect after viscosity reduction.

On one hand, the invention provides a self-breaking type anti-salt heavy oil cold recovery oil displacement agent, which comprises the following components in percentage by mass: 40-50 wt% of active component, 15-20 wt% of additive, 5-8 wt% of penetrating agent and the balance of deionized water; the active components comprise: fatty alcohol polyoxyethylene ether carboxylate, polyoxyethylene castor oil and fatty acid-amine compound in the mass ratio of (8-10) to (1-3) to (4-6).

Further, the mass ratio of the fatty alcohol-polyoxyethylene ether carboxylate, the polyoxyethylene castor oil and the fatty acid-amine compound is 8:3: 5.

Further, the structural formula of the fatty alcohol-polyoxyethylene ether carboxylate is as follows:

RO(CH₂CH₂O)₁₁CH₂COOM, wherein M is a metal ion selected from sodium, potassium, lithium, preferably Na, R is carbonAn alkyl group having 20 to 22 atoms. More preferably, R is C21 alkyl, i.e., a fatty alcohol polyoxyethylene ether carboxylate having the formula: c₂₁H₄₃O(CH₂CH₂O)₁₁CH₂COONa。

In one embodiment, the fatty alcohol polyoxyethylene ether carboxylate is synthesized by the following method: taking a dry and clean 500ml three-necked bottle, and sequentially adding alkyl alcohol ether and a catalyst into the three-necked bottle; heating and raising the temperature, and uniformly stirring the materials in the three-mouth bottle; dropwise adding an alkali solution after uniformly stirring; after the dropwise addition is finished, keeping the temperature at 60 ℃ and reacting for 2 hours; cooling to obtain the final product.

Further, the polymerization degree of polyoxyethylene in the polyoxyethylene castor oil is 20-40, preferably, the polyoxyethylene castor oil can be E L-20 or E L-40, wherein the content of active ingredients in E L-20 or E L-40 is more than 99%, and more preferably E L-20.

Further, the fatty acid-amine complex is formed by compounding fatty acid and amine according to a molar ratio of 1: 1.

In a preferred embodiment, the fatty acid-amine complex is prepared as follows: the fatty acid and organic amine were mixed well at a molar ratio of 1:1 at 35 ℃ and stirred well. Because the fatty acid and the organic amine belong to weak acid and weak base respectively, the fatty acid and the organic amine can form a fatty acid-amine compound through hydrogen bond action by adopting the method.

Further, the fatty acid is selected from one or more of lauric acid, palmitic acid, stearic acid, oleic acid and abietic acid, preferably palmitic acid; the amine is selected from one or more of dodecylamine, hexadecylamine, octadecylamine, ethanolamine and triethanolamine, and is preferably ethanolamine.

Further, the additive is selected from one or more of methanol, ethanol, isopropanol and n-butanol, preferably isopropanol; the penetrating agent is octyl phenol polyoxyethylene ether phosphate, preferably, the polymerization degree of the ethylene oxide in the octyl phenol polyoxyethylene ether phosphate is 5, namely, the octyl phenol polyoxyethylene (5) ether phosphate.

In one embodiment, the above-mentioned heavy oil cold production and displacement agent includes:

the composite material comprises, by weight, 48% of an active component, 17% of an additive, 6% of a penetrating agent and the balance deionized water, wherein the active component comprises fatty alcohol-polyoxyethylene ether carboxylate, polyoxyethylene castor oil and a fatty acid-amine compound in a mass ratio of 8:3: 5.

Preferably, the heavy oil cold production oil displacement agent specifically comprises the following components: 48 wt% of active component, 17 wt% of isopropanol, 6 wt% of octyl phenol polyoxyethylene (5) ether phosphate and the balance of deionized water, wherein the active component comprises: c with the mass ratio of 8:3:5₂₁H₄₃O(CH₂CH₂O)₁₁CH₂COONa, E L-20 and palmitic acid-ethanolamine complex.

In another aspect, the invention also provides a method for preparing the self-breaking type anti-salt heavy oil cold recovery oil displacement agent, which comprises the following steps: adding the raw materials into a reaction kettle according to the proportion, stirring for 1 hour at the temperature of 50-70 ℃, and cooling to normal temperature to obtain the catalyst.

On the other hand, the invention also provides the application of the self-demulsification and salt-resistant heavy oil cold recovery oil displacement agent in heavy oil recovery, wherein the oil displacement agent can be applied to the heavy oil with the viscosity of 150000-20000 mPa-s and the formation water mineralization degree of more than 250000 mg/L at 78 ℃.

Further, the application in heavy oil recovery comprises the application in wellbore viscosity reduction, oil reservoir conditions or pipeline transportation.

Further, the mass fraction of the oil displacement agent added in the application is 0.3%.

The invention can bring the following beneficial effects:

the application provides a from anti salt heavy oil cold recovery oil-displacing agent of demulsification type has fine complex nature between its each component, when being applied to the heavy oil of high viscosity, high stratum water mineralization degree, can demonstrate apparent viscosity reduction performance to can also demonstrate better from breaking emulsion effect after the viscosity reduction. Experiments show that when the oil displacement agent composition provided by the application is used as a displacement fluid, the viscosity reduction rate and the dehydration rate are both better than the effect of various surface active components when the surface active components are used independently, and the oil displacement agent composition has a good synergistic effect. Especially when A is the active ingredient₂₁EO₁₁When the mass ratio of the C-Na, the E L-20 and the palmitic acid-ethanolamine compound is 8:3:5, the viscosity reduction rate is up to 99.65%, the demulsification rate in 1 hour is up to 97.60%, the removed water is clear, the oil-water interface is uniform, and the composite can be used as an optimal displacement fluid for high-viscosity and high-formation water mineralization thick oil.

Detailed Description

In order to more clearly explain the overall concept of the present application, the following detailed description is given by way of example. In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present application. It will be apparent, however, to one skilled in the art, that the present application may be practiced without one or more of these specific details. In other instances, well-known features of the art have not been described in order to avoid obscuring the present application.

Unless otherwise specified, the starting materials and reagents in the following examples are all common commercial products, and the purity is analytical grade. The fatty alcohol-polyoxyethylene ether carboxylate is prepared by self-made synthesis through the following method:

s1, feeding heneicosyl alcohol and potassium hydroxide at about 80 ℃, repeatedly vacuumizing and filling nitrogen for three times, reacting for 2-3h at the temperature of 120-130 ℃ and under the pressure of 0-0.1MPa, feeding ethylene oxide into the reactor for 8 times during the reaction, and cooling after the reaction is finished to obtain an alkyl alcohol ether intermediate;

s2, taking a dry and clean 500ml three-necked bottle, and sequentially adding 210g of the alkyl alcohol ether intermediate obtained in the step S1 and 4.4g of the catalyst into the three-necked bottle; heating and raising the temperature, and uniformly stirring the materials in the three-mouth bottle; after stirring uniformly, 20.5g of sodium hydroxide solution (10.5g of NaOH dissolved in 10g of water) is added dropwise; after the dropwise addition is finished, keeping the temperature at 60 ℃ and reacting for 2 hours; cooling to obtain C₂₁H₄₃O(CH₂CH₂O)₁₁CH₂COONa, abbreviated to A₂₁EO₁₁C-Na。