阅读说明：本技术 一种纳米复合降凝剂及其制备方法、用于高含水原油的降凝工作液 (Nano composite pour point depressant, preparation method thereof and pour point depressing working solution for high-water-content crude oil ) 是由 朱宁宁 王清岭 黄雪松 陈洪杰 瞿定祥 刘玉良 瞿江英 常丽芳 于 2019-10-22 设计创作，主要内容包括：本发明属于石油运输技术领域,具体涉及一种纳米复合降凝剂及其制备方法、用于高含水原油的降凝工作液。本发明的纳米复合降凝剂由纳米氧化铝载体和负载在纳米氧化铝载体上的降凝聚合物构成,所述降凝聚合物的分子量为6000～70000,所述降凝聚合物的结构式如式Ⅰ所示,其中R-1为碳原子个数为4～9的烷基,R-2为碳原子个数为2～4的亚烷基；n＝10～15,p为3～9。本发明的纳米复合降凝剂中降凝聚合物吸附在纳米氧化铝表面及孔结构中,并且降凝聚合物中的S＝O键可以与纳米氧化铝中的铝形成醚键,结合牢固,不易脱落。本发明的纳米复合降凝剂可有效改变蜡晶结构和强度,有效降低了高含水原油的凝点,保障了高含水原油的低温流动性。(The invention belongs to the technical field of petroleum transportation, and particularly relates to a nano composite pour point depressant, a preparation method thereof and a pour point depressing working solution for high-water-content crude oil. The nano composite pour point depressant consists of a nano alumina carrier and a pour point depressing polymer loaded on the nano alumina carrier, wherein the molecular weight of the pour point depressing polymer is 6000-70000, the structural formula of the pour point depressing polymer is shown as a formula I, and R is 1 Is an alkyl group having 4 to 9 carbon atoms, R 2 Is alkylene with 2-4 carbon atoms; n is 10 to 15, and p is 3 to 9. The pour point depressant in the nano composite pour point depressant is adsorbed on the surface and in a pore structure of nano aluminum oxide, and S ═ O bonds in the pour point depressant can form ether bonds with aluminum in the nano aluminum oxide, so that the pour point depressant is firmly combined and is not easy to fall off. Hair brushThe clear nano composite pour point depressant can effectively change the wax crystal structure and strength, effectively reduce the condensation point of the high-water-content crude oil and ensure the low-temperature fluidity of the high-water-content crude oil.)

1. The nano composite pour point depressant is characterized by comprising a nano alumina carrier and a pour point depressing polymer loaded on the nano alumina carrier, wherein the molecular weight of the pour point depressing polymer is 6000-70000, and the structural formula of the pour point depressing polymer is shown as a formula I:

wherein R is₁Is an alkyl group having 4 to 9 carbon atoms, R₂Is alkylene with 2-4 carbon atoms; n is 10 to 15, and p is 3 to 9.

2. The nano composite pour point depressant according to claim 1, wherein the mass ratio of the nano alumina to the pour point depressant polymer is (1-2): 100.

3. the nanocomposite pour point depressant according to claim 1 or 2, wherein the nano alumina has a particle size of 30 to 100 nm.

4. The nanocomposite pour point depressant of claim 1 or 2, wherein the nano-alumina is beta-alumina and/or gamma-alumina.

5. A method for preparing the nanocomposite pour point depressant according to any one of claims 1 to 4, comprising the steps of: uniformly mixing dihydric alcohol, alkenyl sulfonic acid, nano alumina and a solvent, reacting, filtering and drying; obtaining the product; the dihydric alcohol is dihydric alcohol with the carbon atom number of 2-4; the structural formula of the alkenyl sulfonic acid is as follows:

wherein R is₁Is an alkyl group having 4 to 9 carbon atoms, and n is 10 to 15.

6. The preparation method of the nano composite pour point depressant according to claim 5, wherein the reaction is carried out under ultrasonic conditions, and the ultrasonic time is 90-150 min.

7. The method for preparing the nano composite pour point depressant according to claim 6, wherein the power of ultrasound is 150-300W-cm^-2The frequency of the ultrasonic wave is 20-30 kHz.

8. The method for preparing the nano composite pour point depressant according to any one of claims 5 to 7, wherein the mass ratio of the dihydric alcohol to the alkenyl sulfonic acid is 1: (6-15).

9. The method for preparing the nano composite pour point depressant according to any one of claims 5 to 7, wherein the mass of the nano alumina is 1 to 2 percent of the total mass of the dihydric alcohol and the alkenyl sulfonic acid.

10. A pour point depressing working fluid for high water-content crude oil, which is characterized by comprising a solvent and the nano composite pour point depressant according to claims 1 to 4.

Technical Field

The invention belongs to the technical field of petroleum transportation, and particularly relates to a nano composite pour point depressant, a preparation method thereof and a pour point depressing working solution for high-water-content crude oil.

Background

In an oil field crude oil gathering and transportation system, wax crystals are precipitated from highly waxy crude oil and gradually increase along with the reduction of temperature, and finally a three-dimensional network structure is formed, so that the flowability of the crude oil is reduced. The pour point depressant is an oil product additive, can effectively reduce the condensation point and viscosity of the crude oil, and improves the quality and efficiency of the crude oil in the gathering and transportation process. Most of the traditional pour point depressants for crude oil are high molecular polymers such as ethylene-vinyl acetate copolymer and derivatives thereof, acrylic acid higher alcohol-maleic anhydride-vinyl acetate copolymer and the like, and have good pour point and viscosity reducing effects. However, when the oil field enters a high water content or extra high water content period after long-term water injection development, the water content in the produced crude oil is more than 90%. For high-water-content crude oil, the traditional crude oil pour point depressant is influenced by water flow during gathering and transportation, so that the dispersing effect is poor, and the pour point depressing effect is difficult to exert.

At present, researchers utilize the strong dispersibility and adsorbability of nano materials to combine the nano materials with high molecular polymers to form the nano composite pour point depressant, and the using effect of the pour point depressant is effectively improved. For example, chinese patent document No. CN107383268B discloses a nano wax-proofing pour-point depressant which is prepared from natural one-dimensional nano mineral attapulgite modified by a silane coupling agent, high-carbon olefin and acrylic acid high alcohol by an in-situ polymerization method, and can solve the problem of the detachment of effective components from the surface of nano particles. The attapulgite has an intermediate structure between a chain structure and a layered structure, and has good leveling property and compatibility, so that the nano mineral attapulgite can be used as a carrier for a crude oil pour point depressant. However, when the pour point depressant is added into high-water-content crude oil, most of the pour point depressant is dissolved into free water due to strong water absorption, so that the content of effective components in an oil phase is reduced, and the pour point depression effect is poor, so that the pour point depressant is not suitable for the high-water-content crude oil.

Chinese patent application publication No. CN108980622A discloses a nanocomposite pour point depressant prepared by compounding nickel cobaltate nanoparticles and an ethylene-vinyl acetate copolymer. The nickel cobaltate nanoparticles are used as a composite metal oxide with an inverse spinel structure, have strong catalytic performance, and the acetic acid-vinyl acetate copolymer and other materials have good adhesive performance, and after the two are compounded, the composite metal oxide has good pour point depressing and viscosity reducing effects. However, the main component ethylene-vinyl acetate copolymer often has poor effect in changing the wax crystal structure due to overlong molecular chains or self-reticulation structure, and particularly has poor dispersion effect under water flow impact in high-water-content crude oil and poor pour point depression effect.

Disclosure of Invention

The invention aims to provide a nano composite pour point depressant suitable for high-water-content crude oil.

The invention also aims to provide a preparation method of the nano composite pour point depressant.

The invention also aims to provide the pour point depressing working solution for the high-water-content crude oil, and the pour point depressing working solution has a better pour point depressing effect.

In order to achieve the aim, the technical scheme adopted by the nano composite pour point depressant is as follows:

a nano composite pour point depressant is composed of a nano alumina carrier and a pour point depressing polymer loaded on the nano alumina carrier, wherein the molecular weight of the pour point depressing polymer is 6000-70000, and the structural formula of the pour point depressing polymer is shown as a formula I:

wherein R is₁Is an alkyl group having 4 to 9 carbon atoms, R₂Is alkylene with 2-4 carbon atoms; n is 10 to 15, and p is 3 to 9. WhereinIndicating attachment to other structural elements.

The nano-alumina and the pour point depressant in the nano-composite pour point depressant have the function of pour point depression together. The nano-alumina is a porous material and has high surface activity as a carrier, the pour point depressing polymer is easily adsorbed on the surface and in a pore structure of the nano-alumina, S ═ O bonds in the pour point depressing polymer can react with the nano-alumina to form a structure shown in a formula (II), the pour point depressing polymer and the nano-alumina are firmly combined, the pour point depressing polymer is prevented from being separated from the surface of the nano-alumina, and the pour point depressing effect can be better exerted. Non-polar groups such as R in pour point depressant polymers₁The group can be eutectic with paraffin in the growth process of the wax crystal, and other parts can block the further growth of the wax crystal, so that the group has better capability of changing the wax crystal structure.

The nano composite pour point depressant can be uniformly dispersed in high-water-content crude oil, and effectively changes the wax crystal structure and strength, so that the viscosity of the crude oil is greatly reduced, wax deposition is inhibited, the viscosity of an oil-water emulsion and the wall sticking temperature of the crude oil are reduced, and the low-temperature flowing safety of the high-water-content crude oil is guaranteed.

The pour point depression effect of the nano composite pour point depressant is improved by reasonably optimizing the mass ratio of the nano alumina to the pour point depression polymer, preferably, the mass ratio of the nano alumina to the pour point depression polymer is (1-2): 100.

in order to make the nano-alumina have a large specific surface area, the particle size of the nano-alumina is preferably 30-100 nm. Preferably, the nano alumina is beta-alumina and/or gamma-alumina.

The preparation method of the nano composite pour point depressant comprises the following steps: uniformly mixing dihydric alcohol, alkenyl sulfonic acid, nano-alumina and a solvent, reacting, filtering and drying to obtain the catalyst; the dihydric alcohol is dihydric alcohol with the carbon atom number of 2-4; the structural formula of the alkenyl sulfonic acid is as follows:

wherein R is₁Is an alkyl group having 4 to 9 carbon atoms, and n is 10 to 15.

In the preparation method of the invention, the reactions involved are esterification reaction of alkenyl sulfonic acid and dihydric alcohol and polymerization of carbon-carbon double bond. The nano alumina is used as a carrier to adsorb the synthesized pour point depressing polymer and catalyze the generation of ether bonds between the nano alumina and the pour point depressing polymer. In the preparation method of the present invention, the solvent used may be either an organic solvent or water. Preferably, the solvent used is water. Preferably, the dihydric alcohol is ethylene glycol, 1, 3-propanediol, 1, 4-butanediol.

As known in the art, the esterification reaction of alkenyl sulfonic acid and diol is easy to proceed, and the polymerization of carbon-carbon double bond can be initiated by adding initiator or by other commonly used initiation methods. In order to avoid introducing impurities in the polymerization process, the reaction is carried out under the ultrasonic condition, and the ultrasonic time is 90-150 min. Preferably, the ultrasonic power is 150-300W-cm^-2The frequency of the ultrasonic wave is 20-30 kHz.

The prepared nano composite pour point depressant has better performance by optimizing the use amount of the dihydric alcohol and the alkenyl sulfonic acid, and the preferable mass ratio of the dihydric alcohol to the alkenyl sulfonic acid is 1: (6-15). Further preferably, the mass ratio of the dihydric alcohol to the alkenyl sulfonic acid is 1: (7-12).

The proportion of the nano alumina and the pour point depressing polymer is optimized by controlling the amount of the used raw materials, wherein the mass of the nano alumina is 1-2% of the total mass of the dihydric alcohol and the alkenyl sulfonic acid.

The pour point depressing working solution for high-water-content crude oil adopts the technical scheme that:

the pour point depressing working fluid for high water content crude oil includes solvent and the nanometer composite pour point depressant.

The pour point depressing working solution prepared by the nano composite pour point depressant has better pour point depressing effect and can be used for high-water-content crude oil. In order to improve the dispersibility of the nano-composite pour point depressant in the crude oil, the nano-composite pour point depressant is generally dispersed in a solvent such as solvent oil to form a pour point depressing working solution, and then the pour point depressing working solution is added into the crude oil. The concentration of the nano composite pour point depressant in the pour point depressing working solution can be adjusted according to actual needs.

Drawings

FIG. 1 is a graph showing the pour point depressing effect of the nanocomposite pour point depressant in examples 1 to 3 of the present invention.

Detailed Description

The present invention will be further described with reference to the following specific examples.

Examples of one, one-nanometer composite pour point depressant

Example 1

The nano composite pour point depressant of the embodiment is composed of a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is beta-type alumina with the particle size of 40nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 4: 230. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₇H₁₅(n-heptyl), p ═ 8, and the molecular weight of the pour point depressant polymer is 39000. The S ═ O bonds in the pour point depressing polymer can also react with the nano alumina to form ether linkages.

Example 2

The nano composite pour point depressant of the embodiment comprises a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is gamma-type alumina with the particle size of 50nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 2.5: 170. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₉H₁₉(n-nonyl), p ═ 3, and the molecular weight of the pour point depressant polymer was 6300. The S ═ O bond in the pour point depressing polymer can also react with nano alumina to form ether bond.

Example 3

The nano composite pour point depressant of the embodiment is composed of a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is beta-type alumina with the particle size of 50nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 4.5: 293. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₆H₁₃(n-hexyl), p ═ 6, and the molecular weight of the polymer was 24000. The S ═ O bonds in the pour point depressing polymer can also react with the nano alumina to form ether linkages.

Example 4

The nano composite pour point depressant of the embodiment is composed of a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is beta-type alumina with the particle size of 60nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 3.5: 240. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₆H₁₃(n-hexyl), p ═ 7, and the molecular weight of the pour point depressant polymer was 30000. The S ═ O bonds in the pour point depressing polymer can also react with the nano alumina to form ether linkages.

Example 5

The nano composite pour point depressant of the embodiment is composed of a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is beta-type alumina with the particle size of 70nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 4: 255. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₄H₉(n-butyl), p ═ 3, and the molecular weight of the pour point depressant polymer is 6200. The S ═ O bonds in the pour point depressing polymer can also react with the nano alumina to form ether linkages.

Example 6

The nano composite pour point depressant of the embodiment is composed of a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is beta-type alumina with the particle size of 80nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 4.8: 305. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₈H₁₇(n-octyl), p ═ 4, and the molecular weight of the pour point depressant polymer was 11600. The S ═ O bonds in the pour point depressing polymer can also react with the nano alumina to form ether linkages.

Example 7

The nano composite pour point depressant of the embodiment is composed of a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is beta-type alumina with the particle size of 90nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 5: 315. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₈H₁₇(n-octyl), p ═ 8, and the molecular weight of the pour point depressant polymer was 48000. The S ═ O bonds in the pour point depressing polymer can also react with the nano alumina to form ether linkages.

Example 8

The nano composite pour point depressant of the embodiment is composed of a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is beta-type alumina with the particle size of 50nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 4.2: 338. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₄H₉(n-butyl), p ═ 5, and the molecular weight of the pour point depressant polymer was 15600. The S ═ O bonds in the pour point depressing polymer can also react with the nano alumina to form ether linkages.

Example 9

The nano composite pour point depressant of the embodiment is composed of a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is beta-type alumina with the particle size of 60nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 4.5: 348. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₅H₁₁(n-pentyl), p ═ 4, and the molecular weight of the pour point depressant polymer is 11000. The S ═ O bonds in the pour point depressing polymer can also react with the nano alumina to form ether linkages.

Example 10

The nano composite pour point depressant of the embodiment is composed of a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is beta-type alumina with the particle size of 80nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 5: 360. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₇H₁₅(n-heptyl), p ═ 9, and the molecular weight of the pour point depressant polymer was 60000. The S ═ O bonds in the pour point depressing polymer can also react with the nano alumina to form ether linkages.

Example 11

The nano composite pour point depressant of the embodiment is composed of a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is gamma-type alumina with the particle size of 50nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 4: 255. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₆H₁₃(n-hexyl), p ═ 5, and the molecular weight of the pour point depressant polymer is 17000. The S ═ O bonds in the pour point depressing polymer can also react with the nano alumina to form ether linkages.

Example 12

The nano composite pour point depressant of the embodiment comprises a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is gamma-type alumina with the particle size of 60nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 4.5: 310. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₅H₁₁(n-pentyl), p ═ 6, and the molecular weight of the pour point depressant polymer was 25000. The S ═ O bonds in the pour point depressing polymer can also react with the nano alumina to form ether linkages.

Example 13

The nano composite pour point depressant of the embodiment is composed of a nano alumina carrier and a pour point depressing polymer loaded on nano alumina, wherein the nano alumina is gamma-type alumina with the particle size of 80nm, and the mass ratio of the nano alumina to the pour point depressing polymer is 5.2: 370. wherein the structural formula of the pour point depressing polymer is as follows:

wherein R is₁is-C₉H₁₉(n-nonyl), p ═ 5, and the molecular weight of the pour point depressant polymer is 20000. The S ═ O bonds in the pour point depressing polymer can also react with the nano alumina to form ether linkages.

Examples of the preparation method of the second and third nanocomposite pour point depressants

Example 14

This example is a method for preparing the nanocomposite pour point depressant of example 1, and specifically includes the following steps: 20g of ethylene glycol and 210g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle4g of beta type nano alumina, then 82g of water is added, and then ultrasonic treatment is carried out at normal temperature (the power is 300W cm)^-2Frequency of 20kHz) for 150min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Example 15

This embodiment is a method for preparing the nanocomposite pour point depressant of embodiment 2, and specifically includes the following steps: 20g of 1, 4-butanediol and 150g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle) And 2.5g of gamma-type nano alumina, then 60g of water is added, and then ultrasonic treatment is carried out at normal temperature (the power is 150W cm)^-2Frequency of 20kHz) for 90min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Example 16

This embodiment is a method for preparing the nanocomposite pour point depressant of embodiment 3, and specifically includes the following steps: 30g of 1, 3-propylene glycol and 263g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle) And 4.5g of beta-type nano alumina, then 104g of water is added, and then ultrasonic treatment is carried out at normal temperature (the power is 200W cm)^-2Frequency of 20kHz) for 120min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Example 17

This embodiment is a method for preparing the nanocomposite pour point depressant of embodiment 4, and specifically includes the following steps: 20g of ethylene glycol and 220g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle) And 3.5g of beta type nano alumina, then 85g of water is added, and then ultrasonic treatment is carried out at normal temperature (the power is 300W cm)^-2Frequency of 20kHz) for 90min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Example 18

This example is a method for preparing the nanocomposite pour point depressant of example 5, and specifically includes the following steps: 20g of ethylene glycol and 235g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle) And 4g of form beta sodiumRice alumina, then 91g of water was added, followed by sonication at room temperature (power 300W. cm)^-2Frequency of 20kHz) for 100min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Example 19

This embodiment is a method for preparing the nanocomposite pour point depressant of embodiment 6, and specifically includes the following steps: 30g of 1, 3-glycerol and 275g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle) 4.8g of beta type nano alumina, 108g of water and ultrasonic treatment at normal temperature (power of 300W cm)^-2Frequency of 20kHz) for 110min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Example 20

This example is a method for preparing the nanocomposite pour point depressant of example 7, and specifically includes the following steps: 30g of 1, 3-glycerol and 285g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle) And 5g of beta type nano alumina, then 112g of water is added, and then ultrasonic treatment is carried out at normal temperature (the power is 300W cm)^-2Frequency of 20kHz) for 120min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Example 21

This embodiment is a method for preparing the nanocomposite pour point depressant of embodiment 8, and specifically includes the following steps: 40g of 1, 4-butanediol and 298g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle) And 4.2g of beta-type nano alumina, then 119g of water was added, and then ultrasonic treatment was performed at normal temperature (power 300W. cm)^-2Frequency of 20kHz) for 130min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Example 22

This example is a method for preparing the nanocomposite pour point depressant of example 9The method specifically comprises the following steps: 40g of 1, 4-butanediol and 308g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle) And 4.5g of beta-type nano alumina, then 123g of water is added, and then ultrasonic treatment is carried out at normal temperature (the power is 300W cm)^-2Frequency of 20kHz) for 120min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Example 23

This embodiment is a method for preparing the nanocomposite pour point depressant of embodiment 10, and specifically includes the following steps: 40g of 1, 4-butanediol and 320g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle) And 5g of beta type nano alumina, then 127g of water is added, and then ultrasonic treatment is carried out at normal temperature (the power is 300W cm)^-2Frequency of 20kHz) for 150min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Example 24

This example is a method for preparing the nanocomposite pour point depressant of example 11, and specifically includes the following steps: 20g of ethylene glycol and 235g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle) And 4g of gamma-type nano alumina, then 91g of water is added, and then ultrasonic treatment is carried out at normal temperature (the power is 300W cm)^-2Frequency of 20kHz) for 120min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Example 25

This example is a method for preparing the nanocomposite pour point depressant of example 12, and specifically includes the following steps: 30g of 1, 3-propylene glycol and 280g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle) And 4.5g of gamma-type nano alumina, then 110g of water is added, and then ultrasonic treatment is carried out at normal temperature (the power is 300 W.c)m^-2Frequency of 20kHz) for 120min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Example 26

This example is a method for preparing the nanocomposite pour point depressant of example 13, and specifically includes the following steps: 40g of 1, 4-butanediol and 330g of alkenyl sulfonic acid (structural formula is shown in the specification) are added into a reaction kettle) And 5.2g of gamma-type nano alumina, then 131g of water was added, and then ultrasonic treatment was performed at normal temperature (power 300W. cm)^-2Frequency of 20kHz) for 120min, filtering and drying for 3h to obtain the nano composite pour point depressant particles.

Third, example of pour point depressant working fluid for highly hydrous crude oil

Example 27

The pour point depressing working fluid of this example was prepared by dispersing the nanocomposite pour point depressant of example 1 in mineral spirits. The pour point depressing working solution is added into the crude oil, and has a good pour point depressing effect.

In other embodiments of the pour point depressing working fluid for high-water-content crude oil, the nano-composite pour point depressants of embodiments 2 to 13 can be respectively adopted, and the concentration of the nano-composite pour point depressants can be adjusted according to actual needs.

Fourth, test example section

Test example 1

The nano composite pour point depressants of examples 1-3 were added to crude oil samples having a water content of 90% or more in amounts of 30ppm, 50ppm, 80ppm, 100ppm, 120ppm, 150ppm, 180ppm and 200ppm, respectively, and then the pour points of the samples were measured according to the test procedures of standard SY/T0541-2009 "crude oil pour point measurement", and the test results are shown in FIG. 1.

As can be seen from FIG. 1, the pour point depressing effect of the nanocomposite pour point depressant increases with the addition amount; when the addition amount is 100ppm, the nano composite pour point depressant has the best pour point depression effect, and can reduce the pour point of a crude oil sample by 15-20 ℃; when the amount is more than 100ppm, the pour point depressing effect is not remarkably increased.

Test example 2

Pour point depressant A and pour point depressant B are prepared according to the preparation methods of two nano pour point depressants disclosed in CN107383268B and CN108980622A patent documents.

The nano composite pour point depressant and the A, B pour point depressants in examples 1-13 are respectively added to a crude oil sample containing more than 90% of water according to the dosage of 100ppm, the pour point of the oil sample is respectively determined according to the determination process in SY/T0541-2009 crude oil pour point determination method, and the test results are shown in Table 1.

TABLE 1 statistical table of the change in congealing point of high-water-content crude oil before and after addition of the nano-composite pour point depressant

As shown in Table 1, for high-water-content crude oil with water content higher than 90%, the pour point depressing effect of the pour point depressant A and the pour point depressant B is not obvious, and the pour point of a crude oil sample can be reduced by 2-3 ℃; the nano composite pour point depression effect of the invention on high water-containing crude oil is obvious, and the pour point of a high water-containing crude oil sample can be reduced by 15-20 ℃. The test result shows that the nano composite pour point depressant has better pour point depression effect on high-water-content crude oil and better application prospect.