阅读说明：本技术 基于二氧化碳/氮气开关清理石蜡的方法 (Method for cleaning paraffin based on carbon dioxide/nitrogen switch ) 是由 鲁红升 李小江 吕鑫 王娜 戴姗姗 于 2021-08-20 设计创作，主要内容包括：本发明公开了一种基于二氧化碳/氮气开关清理石蜡的方法,包括以下步骤：加入第一溶剂溶解石蜡得到混合液,向混合液中通入气态的CO-(2)且分离得到第二溶剂和石蜡；向第二溶剂中通入气态的N-(2),得到第一溶剂；本发明通过第一溶剂溶解石蜡而使得石蜡从管道中脱落,其次通入二氧化碳,二氧化碳与第一溶剂发生反应生成第二溶剂,第二溶剂与石蜡不相容,因此出现第二溶剂和石蜡分离的现象,继续分离得到第二溶剂,向第二溶剂中加入氮气,氮气与第二溶剂反应得到第一溶剂；实现了溶剂的回收重复利用,并且不需要水即可实现石蜡的清除,节约了水资源,仅仅使用氮气和二氧化碳因此不会造成环境污染。(The invention discloses a method for cleaning paraffin based on a carbon dioxide/nitrogen switch, which comprises the following steps: adding a first solvent to dissolve paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution 2 And separating to obtain a second solvent and paraffin; introducing gaseous N into the second solvent 2 Obtaining a first solvent; the paraffin is dissolved by the first solvent to drop from the pipeline, then carbon dioxide is introduced, the carbon dioxide and the first solvent react to generate a second solvent, the second solvent is incompatible with the paraffin, so that the second solvent and the paraffin are separated, the second solvent is continuously separated to obtain the second solvent, nitrogen is added into the second solvent, and the nitrogen and the second solvent react to obtain the first solvent; realizes the recycling of the solvent, can realize the removal of the paraffin without water, and savesWater resources, only nitrogen and carbon dioxide are used, so that environmental pollution is avoided.)

1. A method for cleaning paraffin based on a carbon dioxide/nitrogen switch is characterized by comprising the following steps:

adding a first solvent to dissolve paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent and paraffin; introducing gaseous N into the second solvent₂And obtaining the first solvent.

2. The carbon dioxide/nitrogen switch-based paraffin wax cleaning method according to claim 2, wherein the first solvent is one of N-ethylbutylamine, di-N-butylamine, and di-N-propylamine.

3. The method for carbon dioxide/nitrogen switch-on and switch-off paraffin wax as claimed in claim 2, wherein when the first solvent is di-n-butylamine or di-n-propylamine, the temperature during the whole process is 25-45 ℃.

4. The carbon dioxide/nitrogen-based on-off paraffin wax cleaning method according to claim 2, wherein when the first solvent is di-n-butylamine or di-n-propylamine, CO₂And N₂The flow rates of (A) and (B) are all 100-300 ml/min.

5. The carbon dioxide/nitrogen switch-based paraffin wax cleaning method according to claim 2, wherein the first solvent is N-ethyl butylamine.

Technical Field

The invention belongs to the technical field of oilfield chemical engineering, and particularly relates to a method for cleaning paraffin based on a carbon dioxide/nitrogen switch.

Background

The wax deposition of an oil well is a phenomenon commonly existing in the development of the oil field, particularly, the wax content is high in the process of thick oil exploitation, the wax contained in crude oil is gradually separated out along with the reduction of pressure and temperature in the exploitation process, the paraffin deposited in an oil well pipe column and a ground oil collecting pipeline can cause the reduction and even blockage of the effective sectional area of the pipeline, the pump efficiency is reduced, the liquid production amount of the oil well is reduced, a sucker rod can be broken due to overload (the ascending load and the descending resistance are increased), the back pressure of the oil well is increased, and the problems that the power consumption of the oil pumping unit is increased, the failure rate is increased and the like are caused. The problem of paraffin deposition is an important problem in the process of oil exploitation and gathering and transportation.

The economic losses due to paraffin deposition and the costs for paraffin deposition control are as high as billions of dollars each year around the world. In order to ensure the smooth operation of crude oil extraction and gathering, wax removal and prevention are needed for wax deposition oil wells and conveying pipelines; most of the existing methods are chemical methods or tools for paraffin removal and prevention of oil wells and conveying pipelines, and the existing methods are widely applied to oil fields. The tool is inconvenient to use, particularly for the conveying pipeline, the conveying pipeline has different sizes, so that the tool with different sizes is required to be prepared for use; and the solvent recovery in the chemical method is difficult.

Disclosure of Invention

In order to achieve the purpose, the invention adopts the following technical scheme: a method for cleaning paraffin based on a carbon dioxide/nitrogen switch comprises the following steps:

adding a first solvent to dissolve paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent and paraffin; introducing gaseous N into the second solvent₂And obtaining the first solvent.

Further, the first solvent is one of N-ethylbutylamine, di-N-butylamine and di-N-propylamine, and N-ethylbutylamine is preferred.

Further, when the first solvent is di-n-butylamine or di-n-propylamine, the temperature during the whole process is 25 to 45 ℃.

Further defined, when the first solvent is di-n-butylamine or di-n-propylamine, CO₂And N₂The flow rates of (A) and (B) are all 100-300 ml/min.

Has the advantages that: the paraffin is dissolved by the first solvent to drop from the pipeline, then carbon dioxide is introduced, the carbon dioxide and the first solvent react to generate a second solvent, the second solvent is incompatible with the paraffin, so that the second solvent and the paraffin are separated, the second solvent is continuously separated to obtain the second solvent, nitrogen is added into the second solvent, and the nitrogen and the second solvent react to obtain the first solvent; the solvent is recycled, the paraffin can be removed without water, the operation is convenient, specific paraffin removal equipment is not needed, water resources and equipment investment cost are saved, and only nitrogen and carbon dioxide are used, so that environmental pollution is avoided; the method for cleaning paraffin based on the carbon dioxide/nitrogen switch can be used for cleaning the paraffin deposited in oil and gas fields, oil and gas transmission pipelines and related equipment.

Drawings

FIG. 1 is a schematic flow diagram of a method for cleaning paraffin on a carbon dioxide/nitrogen switch;

FIG. 2 is a graph of wax recovery versus time for example 1;

FIG. 3 is a graph of wax recovery versus time for example 2;

FIG. 4 is a graph of wax recovery versus time for example 3;

FIG. 5 is a graph showing the results of examples 4 to 6;

FIG. 6 is a graph showing the results of examples 7 to 9;

FIG. 7 is a graph of aeration rate results for examples 10-12;

FIG. 8 is a graph of temperature results for examples 12-14.

Detailed Description

As shown in fig. 1, a method for cleaning paraffin based on carbon dioxide/nitrogen switch comprises the following steps:

adding a first solvent to dissolve paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent and paraffin; first solvent with CO₂Reacting to obtain a second solvent, separating to obtain the second solvent, introducing gaseous N into the second solvent₂A second solvent with N₂The first solvent is generated through reaction, and the first solvent is recycled; the first solvent is one of N-ethylbutylamine, di-N-butylamine and di-N-propylamine, preferably the dissolving rate of paraffin in the N-ethylbutylamine, the di-N-butylamine and the di-N-propylamine meets the industry requirement standard of the paraffin remover (0.016g/min, SY-T6300-2009), wherein the dissolving rates of the 54# and 58# paraffin in the three kinds of paraffin are shown in Table 1.

Table 1 dissolution rate of paraffin wax in a first solvent

	54# Paraffin wax	58# Paraffin wax
			Di-n-propylamine	0.068g/min	0.061g/min
Di-n-butylamine	0.051g/min	0.037g/min
			N-ethyl butylamine	0.054g/min	0.061g/min

When the first solvent is di-n-butylamine or di-n-propylamine, the temperature in the whole process is 25-45 ℃; when the first solvent is di-n-butylamine or di-n-propylamine, CO₂And N₂The introduction rate is 100-300 ml/min; the method can be applied to cleaning the paraffin deposited in oil and gas fields, oil and gas transmission pipelines and related equipment; wherein the first solvent is in a low polarity state when it is in contact with CO₂The second solvent generated after the reaction is in a high-polarity state, so that the green cyclic utilization of the solvent is realized.

Example 1

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding N-ethyl butylamine to dissolve 54# paraffin to obtain mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 1 and paraffin; introducing gaseous N into the second solvent 1₂Second solvent 1 with N₂The N-ethyl butylamine is generated by reaction, the temperature is 25 ℃ in the whole process, and CO is generated₂And N₂The speed of (2) is 300 ml/min; as shown in fig. 2, it is understood from fig. 1 that the recovery rate of wax is close to 70% at 10 minutes, and the increase rate is rapid, and the recovery rate reaches 90% or more at 1 hour, indicating that the wax removal effect is significant.

Example 2

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding N-ethyl butylamine to dissolve 54# paraffin to obtain mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 1 and paraffin; introducing gaseous N into the second solvent 1₂Second solvent 1 with N₂The N-ethyl butylamine is generated by reaction, the temperature is 35 ℃ in the whole process, and CO is generated₂And N₂The rates of (A) and (B) were all 100ml/min, and the results are shown in FIG. 3.

Example 3

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding N-ethyl butylamine to dissolve 54# paraffin to obtain mixed solution, adding into the mixed solutionIntroducing gaseous CO₂And separating to obtain a second solvent 1 and paraffin; introducing gaseous N into the second solvent 1₂Second solvent 1 with N₂The N-ethyl butylamine is generated by reaction, the temperature is 45 ℃ in the whole process, and CO is generated₂And N₂The rates of (A) and (B) were all 200ml/min, and the results are shown in FIG. 4.

Example 4

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding di-n-butylamine to dissolve 54# paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 2 and paraffin; introducing gaseous N into the second solvent 2₂Second solvent 2 with N₂The reaction is carried out to generate di-n-butylamine at the temperature of 25 ℃ in the whole process, and CO is generated₂And N₂The rates of (A) and (B) were all 300ml/min, and the results are shown in FIG. 5.

Example 5

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding di-n-butylamine to dissolve 54# paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 2 and paraffin; introducing gaseous N into the second solvent 2₂Second solvent 2 with N₂The reaction is carried out to generate di-n-butylamine, the temperature is 35 ℃ in the whole process, and CO is generated₂And N₂The rates of (A) and (B) were all 300ml/min, and the results are shown in FIG. 5.

Example 6

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding di-n-butylamine to dissolve 54# paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 2 and paraffin; introducing gaseous N into the second solvent 2₂Second solvent 2 with N₂The reaction is carried out to generate di-n-butylamine, the temperature is 45 ℃ in the whole process, and CO is generated₂And N₂The rates of (A) and (B) were all 300ml/min, and the results are shown in FIG. 5.

Example 7

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding di-n-butylamine to dissolve 54# paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 2 and paraffin; introducing gaseous N into the second solvent 2₂Second solvent 2 with N₂The reaction is carried out to generate di-n-butylamine, the temperature is 45 ℃ in the whole process, and CO is generated₂And N₂The rates of (A) and (B) were all 300ml/min, and the results are shown in FIG. 6.

Example 8

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding di-n-butylamine to dissolve 54# paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 2 and paraffin; introducing gaseous N into the second solvent 2₂Second solvent 2 with N₂The reaction is carried out to generate di-n-butylamine, the temperature is 45 ℃ in the whole process, and CO is generated₂And N₂The rates of (A) and (B) were all 200ml/min, and the results are shown in FIG. 6.

Example 9

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding di-n-butylamine to dissolve 54# paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 2 and paraffin; introducing gaseous N into the second solvent 2₂Second solvent 2 with N₂The reaction is carried out to generate di-n-butylamine, the temperature is 45 ℃ in the whole process, and CO is generated₂And N₂The rates of (A) and (B) were all 100ml/m, and the results are shown in FIG. 6.

Example 10

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding di-n-propylamine to dissolve 54# paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 3 and paraffin; feeding gaseous N into the second solvent 3₂Second solvent 3 with N₂Reacting to generate di-n-propylamine, wherein the temperature is 45 ℃ and CO is generated in the whole process₂And N₂All rates of (2) were 100ml/min, as a resultAs shown in fig. 7.

Example 11

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding di-n-propylamine to dissolve 54# paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 3 and paraffin; feeding gaseous N into the second solvent 3₂Second solvent 3 with N₂Reacting to generate di-n-propylamine, wherein the temperature is 45 ℃ and CO is generated in the whole process₂And N₂The rates of (A) and (B) were all 200ml/min, and the results are shown in FIG. 7.

Example 12

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding di-n-propylamine to dissolve 54# paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 3 and paraffin; feeding gaseous N into the second solvent 3₂Second solvent 3 with N₂Reacting to generate di-n-propylamine, wherein the temperature is 45 ℃ and CO is generated in the whole process₂And N₂The rates of (A) and (B) were all 300ml/min, and the results are shown in FIG. 8.

Example 13

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding di-n-propylamine to dissolve 54# paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 3 and paraffin; feeding gaseous N into the second solvent 3₂Second solvent 3 with N₂Reacting to generate di-n-propylamine, wherein the temperature is 35 ℃ and CO is generated in the whole process₂And N₂The rates of (A) and (B) were all 300ml/min, and the results are shown in FIG. 8.

Example 14

The method for cleaning paraffin based on the carbon dioxide/nitrogen switch comprises the following steps:

adding di-n-propylamine to dissolve 54# paraffin to obtain a mixed solution, and introducing gaseous CO into the mixed solution₂And separating to obtain a second solvent 3 and paraffin; feeding gaseous N into the second solvent 3₂A second solvent 3 withN₂Reacting to generate di-n-propylamine, wherein the temperature is 25 ℃ and CO is generated in the whole process₂And N₂The rates of (A) and (B) were all 300ml/min, and the results are shown in FIG. 8.

From the above, the paraffin separation process is mainly controlled by the factors of temperature and gas velocity, and the influence of the gas velocity is most significant, so that the lowest recovery rate is achieved at the gas velocity of 100ml/min and the highest recovery rate is achieved at 300ml/min in the same time.

Finally, it should be noted that: the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.