High flash point oil well paraffin remover, preparation method and application thereof

Abstract

The present application relates to the technical field of oil well treatment agent, and is a high-flash-point oil well paraffin remover, a preparation method and application thereof, wherein the high-flash-point oil well paraffin remover is obtained by the following method: first, adding a dispersing agent and an alkyl sulfonate into trimethylbenzene and stirring uniformly to obtain a reddish-brown liquid; then, adding heavy aromatic hydrocarbon and white oil into solvent oil and stirring uniformly to obtain a light yellow liquid; finally, stirring the reddish-brown liquid and the light yellow liquid uniformly to obtain the high-flash-point oil well paraffin remover. The high-flash-point oil well paraffin remover has a high flash point, a good paraffin dissolving efficiency, and a performance meeting the requirements of the petroleum industry standard, and can safely and efficiently dissolve the paraffin in oil wells, reduce the frequency of well repair affected by wax, improve the production rate of oil wells, and effectively solve the problems of low flash point and poor paraffin dissolving efficiency of the existing oil well paraffin remover.

Description

Technical Field

[0001] This invention relates to the field of oil well treatment agent technology, specifically a high flash point oil well dewaxing agent, its preparation method, and its application. Background Technology

[0002] As oilfield development enters the middle and late stages, wax buildup in oil wells becomes increasingly severe, causing pump jamming and leakage, which prevents normal production. Only after well repair and pump inspection can oil well production be restored, which greatly reduces the production rate of oil wells and significantly affects oil well output.

[0003] Currently, the annual maintenance costs for oil wells due to wax detection pumps remain high and are increasing year by year. The main reason is that as oilfield development time increases, the amount of heavy components in crude oil increases, and the wax melting point becomes higher, with most blocks having wax melting points above 80℃. Simultaneously, the wax precipitation point of crude oil is high (around 30℃), and the depth of wax-laden well sections exceeds 1200 meters. Conventional hot washing of the wellbore is no longer sufficient to meet the requirements for wax removal. In recent years, some oil wells have shifted from hot washing to chemical wax removal, but without significant results. One major reason is that conventional oil-soluble wax removers have low flash points (25℃), are flammable and explosive, posing significant safety hazards to personnel involved in chemical dosing. Currently, the main method is intermittent wellbore chemical dosing, which cannot continuously remove wax from the produced fluid. Therefore, there is an urgent need to develop targeted, safe, and reliable high-flash-point oil well wax removers to meet the requirements of safely and efficiently removing wax from the wellbore or slowing down the wax deposition rate and reducing the frequency of well workovers. Summary of the Invention

[0004] This invention provides a high flash point oil well dewaxing agent, its preparation method, and its application, overcoming the shortcomings of the prior art. It can effectively solve the problems of low flash point and poor wax dissolving efficiency of existing oil well dewaxing agents.

[0005] One of the technical solutions of the present invention is achieved by the following measures: a high flash point oil well dewaxing agent, the raw materials being composed of 25% to 35% white oil, 20% to 25% trimethylbenzene, 5% to 10% heavy aromatic hydrocarbons, 3% to 5% dispersant, 1% to 2% alkyl sulfonate and the balance being solvent oil by mass percentage.

[0006] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions:

[0007] The dispersant mentioned above is dispersant DW-29.

[0008] The solvent oil mentioned above is one or more of the following: 6# solvent oil, 120# solvent oil, and 200# solvent oil.

[0009] The above-mentioned high flash point oil well dewaxing agent is obtained by the following method: First, add the required amount of dispersant and alkyl sulfonate to the required amount of trimethylbenzene, stir evenly and react to obtain a reddish-brown liquid; Second, add the required amount of heavy aromatic hydrocarbon to the required amount of solvent oil for pre-stirring, then add the required amount of white oil and continue stirring evenly to obtain a light yellow liquid; Third, stir the reddish-brown liquid and the light yellow liquid evenly and react to obtain the high flash point oil well dewaxing agent.

[0010] In the first step above, the stirring time is 30 to 50 minutes and the stirring temperature is 30 to 40 degrees Celsius.

[0011] In the second step above, the pre-stirring time is 10 to 20 minutes, and the stirring time is 25 to 35 minutes. During stirring, the temperature is 20°C to 25°C.

[0012] In the third step above, the stirring time is 25 to 30 minutes, and the stirring temperature is 20°C to 25°C.

[0013] The second technical solution of the present invention is achieved through the following measures: A method for preparing a high flash point oil well dewaxing agent, which is carried out according to the following steps: First, add a required amount of dispersant and alkyl sulfonate to a required amount of trimethylbenzene, stir evenly and react to obtain a reddish-brown liquid; Second, add a required amount of heavy aromatic hydrocarbon to a required amount of solvent oil for pre-stirring, then add a required amount of white oil and continue stirring evenly to obtain a light yellow liquid; Third, stir the reddish-brown liquid and the light yellow liquid evenly and react to obtain a high flash point oil well dewaxing agent.

[0014] The third technical solution of the present invention is achieved through the following measures: the application of a high flash point oil well dewaxing agent in oil wells.

[0015] This invention provides a high flash point oil well dewaxing agent with a high flash point and good wax dissolving efficiency. Its performance meets the requirements of petroleum industry standards and can safely and efficiently dissolve wax deposits in oil wells, reduce the frequency of well workovers due to wax, and improve the production rate of oil wells. It effectively solves the problems of low flash point and poor wax dissolving efficiency of existing oil well dewaxing agents. Detailed Implementation

[0016] This invention is not limited to the following embodiments, and specific implementation methods can be determined according to the technical solutions and actual conditions of this invention. Unless otherwise specified, all chemical reagents and chemicals mentioned in this invention are well-known and commonly used chemical reagents and chemicals in the prior art; unless otherwise specified, all percentages in this invention are mass percentages; unless otherwise specified, all solutions in this invention are aqueous solutions with water as the solvent, for example, hydrochloric acid solution is an aqueous solution of hydrochloric acid; room temperature in this invention generally refers to a temperature between 15°C and 25°C, generally defined as 25°C.

[0017] The present invention will be further described below with reference to embodiments:

[0018] Example 1: This high flash point oil well dewaxing agent is composed of raw materials by mass percentage: 25% to 35% white oil, 20% to 25% trimethylbenzene, 5% to 10% heavy aromatics, 3% to 5% dispersant, 1% to 2% alkyl sulfonate, and the balance being solvent oil.

[0019] In this invention, the heavy aromatic hydrocarbon is mainly a mixture of n-propylbenzene, isopropylbenzene and ethyltoluene, wherein the content of n-propylbenzene is 35% to 41%, the content of isopropylbenzene is 35% to 41%, and the content of ethyltoluene is 13% to 15%.

[0020] Example 2: As an optimization of the above example, the dispersant is dispersant DW-29.

[0021] Example 3: As an optimization of the above example, the solvent oil is one or more of 6# solvent oil, 120# solvent oil and 200# solvent oil.

[0022] Example 4: As an optimization of the above example, a high flash point oil well dewaxing agent is obtained by the following method: First, add the required amount of dispersant and alkyl sulfonate to the required amount of trimethylbenzene, stir evenly and react to obtain a reddish-brown liquid; Second, add the required amount of heavy aromatic hydrocarbon to the required amount of solvent oil for pre-stirring, then add the required amount of white oil and continue stirring evenly to obtain a light yellow liquid; Third, stir the reddish-brown liquid and the light yellow liquid evenly and react to obtain a high flash point oil well dewaxing agent.

[0023] Example 5: As an optimization of the above example, in the first step, the stirring time is 30 min to 50 min and the stirring temperature is 30°C to 40°C.

[0024] Example 6: As an optimization of the above example, in the second step, the pre-stirring time is 10 min to 20 min, the continued stirring time is 25 min to 35 min, and the temperature during stirring is 20°C to 25°C.

[0025] Example 7: As an optimization of the above example, in the third step, the stirring time is 25 min to 30 min and the stirring temperature is 20°C to 25°C.

[0026] Example 8: Application of the high flash point oil well dewaxing agent in oil wells. The specific usage method is as follows: Add the high flash point oil well dewaxing agent to the continuous drip dosing storage tank, and inject the high flash point oil well dewaxing agent into the annulus through the plunger metering pump and pipeline. The dosage is designed according to the oil production of the oil well. The daily dosage for a single well is 3kg to 15kg. When the agent (high flash point oil well dewaxing agent) enters the wellbore along with the produced fluid, it achieves the purpose of dissolving the wax in the wellbore.

[0027] Example 9:

[0028] This high flash point oil well dewaxing agent comprises, by mass percentage, 25% white oil, 20% trimethylbenzene, 5% heavy aromatics, 3% dispersant DW-29, 2% alkyl sulfonate, and 45% solvent oil. It is obtained as follows: First, add the required amount of dispersant DW-29 and alkyl sulfonate to the required amount of trimethylbenzene and mix. Stir at 30°C for 30 minutes to obtain a reddish-brown liquid. Second, add the required amount of heavy aromatics to the required amount of solvent oil at 20°C and pre-stir for 10 minutes. Then add the required amount of white oil and continue stirring for 25 minutes to obtain a pale yellow liquid. Third, mix the reddish-brown liquid and the pale yellow liquid at 20°C for 25 minutes to obtain the high flash point oil well dewaxing agent.

[0029] Example 10:

[0030] This high flash point oil well dewaxing agent comprises, by mass percentage, 30% white oil, 25% trimethylbenzene, 8% heavy aromatics, 4% dispersant DW-29, 1% alkyl sulfonate, and 32% solvent oil. It is obtained as follows: First, add the required amount of dispersant DW-29 and alkyl sulfonate to the required amount of trimethylbenzene and mix. Stir at 35°C for 40 minutes to obtain a reddish-brown liquid. Second, add the required amount of heavy aromatics to the required amount of solvent oil at 25°C and pre-stir for 15 minutes. Then add the required amount of white oil and continue stirring for 30 minutes to obtain a pale yellow liquid. Third, mix the reddish-brown liquid and the pale yellow liquid at 25°C for 30 minutes to obtain the high flash point oil well dewaxing agent.

[0031] Example 11:

[0032] This high flash point oil well dewaxing agent comprises, by mass percentage, 35% white oil, 25% trimethylbenzene, 10% heavy aromatics, 5% dispersant DW-29, 1% alkyl sulfonate, and 24% solvent oil. It is obtained as follows: First, add the required amount of dispersant DW-29 and alkyl sulfonate to the required amount of trimethylbenzene and mix. Stir at 40°C for 50 minutes to obtain a reddish-brown liquid. Second, add the required amount of heavy aromatics to the required amount of solvent oil at 25°C and pre-stir for 20 minutes. Then add the required amount of white oil and continue stirring for 35 minutes to obtain a pale yellow liquid. Third, mix the reddish-brown liquid and the pale yellow liquid at 25°C for 30 minutes to obtain the high flash point oil well dewaxing agent.

[0033] Comparative Example 1: The difference from Example 9 is that the raw material "trimethylbenzene" was changed to "xylene", while the other raw materials and steps were the same as in Example 9.

[0034] Comparative Example 2: The difference from Example 9 is that the raw material "white oil" was changed to "gasoline", while the other raw materials and steps are the same as in Example 9.

[0035] Comparative Example 3: KRQ-1, a commercially available benzene-based wax remover.

[0036] Example 1: Performance testing of the high flash point oil well dewaxing agent of the present invention. Test method: The performance of the high flash point oil well dewaxing agents prepared in Examples 9 to 11 of the present invention was tested according to the methods specified in SY / T 6300-2009 "Technical Conditions for Dewaxing and Inhibiting Agents for Oil Production". The performance tests included flash point (°C) and wax dissolution rate (g / min). Comparative Examples 1 to 3 of the present invention were used as controls. The test results are shown in Table 1. Table 1 shows that the wax dissolution rates of the high flash point oil well dewaxing agents prepared in Comparative Examples 1 to 3 and Examples 9 to 11 are all >0.016, meeting the standard requirements. The flash point of the high flash point oil well dewaxing agent prepared in Examples 9 to 11 of the present invention is greater than 48°C, meeting the standard requirements, while the flash points of Comparative Examples 1 to 3 do not meet the standard requirements, and the flash points of Comparative Examples 2 and 3 are even lower. Therefore, the high flash point oil well dewaxing agent obtained by blending the raw materials of the present invention has a high flash point and a good wax dissolution rate.

[0037] Example 2: Application of the high flash point oil well dewaxing agent of the present invention in oil wells. Experimental method: The high flash point oil well dewaxing agent prepared in Example 9 of the present invention was added to a continuous drip dosing storage tank. The agent was injected into the annulus through a plunger metering pump and pipeline. The dosage was designed based on the oil well's production rate. Wells LU3113 and LU30, which had severe wax buildup, were selected for the experiment. The daily dosage per well was 5 kg, 10 kg, and 15 kg, respectively. Before use, the daily dosages were 125 days, 212 days, and 186 days, respectively. After using the high flash point oil well dewaxing agent of the present invention, the pump inspection cycle was extended by 45 days, 92 days, and 68 days, respectively. This extended pump inspection cycle improved the oil well production rate and achieved a better oil well dewaxing effect.

[0038] In summary, the high flash point oil well dewaxing agent of this invention has a high flash point, good wax dissolving efficiency, and its performance meets the requirements of petroleum industry standards. It can safely and efficiently dissolve wax deposits in oil wells, reduce the frequency of well workovers due to wax, and improve the production rate of oil wells.

[0039] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

[0040]

Claims

1. A high flash point oil well dewaxing agent, characterized in that... The raw materials, by mass percentage, consist of 25% to 35% white oil, 20% to 25% trimethylbenzene, 5% to 10% heavy aromatics, 3% to 5% dispersant, 1% to 2% alkyl sulfonate, and the balance being solvent oil. The heavy aromatics are a mixture of n-propylbenzene, isopropylbenzene, and ethyltoluene, wherein the content of n-propylbenzene in the mixture of n-propylbenzene, isopropylbenzene, and ethyltoluene is 35% to 41%, the content of isopropylbenzene is 35% to 41%, and the content of ethyltoluene is 13% to 15%.

2. The high flash point oil well dewaxing agent according to claim 1, characterized in that... The dispersant is dispersant DW-29.

3. The high flash point oil well dewaxing agent according to claim 2, characterized in that... The solvent oil is one or more of the following: 6# solvent oil, 120# solvent oil, and 200# solvent oil.

4. The high flash point oil well dewaxing agent according to claim 1, 2, or 3, characterized in that... The following steps are taken: First, add the required amount of dispersant and alkyl sulfonate to the required amount of trimethylbenzene, stir and react to obtain a reddish-brown liquid; Second, add the required amount of heavy aromatic hydrocarbon to the required amount of solvent oil, stir, then add the required amount of white oil and continue stirring until uniform, to obtain a pale yellow liquid; Third, stir the reddish-brown liquid and the pale yellow liquid together and react to obtain a high flash point oil well dewaxing agent.

5. The high flash point oil well dewaxing agent according to claim 4, characterized in that... In the first step, the stirring time is 30 to 50 minutes, and the stirring temperature is 30°C to 40°C.

6. The high flash point oil well dewaxing agent according to claim 5, characterized in that... In the second step, the pre-stirring time is 10 to 20 minutes, and the stirring time is 25 to 35 minutes. During stirring, the temperature is 20°C to 25°C.

7. The high flash point oil well dewaxing agent according to claim 5 or 6, characterized in that... In the third step, the stirring time is 25 to 30 minutes, and the stirring temperature is 20°C to 25°C.

8. A method for preparing a high flash point oil well dewaxing agent according to any one of claims 1 to 3, 5 to 6, characterized in that... The process is as follows: First, add the required amount of dispersant and alkyl sulfonate to the required amount of trimethylbenzene, stir until homogeneous and react to obtain a reddish-brown liquid; Second, add the required amount of heavy aromatic hydrocarbon to the required amount of solvent oil, stir before stirring, then add the required amount of white oil and continue stirring until homogeneous to obtain a pale yellow liquid; Third, stir the reddish-brown liquid and the pale yellow liquid until homogeneous and react to obtain a high flash point oil well dewaxing agent.

9. The application of a high flash point oil well dewaxing agent according to any one of claims 1 to 7 in oil wells.

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