A paraffin removal agent for oil production and a preparation method thereof

Abstract

The present application relates to a kind of asphalt dispersion wax removal agent for oil production.The main problem to be solved is that the existing chemical removal method is single dispersion or removal of asphaltene and wax, which limits the actual effect.The characteristics are as follows: the components and the ratio are as follows: asphaltene deposition inhibitor 10% to 20%, surfactant 10% to 20%, flash point enhancer 1% to 5%, and organic hydrocarbon solvent 55% to 79%.The preparation method is as follows: add asphaltene deposition inhibitor to organic hydrocarbon solvent, stir and dissolve, then add surfactant, stir, then add flash point enhancer, and stir to make the system dissolve and disperse uniformly.The asphalt dispersion wax removal agent for oil production can disperse and inhibit the precipitation of asphaltene during crude oil production, prevent the crystallization of wax as temperature and pressure decrease and light components continuously escape, effectively remove the wax, ensure the smooth flow of oil in the well bottom formation and wellbore, and reduce energy loss.

Description

Technical fields:

[0001] This invention relates to the field of chemical agents for oilfield production, and more particularly to an asphalt dispersing and dewaxing agent for oilfield production and its preparation method. Background technology:

[0002] During oil extraction and the application of certain oil production technologies, the balance between the asphaltene solution and colloidal system components of crude oil in the reservoir is disrupted, leading to the deposition of heavy components such as asphaltene within the reservoir, wellbore, and wellhead equipment. During crude oil extraction, as temperature and pressure decrease and lighter components continuously escape, the wax-dissolving capacity of the crude oil also decreases. Under certain conditions, wax in the crude oil precipitates, accumulates, and deposits in the form of crystals on the inner walls of the casing, the surface of the sucker rod, and equipment such as the pump, resulting in wax deposition in the oil well.

[0003] There are many methods for removing asphaltene and waxy substances both domestically and internationally, mainly including mechanical removal, thermal removal, microbial removal, and chemical removal. Mechanical removal uses cutting tools to scrape away asphaltene cement and crystalline wax; it is relatively inexpensive, but its effective removal cycle is short and the removal location is limited. Thermal removal uses heat to raise the temperature of the liquid in the sucker rod and tubing, making the ambient temperature higher than the melting temperature of the asphaltene and wax, thus achieving the removal purpose. Thermal removal is the most direct and effective method; however, it consumes a lot of energy, has a relatively long construction cycle, and improper operation during production can lead to reservoir contamination. Microbial removal uses microorganisms to degrade long-chain hydrocarbon macromolecules or produce surfactants to reduce the interaction between crude oil and the wellbore, reducing the blockage of rock channels by debris. Microbial removal is inexpensive and environmentally friendly, but the production of biological enzymes is complex, and the application conditions are demanding. Chemical removal utilizes chemical agents to stabilize crude oil components, reducing asphaltenes deposition and wax crystallization, and effectively removing crystallized wax deposits. Compared to other technologies, chemical removal offers significant advantages and is a commonly used method. However, current chemical removal methods primarily disperse or remove asphaltenes and waxes individually, limiting their practical effectiveness. During crude oil extraction, the precipitation and crystallization of asphaltenes and waxes occur simultaneously; therefore, while dispersing asphaltenes, it is crucial to effectively prevent and remove wax deposition. Summary of the Invention:

[0004] The purpose of this invention is to overcome the limitations of existing chemical removal methods, which only disperse or remove asphaltenes and waxes, resulting in limited effectiveness. This invention provides an asphaltenes dispersing and dewaxing agent for oil production. This agent not only disperses and inhibits the precipitation of asphaltenes during crude oil extraction, but also prevents wax crystallization as temperature and pressure decrease and lighter components escape. It effectively removes existing wax, ensuring smooth oil flow in the wellbore and formation, reducing energy loss, and guaranteeing normal crude oil extraction and production. This invention also provides a method for preparing the asphaltenes dispersing and dewaxing agent for oil production.

[0005] To achieve the above objectives, the first aspect of the present invention provides an oilfield asphalt dispersing and dewaxing agent, the components and proportions of which are as follows by mass percentage: 10% to 20% asphalt deposition inhibitor, 10% to 20% surfactant, 1% to 5% flash point enhancer, and 55% to 79% organic hydrocarbon solvent.

[0006] Preferably, the asphaltene deposition inhibitor is selected from one or more of fatty acid amides, dodecylbenzene sulfonic acid, or polyol fatty acid esters.

[0007] Preferably, the surfactant is selected from at least one of ethylene vinyl acetate copolymer, polyethylene polyamine block polyether, or dodecylphenol polyoxyethylene ether.

[0008] Preferably, the flash point enhancer is selected from at least one of isopropyl myristate or ethylene glycol monomethyl ether.

[0009] Preferably, the organic hydrocarbon solvent is selected from at least one of toluene, xylene, or diesel oil.

[0010] Another aspect of the present invention provides a method for preparing an oilfield asphalt dispersion dewaxing agent, comprising the following steps:

[0011] Step 1: Add asphaltene deposition inhibitor to the organic hydrocarbon solvent in the specified proportion and stir to dissolve;

[0012] Step 2: Then add the surfactant and stir.

[0013] Step 3: Finally, add the flash point enhancer and stir to dissolve and disperse the system evenly to obtain the asphalt dispersion dewaxing agent for oil production.

[0014] Preferably, in step 1, an asphaltene deposition inhibitor is added to the organic hydrocarbon solvent, and the stirring and dissolution time is 20-30 minutes.

[0015] Preferably, in step 2, after adding the surfactant, the stirring time is 10-20 minutes.

[0016] Preferably, in step 3, after adding the flash point enhancer, the stirring time is 30-40 minutes.

[0017] The functions of each component in the asphalt dispersant and dewaxing agent for oil extraction of this invention are as follows:

[0018] The asphaltene deposition inhibitor mainly inhibits the precipitation of asphaltene in crude oil and effectively disperses the precipitated asphaltene, reducing its adhesion to formation voids and oil pipelines.

[0019] The surfactant is mainly used to prevent the crystallization of waxes in crude oil.

[0020] The flash point enhancer is mainly used to adjust the flash point of the product system.

[0021] The organic hydrocarbon solvent is mainly used to dissolve the above materials to form a homogeneous system, and to dissolve and remove the wax that has formed in the oil pipeline.

[0022] Compared with the above-mentioned background technology, the present invention has the following beneficial effects:

[0023] This invention provides an asphalt dispersant and dewaxing agent. The system consists of asphaltene deposition inhibitors, surfactants, flash point enhancers, and organic hydrocarbon solvents. It is particularly effective for oil wells with high asphaltene and wax content in produced fluids, asphaltene blockage, and severe wax buildup, demonstrating excellent asphaltene dispersion and wax removal properties. It exhibits good effects on asphaltene dispersion and wax removal during oil production. It can achieve a relative asphalt dispersion rate greater than 80%, a wax dissolution rate greater than 0.01 g / min, and a flash point greater than 28℃. It can be used in various oilfields to inhibit and disperse asphaltene deposition, prevent wax crystal precipitation, and effectively remove crystallized wax deposits. Detailed implementation method:

[0024] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0025] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0026] This invention provides an oilfield asphalt dispersion and dewaxing agent, the components and proportions of which are as follows by mass percentage: 10%–20% asphalt deposition inhibitor, 10%–20% surfactant, 1%–5% flash point enhancer, and 55%–79% organic hydrocarbon solvent.

[0027] The asphaltene deposition inhibitor is selected from one or more of fatty acid amides, dodecylbenzene sulfonic acid, and polyol fatty acid esters. The main function of the asphaltene deposition inhibitor is to inhibit the precipitation of asphaltene in crude oil and to effectively disperse the precipitated asphaltene, thereby reducing its adhesion to formation voids and oil pipelines.

[0028] The surfactant is selected from one or more of ethylene vinyl acetate copolymer, polyethylene polyamine block polyether, and dodecylphenol polyoxyethylene ether; the main function of the surfactant is to prevent wax crystallization in crude oil.

[0029] The flash point enhancer is selected from one or more of isopropyl myristate and ethylene glycol monomethyl ether; the main function of the flash point enhancer is to adjust the flash point of the product system.

[0030] The organic hydrocarbon solvent is selected from one or more of toluene, xylene, and diesel oil. The main function of the organic hydrocarbon solvent is to dissolve the above materials, forming a homogeneous system, and to dissolve and remove the wax that has formed in the oil pipeline.

[0031] The preparation process of the asphalt dispersion dewaxing agent for oil production includes:

[0032] Add asphaltene deposition inhibitor to the organic hydrocarbon solvent in proportion, stir to dissolve for 20-30 minutes, then continue to add surfactant, stir for 10-20 minutes, and finally add flash point enhancer, stir for 30-40 minutes to make the system dissolve and disperse evenly.

[0033] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0034] Example 1

[0035] (1) Formula: Ingredients and composition are proportioned according to the percentage of total mass:

[0036] The asphaltene deposition inhibitor is 10% fatty acid amide and dodecylbenzene sulfonic acid (fatty acid amide and dodecylbenzene sulfonic acid in a mass ratio of 1:1);

[0037] The surfactant is 10% ethylene vinyl acetate copolymer and polyethylene polyamine block polyether (ethylene vinyl acetate copolymer and polyethylene polyamine block polyether in a mass ratio of 1:1);

[0038] Flash point enhancer: 5% isopropyl myristate;

[0039] Xylene, an organic hydrocarbon solvent, accounts for 75%.

[0040] (2) Preparation process: Add asphalt deposition inhibitor to organic hydrocarbon solvent in proportion, stir and dissolve for 20 min, then continue to add surfactant, stir for 10 min, and finally add flash point enhancer, stir for 30 min to make the system dissolve and disperse evenly.

[0041] Example 2

[0042] (1) Formula: Ingredients and composition are proportioned according to the percentage of total mass:

[0043] Asphalt deposition inhibitor dodecylbenzenesulfonic acid and polyol fatty acid ester (mass ratio of dodecylbenzenesulfonic acid and polyol fatty acid ester is 1:1) 10%;

[0044] Surfactant: 20% ethylene vinyl acetate copolymer and polyethylene polyamine block polyether (ethylene vinyl acetate copolymer and polyethylene polyamine block polyether in a mass ratio of 1:1);

[0045] Flash point enhancer: Isopropyl myristate 3%;

[0046] Organic hydrocarbon solvents xylene and diesel (xylene to diesel mass ratio of 1:1) 67%.

[0047] (2) Preparation process: Add asphalt deposition inhibitor to organic hydrocarbon solvent in proportion, stir and dissolve for 20 min, then continue to add surfactant, stir for 10 min, and finally add flash point enhancer, stir for 30 min to make the system dissolve and disperse evenly.

[0048] Example 3

[0049] (1) Formula: Ingredients and composition are proportioned according to the percentage of total mass:

[0050] Asphalt deposition inhibitor fatty acid amide, dodecylbenzene sulfonic acid and polyol fatty acid ester (fatty acid amide, dodecylbenzene sulfonic acid and polyol fatty acid ester in a mass ratio of 1:1:1) 20%;

[0051] Surfactant: 10% polyethylene polyamine block polyether and dodecylphenol polyoxyethylene ether (mass ratio of polyethylene polyamine block polyether and dodecylphenol polyoxyethylene ether is 1:1);

[0052] Flash point enhancer isopropyl myristate and ethylene glycol monomethyl ether (mass ratio of isopropyl myristate to ethylene glycol monomethyl ether is 1:1) 1%;

[0053] Organic hydrocarbon solvents: toluene and xylene (toluene to xylene mass ratio 1:1) 69%.

[0054] (2) Preparation process: Add asphalt deposition inhibitor to organic hydrocarbon solvent in proportion, stir and dissolve for 20 min, then continue to add surfactant, stir for 10 min, and finally add flash point enhancer, stir for 30 min to make the system dissolve and disperse evenly.

[0055] Comparative Example 1

[0056] (1) Formula: The ingredients and composition are proportioned according to the percentage of total mass as follows:

[0057] Asphalt deposition inhibitor (fatty acid amide, dodecylbenzene sulfonic acid, and polyol fatty acid ester in a mass ratio of 1:1:1) 20%;

[0058] 10% surfactant (polyethylene polyamine block polyether and dodecylphenol polyoxyethylene ether in a mass ratio of 1:1);

[0059] Organic hydrocarbon solvents (toluene and xylene in a 1:1 mass ratio) 70%.

[0060] (2) Preparation process: Add asphalt deposition inhibitor to organic hydrocarbon solvent in proportion, stir and dissolve for 20 min, then continue to add surfactant and stir for 10 min to make the system dissolve and disperse evenly.

[0061] Comparative Example 2

[0062] (1) Formula: The ingredients and composition are proportioned according to the percentage of total mass as follows:

[0063] Surfactant: 10% polyethylene polyamine block polyether, dodecylphenol polyoxyethylene ether (polyethylene polyamine block polyether: dodecylphenol polyoxyethylene ether = 1:1);

[0064] Flash point enhancer isopropyl myristate and ethylene glycol monomethyl ether (isopropyl myristate: ethylene glycol monomethyl ether = 1:1) 3%;

[0065] Organic hydrocarbon solvents, toluene and xylene (toluene:xylene = 1:1), 87%.

[0066] (2) Preparation process: Add surfactant to organic hydrocarbon solvent according to proportion, stir for 10 min, and finally add flash point enhancer, stir for 30 min to make the system dissolve and disperse evenly.

[0067] The performance of the products obtained in the above embodiments is evaluated below:

[0068] Testing standards:

[0069] The relative dispersion rate of the asphalt is tested according to the method in the product enterprise standard "Q / DYKP 071-2023 Oilfield Asphalt Dispersing Dewaxing Agent Polymer Type LQFS";

[0070] Wax melting rate test standard: The test shall be conducted in accordance with the method in the petroleum and natural gas industry standard "SY / T 6300-2009 Technical Conditions for Wax Removers and Inhibitors in Oil Production";

[0071] Flash point test standard: The test shall be conducted in accordance with the method in the national recommended standard "GB / T261 Determination of flash point by the Binsky-Martin closed cup method".

[0072] The products prepared in Examples 1, 2, and 3, as well as Comparative Examples 1 and 2, were tested using the above method. The test results are shown in Table 1.

[0073] Table 1 Performance of different formulations

[0074] Example Relative dispersion of asphalt Wax melting rate (g / min) Flash point ℃ 1 82％ 0.015 34 2 85％ 0.012 31 3 90％ 0.012 29 4 90％ 0.012 25 5 20％ 0.017 30

[0075] As shown in Table 1, Examples 1-3, using the formulation system of this invention composed of asphalt deposition inhibitor, surfactant, flash point enhancer, and organic hydrocarbon solvent, compared with Comparative Examples 1-2, can achieve a relative asphalt dispersion rate of greater than 80%, a wax dissolution rate of greater than 0.01 g / min, and a flash point of greater than 28°C. It can be used to inhibit and disperse asphalt deposition in oil wells of various oil fields, prevent wax crystal precipitation, and effectively remove and clean crystallized wax scale.

[0076] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of them. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Although the specific embodiments of the present invention have been described above, they are not intended to limit the protection scope of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. An asphalt dispersant dewaxing agent for oil recovery, characterized by: The components and the ratio of the components are as follows: 10-20% of asphaltene deposition inhibitor; 10-20% of surfactant; 1-5% of flash point improver; 55-79% of organic hydrocarbon solvent; The asphaltene deposition inhibitor is a mixture of fatty acid amide and dodecyl benzene sulfonic acid, a mixture of dodecyl benzene sulfonic acid and polyhydric alcohol fatty acid ester, or a mixture of fatty acid amide, dodecyl benzene sulfonic acid and polyhydric alcohol fatty acid ester; The surfactant is a mixture of ethylene-vinyl acetate copolymer and polyethylene polyamine block polyether, or a mixture of polyethylene polyamine block polyether and dodecyl phenol polyoxyethylene ether; The flash point improver is isopropyl myristate, or a mixture of isopropyl myristate and ethylene glycol monomethyl ether; The organic hydrocarbon solvent is xylene, a mixture of xylene and diesel oil, or a mixture of toluene and xylene.

2. The method for preparing the pitch dispersant dewaxing agent for oil extraction according to claim 1, characterized in that: The method comprises the following steps: Step 1: adding asphaltene deposition inhibitor into organic hydrocarbon solvent in proportion, stirring and dissolving to form a first solution; Step 2: then adding surfactant into the first solution, stirring to form a second solution; Step 3: finally adding flash point improver into the second solution, stirring to make the system uniformly dissolved and dispersed to obtain the asphaltene dispersion wax removal agent for oil extraction.

3. The preparation method according to claim 2, characterized in that: The stirring and dissolving time of the step 1 is 20-30 min.

4. The method of claim 2, wherein: The stirring time after adding surfactant into the first solution in the step 2 is 10-20 min.

5. The method of claim 2, wherein: The stirring time after adding flash point improver into the second solution in the step 3 is 30-40 min.