An oil-based chemical paraffin remover for oil fields and a preparation method thereof

Abstract

The application discloses an oil-based chemical wax remover for oil fields and a preparation method thereof. The oil-based chemical wax remover for oil fields is composed of the following raw materials in mass percentage: 20wt.%-45wt.% of cyclic dienes, 20wt.%-45wt.% of esters, 20wt.%-45wt.% of amines and 5wt.%-10wt.% of alcohols. The cyclic dienes are a mixture of one or more of terpene compounds, the esters are organic carboxylic acids and derivatives thereof, and the amines are tertiary amine compounds. The components are uniformly stirred according to the mass ratio to obtain the oil-based chemical wax remover. The wax remover has a flash point of 50-65 DEG C, a freezing point of less than -40 DEG C, a boiling point of more than 160 DEG C, a wax dissolving rate of 0.0430 g / min at room temperature of 30 DEG C, and does not contain sulfur, chlorine and halogen elements. The oil-based chemical wax remover has the advantages of safety, high efficiency and good wax dissolving effect.

Description

Technical Field

[0001] This invention belongs to the field of oilfield applied chemistry, specifically relating to an oil-based chemical dewaxing agent for oilfield use and its preparation method. Background Technology

[0002] Eighty percent of the crude oil produced in Chinese oilfields is waxy crude oil, with a wax content ranging from 15% to 37%. It is characterized by high pour point, high viscosity, complex rheological properties, and poor low-temperature fluidity. While waxy crude oil exhibits good fluidity under high temperature and pressure conditions in reservoirs, wax blockage often occurs as the oil is lifted and depressurized in the wellbore. The wax deposits adsorbed on the tubing string reduce the effective inner diameter of the tubing, increasing transport friction resistance and leading to a significant decrease in oil and gas production. In severe cases, this can cause tubing blockage and production shutdown, increasing the difficulty and risk of producing waxy crude oil. Furthermore, the wax deposition problem associated with waxy crude oil persists throughout the entire gathering and transportation process, already causing serious impacts in many oilfields and resulting in substantial economic losses.

[0003] To address the wax buildup problem in the production and transportation of waxy crude oil, physical, chemical, and biological wax removal technologies have been developed. Chemical wax removal technology, in particular, is widely used due to its advantages of rapid action, thorough wax removal, and minimal disruption to normal well production. However, with the increasing exploitation of crude oil resources, wax blockage in high-wax and microcrystalline wax oil and gas resources is becoming increasingly serious. Currently, conventional chemical wax removers suffer from low flash points (<45℃), poor low-temperature wax dissolution (poor room-temperature wax dissolution), poor dissolution of microcrystalline wax, and the presence of corrosive elements such as sulfur and chlorine. These limitations result in poor wax dissolution effects for high-wax oil and gas resources, and also pose safety risks during use.

[0004] Therefore, developing a highly efficient and safe oil-soluble chemical dewaxing agent, making it suitable not only for unclogging conventional oil wells but also for unclogging oil wells in complex conditions such as high wax content, is of great significance for maintaining crude oil production. Summary of the Invention

[0005] To address the above problems, this invention aims to solve the aforementioned technical challenges by providing an oil-based chemical wax remover for oil fields, which features a high flash point, low pour point, high wax dissolving efficiency, wide applicability, and is free of sulfur, chlorine, and halogen elements.

[0006] To achieve the above-mentioned objectives of this invention, the technical solution provided by this invention is as follows:

[0007] An oil-based chemical wax remover for oilfield use, the oil-based chemical wax remover being composed of the following components: cyclic dienes, esters, amines, and alcohols.

[0008] Furthermore, the oil-based chemical wax remover comprises the following components: 20 wt.% to 45 wt.% cyclic dienes, 20 wt.% to 45 wt.% esters, 20 wt.% to 45 wt.% amines, and 5 wt.% to 10 wt.% alcohols.

[0009] Furthermore, the oil-based chemical wax remover comprises the following components: 30 wt.% to 35 wt.% cyclic dienes, 25 wt.% to 30 wt.% esters, 25 wt.% to 35 wt.% amines, and 5 wt.% to 10 wt.% alcohols.

[0010] The cyclic diene is selected from one or more of terpinene, cycloterpinene, and limonene.

[0011] The esters are one or more of the (C2-C8) acid (C2-C8) esters, and their structural formulas are shown in Formula I:

[0012]

[0013] In Formula I, n is a natural number from 2 to 8.

[0014] The amines are long-chain alkanes (C3) ～ C 16 The tertiary amine structure of ) is shown in Formula II:

[0015]

[0016] In Equation II, n is a natural number from 1 to 14.

[0017] The alcohols are C5-C8 alcohols.

[0018] The present invention also provides a method for preparing the above-mentioned oil-based chemical dewaxing agent for oil fields.

[0019] The preparation method of the oil-based chemical dewaxing agent for oil fields provided by the present invention includes the following steps: heating, mixing and stirring the cyclic dienes, esters and amines until uniform for a period of time, adding alcohols and stirring until uniform for a period of time, cooling to room temperature, and obtaining the safe oil-soluble chemical dewaxing agent.

[0020] Preferably, the heating temperature is 50–60°C.

[0021] Preferably, the time for heating and stirring the cyclic dienes, esters, and amines to achieve uniformity is 30–45 min, the time for stirring the added alcohols to achieve uniformity is 15–20 min, and the stirring speed is 200–300 rpm.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The oil-based chemical wax remover of the present invention has a good wax removal effect, and the wax dissolving rate at room temperature (30°C) reaches 0.0430 g / min;

[0024] (2) The oil-based chemical wax remover of the present invention has a high flash point and is highly safe for field use;

[0025] (3) The oil-based chemical wax remover of the present invention does not contain sulfur, chlorine or halogen elements;

[0026] (4) The oil-based chemical wax remover of the present invention has a low pour point, which can meet the conditions for use in winter. Attached Figure Description

[0027] Figure 1 Experimental images of the oil-soluble chemical wax remover prepared in Example 1;

[0028] Figure 2 Experimental images of the oil-soluble chemical wax remover prepared in Comparative Example 1;

[0029] Figure 3 Experimental images of the oil-soluble chemical wax remover prepared in Comparative Example 2;

[0030] Figure 4 Experimental images of the oil-soluble chemical wax remover prepared for Comparative Example 3. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0032] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0033] Example 1:

[0034] This embodiment describes an oil-based chemical wax remover comprising the following raw materials by mass percentage: 35 wt.% cyclic dienes, 30 wt.% esters, 25 wt.% amines, and 10 wt.% alcohols. Specifically, the cyclic dienes are terpinene, the esters are pentyl valerate, the amines are tetradecyl dimethyl tertiary amine, and the alcohols are C8 alcohols.

[0035] The preparation method of the above-mentioned oil-based chemical wax remover includes the following steps:

[0036] The cyclic dienes, esters, and amines are mixed and heated to 50°C, stirred at 200 rpm for 30 min until homogeneous, then alcohols are added and stirred at 200 rpm for 20 min until homogeneous. After cooling to room temperature, the oil-based chemical wax remover is obtained.

[0037] Example 2:

[0038] This embodiment describes an oil-soluble chemical wax remover comprising the following raw materials by weight percentage: 30 wt.% cyclic dienes, 25 wt.% esters, 35 wt.% amines, and 10 wt.% alcohols. Specifically, the cyclic dienes are cycloterpinene, the esters are butyl hexanoate, the amines are N,N-dimethyldecane, and the alcohols are heptanol.

[0039] The preparation method of the above-mentioned oil-soluble chemical wax remover includes the following steps:

[0040] The cyclic dienes, esters, and amines are mixed and heated to 50°C, stirred at 200 rpm for 30 min until homogeneous, then alcohols are added and stirred at 200 rpm for 20 min until homogeneous. After cooling to room temperature, the safe oil-soluble chemical wax remover is obtained.

[0041] Example 3:

[0042] This embodiment describes an oil-soluble chemical wax remover comprising the following raw materials by weight percentage: 30 wt.% cyclic dienes, 30 wt.% esters, 30 wt.% amines, and 10 wt.% alcohols. Specifically, the cyclic dienes are limonene, the esters are amyl valerate, the amines are N,N-dimethyldecane, and the alcohols are heptanol.

[0043] The preparation method of the above-mentioned oil-soluble chemical wax remover includes the following steps:

[0044] The cyclic dienes, esters, and amines are mixed and heated to 50°C, stirred at 200 rpm for 30 min until homogeneous, then alcohols are added and stirred at 200 rpm for 20 min until homogeneous. After cooling to room temperature, the safe oil-soluble chemical wax remover is obtained.

[0045] Example 4:

[0046] This embodiment describes an oil-soluble chemical wax remover comprising the following raw materials by mass percentage: 35 wt.% cyclic dienes, 30 wt.% esters, 25 wt.% amines, and 10 wt.% alcohols. Specifically, the cyclic dienes are terpinene, the esters are pentyl valerate, the amines are tetradecyl dimethyl tertiary amine, and the alcohols are C8 alcohols.

[0047] The preparation method of the above-mentioned oil-soluble chemical wax remover includes the following steps:

[0048] The cyclic dienes, esters, and amines are mixed and heated to 30°C, stirred at 200 rpm for 10 minutes until homogeneous, then alcohols are added and stirred at 200 rpm for 10 minutes until homogeneous. After cooling to room temperature, the safe oil-soluble chemical wax remover is obtained.

[0049] Comparative Example 1:

[0050] This comparative example uses an oil-soluble chemical wax remover comprising the following raw materials by mass percentage: 90 wt.% cyclic dienes, 0 wt.% esters, 0 wt.% amines, and 10 wt.% alcohols. Specifically, the cyclic dienes are terpinene and the alcohols are C8 alcohols.

[0051] The preparation method of the above-mentioned oil-soluble chemical wax remover includes the following steps:

[0052] The cyclic diene was heated to 50°C and stirred at 200 rpm for 30 minutes until homogeneous. Then, an alcohol was added and stirred at 200 rpm for 20 minutes until homogeneous. After cooling to room temperature, the safe oil-soluble chemical wax remover was obtained.

[0053] Comparative Example 2:

[0054] This comparative example uses an oil-soluble chemical wax remover comprising the following raw materials by mass percentage: 0 wt.% cyclic dienes, 90 wt.% esters, 0 wt.% amines, and 10 wt.% alcohols. Specifically, the ester is amyl valerate, and the alcohol is C8 alcohol.

[0055] The preparation method of the above-mentioned oil-soluble chemical wax remover includes the following steps:

[0056] The esters were heated to 50°C and stirred at 200 rpm for 30 minutes until homogeneous. Then, alcohols were added and stirred at 200 rpm for 20 minutes until homogeneous. After cooling to room temperature, a safe oil-soluble chemical dewaxing agent was obtained.

[0057] Comparative Example 3:

[0058] This comparative example uses an oil-soluble chemical wax remover comprising the following raw materials by mass percentage: 0 wt.% cyclic dienes, 0 wt.% esters, 90 wt.% amines, and 10 wt.% alcohols. Specifically, the amine is tetradecyl dimethyl tertiary amine, and the alcohol is C8 alcohol.

[0059] The preparation method of the above-mentioned oil-soluble chemical wax remover includes the following steps:

[0060] The amines were heated to 50°C and stirred at 200 rpm for 30 minutes until homogeneous. Then, alcohols were added and stirred at 200 rpm for 20 minutes until homogeneous. After cooling to room temperature, the safe oil-soluble chemical wax remover was obtained.

[0061] Experimental Example 1:

[0062] The safe oil-soluble chemical wax removers obtained from Experimental Examples 1-3 and Comparative Examples 1-3 were subjected to wax dissolution rate tests, pour point tests, and flash point tests.

[0063] The method for testing the wax melting rate is as follows:

[0064] At room temperature, using a wide-mouth glass bottle as the test container, a wax ball cast from a wax ball mold was weighed (m1) and placed on a support. A certain amount of initial screening reagent was measured and poured into the glass bottle, completely immersing the wax sample. The test time was 1 hour. The incompletely dissolved wax balls were dried, weighed (m2), and the wax dissolution rate was determined. The wax dissolution rate r = (m1 - m2) / 60. The following test results were obtained:

[0065] Table 1. Results of paraffin melting rate tests in Examples 1-3 and Comparative Examples 1-3

[0066] Example 1 0.0430 60.4 -90.3 Example 2 0.0322 56.3 -89.5 Example 3 0.0352 52.2 -90.6 Example 4 0.0337 57.6 -89.7 Comparative Example 1 0.0370 51.8 -60.2 Comparative Example 2 0.0246 48.3 -91.3 Comparative Example 3 0.0189 65.2 -57.2

[0067] As can be seen from Table 1:

[0068] Comparing Examples 1-3 and Comparative Examples 2-3, it can be seen that Example 1 has the highest wax dissolution rate, reaching 0.0430 g / min, while the wax dissolution rates of the other examples are all higher than 0.0300 g / min. The wax dissolution rates of Comparative Examples 2-3 are relatively low. This is mainly because the cyclic diene acts as one of the main solvents in the wax-removing agent, playing a role in dissolving the wax sample. Comparative Examples 2-3 do not contain cyclic dienes.

[0069] By comparing Examples 1 to 3, it can be seen that Example 1 has the highest wax dissolution rate, reaching 0.0430 g / min, while the wax dissolution rates of the other examples are relatively low. This shows that different contents of raw materials and components in this invention will affect the wax dissolution rate of the wax remover.

[0070] Comparative Examples 1-3 and 3 show that the mixing rate of the raw material components in this invention is relatively high. This is because esters and amines, as the main solvents, have a certain decomposition and breaking effect on wax deposits. The three main solvents have a certain synergistic effect when mixed.

[0071] By comparing Example 1 and Example 4, it can be seen that the heating temperature, stirring speed and time have a certain influence on the effect of the wax removal agent in this invention. This is mainly because, under appropriate heating temperature, stirring speed and time, the cyclic dienes, esters and amines can be completely mixed and have good interaction.

[0072] As can be seen from the table above, the flash points of Examples 1-4 and Comparative Examples 1-3 are all above 50°C, and the freezing points are all below -57°C, indicating good safety and applicability.

[0073] The invention has been described with reference to typical embodiments, but it should be understood that the terms used herein are descriptive and explanatory, not limiting. Modifications and revisions can be made to the invention within the scope of the claims as specified herein, without departing from the scope and spirit of the invention. Although the invention described herein relates to specific methods, materials, and embodiments, it does not mean that the invention is limited to the specific examples disclosed herein; on the contrary, the invention can be extended to all other methods and applications having the same function.

Claims

1. An oil-based chemical wax remover for oilfield use, comprising the following components: Cyclic dienes, esters, amines, alcohols; The oil-based chemical wax remover is composed of the following components in the indicated mass percentages: cyclic dienes 20 wt.%~45 wt.%, esters 20 wt.%~45 wt.%, amines 20 wt.%~45 wt.%, and alcohols 5 wt.%~10 wt.%. The cyclic diene is selected from one or more of terpinene, cycloterpinene, and limonene; The esters are one or more of C2-C8 acids and C2-C8 esters, and their structural formulas are shown in Formula I: In Formula I, n is a natural number from 2 to 8; The amines are tertiary amines with long-chain alkanes having a C3-C16 structure; The alcohols are C5-C8 alcohols.

2. The preparation method of the oil-based chemical dewaxing agent for oilfields according to claim 1 includes the following steps: heating, mixing and stirring the cyclic dienes, esters and amines until uniform for a period of time, adding alcohols and stirring until uniform for a period of time, and cooling to room temperature to obtain the product.

3. The preparation method according to claim 2, characterized in that: The heating temperature is 50~60℃.

4. The preparation method according to claim 2 or 3, characterized in that: The cyclic dienes, esters, and amines are mixed and stirred evenly for 30-45 minutes. Alternatively, the stirring time for adding the alcohol is 15-20 minutes; Alternatively, the stirring speed is 200-300 rpm.

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