Emulsion type paraffin removal and inhibition agent and preparation method thereof

Abstract

The invention provides an emulsion type paraffin removal and inhibition agent and a preparation method thereof. The emulsion type paraffin removal and inhibition agent is prepared from the following components in percentage by volume: 45 to 70 percent of oil phase solvent, 1.5 to 4.5 percent of emulsifier, 0.5 to 3.5 percent of surfactant, 0.5 to 3.5 percent of mutual solvent, 0.2 to 1.5 percent of alkaline regulator and 25 to 42 percent of water phase. The emulsion type paraffin remover and inhibitor prepared by the invention has the advantages that the organochlorine content is 0, the carbon disulfide content is 0, the emulsion type paraffin remover and inhibitor is environment-friendly, safe and easy to store, and the flash point is greater than 58 DEG C; the paraffin removal agent is high in paraffin removal capacity and good in stability, can stably exist for more than 7 days under the ground condition, and can quickly demulsify at the oil well paraffin precipitation temperature, the field static paraffin dissolution rate is greater than 0.065 g / min, and the maximum dynamic paraffin dissolution rate can reach 0.092 g / min; the paraffin remover and inhibitor has a remarkable effect on pour point depressing and viscosity reduction of crude oil, can be applied at low temperature, and at the low temperature of-10 DEG C, the static paraffin removal rate is still kept to be 0.013 g / min or above, and the dynamic paraffin removal rate is kept to be 0.035 g / min or above.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield applied chemistry, and in particular relates to an emulsion type wax removing and preventing agent and a preparation method thereof. Background Art

[0002] In the field of oil extraction, paraffin is an alkane with carbon atoms between 16 and 64 in crude oil. When in the formation, the wax in crude oil usually exists in a dissolved state. During the crude oil extraction process, as the temperature and pressure decrease and the dissolved gas escapes, the wax precipitates, grows, aggregates and deposits on the walls of the oil pipeline and the gathering and transportation pipeline in the form of crystals, causing pipeline blockage, excessive system load and other problems.

[0003] How to enhance the wax removal and wax prevention effects of wax removal and prevention agents and ensure the environmental friendliness, safety and stability of the agents is a major issue in the current research work on wax removal agents.

[0004] Chemical wax removal and prevention technology is to add chemical wax removal and prevention agents to reduce the wax deposition rate, change the fluidity of crude oil, slow down and inhibit the formation of wax crystals. Commonly used wax removal and prevention agents are oil-based wax removal and prevention agents and water-based wax removal and prevention agents. Among them, oil-based wax removal and prevention agents dissolve wax faster, but are generally highly toxic, have single properties, are flammable and explosive, and have poor safety.

[0005] Water-based wax removers use water as a dispersion medium, are green and non-toxic, and mainly remove wax attached to the surface of metal workpieces through the reversal, wetting, penetration and cleaning effects of surfactants. For example, the Chinese invention patent with application number CN201610650119.2 discloses a crude oil efficient water-based wax remover, which is based on the mass of maleic anhydride monomer and has a weight composition of maleic anhydride, 0.3 to 0.7 times of methacrylic acid, 0.8 to 1.2 times of sodium allyl sulfonate, and 0.04 to 0.08 times of initiator ammonium persulfate. The preparation method of the crude oil high-efficiency water-based wax remover and wax preventer is as follows: (1) Solution preparation: maleic anhydride, methacrylic acid, sodium allyl sulfonate and initiator ammonium persulfate are respectively prepared into 10-20% aqueous solution with distilled water; (2) Synthesis reaction: stirring, heating the sodium allyl sulfonate solution to 80-90°C, adding a mixed solution of maleic anhydride and methacrylic acid monomers and an initiator ammonium persulfate solution, and reacting at a constant temperature for 1-2 hours; (3) pH adjustment: adjusting the pH value to 5-7 with NaOH. Although the water-based wax remover and wax preventer is simple to prepare, easy to use, and has high wax removal and wax prevention efficiency, its use effect is controlled by temperature. The water-based wax remover and wax preventer has a slow effect rate when added to the oil well, and its fluidity needs to be further improved when used in the severe winter, and its promotion and application scope is limited. Summary of the invention

[0006] Since oil-based wax removers and water-based wax removers and wax inhibitors each have certain disadvantages, the first purpose of the present invention is to provide a safe and efficient emulsion-type wax remover and wax inhibitor that can both remove wax and prevent wax, has good demulsification performance, and is stable in storage. The second purpose is to provide a method for preparing an emulsion-type wax remover and wax inhibitor.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows: An emulsion type wax remover and wax inhibitor, comprising the following components by volume percentage: Oil phase solvent 45~70%, emulsifier 1.5%~4.5%, surfactant 0.5%~3.5%, mutual solvent 0.5~3.5%, alkaline regulator 0.2~1.5%, aqueous phase 25%~42%. Furthermore, the oil phase solvent is a mixture of xylene, kerosene, cyclohexane, n-heptane and petroleum ether in a volume ratio of (8-13): (6-11): (4-10): (0.5-3.5): (6-12).

[0008] Preferably, the oil phase solvent is a mixture of xylene, kerosene, cyclohexane, n-heptane and petroleum ether in a volume ratio of (8-13): (6-10): (4-8): (0.5-2.0): (6-9).

[0009] Preferably, the oil phase solvent is a mixture of xylene, kerosene, cyclohexane, n-heptane and petroleum ether in a volume ratio of 10:9:7:1:6.

[0010] Furthermore, the emulsifier is one or a mixture of two of emulsifier NP-40 and emulsifier OP-10.

[0011] Preferably, the emulsifier is a mixture of NP-40 and OP-10 in a volume ratio of 1:1.

[0012] Furthermore, the surfactant is one or a mixture of Tween 80, Peregal 25, surfactant NP10, penetrant JFC, and coconut oil fatty acid diethanolamide 6501.

[0013] Preferably, the surfactant is a mixture of Peregal 25 and a penetrant JFC in a volume ratio of 1:1.

[0014] Furthermore, the mutual solvent is one or a mixture of n-octanol, n-pentanol, methanol, isopropanol, ethylene glycol, and alcohol ether.

[0015] Furthermore, the mutual solvent is a mixture of n-pentanol and ethylene glycol butyl ether in a volume ratio of 7:1.

[0016] Furthermore, the alkaline regulator is one of sodium oleate and sodium salicylate or a mixture of both.

[0017] A method for preparing an emulsion type wax removing and wax preventing agent comprises the following steps: (1) Mix petroleum ether, kerosene, xylene, cyclohexane and n-heptane in a certain volume ratio to form the oil phase; (2) Add a certain volume of emulsifier, surfactant and mutual solvent to the prepared oil phase in sequence, and stir and mix them evenly at a stirring speed of 120-180 r / min to form a mixed solution; (3) preparing an aqueous solution of an alkaline regulator as a water phase; (4) Slowly add the aqueous phase prepared in step (3) into the mixed solution prepared in step (2), and stir the mixture rapidly at a stirring speed of 500 r / min to obtain an emulsion type wax remover and wax inhibitor.

[0018] Compared with the existing wax removal agent, the present invention has the following beneficial effects: The prepared emulsion type wax removing and wax preventing agent has 0 organic chlorine content and 0 carbon disulfide content, is environmentally friendly and safe, easy to store, and has a flash point greater than 58°C; has strong wax removing ability and good stability, can stably exist for more than 7 days under ground conditions, can quickly demulsify at the waxing temperature of the oil well, has an on-site static wax dissolving rate greater than 0.065 g / min, and a dynamic wax dissolving rate of up to 0.092 g / min; has a significant effect on reducing the pour point and viscosity of crude oil; the wax removing and wax preventing agent can be used at low temperatures, and at a low temperature of -10°C, the static wax removing rate is still maintained at more than 0.013 g / min, and the dynamic wax removing rate is maintained at more than 0.035 g / min.

[0019] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below.

[0021] Figure 1 This is a wax block test sample before being treated with a wax remover; Figure 2 This is a wax block experimental sample after being treated with a wax remover. DETAILED DESCRIPTION

[0022] The content of the present invention can be further understood by combining the following detailed description of the preferred implementation method of the present invention and the embodiments included. Unless otherwise stated, all technical and scientific terms used in this article have the same meaning as those of ordinary skill in the art to which the present invention belongs. If the definition of a specific term disclosed in the prior art is inconsistent with any definition provided in the present invention, the definition of the term provided in the present invention shall prevail.

[0023] It should be noted that the implementation conditions used in the examples can be further adjusted according to the specific experimental environment, and the implementation conditions not specified are usually the conditions in conventional experiments. The preparation methods mentioned in the present invention are all conventional methods unless otherwise specified; the various chemical reagents and chemicals mentioned in the following examples / in the present invention are all chemical reagents and chemicals known and used in the prior art unless otherwise specified.

[0024] The invention discloses an emulsion type wax removing and preventing agent, which comprises the following components in volume percentage: 45-70% of an oil phase solvent, 1.5-4.5% of an emulsifier, 0.5-3.5% of a surfactant, 0.5-3.5% of a mutual solvent, 0.2-1.5% of an alkaline regulator and 25-42% of an aqueous phase. The above-mentioned oil phase solvent is a mixture of xylene, kerosene, cyclohexane, n-heptane, and petroleum ether in a volume ratio of (8-13): (6-11): (4-10): (0.5-3.5): (6-12). The above-mentioned oil phase solvent is preferably a mixture of xylene, kerosene, cyclohexane, n-heptane, and petroleum ether in a volume ratio of (8-13): (6-10): (4-8): (0.5-2.0): (6-9). The oil phase solvent is best selected to be a mixture of xylene, kerosene, cyclohexane, n-heptane, and petroleum ether in a volume ratio of 10:9:7:1:6.

[0025] The emulsifier is one or a mixture of emulsifier NP-40 and emulsifier OP-10. The emulsifier is preferably a mixture of NP-40 and OP-10 in a volume ratio of 1:1.

[0026] The above-mentioned surfactant is one or a mixture of Tween 80, Peregal 25, surfactant NP10, penetrant JFC, and coconut oil fatty acid diethanolamide 6501.

[0027] Preferably, the surfactant is a mixture of Peregal 25 and a penetrant JFC in a volume ratio of 1:1.

[0028] The above-mentioned mutual solvent is one or a mixture of n-octanol, n-pentanol, methanol, isopropanol, ethylene glycol, and alcohol ether. The above-mentioned mutual solvent is preferably a mixture of n-pentanol and ethylene glycol butyl ether in a volume ratio of 7:1. The best choice of mutual solvent is ethylene glycol butyl ether.

[0029] The alkaline regulator is one of sodium oleate and sodium salicylate or a mixture of the two, and the best choice is sodium salicylate.

[0030] The present invention also provides a method for preparing an emulsion type wax removing and wax preventing agent, comprising the following steps: (1) Mix petroleum ether, kerosene, xylene, cyclohexane and n-heptane in a certain volume ratio to form the oil phase; (2) Add a certain volume of emulsifier, surfactant and mutual solvent to the prepared oil phase in sequence, and stir and mix them evenly at a stirring speed of 120-180 r / min to form a mixed solution; (3) preparing an aqueous solution of an alkaline regulator as a water phase; (4) Slowly add the aqueous phase prepared in step (3) into the mixed solution prepared in step (2), and stir the mixture rapidly at a stirring speed of 500 r / min to obtain an emulsion type wax remover and wax inhibitor.

[0031] Example 1 The raw materials of the emulsion type wax removing and preventing agent provided in this embodiment include: 600 mL of oil phase solvent, 35 mL of emulsifier, 25 mL of surfactant, 5 mL of mutual solvent, 10 mL of alkaline regulator, and 325 mL of distilled water.

[0032] In this embodiment, the oil phase solvent is a mixture of xylene, kerosene, cyclohexane, n-heptane, and petroleum ether in a volume ratio of 10:9:7:1:6, the emulsifier is a mixture of NP-40 and OP-10 in a volume ratio of 1:1, the surfactant is a mixture of Peregal 25 and the penetrant JFC in a volume ratio of 1:1, the mutual solvent is ethylene glycol butyl ether, and the alkaline regulator is sodium salicylate.

[0033] Example 2 The raw materials of the emulsion type wax removing and preventing agent provided in this embodiment include: 600 mL of oil phase solvent, 35 mL of emulsifier, 25 mL of surfactant, 5 mL of mutual solvent, 10 mL of alkaline regulator, and 325 mL of distilled water.

[0034] In this embodiment, the oil phase solvent used is a mixture of xylene, kerosene, cyclohexane, n-heptane, and petroleum ether in a volume ratio of 10:7:5:2:7, and the amounts and volume ratios of other raw materials are the same as those in Example 1.

[0035] Example 3 The raw materials of the emulsion type wax removing and preventing agent provided in this embodiment include: 550 mL of oil phase solvent, 25 mL of emulsifier, 15 mL of surfactant, 35 mL of mutual solvent, 15 mL of alkaline regulator, and 360 mL of distilled water.

[0036] The oil phase solvent, emulsifier, surfactant, mutual solvent and alkaline regulator of this embodiment are the same as those of embodiment 1.

[0037] Example 4 The raw materials of the emulsion type wax removing and preventing agent provided in this embodiment include: 550 mL of oil phase solvent, 25 mL of emulsifier, 15 mL of surfactant, 35 mL of mutual solvent, 15 mL of alkaline regulator, and 360 mL of distilled water.

[0038] In this example, the emulsifier used is OP-10, and the amounts and volume ratios of other raw materials are the same as those in Example 3.

[0039] Example 5 The raw materials of the emulsion type wax removing and preventing agent provided in this embodiment include: 550 mL of oil phase solvent, 25 mL of emulsifier, 15 mL of surfactant, 35 mL of mutual solvent, 15 mL of alkaline regulator, and 360 mL of distilled water.

[0040] In this embodiment, the emulsifier used is NP-40 emulsifier, and the amounts and volume ratios of other raw materials are the same as those in Example 3.

[0041] Example 6 The raw materials of the emulsion type wax removing and preventing agent provided in this embodiment include: 550 mL of oil phase solvent, 25 mL of emulsifier, 15 mL of surfactant, 35 mL of mutual solvent, 15 mL of alkaline regulator, and 360 mL of distilled water.

[0042] In this embodiment, the surfactant used is Peregal 25, and the amounts and volume ratios of other raw materials are the same as those in Example 1.

[0043] Example 7 The raw materials of the emulsion type wax removing and preventing agent provided in this embodiment include: 550 mL of oil phase solvent, 25 mL of emulsifier, 15 mL of surfactant, 35 mL of mutual solvent, 15 mL of alkaline regulator, and 360 mL of distilled water.

[0044] In this embodiment, the mutual solvent used is a mixture of n-pentanol and ethylene glycol butyl ether in a volume ratio of 7:1, and the amounts and volume ratios of other raw materials are the same as those in Example 3.

[0045] The emulsion type wax removing and preventing agent prepared by the present invention has an organic chlorine content of 0 and a carbon disulfide content of 0, is environmentally friendly, safe and easy to store.

[0046] The following tests were carried out on the prepared emulsion wax remover and wax inhibitor: 1. Flash point determination With reference to "Determination of Flash Point (Closed-loop Method)" (GB / T 261-2008), the flash points of the emulsion wax removers and wax inhibitors prepared in Examples 1-7 were measured using a flash point tester. The experimental data are shown in Table 1.

[0047] Table 1 Flash point of the emulsion type wax remover and wax inhibitor The results show that the flash points of the emulsion wax remover and wax inhibitor prepared by the present invention are all greater than 58°C.

[0048] 2. Determination of the Pour Point Depression Rate The pour point depression rate refers to the rate of decrease in the freezing point of crude oil, which is determined by referring to the freezing point determination method for crude oil (SY / T 0541-2009). The experimental data are shown in Table 2 below.

[0049] Table 2 Changes in the freezing point of crude oil before and after adding chemicals The results show that the emulsion type wax removal and wax inhibitor prepared by the present invention has a significant effect on depressing the pour point of crude oil.

[0050] 3. Wax removal rate Static and dynamic wax removal rate test at 1.25℃ Experimental methods: Measure 20 mL of the paraffin remover to be tested, record it as V, and transfer it into a 25 mL stoppered test tube. Place the stoppered test tube in a constant temperature water bath at 25℃±1℃ and keep the temperature constant for 10 min.

[0051] Pour the melted wax sample into the prepared mold, and hang a thin wire on the upper end of the mold. After the liquid wax cools into a wax block, the thin wire is passed through the middle. After the wax block cools, remove the wax block. Figure 1 shown.

[0052] Place the thin wire with the wax block hanging on it into a thermostatically controlled test tube with a stopper, tie the other end to the bottle cap, cover it tightly, and keep it in a 25℃ water bath for a certain period of time. Then take out the wax block. Figure 2 As shown, weigh after drying, and calculate the wax removal rate of the wax removal agent according to the following formula. The experimental results are shown in Table 3: The wax removal rate calculation formula is: Where: f——wax removal rate, %; m0——mass of the initial wax block, g; m1——The remaining mass of the wax block after being immersed in the treatment agent for a certain period of time, g.

[0053] The deviation between two consecutive measurement results should be ≤1.0%.

[0054] Table 3 shows the static and dynamic wax removal rates at 25°C Judging from the static wax removal rate and the dynamic wax removal rate, the compounded wax removal and wax prevention agent has a very good wax removal effect. The static wax removal rate at 25°C reaches 0.017 g / min, and the dynamic wax removal rate reaches 0.043 g / min.

[0055] 2. Static and dynamic wax removal rate test at -10℃ The emulsion wax removal and wax inhibitor prepared in Examples 1-3 were subjected to static and dynamic wax removal rate tests at a low temperature of -10°C. The test results are shown in Table 4: Table 4 shows the static and dynamic wax removal rates at -10°C It can be seen from Table 4 that even at a low temperature of -10°C, the static wax removal rate of the wax removal and wax inhibitor is still maintained at above 0.013g / min, and the dynamic wax removal rate is maintained at above 0.035g / min. Although the wax removal rate is not as fast as at room temperature, it can still achieve a good wax removal effect at such a low temperature, proving that the wax removal and wax inhibitor does have a high practical value.

[0056] 4. Wax removal effect test The emulsion type wax removal and wax inhibitor prepared by the present invention was tested for static and dynamic wax removal rates and wax removal effects at 45°C. The test results are shown in Tables 5 and 6.

[0057] Static wax dissolution rate test: The dosage of the agent is 20 mg / L. At 45°C, the wax removal rate of the wax removal and prevention agent for different well wax samples is shown in Table 5.

[0058] Table 5 Static wax removal rate of different oil well wax samples Dynamic wax dissolution rate: When the dosage of the agent is 20 mg / L and the temperature is 45°C, the wax removal rate of the wax removal and prevention agent for wax samples from different wells is shown in Table 2.

[0059] Table 6 Dynamic wax removal rate of different oil well wax samples Judging from the static wax removal rate and the dynamic wax removal rate, the compounded wax removal and prevention agent has a very good wax removal effect, with an average wax removal rate of 0.084 g / min and a maximum of 0.092 g / min.

[0060] 5. On-site dosing test The average wax cleaning cycle before and after adding the drug was used as the evaluation standard and compared with the existing average wax cleaning cycle on site, as shown in Table 7.

[0061] Table 7 Wax cleaning cycle summary It can be seen from Table 7 that the wax cleaning cycle is significantly extended before and after adding the drug. The wax cleaning and wax prevention agent has good wax cleaning and wax prevention effects, which prolongs the wax cleaning time from an average of 1.5 months / time to 8.75 months / time, or even longer. In other words, the wax cleaning cycle is reduced from 8 times / year to 1.37 times / year. Based on the average cost of adding drug per time of 10,000 yuan, each well saves 66,300 yuan per year, and the economic benefits of promotion and application are significant.

[0062] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, without departing from the technical principles of the present invention, the skilled person can design many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed in this application. More specifically, within the scope of the disclosure, drawings and claims of this application, various modifications and improvements can be made to the components and / or layout of the subject combination layout. In addition to the deformation and improvement of the components and / or layout, other uses will also be obvious to those skilled in the art.

Claims

1. An emulsion type wax removing and wax preventing agent, characterized in that: The composition includes the following components by volume percentage: Oil phase solvent 45~70%, emulsifier 1.5%~4.5%, surfactant 0.5%~3.5%, mutual solvent 0.5~3.5%, alkaline regulator 0.2~1.5%, aqueous phase 25%~42%.

2. The emulsion type wax removing and wax preventing agent according to claim 1, characterized in that: The oil phase solvent is a mixture of xylene, kerosene, cyclohexane, n-heptane and petroleum ether in a volume ratio of (8-13): (6-11): (4-10): (0.5-3.5): (6-12).

3. The emulsion type wax removing and wax preventing agent according to claim 1 or 2, characterized in that: The oil phase solvent is a mixture of xylene, kerosene, cyclohexane, n-heptane and petroleum ether in a volume ratio of (8-13): (6-10): (4-8): (0.5-2.0): (6-9).

4. The emulsion type wax removing and wax preventing agent according to claim 1, characterized in that: The emulsifier is one of emulsifier NP-40 and emulsifier OP-10 or a mixture of both.

5. The emulsion type wax removing and wax preventing agent according to claim 1, characterized in that: The surfactant is one or a mixture of Tween 80, Peregal 25, surfactant NP10, penetrant JFC, and coconut oil fatty acid diethanolamide 6501.

6. The emulsion type wax removing and wax preventing agent according to claim 1, characterized in that: The surfactant is prepared by mixing Peregal 25 and the penetrant JFC in a volume ratio of 1:

1.

7. The emulsion type wax removing and wax preventing agent according to claim 1, characterized in that: The mutual solvent is one or a mixture of n-octanol, n-pentanol, methanol, isopropanol, ethylene glycol and alcohol ether.

8. The emulsion type wax removing and wax preventing agent according to claim 1 or 7, characterized in that: The mutual solvent is a mixture of n-pentanol and ethylene glycol butyl ether in a volume ratio of 7:

1.

9. The emulsion type wax removing and wax preventing agent according to claim 1, characterized in that: The alkaline regulator is one of sodium oleate and sodium salicylate or a mixture of the two.

10. A method for preparing an emulsion type wax removing and wax inhibiting agent, characterized in that: The following steps are involved: (1) Mix petroleum ether, kerosene, xylene, cyclohexane and n-heptane in a certain volume ratio to form the oil phase; (2) Add a certain volume of emulsifier, surfactant and mutual solvent to the prepared oil phase in sequence, and stir and mix them evenly at a stirring speed of 120-180 r / min to form a mixed solution; (3) preparing an aqueous solution of an alkaline regulator as a water phase; (4) Slowly add the aqueous phase prepared in step (3) into the mixed solution prepared in step (2), and stir the mixture rapidly at a stirring speed of 500 r / min to obtain an emulsion type wax remover and wax inhibitor.

Images