Hyperbranched polyamide acrylate demulsifiers, methods of making and use

Abstract

The application relates to the technical field of demulsifier preparation, and is a hyperbranched polyamide ethyl acrylate demulsifier and a preparation method and application thereof, which are prepared according to the following steps: a required amount of diethyleneglycol amine, maleic anhydride and excessive triethylamine are mixed in a reaction container, constant temperature reaction is carried out, the obtained crude product diethyleneglycol difumarate is washed with dilute hydrochloric acid and rotary evaporated, the liquid phase is collected, column chromatography is used for purification, the purified diethyleneglycol difumarate is added into a solvent which is mutually soluble, a catalyst is further added, after reaction, the solvent and the catalyst are removed, diethyleneglycol amine and triethylamine are added into the obtained reaction product and reacted, and the hyperbranched polyamide ethyl acrylate demulsifier is obtained. The synthetic raw material is cheap and low-toxic, meanwhile, the demulsifier has strong adaptability to the temperature, water content and crude oil viscosity of crude oil emulsion, the preparation process is simple, the cost is low, the demulsification effect is good, and the demulsifier is a novel technical approach for solving the formation emulsion pollution.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of demulsifier preparation, and is a hyperbranched polyamide ethyl acrylate demulsifier, a preparation method and application thereof. BACKGROUND

[0002] With the gradual acceleration of oil development and the development of tertiary oil recovery technology, the water content of oil and gas produced fluid is increasing, and the amount of O / W emulsion to be treated is increasing sharply. At the same time, the aging oil produced by the tertiary oil recovery process, oil transportation process, microbial action, dirty oil and fallen crude oil can produce viscous W / O emulsion, shorten the service life of equipment and materials, and are difficult to treat. During the development of oil and gas field reservoirs, such as enhanced oil recovery, fracturing and drilling, a large amount of non-flowing emulsion is produced in the near wellbore pore throat due to the immiscibility of water-based phase and oil phase, the reservoir water lock and Jiamin damage are aggravated, which reduces the oil and gas well production or increases the production (lifting) cost.

[0003] Therefore, it is urgent to design a hyperbranched polyamide ethyl acrylate demulsifier to realize the oil-water separation of near wellbore emulsion and ground emulsion, achieve the purpose of cleaning near wellbore and inhibiting emulsion pollution, and further improve the oil and gas development efficiency and reduce the oil and gas development cost, which has high strategic significance for oil and gas stable production and environmental protection process. SUMMARY

[0004] The present application provides a hyperbranched polyamide ethyl acrylate demulsifier, a preparation method and application thereof, which overcomes the shortcomings of the prior art. It can effectively solve the problem of existing formation pore throat producing a large amount of non-flowing emulsion, reservoir water lock and Jiamin effect damage during oil production, fracturing, reservoir development and other processes, thereby reducing the oil and gas well production or increasing the production (lifting) cost.

[0005] One of the technical solutions of the present application is realized by the following measures: a hyperbranched polyamide ethyl acrylate demulsifier, the structural formula is:

[0006]

[0007] The following is a further optimization or / and improvement of the above-mentioned one of the technical solutions:

[0008] The above is prepared by the following steps: first, a desired amount of diethylene glycol amine, maleic anhydride and excess triethylamine are mixed in a reaction vessel, constant temperature reaction is carried out, and a crude product diethylene glycol difumarate is obtained; second, the crude product diethylene glycol difumarate is washed with dilute hydrochloric acid and rotary evaporated, the liquid phase is collected, and column chromatography is used for purification to obtain purified diethylene glycol difumarate; third, a solvent is added to a desired amount of purified diethylene glycol difumarate and stirred until completely miscible, a desired amount of catalyst is added, and reaction is carried out under negative pressure; after the reaction is cooled, the solvent and catalyst are removed, and a reaction product is obtained; fourth, excess diethylene glycol amine and triethylamine are added to the reaction product, constant temperature reaction is carried out again, and after the reaction is cooled and concentrated, a light yellow viscous liquid, i.e. the hyperbranched polyamide ethyl acrylate demulsifier, is obtained.

[0009] In the first step, the molar ratio of diethylene glycol amine to maleic anhydride is 1:2.1.

[0010] In the first step, the constant temperature reaction temperature is room temperature, and the reaction time is 5h.

[0011] In the third step, the solvent is N,N-dimethylformamide, and 50mL of N,N-dimethylformamide is added per 0.05mol of purified diethylene glycol difumarate.

[0012] In the third step, the catalyst is p-toluenesulfonic acid, and 0.02mol of p-toluenesulfonic acid is added per 0.05mol of purified diethylene glycol difumarate.

[0013] In the third step, the reaction temperature is 130℃, and the reaction time is 10h.

[0014] In the fourth step, the constant temperature reaction temperature is 50℃, and the reaction time is 5.5h.

[0015] The second technical solution of the present application is realized by the following measures: a preparation method of a hyperbranched polyamide ethyl acrylate demulsifier, which is carried out by the following steps: first, a desired amount of diethylene glycol amine, maleic anhydride and excess triethylamine are mixed in a reaction vessel, constant temperature reaction is carried out, and a crude product diethylene glycol difumarate is obtained; second, the crude product diethylene glycol difumarate is washed with dilute hydrochloric acid and rotary evaporated, the liquid phase is collected, and column chromatography is used for purification to obtain purified diethylene glycol difumarate; third, a solvent is added to a desired amount of purified diethylene glycol difumarate and stirred until completely miscible, a desired amount of catalyst is added, and reaction is carried out under negative pressure; after the reaction is cooled, the solvent and catalyst are removed, and a reaction product is obtained; fourth, excess diethylene glycol amine and triethylamine are added to the reaction product, constant temperature reaction is carried out again, and after the reaction is cooled and concentrated, a light yellow viscous liquid, i.e. the hyperbranched polyamide ethyl acrylate demulsifier, is obtained.

[0016] The third technical scheme of the present application is realized by the following measure: application of the hyperbranched polyamide ethyl acrylate demulsifier in eliminating emulsion damage in the near wellbore zone of the oil and gas reservoir and in oil-water separation of the produced liquid.

[0017] The synthetic raw material of the present application is cheap and low-toxic, and has strong adaptability to the temperature, water content and crude oil viscosity of the crude oil emulsion, and the preparation process is simple, the cost is low, and the demulsification effect is good. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is an infrared spectrum of the hyperbranched polyamide ethyl acrylate demulsifier of the present application. Figure 1 Figure 2 is a graph of the relationship between the surface tension and the concentration of the hyperbranched polyamide ethyl acrylate demulsifier of the present application.

[0019] Figure 2 Figure 3 is a graph of the effect of the demulsifier content on the dehydration rate of the emulsion in the static demulsification experiment of the hyperbranched polyamide ethyl acrylate demulsifier of the present application.

[0020] Figure 4 is a graph of the effect of the temperature on the dehydration rate of the emulsion in the static demulsification experiment of the hyperbranched polyamide ethyl acrylate demulsifier of the present application. Figure 3 Figure 5 is a graph of the effect of the water content of the emulsion on the dehydration rate of the emulsion in the static demulsification experiment of the hyperbranched polyamide ethyl acrylate demulsifier of the present application.

[0021] Figure 4 Figure 6 is a graph of the effect of the viscosity of the crude oil on the dehydration rate of the emulsion in the static demulsification experiment of the hyperbranched polyamide ethyl acrylate demulsifier of the present application.

[0022] Figure 7 is a graph of the dehydration rate of the emulsion with different demulsifiers in the static demulsification experiment of the hyperbranched polyamide ethyl acrylate demulsifier of the present application. Figure 5 Figure 8 is a graph of the dehydration rate of the emulsion with different demulsifiers in the static demulsification experiment of the hyperbranched polyamide ethyl acrylate demulsifier of the present application.

[0023] Figure 6 Figure 9 is a graph of the dehydration rate of the emulsion with different demulsifiers in the static demulsification experiment of the hyperbranched polyamide ethyl acrylate demulsifier of the present application.

[0024] Figure 10 is a graph of the dehydration rate of the emulsion with different demulsifiers in the static demulsification experiment of the hyperbranched polyamide ethyl acrylate demulsifier of the present application. Figure 7 DETAILED DESCRIPTION

[0025] The present application is not limited by the following examples, and the specific implementation can be determined according to the technical scheme of the present application and the actual situation. The various chemical reagents and chemical supplies mentioned in the present application are generally known and commonly used chemical reagents and chemical supplies in the prior art unless otherwise specified. The normal temperature and room temperature in the present application generally refer to a temperature of 15℃ to 25℃, and are generally defined as 25℃.

[0026] The present application will be further described below in conjunction with examples:

[0027] ​​​​Example 1: The hyperbranched polyamide ethyl acrylate demulsifier, the structural formula is:

[0028]

[0029] The synthesis route of the hyperbranched polyamide ethyl acrylate (P-DAEA) in the application is as follows:

[0030]

[0031] In the formula, DGA is diethyleneglycol amine, TEA is triethylamine, TsOH is p-toluene sulfonic acid, and P-DAEA is the target product hyperbranched polyamide ethyl acrylate.

[0032] Example 2: As an optimization of the above example, the following steps are taken: in the first step, a required amount of diethyleneglycol amine, maleic anhydride and excess triethylamine are mixed in a reaction container and subjected to constant temperature reaction to obtain a crude product diethyleneglycol difumarate; in the second step, the crude product diethyleneglycol difumarate is washed with dilute hydrochloric acid and subjected to rotary evaporation, and then the liquid phase is collected and purified by column chromatography to obtain purified diethyleneglycol difumarate; in the third step, a solvent is added to the required amount of purified diethyleneglycol difumarate and stirred until complete mutual solubility, and then a required amount of catalyst is added and subjected to reaction under negative pressure, and after the reaction product is cooled, the solvent and catalyst are removed to obtain a reaction product; in the fourth step, excess diethyleneglycol amine and triethylamine are added to the reaction product, and then constant temperature reaction is carried out, and after the reaction is cooled and concentrated, a light yellow viscous liquid, i.e. the hyperbranched polyamide ethyl acrylate demulsifier, is obtained.

[0033] In the application, diethyleneglycol amine is selected because it not only has certain surface activity itself, but also can provide amine groups and hydroxyl groups, and can be subjected to amidation and esterification reactions; and it has low cost, good water solubility, good wettability and strong reaction activity, and is a good polymerization raw material.

[0034] Maleic anhydride can be subjected to amidation reaction with primary amine, has strong reaction activity and low boiling point, has low synthesis and processing cost, and is very suitable for being used as an oil and gas field chemical raw material. After maleic anhydride is subjected to amidation with diethyleneglycol amine, carboxyl groups required for esterification reaction are provided for the hyperbranched structure.

[0035] In the first step of the preparation process of the hyperbranched polyamide ethyl acrylate demulsifier, triethylamine is selected as an acid-binding agent and catalyst because it has low cost, high catalytic efficiency, can be combined with carboxyl groups, avoids the reaction from being unable to proceed due to the protonation of amine caused by carboxylic acid, and can be washed to weak acidity with dilute hydrochloric acid, is insoluble in water and is easy to remove after rotary evaporation.

[0036] Example 3: As an optimization of the above example, in the first step, the molar ratio of diethyleneglycol amine to maleic anhydride is 1:2.1.

[0037] Example 4: As an optimization of the above examples, in the first step, the constant temperature reaction temperature is room temperature, and the reaction time is 5h.

[0038] In the present application, in the first step of the preparation process of the hyperbranched polyamide ethyl acrylate demulsifier, the temperature of the constant temperature reaction is controlled at room temperature, so that maleic anhydride can be amidated with primary amine under mild conditions, and the reaction time is controlled at 5h to ensure sufficient reaction of the reactants. If the reaction time is less than 5h, the reaction is insufficient and the conversion rate is low. If the reaction time is greater than 5h, the conversion rate does not change significantly. Considering the conversion rate, time cost and energy consumption, the reaction time at room temperature is selected as 5h.

[0039] Example 5: As an optimization of the above examples, in the third step, the solvent is N,N-dimethylformamide (DMF), and 50mL of N,N-dimethylformamide is added to every 0.05mol of purified diethylene glycol difumarate.

[0040] Example 6: As an optimization of the above examples, in the third step, the catalyst is p-toluenesulfonic acid, and 0.02mol of p-toluenesulfonic acid is added to every 0.05mol of purified diethylene glycol difumarate.

[0041] Example 7: As an optimization of the above examples, in the third step, the reaction temperature is 130℃, and the reaction time is 10h.

[0042] In the present application, in the third step of the preparation process of the hyperbranched polyamide ethyl acrylate demulsifier, p-toluenesulfonic acid is selected as the catalyst for the hyperbranched (esterification) reaction because of its low cost and high catalytic efficiency. The constant temperature of 130℃ under negative pressure is because esterification reaction needs to be carried out at high temperature. Negative pressure reduces the reaction temperature and the corresponding reaction activation energy. Above 130℃, the conversion rate does not change significantly and by-products are easily produced. Below this temperature, esterification reaction cannot be carried out. If the reaction time is less than 10h, the reaction is insufficient and the conversion rate is low. If the reaction time is greater than 10h, the conversion rate does not change significantly. Considering the conversion rate, time cost and energy consumption, the reaction time at room temperature is selected as 10h.

[0043] Example 8: As an optimization of the above examples, in the fourth step, the constant temperature reaction temperature is 50℃, and the reaction time is 5.5h.

[0044] In the present application, in the fourth step of the preparation process of the hyperbranched polyamide ethyl acrylate demulsifier, the optimal reaction temperature is selected as 50℃, and the optimal reaction time is 5.5h, which can reduce by-products and reduce the cost of raw materials and reaction.

[0045] Example 9: The preparation method of the hyperbranched polyamide ethyl acrylate demulsifier is carried out according to the following steps: first, a required amount of diethyleneglycol amine, maleic anhydride and excess triethylamine are mixed in a reaction container and reacted at a constant temperature to obtain a crude product diethyleneglycol difumarate; second, the crude product diethyleneglycol difumarate is washed with dilute hydrochloric acid and rotary evaporated, the liquid phase is collected and purified by column chromatography to obtain purified diethyleneglycol difumarate; third, a required amount of the purified diethyleneglycol difumarate is added with a solvent and stirred until completely miscible, a required amount of catalyst is added and reacted under negative pressure, the reaction product is obtained after the reaction is cooled; fourth, excess diethyleneglycol amine and triethylamine are added to the reaction product and reacted at a constant temperature, the hyperbranched polyamide ethyl acrylate demulsifier is obtained after the reaction is cooled and concentrated.

[0046] Example 10: The application of the hyperbranched polyamide ethyl acrylate demulsifier in eliminating emulsification damage in the near wellbore zone of oil and gas reservoirs and oil-water separation of produced liquid.

[0047] Example 11: The hyperbranched polyamide ethyl acrylate demulsifier is prepared according to the following steps: first, 2.10 g of diethyleneglycol amine, 4.20 g of maleic anhydride and excess triethylamine are mixed in a three-necked glass flask and reacted at a constant temperature for 5 h under stirring at room temperature, the whole reaction is carried out under nitrogen atmosphere to ensure oxygen-free conditions, a yellowish liquid, i.e. the crude product diethyleneglycol difumarate, is obtained; second, the crude product diethyleneglycol difumarate is washed with dilute hydrochloric acid for 2-3 times, the liquid phase is collected after rotary evaporation under negative pressure at 40°C, and the purified diethyleneglycol difumarate is obtained by chromatographic separation using silica gel column (eluent: 10:1 chloroform and methanol); third, 50 mL of solvent DMF is added to 11.35 g of the purified diethyleneglycol difumarate, which is stirred until completely miscible in a flask, 0.02 mol of p-toluenesulfonic acid is added and reacted under negative pressure at 130°C for 10 h, the reaction product is obtained after the reaction is cooled; fourth, excess diethyleneglycol amine and triethylamine are added to 11.2 g of the reaction product and reacted at a constant temperature for 5.5 h at 50°C, the hyperbranched polyamide ethyl acrylate demulsifier is obtained after the reaction is cooled, washed with dilute hydrochloric acid and rotary evaporated.

[0048] The diethyleneglycol difumarate and the hyperbranched polyamide ethyl acrylate demulsifier (P-DAEA) obtained in Example 11 are tested as follows:

[0049] 1. Infrared characterization

[0050] A small amount of dried KBr was taken and pressed into a tablet using an infrared tablet press; the P-DAEA prepared in Example 11 was applied to the KBr tablet and dried; the infrared spectrum was scanned using a WQF-520 infrared spectrometer, and the background of the instrument was collected; the infrared spectrum of the multifunctional cleaning agent is shown in Figure 1 .

[0051] From Figure 1 it can be seen that the absorption peak near 3500 cm -1 is the stretching vibration peak of -OH; the absorption peak near 2900 cm -1 to 3200 cm -1 is the stretching vibration peak of amide; the absorption peak near 1680 cm -1 to 1630 cm -1 is the amide I band; the absorption peak near 1570 cm -1 to 1510 cm -1 and 1335 cm -1 to 1200 cm -1 is the amide II band and the amide III band caused by the coupling between N-H and C-N; the absorption peak near 1150 cm -1 is the stretching vibration peak of -O-, and the characteristic absorption peaks of each monomer are present in the spectrum, proving that the target product has been synthesized.

[0052] 2. Surface tension and critical micelle concentration (cmc) of P-DAEA

[0053] P-DAEA aqueous solutions with concentration gradients of 0.01 mg / L, 0.1 mg / L, 1 mg / L, 100 mg / L, 300 mg / L, 500 mg / L, 550 mg / L, 600 mg / L, 650 mg / L, 700 mg / L, 750 mg / L, 800 mg / L, 1000 mg / L, and 10000 mg / L were prepared, respectively, and the surface tension was determined using a German KRUSS DSA30S interfacial parameter integrated measurement system. A scatter plot was made , and a curve was fitted to determine the critical micelle concentration. The experimental results are shown in Figure 5 .

[0054] Figure 5 The function relationship is , the inflection point coordinates are (650, 32.5), i.e., the function point corresponding to the critical micelle, and the surface tension is 32.5 mN / m. When the concentration of P-DAEA is higher than 650 mg / L, the surface tension is almost unchanged, so the critical micelle concentration is 32.5 mN / m. A lower critical micelle concentration corresponds to a low dosage, high surface activity, and strong ability to reduce the oil-water interfacial tension in the emulsion and to break the oil-water interface.

[0055] 3. Determination of the cloud point, HLB value (hydrophilic-lipophilic balance) and RSN (relative solubility number) of P-DAEA

[0056] The solubility of non-ionic surfactants in aqueous solution decreases with increasing temperature and becomes turbid at a certain temperature value, and two liquid phases can be obtained by standing or centrifugation. This temperature is called the cloud point of the surfactant. Weigh 0.5 g (accurate to 0.01 g) of P-DAEA, add 100 mL of deionized water, and stir until completely dissolved. Take 15 mL of the above P-DAEA solution and place it in a test tube. Insert the thermometer and place the test tube in a water bath. Stir gently with the thermometer until the solution becomes completely turbid (the solution temperature does not exceed 10°C of the turbidity temperature). Stop heating and keep the test tube in the beaker. Slowly cool under the stirring of the thermometer and record the temperature at which the turbidity completely disappears. Repeat the test twice, and the difference between the parallel results should not be more than 0.5°C. Take the arithmetic mean as the cloud point of P-DAEA. Compare with commonly used block polyether demulsifiers.

[0057] HLB value is also called hydrophilic-lipophilic balance, also known as water-oil degree. HLB is equal to the hydrophilicity of hydrophilic group / the lipophilicity of lipophilic group. The larger the HLB value, the stronger the hydrophilicity, and the smaller the HLB value, the stronger the lipophilicity. Its size is related to the surface (interface) tension, adsorption on the interface, emulsification and emulsion stability, dispersibility, solubility, detergency, etc. The basic performance of surfactants. HLB value is generally between 1 and 40, the hydrophilic-lipophilic transition point HLB is 10, less than 10 is lipophilic, and greater than 10 is hydrophilic. Compare with commonly used block polyether demulsifiers. According to the HLB calculation formula of non-ionic surfactant:

[0058] HLB = 7 + 4.02 log (1 / cmc)

[0059] The RSN value is also used to evaluate the lipophilicity and hydrophilicity of surfactants. The larger the value, the stronger the hydrophilicity of P-DAEA, and the smaller the value, the stronger the lipophilicity of P-DAEA. Prepare a certain amount of toluene (2.6 vol%) in ethylene glycol dimethyl ether solution as the RSN value determination solution. Dissolve 1 g of sample in 30 mL of RSN determination solution, and the volume of deionized water consumed is the RSN value of P-DAEA. Take the average of three measurements. Compare with commonly used block polyether demulsifiers.

[0060] The cloud point, HLB value and RSN value of P-DAEA and block polyether are shown in Table 1.

[0061] From Table 1, P-DAEA shows a higher HLB value, indicating that it is a hydrophilic surfactant, which can effectively adsorb water molecules in W / O, break the water molecule layer of O / W, and has good dehydration performance on emulsion; the cloud point of P-DAEA indicates that the hyperbranched molecule has more hydrophilic groups that can be adsorbed with water molecules by hydrogen bonding force, and has good dehydration performance; the higher the RSN value, the stronger the hydrophilicity of P-DAEA, and the stronger the dehydration and demulsification ability of the emulsion.

[0062] 4. Static demulsification experiment of hyperbranched polyamide ethyl acrylate demulsifier

[0063] According to the People's Republic of China Petroleum and Natural Gas Industry Standard SY / T5281-2000 "Crude Oil Demulsifier Performance Test Method (Bottle Test)", the static demulsification experiment of the hyperbranched polyamide ethyl acrylate demulsifier of the present application is designed, and the specific implementation scheme is as follows.

[0064] Crude oil emulsion preparation method: accurately weigh 500g of crude oil and 500g of water into a beaker, preheat at 40℃ for 30min. Put the preheated crude oil and water mixture into a HT-2 type high-speed mixing device at one time, stir at 3000rpm for 30min, and complete the preparation of uniform water-containing crude oil emulsion (water content 50%). The experimental crude oil emulsion is prepared and used immediately to ensure that fresh crude oil emulsion is used in each experiment to prevent aging of the emulsion due to long preparation time.

[0065] Preparation method of hyperbranched polyamide ethyl acrylate demulsifier solution to be tested: accurately weigh a certain amount of P-DAEA sample in a beaker, transfer to a volumetric flask, dilute to the mark line with deionized water, and shake well to make the mass concentration of P-DAEA aqueous solution 1g / 100mL (i.e. 10000mg / L).

[0066] (1) Effect of P-DAEA content on crude oil emulsion demulsification rate

[0067] Put the above 70mL of crude oil emulsion (water content 50%) into a 100mL graduated test tube with a stopper, preheat in a constant temperature water bath (40℃) for 30min, add a certain amount of hyperbranched polyamide ethyl acrylate demulsifier of the present application, ensure that the concentration of P-DAEA is 10mg / L, 20mg / L, 40mg / L, 60mg / L, 80mg / L, 100mg / L, 200mg / L, 500mg / L, 1000mg / L, 10000mg / L, shake 200 times (shake 100 times with left and right hands respectively), the shaking amplitude is greater than 20cm, then place it in a constant temperature water bath, record the volume of water discharged at different times, and calculate the dehydration rate of crude oil from the volume of water discharged. The experimental results are shown in Table 2. Figure 3 ​

[0068] Figure 3 It can be seen that the hyperbranched polyamide ethyl acrylate demulsifier of the present application has obvious improvement in the dehydration rate of crude oil emulsion when the P-DAEA content is higher than 40 mg / L, and the dehydration rate is greater than 50% within 20 min; when the P-DAEA content is greater than 80 mg / L, the dehydration rate of crude oil emulsion is as high as 65% within 20 min, and the dehydration rate is greater than 90% within 100 min. With the increase of P-DAEA content, the adsorption amount of the hyperbranched polyamide ethyl acrylate demulsifier on the oil-water interface is greater, the interface molecular replacement is stronger, the damage to the oil-water interface is greater, and the dehydration rate is higher. Therefore, the hyperbranched polyamide ethyl acrylate demulsifier of the present application can meet the demulsification needs of crude oil emulsion in oil and gas field development sites when the effective content is 80 mg / L.

[0069] (2) Effect of temperature on the demulsification rate of crude oil emulsion

[0070] The above 70 mL of crude oil emulsion (water content 50%) was loaded into a 100 mL capacity test tube with a stopper, and was preheated in different constant temperature water baths for 30 min, with the temperature being 30℃, 40℃, 50℃, 60℃, 70℃, 80℃ and 90℃, respectively. A certain amount of the hyperbranched polyamide ethyl acrylate demulsifier of the present application was added to ensure that the P-DAEA concentration was 80 mg / L, and was shaken for 200 times (100 times for each hand), with the shaking amplitude being greater than 20 cm. Then it was placed in a constant temperature water bath (temperature same as above), and the volume of water discharged at different times was recorded, and the dehydration rate of crude oil was calculated from the volume of water discharged. The experimental results are shown in Table 1. Figure 4

[0071] Figure 4 It can be seen that the hyperbranched polyamide ethyl acrylate demulsifier of the present application has good dehydration rate of crude oil emulsion at 30℃-80℃, and the final dehydration rate can reach more than 94% within 120 min. When the temperature is higher than 70℃, the dehydration rate increases obviously, because the molecular motion is intense at high temperature, which accelerates the interaction between P-DAEA molecules and the oil-water interface. Increasing the temperature is more conducive to the dehydration rate of the hyperbranched polyamide ethyl acrylate demulsifier to the crude oil emulsion.

[0072] (3) Effect of water content of emulsion on the dehydration rate of emulsion

[0073] ​Freshly prepared 70 mL of crude oil emulsion (water content of 30%, 40%, 50%, 60%, 70%, respectively) was respectively loaded into a 100 mL capacity graduated test tube with a stopper, and was respectively placed in a constant temperature water bath (40°C) for preheating for 30 min. A certain amount of the hyperbranched polyamide ethyl acrylate demulsifier of the application was added to ensure that the P-DAEA concentration was 80 mg / L, and was shaken for 200 times (100 times for each hand), with the shaking amplitude being greater than 20 cm. Then, it was placed in a constant temperature water bath (the temperature was the same as above), and the volume of water separated out at different times was recorded. The crude oil dehydration rate was calculated from the volume of water separated out. The experimental results are shown in Table 2. Figure 5

[0074] Figure 5 It can be seen that the higher the water content of the crude oil emulsion, the higher the dehydration rate of the hyperbranched polyamide ethyl acrylate demulsifier of the application. When the water content of the crude oil emulsion is higher than 50%, the emulsion is O / W type, the P-DAEA molecule is a hydrophilic molecule, has strong interfacial activity, has strong water molecule displacement capacity on the outer layer of the oil droplet, can effectively destroy the oil-water interface, and achieve the demulsification purpose. At the same time, for the low water content crude oil emulsion, i.e. the W / O emulsion, the hyperbranched polyamide ethyl acrylate demulsifier of the application can still achieve a dehydration rate of 90% within 100 min. In summary, the hyperbranched polyamide ethyl acrylate demulsifier of the application has strong adaptability to the type of crude oil emulsion, and can meet the needs of eliminating the damage of crude oil emulsification in oil and gas field sites.

[0075] (4) Effect of crude oil viscosity on the dehydration rate of emulsion

[0076] According to the viscosity of the ground crude oil, it can be divided into low viscosity crude oil when μOS< 10 mPa·s, medium viscosity crude oil when μOS= 10 mPa·s to 100 mPa·s, and high viscosity crude oil when μOS> 100 mPa·s. The low, medium and high viscosity crude oils used in the application are different layer crude oils in Mahu area of Xinjiang, China.

[0077] Freshly prepared 70 mL of crude oil emulsion (crude oil viscosity of 8.6 mPa·s, 54.5 mPa·s, 189.5 mPa·s, 307.8 mPa·s, respectively) was respectively loaded into a 100 mL capacity graduated test tube with a stopper, and was respectively placed in a constant temperature water bath (40°C) for preheating for 30 min. A certain amount of the hyperbranched polyamide ethyl acrylate demulsifier of the application was added to ensure that the P-DAEA concentration was 80 mg / L, and was shaken for 200 times (100 times for each hand), with the shaking amplitude being greater than 20 cm. Then, it was placed in a constant temperature water bath (the temperature was the same as above), and the volume of water separated out at different times was recorded. The experimental results are shown in Table 2. Figure 6

[0078] Figure 6 ​​It can be seen that the lower the viscosity of the crude oil, the higher the dehydration rate of the hyperbranched polyamide ethyl acrylate demulsifier of the present application to the emulsion, because the lower the viscosity of the crude oil, the lower the relative molecular weight of the organic hydrocarbons, and the weaker the oil-water interface force, the easier to be destroyed. At the same time, for thick oil, the dehydration rate of the present application is still more than 85% within 120 minutes, which can meet the demulsification of most oil reservoirs.

[0079] (5) Dehydration rate of different demulsifiers to emulsion

[0080] Several demulsifiers commonly used in the market and oil and gas fields in China, including ionic demulsifiers and non-ionic demulsifiers, were selected for comparison with the hyperbranched polyamide ethyl acrylate demulsifier of the present application under uniform test conditions. The basic information of the selected demulsifiers is shown in Table 2.

[0081] Freshly prepared 70 mL of crude oil emulsion was respectively placed in a 100 mL capacity test tube with a stoppered scale, and was preheated in a constant temperature water bath (40°C) for 30 minutes. A certain amount of quaternary ammonium salt demulsifier, carboxylate demulsifier, chain block polyether demulsifier, branched two-section polyether demulsifier and the hyperbranched polyamide ethyl acrylate demulsifier of the present application were respectively added to ensure the concentration of active ingredients was 80 mg / L, and were shaken 200 times (100 times by left and right hands respectively), with a shaking amplitude greater than 20 cm, and were then placed in a constant temperature water bath (same temperature as above). The volume of water discharged at different times was recorded, and the dehydration rate of the crude oil was calculated from the volume of water discharged. The experimental results are shown in Table 3. Figure 7

[0082] Figure 7 It can be seen that the hyperbranched polyamide ethyl acrylate demulsifier of the present application has the highest dehydration rate of crude oil emulsion compared with other types of products, and the dehydration rate increases faster than other types of products over time, because the hyperbranched polyamide ethyl acrylate demulsifier of the present application has multiple hydrophilic groups in the hyperbranched molecular structure of the active ingredient P-DAEA, which can utilize a large area, and the oil-water interface effect is more significant. Due to the compatibility with crude oil and other problems, anionic and cationic types may have flocculation phenomenon caused by electrostatic interaction, which reduces the effect of active ingredients. Therefore, the hyperbranched polyamide ethyl acrylate demulsifier of the present application has a fast dehydration rate of crude oil emulsion within 180 minutes, and has a significant dehydration effect, which can meet the requirements of oil and gas field development sites.

[0083] 5. Dynamic demulsification experiment of hyperbranched polyamide ethyl acrylate demulsifier

[0084] (1) Preparation of experimental fluid (base fluid)

[0085] Preparation method of hyperbranched polyamide ethyl acrylate demulsifier: accurately weigh 0.08 g of P-DAEA and dissolve in deionized water, and then dilute to 1000 mL with a volumetric flask;​

[0086] Crude oil emulsion preparation method: accurately take 500g of crude oil and 500g of water into a beaker, preheat at 40℃ for 30min. Put the preheated crude oil and water mixed solution into a HT-2 type high-speed mixing device at one time, stir at 3000rpm for 30min to complete the preparation of the uniform water-containing crude oil emulsion (water content 50%). The experimental crude oil emulsion is prepared and used immediately to ensure that fresh crude oil emulsion is used in each experiment to prevent aging of the emulsion due to long preparation time.

[0087] (2) Core preparation

[0088] ① The core is taken from artificial core of sandstone, and the treatment is performed according to SY / T5336-2006 Core Analysis Method.

[0089] ① The core is cut into a cylindrical shape with a diameter of about 25mm and a length of 1-1.5 times the diameter, the two end faces are ground flat and perpendicular to the smooth cylindrical surface, and the cuttings are classified and reserved, and the label is written and properly stored.

[0090] ② The cut core is placed in an oven at about 100℃ for drying, and the core weight is measured at intervals to confirm that the weight is constant, which indicates that the drying is complete.

[0091] ③ The core is vacuumed and saturated with 1.5% KCl brine.

[0092] (3) Core emulsion damage repair experiment:

[0093] Using a multifunctional core displacement experiment device, water is used for forward displacement at a temperature (60℃) and a displacement rate of 0.5mL·min -1 , and the base water phase permeability K1 is measured; then the core is forward displaced by 1.5PV of crude oil emulsion (water content 50%) and the pressure change is recorded; then the core is reverse displaced by 2PV of repair liquid, the temperature is maintained, and the core is left for 0.5h; then the core is forward displaced by water again, and the oil phase permeability is measured. The experimental results are shown in Tables 3 and 4.

[0094] As shown in Tables 3 and 4, the core permeability decreases from 19.75mD to 10.21mD after the core is injected with crude oil emulsion, and the permeability recovery rate is as high as 85.92% after the core is injected with the hyperbranched polyamide ethyl acrylate demulsifier, so it is shown that the hyperbranched polyamide ethyl acrylate demulsifier has good dynamic demulsification performance.

[0095] In summary, the raw materials for synthesizing the present application are cheap and low-toxic, and the present application has strong adaptability to the temperature, water content and crude oil viscosity of the crude oil emulsion, and has simple preparation process, low cost, good demulsification effect, and is a new technical approach to solve the formation emulsion pollution.

[0096] The above technical features constitute embodiments of the present application, which have strong adaptability and implementation effects. Non-essential technical features can be added or removed according to actual needs to meet the needs of different situations.

[0097] Table 1

[0098] Name Cloud point (°C) HLB value RSN value P-DAEA 39.5 26.9 12.8 Block polyether 36.0 13.2 9.8

[0099] Table 2

[0100]

[0101] Table 3

[0102] Core number Dry weight / kg Pore volume / cm3 Permeability / mD Water injection pressure / MPa L-2357 0.103 16.4 19.75 0.129

[0103] Table 4

[0104]

Claims

1. A hyperbranched polyamide acrylate demulsifier characterized in that The preparation is carried out according to the following steps: in the first step, a required amount of diethylene glycol amine, maleic anhydride and excess triethylamine are mixed in a reaction container and constant temperature reaction is carried out to obtain a crude product diethylene glycol difumarate, wherein the molar ratio of diethylene glycol amine and maleic anhydride is 1:2.1; in the second step, the crude product diethylene glycol difumarate is washed with dilute hydrochloric acid and rotary evaporated, then the liquid phase is collected and purified by column chromatography to obtain purified diethylene glycol difumarate; in the third step, a solvent is added to the required amount of purified diethylene glycol difumarate and stirred until completely miscible, then a required amount of catalyst is added and reaction is carried out under negative pressure, after the reaction is cooled, the solvent and catalyst are removed to obtain a reaction product; in the fourth step, excess diethylene glycol amine and triethylamine are added to the reaction product and constant temperature reaction is carried out, after the reaction is cooled and concentrated, a light yellow viscous liquid, i.e. the hyperbranched polyamide ethyl acrylate demulsifier, is obtained.

2. The hyperbranched polyamide acrylate demulsifier according to claim 1, characterized in that In the first step, the constant temperature reaction temperature is room temperature and the reaction time is 5 h.

3. The hyperbranched polyamide acrylate demulsifier according to claim 1 or 2, characterized in that In the third step, the solvent is N,N-dimethylformamide and 50 mL of N,N-dimethylformamide is added to every 0.05 mol of the purified diethylene glycol difumarate.

4. The hyperbranched polyamide acrylate demulsifier of claim 3, wherein In the third step, the catalyst is p-toluenesulfonic acid and 0.02 mol of p-toluenesulfonic acid is added to every 0.05 mol of the purified diethylene glycol difumarate.

5. The hyperbranched polyamide acrylate demulsifier according to claim 1 or 2 or 4, characterized in that In the third step, the reaction temperature is 130°C and the reaction time is 10 h.

6. The hyperbranched polyamide acrylate demulsifier of claim 5, wherein In the fourth step, the constant temperature reaction temperature is 50°C and the reaction time is 5.5 h.

7. A process for the preparation of a hyperbranched polyamide acrylate demulsifier according to any one of claims 2 to 6, characterized in that The preparation is carried out according to the following steps: in the first step, a required amount of diethylene glycol amine, maleic anhydride and excess triethylamine are mixed in a reaction container and constant temperature reaction is carried out to obtain a crude product diethylene glycol difumarate, wherein the molar ratio of diethylene glycol amine and maleic anhydride is 1:2.1; in the second step, the crude product diethylene glycol difumarate is washed with dilute hydrochloric acid and rotary evaporated, then the liquid phase is collected and purified by column chromatography to obtain purified diethylene glycol difumarate; In the third step, a solvent is added to the required amount of purified diethylene glycol difumarate and stirred until completely miscible, then a required amount of catalyst is added and reaction is carried out under negative pressure, after the reaction is cooled, the solvent and catalyst are removed to obtain a reaction product; In the fourth step, excess diethylene glycol amine and triethylamine are added to the reaction product and constant temperature reaction is carried out, after the reaction is cooled and concentrated, a light yellow viscous liquid, i.e. the hyperbranched polyamide ethyl acrylate demulsifier, is obtained.

8. Application of the hyperbranched polyamide ethyl acrylate demulsifier according to any one of claims 1 to 6 in the elimination of emulsification damage of oil and gas reservoir near wellbore and oil-water separation of produced liquid.

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