High carbon number black condensate oil resistant foam drainage agent, preparation method and application thereof

Abstract

The invention relates to a high carbon number black condensate oil resistant foam drainage agent, a preparation method and application thereof, and the foam drainage agent is prepared from the following components by weight: 17%-25% of tetradecyl amide propyl dimethyl tertiary amine, 3%-5% of octadecyl amide propyl dimethyl tertiary amine, 15%-20% of sodium 3-chloro-2-hydroxy propanesulfonate, 5%-10% of N, N-dimethylformamide, 5%-10% of sodium dodecyl benzene sulfonate, 5%-10% of sodium dodecyl benzene sulfonate, and the balance of water. The invention relates to a water-based cleaning agent which is prepared from the following components in percentage by weight: 2-5% of N, N-dimethylformamide, 3-5% of isophorone diisocyanate, 3-6% of a nonionic surfactant, 0.5-3% of a perfluorooctyl polyether surfactant and the balance of water. The high-carbon-number black condensate oil resistant foam drainage agent is prepared by compounding the gemini betaine surfactant with low surface tension and good oil resistance, the nonionic surfactant and the perfluorooctyl polyether surfactant, still has good foam drainage effect in the presence of the high-carbon-number black condensate oil, and can be used as a high-carbon-number black condensate oil resistant foam drainage agent. The liquid carrying rate is relatively high.

Description

Technical Field

[0001] The present invention relates to an anti-high-carbon-number black condensate foam drainage agent, a preparation method thereof, and an application thereof, belonging to the technical field of foam drainage agents for natural gas wells. Background Art

[0002] During the exploitation process of natural gas wells, as the exploitation time of the gas wells extends, a large amount of natural gas is produced, and the reservoir pressure gradually decreases. The gas production of the gas wells decreases, the flow rate of natural gas decreases, and the condensate water, heavy hydrocarbon substances (such as high-carbon-number black condensate) in natural gas and the formation produced fluids accumulated in the near-well zone of the gas wells cannot be carried out of the wellbore and accumulate in the wellbore and the near-well zone, thus causing the "blockage" of the natural gas seepage channel, and the produced fluids cannot be discharged and deposit in the wellbore. As the formation pressure continues to decrease, the bottom-hole liquid accumulation continuously increases. When the liquid column pressure of the bottom-hole liquid accumulation is greater than the formation pressure, the liquid column in the wellbore will form a hydrostatic backpressure on the gas reservoir, and the gas flow cannot penetrate the liquid column. As a result, the gas wells are "drowned" by the produced fluids.

[0003] To ensure the normal production of gas wells, foam drainage agents are often added to assist the production of gas wells. This process is mainly: adding a foam drainage agent to the produced fluids, so that rich foam is generated under the agitation of natural gas in the wellbore, thereby reducing the density of the liquid accumulation in the wellbore, enabling the gas wells to better penetrate the liquid accumulation and reach the ground. At the same time, the generated foam also continuously carries the liquid accumulation in the wellbore to the ground along with the gas flow.

[0004] The foam drainage gas production process is one of the most common drainage processes in the middle and late stages of natural gas well exploitation, and there has been more than 30 years of on-site application experience. Currently, the existing foam drainage agents have good foaming, foam stability, and liquid-carrying capabilities in pure formation water (without condensate) or formation water containing a small amount of light condensate. However, there are generally problems such as poor foaming ability (or no foaming), no foam stability ability, and poor liquid-carrying ability in the formation water with high-carbon-number black condensate. Summary of the Invention

[0005] The first object of the present invention is to provide an anti-high-carbon-number black condensate foam drainage agent to solve the problems in the prior art that the foam drainage agent generally has poor foaming ability (or no foaming) and no foam stability ability in the formation water with high-carbon-number black condensate, resulting in poor liquid-carrying ability.

[0006] The second object of the present invention is to provide a preparation method of the above anti-high-carbon-number black condensate foam drainage agent to solve the problems in the prior art that the foam drainage agent generally has poor foaming ability (or no foaming) and no foam stability ability in the formation water with high-carbon-number black condensate, resulting in poor liquid-carrying ability.

[0007] The third object of the present invention is to provide an application of an anti-high-carbon-number black condensate foam drainage agent in gas drainage and production in a high-carbon-number black condensate environment, so as to solve the problems that the foam drainage agent in the prior art generally has poor foaming ability (or no foaming), no foam stabilizing ability and poor liquid carrying ability in the formation water of high-carbon-number black condensate oil.

[0008] In order to achieve the above object, the technical solution of an anti-high-carbon-number black condensate foam drainage agent in the present invention is as follows:

[0009] An anti-high-carbon-number black condensate foam drainage agent is made of the following components by weight percentage: 17% - 25% of tetradecylamidopropyl dimethyl tertiary amine, 3% - 5% of octadecylamidopropyl dimethyl tertiary amine, 15% - 20% of 3-chloro-2-hydroxypropyl sulfonate sodium, 2% - 5% of N,N-dimethylformamide, 3% - 5% of isophorone diisocyanate, 3% - 6% of non-ionic surfactant, 0.5% - 3% of perfluorooctyl polyether surfactant, and the balance is water.

[0010] The beneficial effects of the above technical solution are as follows: The present invention belongs to an exploratory invention. Using tetradecylamidopropyl dimethyl tertiary amine, octadecylamidopropyl dimethyl tertiary amine, 3-chloro-2-hydroxypropyl sulfonate sodium and isophorone diisocyanate as reaction raw materials, a gemini betaine surfactant is prepared through two-step reaction. The present invention synthesizes the corresponding gemini betaine surfactant by using dimethyl tertiary amines with different carbon chains, and selects the on-site high-carbon-number condensate oil for testing. It is found that the gemini surfactant synthesized by tetradecylamidopropyl dimethyl tertiary amine has better foaming and liquid carrying abilities than those of other carbon chain tertiary amines; the gemini surfactant synthesized by octadecylamidopropyl dimethyl tertiary amine has better foam stabilizing effect in the presence of condensate oil. In order to achieve the best foaming, foam stabilizing and liquid carrying effects, the gemini betaine surfactant is synthesized by combining tetradecylamidopropyl dimethyl tertiary amine and octadecylamidopropyl dimethyl tertiary amine. The addition of 3-chloro-2-hydroxypropyl sulfonate sodium helps to improve the penetration ability of the gemini betaine surfactant to condensate oil. The gemini betaine surfactant prepared by the present invention has a low surface tension and good anti-oil performance. After being compounded with non-ionic surfactant and perfluorooctyl polyether surfactant, it still has good foam drainage effect and high liquid carrying rate in the environment where high-carbon-number black condensate oil exists.

[0011] Specifically, the high-carbon-number black condensate oil is the condensate oil with the carbon number of condensate oil greater than 9 when analyzing the carbon number of condensate oil according to the SY / T 0542-2008 standard.

[0012] As a further improvement, the non-ionic surfactant is fatty alcohol polyoxyethylene ether; the perfluorooctyl polyether surfactant is perfluorononenyloxy benzene sulfonate sodium.

[0013] The beneficial effects of the above technical solution are as follows: When it is proved by screening that the non-ionic surfactant is fatty alcohol polyoxyethylene ether and the perfluorooctyl polyether surfactant is sodium perfluorononenyloxybenzenesulfonate, the foam drainage agent has better adaptability to the environment of high-carbon-number black condensate oil.

[0014] In order to achieve the above object, the technical solution of a preparation method of an anti-high-carbon-number black condensate oil foam drainage agent in the present invention is:

[0015] A preparation method of an anti-high-carbon-number black condensate oil foam drainage agent is prepared by a method including the following steps:

[0016] S1. Tetradecylamidopropyldimethyl tertiary amine, octadecylamidopropyldimethyl tertiary amine and 3-chloro-2-hydroxypropyl sulfonate react in water to generate alkylamidopropyldimethyl sulfonate betaine;

[0017] S2. Add N, N-dimethylformamide and isophorone diisocyanate to react in the alkylamidopropyldimethyl sulfonate betaine obtained in S1 to obtain a gemini betaine surfactant;

[0018] S3. Add a non-ionic surfactant and a perfluorooctyl polyether surfactant to the gemini betaine surfactant obtained in S2, and mix them to obtain the product.

[0019] The beneficial effects of the above technical solution are as follows: The synthesis steps of the anti-high-carbon-number black condensate oil foam drainage agent of the present invention are simple, the raw materials are easy to obtain, and it is easy to industrialize. Moreover, the prepared anti-high-carbon-number black condensate oil foam drainage agent has a low surface tension and good oil resistance, and is especially suitable for anti-high-carbon-number black condensate oil.

[0020] Specifically, the present invention first uses tetradecylamidopropyldimethyl tertiary amine, octadecylamidopropyldimethyl tertiary amine, and 3-chloro-2-hydroxypropyl sulfonate to react in water to generate alkylamidopropyldimethyl sulfonate betaine, adds N, N-dimethylformamide and isophorone diisocyanate to react to generate a gemini betaine surfactant, and then mixes it evenly with a non-ionic surfactant and a perfluorooctyl polyether surfactant to obtain an anti-high-carbon-number black condensate oil foam drainage agent. The equations involved in the reaction are as Figure 1 shown, and the specific preparation process is as Figure 2 shown.

[0021] As a further improvement, the temperature of the reaction in S1 is 60-80 °C.

[0022] The beneficial effects of the above technical solution are as follows: Controlling the above reaction temperature helps to reduce the by-products generated by the reaction and improve the foaming and foam-stabilizing properties of the generated gemini betaine surfactant.

[0023] As a further improvement, a solution of sodium 3-chloro-2-hydroxypropanesulfonate is dropped into an aqueous solution mixture of tetradecylamidopropyldimethylamine and octadecylamidopropyldimethylamine. The dropping time is 3 - 3.5 h, and the heat preservation time after dropping is 3 - 4 h.

[0024] The beneficial effect of the above technical solution is that the dropping method helps to control the reaction rate. If the dropping rate is too fast, the reaction rate is likely to be too fast, the solution will quickly produce foam and overflow the reaction kettle.

[0025] As a further improvement, the temperature of the reaction described in S2 is 40 - 50 °C.

[0026] The beneficial effect of the above technical solution is that controlling the above reaction temperature helps to reduce the by-products generated by the reaction and improve the foaming and foam-stabilizing properties of the generated gemini betaine surfactant.

[0027] As a further improvement, isophorone diisocyanate is dropped into a mixed solution composed of alkylamidopropyldimethylsulfonate betaine and N,N-dimethylformamide. The dropping time is 1 - 1.5 h, and the heat preservation time after dropping is 2 - 3 h.

[0028] The beneficial effect of the above technical solution is that the dropping method helps to control the reaction rate. If the dropping rate is too fast, the reaction rate is likely to be too fast, the solution will quickly produce foam and overflow the reaction kettle.

[0029] To achieve the above object, the technical solution for the application of the anti-high-carbon-number black condensate foam drainage agent in the drainage gas production of high-carbon-number black condensate oil in the present invention is:

[0030] The application of the anti-high-carbon-number black condensate foam drainage agent in the drainage gas production of high-carbon-number black condensate oil.

[0031] The beneficial effect of the above technical solution is that through experimental verification and field application, it is proved that the anti-high-carbon-number black condensate foam drainage agent of the present invention still has good foaming ability, foam-stabilizing ability and liquid-carrying ability in the presence of high-carbon-number black condensate oil, laying a foundation for the oil and gas production of gas wells with high-carbon-number black condensate oil. Description of the Drawings

[0032] Figure 1 It is the reaction equation involved in the preparation process of the gemini betaine surfactant in the anti-high-carbon-number black condensate foam drainage agent of the present invention;

[0033] Figure 2 It is the flow chart of the preparation method of the anti-high-carbon-number black condensate foam drainage agent of the present invention;

[0034] Figure 3It is the optimization result diagram of the screening and addition amount of non-ionic surfactants in Experimental Example 1 of the present invention;

[0035] Figure 4 It is the optimization result diagram of the addition amount of perfluorooctyl polyether surfactants in Experimental Example 2 of the present invention;

[0036] Figure 5 It is the effect of Field Application 2 in Experimental Example 4 of the present invention Figure 1 ;

[0037] Figure 6 It is the effect of Field Application 2 in Experimental Example 4 of the present invention Figure 2 ;

[0038] Figure 7 It is the effect of Field Application 2 in Experimental Example 4 of the present invention Figure 3 ;

[0039] Figure 8 It is the effect of Field Application 2 in Experimental Example 4 of the present invention Figure 4 。 Specific Embodiments

[0040] The present invention will be further described below in conjunction with specific embodiments. It should be noted that, on the premise of no conflict, the following described embodiments or technical features can be arbitrarily combined to form new embodiments. The equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following embodiments are conventional methods in the art unless otherwise specified.

[0041] I. Specific Embodiments of an Anti-High-Carbon-Number Black Condensate Foam Drainage Agent and Its Preparation Method

[0042] Example 1

[0043] The anti-high-carbon-number black condensate foam drainage agent of this example is composed of the following percentage components:

[0044]

[0045] The specific preparation method is as follows:

[0046] S1. Add 170 kg of tetradecylamidopropyl dimethyl tertiary amine, 30 kg of octadecylamidopropyl dimethyl tertiary amine, and 370 kg of water into the reaction kettle, stir and heat to 60 °C. After complete dissolution, slowly dropwise add a mixed solution of 150 kg of 3-chloro-2-hydroxypropyl sulfonate and 195 kg of water. The dropping rate is controlled to be completed within 3 h, and then keep warm for 4 h;

[0047] S2. Cool down to 40 °C. Then add 20 kg of N,N-dimethylformamide. After mixing evenly, slowly dropwise add 30 kg of isophorone diisocyanate. Control the dropping rate to finish dropping within 1 h, and then keep the temperature for 2 h to obtain the oil-resistant gemini betaine surfactant;

[0048] S3. At a temperature of 40 °C, add 30 kg of AEO-7 and 5 kg of perfluorononenyloxybenzenesulfonate to the gemini betaine surfactant prepared in S2, and stir and mix for 0.5 h to obtain the foam drainage agent for high-carbon-number black condensate oil.

[0049] Example 2

[0050] The foam drainage agent for high-carbon-number black condensate oil in this example is composed of the following percentage components:

[0051]

[0052] The specific preparation method is as follows:

[0053] S1. Add 230 kg of tetradecylamidopropyldimethylamine, 40 kg of octadecylamidopropyldimethylamine, and 300 kg of water into the reaction kettle, stir and heat to 70 °C. After complete dissolution, slowly dropwise add the mixed solution of 170 kg of 3-chloro-2-hydroxypropanesulfonic acid sodium salt and 140 kg of water. Control the dropping rate to finish dropping within 3.5 h, and then keep the temperature for 3 h.

[0054] S2. Cool down the mixed solution to 45 °C. Then add 30 kg of N,N-dimethylformamide. After mixing evenly, slowly dropwise add 40 kg of isophorone diisocyanate. Control the dropping rate to finish dropping within 1 h, and then keep the temperature for 2.5 h. Obtain the oil-resistant gemini betaine surfactant;

[0055] S3. At a temperature of 45 °C, add 40 kg of AEO-7 and 10 kg of perfluorononenyloxybenzenesulfonate to the gemini betaine surfactant prepared in S2, and stir and mix for 0.5 h to obtain the foam drainage agent for high-carbon-number black condensate oil.

[0056] Example 3

[0057] The foam drainage agent for high-carbon-number black condensate oil in this example is composed of the following percentage components:

[0058]

[0059] The specific preparation method is as follows:

[0060] S1. Add 250 kg of tetradecylamidopropyldimethyl tertiary amine, 50 kg of octadecylamidopropyldimethyl tertiary amine, and 250 kg of water into a reaction kettle. Stir and heat to 80 °C. After complete dissolution, slowly add a mixed solution of 200 kg of 3-chloro-2-hydroxypropyl sulfonate and 60 kg of water dropwise. Control the dropping rate to complete the addition within 3.5 h, and then keep the temperature constant for 4 h.

[0061] S2. Cool the mixed solution to 50 °C. Then add 50 kg of N,N-dimethylformamide. After mixing evenly, slowly add 50 kg of isophorone diisocyanate dropwise. Control the dropping rate to complete the addition within 1.5 h, and then keep the temperature constant for 3 h. An oil-resistant gemini betaine surfactant is obtained:

[0062] S3. At a temperature of 50 °C, add 60 kg of AEO-7 and 30 kg of perfluorononenyloxybenzenesulfonate to the gemini betaine surfactant prepared in S2, and stir and mix for 0.5 h to obtain a foam drainage agent for high-carbon-number black condensate oil.

[0063] III. Experimental Examples

[0064] The present invention detects the foaming ability, foam stability ability, and liquid-carrying ability of the foam drainage agent to evaluate the performance of the foam drainage agent. At 70 °C and a foam drainage agent concentration of 0.5%, water samples and high-carbon-number black oil samples from gas wells are taken to conduct performance tests on the oil-resistant foam drainage agent. The specific operation steps are as follows:

[0065] 1. Test of foaming ability and foam stability ability

[0066] Weigh 1.25 g of the foam drainage agent sample into a 1000 mL beaker, add water and condensate oil (the addition amount of condensate oil is added according to actual needs, such as adding high-carbon-number black condensate oil at 5%, 10%, 20%, and 30% of the total amount), and finally obtain a test sample solution with a foam drainage agent concentration of 5.00‰. Place the test sample solution in a constant temperature water bath and heat it to 70 °C for standby.

[0067] Preheat the Ross foam meter with a super constant temperature water bath and keep it at a constant temperature of 70 °C. Use a 200 mL pipette to transfer 50 mL of the test sample solution and pour it along the inner wall of the Ross foam meter to wash the inner wall. After the washing liquid has drained, close the valve at the lower end of the Ross foam meter. Then transfer 50 mL of the test sample solution and pour it along the inner wall of the Ross foam meter to form a liquid surface at the bottom. Then use a pipette to transfer 200 mL of the test sample solution and place it at the center position at the upper end of the Ross foam meter, and drop it vertically against the liquid surface. Immediately start the stopwatch after the sample solution has been dropped, and record the height of the foam rising in the Ross foam meter, which is the foaming ability of the experimental sample. Record the height of the foam in the Ross foam meter again at 5 min, which is the foam stability ability of the experimental sample.

[0068] 2. Test of liquid-carrying ability

[0069] Weigh 1.25 g of the foam drainage agent sample into a 1000 mL beaker, add water and high-carbon-number black condensate oil (the addition amount of condensate oil is added according to actual needs, e.g., add high-carbon-number black condensate oil at 5%, 10%, 20%, and 30% of the total amount), and finally obtain a test sample solution with a foam drainage agent concentration of 5.00‰. Place the test sample solution in a constant temperature water bath and heat it to 70 °C. Place the test sample solution in a constant temperature water bath and heat it to 70 °C for standby. Preheat the constant temperature liquid-carrying instrument with a super constant temperature water bath and keep it at a constant temperature of 70 °C. Turn on the air pump and fill it with gas at a rate of 7 L / min. Pour the preheated test sample solution into the constant temperature liquid-carrying instrument to make the solution foam. When the foam flows out of the elbow pipe, use a liquid collector to collect the liquid carried out by the liquid-carrying instrument until no more foam is carried out.

[0070] Measure the volume of the liquid carried out by the collector, which is the liquid-carrying capacity of the experimental sample. Liquid-carrying rate = volume of the carried-out liquid / total volume of the sample solution × 100%.

[0071] Experimental Example 1 Screening and Optimization of the Addition Amount of Non-ionic Surfactants

[0072] This experimental example is for the screening and optimization of the addition amount of non-ionic surfactants. The specific operation steps are as follows:

[0073] 1. Screening of non-ionic surfactants

[0074] Based on the formula of Example 1 as the basic formula, without adding perfluorooctyl polyether surfactants, the addition amount of non-ionic surfactants is 2%, and it is specifically composed of the following percentage components:

[0075]

[0076] The non-ionic surfactants are respectively selected from TX-4, TX-10, AEO-7, and AEO-9. Foam drainage agents are respectively prepared (the preparation process is as in Example 1), and the performance tests of the prepared foam drainage agents are carried out according to the above-mentioned foaming ability, foam stability ability test, and liquid-carrying ability test. When detecting, the water is simulated formation water with a salinity of 200,000, and the condensate oil is kerosene. The addition amount of kerosene is 20%. The detection results are as Figure 3 shown. It can be seen from the figure that among the selected non-ionic surfactants, AEO-7 has the strongest synergistic ability.

[0077] 2. Optimization of the addition amount of AEO-7

[0078] Based on the formula of Example 1 as the basic formula, without adding perfluorooctyl polyether surfactants, the non-ionic surfactant is AEO-7, and its addition amount is 1 - 10%, and it is specifically composed of the following percentage components:

[0079]

[0080] Prepare foam drainers with the addition amounts of AEO-7 being 1%, 2%, 3%, 5%, 7% and 10% respectively (the preparation process is as in Example 1), and conduct performance tests on the prepared foam drainers according to the foaming ability, foam stability ability test and liquid-carrying ability test described above. When detecting, the water is simulated formation water with a salinity of 200,000, the condensate oil is kerosene, and the addition amount of kerosene is 20%. The test results are as Figure 3 shown. It can be seen from the figure that the best effect is achieved when the addition amount of AEO-7 is 3%.

[0081] Experimental Example 2 Optimization of the addition amount of perfluorooctyl polyether surfactants

[0082] This experimental example is for the optimization of the addition amount of perfluorooctyl polyether surfactants. The specific operation steps are as follows:

[0083] Based on the formula of Example 1 as the basic formula, the perfluorooctyl polyether surfactant selects sodium perfluorononenyloxybenzenesulfonate, the non-ionic surfactant is AEO-7, and the addition amount is 3%. It is specifically composed of the following percentage components:

[0084]

[0085] Prepare foam drainers with the addition amounts of sodium perfluorononenyloxybenzenesulfonate being 0.1%, 0.2%, 0.3%, 0.4%, 0.5% and 0.7% respectively (the preparation process is as in Example 1), and conduct performance tests on the prepared foam drainers according to the foaming ability, foam stability ability test and liquid-carrying ability test described above. When detecting, the water is simulated formation water with a salinity of 200,000, the condensate oil is kerosene, and the addition amount of kerosene is 20%. The test results are as Figure 4 shown. It can be seen from the figure that the best effect is achieved when the addition amount of sodium perfluorononenyloxybenzenesulfonate is 0.3%.

[0086] Experimental Example 3 Foaming, foam stability and liquid-carrying performance tests of foam drainers for high-carbon-number black condensate oil

[0087] In this experimental example, the foaming ability, foam stability ability and liquid-carrying ability of the foam drainers for high-carbon-number black condensate oil in Examples 1 to 3 and the external sample 1# anti-oil foam drainer (UT-11C of Chengdu Fuji Ke) and the external sample 2# fluorine-containing anti-oil foam drainer (XH-6 of Chengdu Huayang Hua) are compared on-site. The specific operation steps are as described in the specific implementation manner. When detecting, the water is real formation water with a salinity of 70,000 - 80,000, the condensate oil is on-site high-carbon-number black condensate oil, and the addition amount of high-carbon-number black condensate oil is added at 5%, 10%, 20% and 30% of the total amount. The test results are shown in Tables 1 - 4.

[0088] Table 1 Performance comparison test of foam drainers for anti-condensate oil and traditional anti-oil foam drainers (under the condition of containing 5% on-site black condensate oil)

[0089] Test sample Initial foam height (mm) Foam height after 3 min (mm) Liquid-carrying rate (%) External sample 1# anti-oil foam drainage agent 145 0 56.8 External sample 2# fluorine-containing anti-oil foam drainage agent 158 0 64.5 Example 1 185 168 90.2 Example 2 208 185 95.5 Example 3 230 198 97.2

[0090] Table 2 Performance Comparison Test of Foam Drainage Agent for Anti-Condensate Oil and Traditional Anti-Oil Foam Drainage Agent (Under the Condition of 10% Field Black Condensate Oil)

[0091] Test sample Initial foam height (mm) Foam height after 3 min (mm) Liquid-carrying rate (%) External sample 1# anti-oil foam drainage agent 58 0 0 External sample 2# fluorine-containing anti-oil foam drainage agent 65 0 0 Example 1 170 145 86 Example 2 190 170 90.5 Example 3 210 175 93.3

[0092] Table 3 Performance Comparison Test of Foam Drainage Agent for Anti-Condensate Oil and Traditional Anti-Oil Foam Drainage Agent (Under the Condition of 20% Field Black Condensate Oil)

[0093] Test sample Initial foam height (mm) Foam height after 3 min (mm) Liquid-carrying rate (%) External sample 1# anti-oil foam drainage agent 15 0 0 External sample 2# fluorine-containing anti-oil foam drainage agent 20 0 0 Example 1 155 125 80.4 Example 2 165 145 85.6 Example 3 183 160 90.2

[0094] Table 4 Performance Comparison Test of Foam Drainage Agent for Anti-Condensate Oil and Traditional Anti-Oil Foam Drainage Agent (Under the Condition of 30% Field Black Condensate Oil)

[0095]

[0096]

[0097] As can be seen from Table 1, when the content of black condensate oil is relatively low (5%), the traditional anti-oil foam drainage agent has a certain foaming ability, but it is significantly weaker than the foam drainage agent for anti-condensate oil of the present invention. Moreover, the foam height is 0 after 3 minutes, indicating that black condensate oil has a great influence on the foam stability ability of the traditional anti-oil foam drainage agent. At the same time, when the content of black condensate oil is relatively low (5%), the liquid-carrying rate of the traditional anti-oil foam drainage agent is only 55% - 65%, which is much lower than that of the foam drainage agent for anti-condensate oil of the present invention. As can be seen from Tables 2 - 4, with the increase of the content of black condensate oil, the foaming ability of the traditional anti-oil foam drainage agent decreases significantly. When the content of black condensate oil is 30%, it has no foaming ability. At the same time, when the content of black condensate oil is 10%, the liquid-carrying rate of the traditional anti-oil foam drainage agent has decreased to 0, and it does not have the liquid-carrying ability. Although the foaming ability, foam stability ability and liquid-carrying ability of the foam drainage agent for anti-condensate oil of the present invention decrease with the increase of the content of black condensate oil, when the content of black condensate oil is 30%, the liquid-carrying rate is still above 55%.

[0098] Experimental Example 4 Application of Foam Drainage Agent for Anti-High Carbon Number Black Condensate Oil in Gas Drainage and Production in High Carbon Number Black Condensate Oil Environment

[0099] 1. On-site Application 1

[0100] The oil pressure before the test was 1.5 Mpa, the casing pressure was 6.5 Mpa, and the daily water production was 3 - 4 m 3 , and the average daily gas production in the week before the test was about 0.93×104 m 3, black oil is produced. At the site, 50 L / d of UT-11D foam drainage agent is used, with a dilution ratio of 1:5, and it is added in 8 times. Before the test, it could not produce continuously by itself, and it was necessary to frequently empty the well and resume production with liquid.

[0101] Subsequently, the black condensate oil foam drainage agent of the present invention (using the formula of Example 3) was used. The dosage of the agent was 50 L / d, the dilution ratio was 1:10, and it was added in 24 times. After replacing the agent, continuous production has been achieved. The oil pressure is 1.3 Mpa, the casing pressure is 2.6 Mpa, and the daily gas production is 1.28×104 m 3 . With the dosage of the agent unchanged, the gas production increased by 37%. The oil-casing pressure difference decreased from 5 Mpa to 1.3 Mpa, and the foam drainage effect was good.

[0102] 2. Field application 2

[0103] Before the test, the oil pressure was 1.1 Mpa, the casing pressure was 2.7 Mpa, and the daily water production was 3 - 4 m 3 , black oil was produced, and it could not be resumed after being flooded before the test. At the site, 30 L / d of NM8-14 foam drainage agent was used, with a dilution ratio of 1:5, and it was added in 5 times. Before the test, it could not produce continuously by itself. After emptying the well and with liquid, it could not continuously produce with liquid during the production process either, and the well was often flooded. This well could only produce intermittently.

[0104] It was replaced with the black condensate oil foam drainage agent of the present invention (using the formula of Example 3). The dosage of the agent was 30 L / d, the dilution ratio was 1:9, and it was added in 8 times. Continuous production was achieved. The oil pressure was 0.9 Mpa, the casing pressure was 2.1 Mpa, and the daily gas production was 0.75×104 m 3 . The oil-casing pressure difference decreased from 1.6 Mpa to 1.2 Mpa, and the foam drainage effect was good.

[0105] Figures 5 to 8 It is the instantaneous gas production diagram of the gas well during the process of field application 2 of Example 3. It can be seen from the figure that after adding the foam drainage agent of the present invention, the instantaneous production fluctuation of the gas well is small, the production is stable, and the gas production increases.

[0106] The above is only the preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention is subject to the claims. All equivalent structural changes made by using the content of the specification of the present invention should be included in the protection scope of the present invention by the same token.

Claims

1. An anti-high-carbon-number black condensate foam drainage agent, characterized in that: It is made of the following components by weight percentage: 17% - 25% of tetradecylamidopropyl dimethyl tertiary amine, 3% - 5% of octadecylamidopropyl dimethyl tertiary amine, 15% - 20% of 3-chloro-2-hydroxypropyl sulfonate sodium, 2% - 5% of N,N-dimethylformamide, 3% - 5% of isophorone diisocyanate, 3% - 6% of non-ionic surfactant, 0.5% - 3% of perfluorooctyl polyether surfactant, and the balance is water.

2. The anti-high-carbon-number black condensate foam drainage agent according to claim 1, characterized in that: The non-ionic surfactant is fatty alcohol polyoxyethylene ether; the perfluorooctyl polyether surfactant is perfluorononenyloxy benzene sulfonate sodium.

3. A preparation method of the anti-high-carbon-number black condensate foam drainage agent as claimed in claim 1 or 2, characterized in that: It is prepared by a method including the following steps: S1. Tetradecylamidopropyl dimethyl tertiary amine, octadecylamidopropyl dimethyl tertiary amine and 3-chloro-2-hydroxypropyl sulfonate sodium react in water to generate alkylamidopropyl dimethyl sulfonate betaine; S2. Add N,N-dimethylformamide and isophorone diisocyanate to the alkylamidopropyl dimethyl sulfonate betaine obtained in S1 and react to obtain a gemini betaine surfactant; S3. Add a non-ionic surfactant and a perfluorooctyl polyether surfactant to the gemini betaine surfactant obtained in S2 and mix to obtain.

4. The preparation method of the anti-high-carbon-number black condensate foam drainage agent according to claim 3, characterized in that: The temperature of the reaction in S1 is 60 - 80 °C.

5. The preparation method of the anti-high-carbon-number black condensate foam drainage agent according to claim 4, characterized in that: Drop the 3-chloro-2-hydroxypropyl sulfonate sodium solution into the mixed aqueous solution of tetradecylamidopropyl dimethyl tertiary amine and octadecylamidopropyl dimethyl tertiary amine, the dropping time is 3 - 3.5 h, and the holding time after dropping is 3 - 4 h.

6. The preparation method of the anti-high-carbon-number black condensate foam drainage agent according to claim 3, characterized in that: The temperature of the reaction in S2 is 40 - 50 °C.

7. The preparation method of the anti-high-carbon-number black condensate foam drainage agent according to claim 6, characterized in that: Drop isophorone diisocyanate into the mixed solution composed of alkylamidopropyl dimethyl sulfonate betaine and N,N-dimethylformamide, the dropping time is 1 - 1.5 h, and the holding time after dropping is 2 - 3 h.

8. An application of the anti-high-carbon-number black condensate foam drainage agent as claimed in claim 1 or 2 in drainage gas production in a high-carbon-number black condensate environment.

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