Nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells and preparation method thereof

Abstract

The invention relates to the technical field of additives for drainage and gas production, and is a nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells and a preparation method thereof. The raw materials are composed of a high-temperature azo modified gas generating agent system, a medium-temperature gas generating agent system, a modified nano-silicon dioxide foam stabilizing material oligomer, and a high-efficiency foaming agent system. The high-temperature azo modified gas generating agent system, the medium-temperature gas generating agent system, and the modified nano-silicon dioxide foam stabilizing material are sequentially added to water, stirred and dissolved to obtain a mixed solution, and the high-efficiency foaming agent system and the oligomer are sequentially added to the mixed solution to obtain a product. The invention introduces active groups such as energy-enhancing, foaming, and foam stabilizing through chemical synthesis and functional combination of the high-temperature azo modified gas generating agent system, the medium-temperature gas generating agent system, the modified nano-silicon dioxide foam stabilizing material, and the oligomer, thereby forming an energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells with excellent performance, which has the characteristics of high temperature resistance, high resistance to condensate oil, and high foam liquid carrying rate.

Description

Technical Field

[0001] The invention relates to the technical field of additives for drainage and gas production, and is a nano energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells and a preparation method thereof. Background Art

[0002] Most of the domestic oil and gas fields have entered the middle and late stages of development. The quality of oil and gas reservoirs is getting worse and worse. Some gas wells have weak formation energy due to long-term production, and the formation pressure cannot be used to discharge the wellbore fluid from the ground, increase the pressure, or replenish the pressure. The condensate content in the produced water of some gas fields is as high as 35%. Most of the formation water with high condensate content causes the foaming agent to fail, making it difficult to carry the formation water with high condensate content out of the ground. It is urgent to find an oil-resistant and lipophilic foaming agent. At the same time, the foam liquid film quickly thins and breaks under ultra-high temperature conditions, resulting in an extremely low liquid carrying rate. At present, a high-temperature resistant foaming agent for reservoir temperatures below 220°C has not yet been developed.

[0003] The conventional plunger drainage gas production process is aimed at ultra-deep and high-temperature gas wells. Due to the requirements of drilling and completion, the wellbore size is small, and it is difficult to lower general tools, which increases the difficulty of process implementation; the conventional energizer is an ammonium chloride and sodium nitrite system, which starts to generate gas energizer at 70°C, but has limited effect on high-temperature gas wells; conventional bubbles burst quickly under high-temperature and high-condensate conditions, and general foam stabilizers are mainly sodium dodecylbenzene sulfonate, LAO, etc., which mainly adopt measures such as reducing surface interfacial tension to maintain the stability of the liquid film, and its temperature and oil resistance are limited.

[0004] Therefore, it is necessary to develop an ultra-high temperature and high condensate oil gas generation energy-enhancing foaming agent to solve the technical difficulties of low foam liquid carrying rate under the conditions of low reservoir pressure, high temperature deep layer and high condensate oil content. Summary of the invention

[0005] The present invention provides a nano energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells and a preparation method thereof, which overcomes the shortcomings of the above-mentioned prior art and can effectively solve the problems of poor high-temperature energy-enhancing effect of the foaming agent, almost no heat and oil resistance, and low foam liquid carrying rate in wellbores with low reservoir pressure, ultra-high temperature, high condensate oil content, etc. in the development of existing oil and gas fields.

[0006] One of the technical solutions of the present invention is achieved by the following measures: a nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells, wherein the raw material composition is 30% to 40% by mass of a high-temperature azo modified gas-generating agent system, 10% to 20% by mass of a medium-temperature gas-generating agent system, 5% to 10% by mass of a modified nano-silica foam-stabilizing material, 10% to 15% by mass of an oligomer, and 30% to 50% by mass of a high-efficiency foaming agent system, and the balance is water, wherein the high-temperature azo modified gas-generating agent system is composed of zinc acetate, azodicarbonamide, sodium bicarbonate and water, the medium-temperature gas-generating agent system is composed of sodium nitrite and ammonium chloride, the oligomer is a polyacrylamide oligomer, and the high-efficiency foaming agent system is a mixture of any four substances selected from lauroamidopropyl hydroxysulfobetaine, cocoamidopropyl hydroxysulfobetaine, lauroamidopropyl amine oxide, alkylphenol polyoxyethylene ether and lauryl glucoside.

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

[0008] The above was prepared according to the following steps:

[0009] First, a high-temperature azo modified foaming agent system, a medium-temperature foaming agent system, and a modified nano-silica foam stabilizing material are sequentially added to a required amount of water, and stirred and dissolved to obtain a mixed solution; then, a high-efficiency foaming agent system and an oligomer are sequentially added to the mixed solution, and stirred and dispersed to obtain a nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells.

[0010] In the above-mentioned high-temperature azo modified gasifier system, the mass ratio of zinc acetate, azodicarbonamide, sodium bicarbonate and water is 0.8:1:0.5:2.

[0011] In the above medium-temperature gas generating agent system, the mass ratio of sodium nitrite to ammonium chloride is 1:1.

[0012] The modified nano-silicon dioxide foam stabilizing material is prepared according to the following steps:

[0013] S1, dispersing a required amount of nano-silicon dioxide in anhydrous ethanol to obtain a first mixed solution;

[0014] S2, mixing perfluorododecyltriethoxysilane and water in a volume ratio of 1:2 and stirring to obtain a second mixed solution;

[0015] S3, mixing the first mixed liquid and the second mixed liquid in a volume ratio of 3.5 to 5.5:1 and reacting them to obtain a modified nano-silicon dioxide foam stabilizing material.

[0016] In the above step S3, the reaction temperature is 65°C to 75°C, and the reaction time is 2.5h to 3.5h.

[0017] The oligomer has a number average molecular weight of 1,500 to 3,000.

[0018] The mass ratio of any four substances in the above-mentioned high-efficiency foaming agent system is 1:1:1:1.

[0019] The above stirring speeds are all in the range of 100 rpm to 500 rpm.

[0020] The second technical solution of the present invention is achieved by the following measures: One is carried out according to the following steps:

[0021] First, a high-temperature azo modified foaming agent system, a medium-temperature foaming agent system, and a modified nano-silica foam stabilizing material are sequentially added to a required amount of water, and stirred and dissolved to obtain a mixed solution; then, a high-efficiency foaming agent system and an oligomer are sequentially added to the mixed solution, and stirred and dispersed to obtain a nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells.

[0022] The present invention introduces active groups such as energy enhancement, foaming and foam stabilization through chemical synthesis and functional combination of a high-temperature azo modified gas generating agent system, a medium-temperature gas generating agent system, a modified nano-silica foam stabilizing material and an oligomer, thereby forming an energy enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells with excellent performance, which has the characteristics of high temperature resistance, high resistance to condensate oil and high foam liquid carrying rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Attached Figure 1 It is a production curve change diagram before and after adopting the present invention. DETAILED DESCRIPTION

[0024] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical scheme of the present invention and actual conditions. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all known and commonly used chemical reagents and chemicals in the prior art.

[0025] The present invention will be further described below in conjunction with embodiments:

[0026] Embodiment 1: The nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells comprises 30% to 40% of a high-temperature azo modified gas generating agent system, 10% to 20% of a medium-temperature gas generating agent system, 5% to 10% of a modified nano-silica foam stabilizing material, 10% to 15% of an oligomer, and 30% to 50% of a high-efficiency foaming agent system in terms of mass percentage, and the balance is water, wherein the high-temperature azo modified gas generating agent system is composed of zinc acetate, azodicarbonamide, sodium bicarbonate and water, the medium-temperature gas generating agent system is composed of sodium nitrite and ammonium chloride, the oligomer is a polyacrylamide oligomer, and the high-efficiency foaming agent system is a mixture of any four substances selected from lauroamidopropyl hydroxysulfonyl betaine, cocoamidopropyl hydroxysulfonyl betaine, lauroamidopropyl amine oxide, alkylphenol polyoxyethylene ether and lauryl glucoside.

[0027] On the one hand, the present invention enhances the strength of the foam film by developing modified nano-silica foam stabilizing materials, and compounding oligomers with a molecular weight of 1500 to 3000 to further enhance the viscosity of the foam liquid film and enhance its heat-resistant and oil-resistant foam stabilizing ability; on the other hand, the sandstone is wetted and modified by the modified nano-silica foam stabilizing materials to further provide driving energy.

[0028] At the same time, the present invention mainly uses high-temperature azo modified gas generators, sodium nitrite, ammonium chloride, nano-silicon dioxide and other additives to form a nano-energy-enhancing foaming agent suitable for ultra-high temperature and high condensate oil and gas wells with ultra-deep well temperatures reaching less than 220°C, which breaks through the drainage problem of high-temperature and high-condensate oil and gas wells, and improves the additive sequence of ultra-high temperature and high-condensate oil water-flooded gas wells, and has high research and application value.

[0029] Example 2: As an optimization of the above example, the following steps were followed to prepare:

[0030] First, a high-temperature azo modified foaming agent system, a medium-temperature foaming agent system, and a modified nano-silica foam stabilizing material are sequentially added to a required amount of water, and stirred and dissolved to obtain a mixed solution; then, a high-efficiency foaming agent system and an oligomer are sequentially added to the mixed solution, and stirred and dispersed to obtain a nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells.

[0031] Example 3: As an optimization of the above example, in the high-temperature azo modified gasifier system, the mass ratio of zinc acetate, azodicarbonamide, sodium bicarbonate and water is 0.8:1:0.5:2.

[0032] In the present invention, the outer electron configuration of zinc ions is 4s 2 4p 2 , with empty orbitals, while there are lone pairs of electrons on the nitrogen and oxygen atoms in the azodicarbonamide molecule. According to the Lewis acid-base coordination principle, the two are complexed, and the lone pairs of electrons on the nitrogen and oxygen atoms are lost, causing the electron cloud concentration on the double bond to flow to both sides, reducing the overlap in the middle, resulting in the double bond breaking into a single bond, thereby activating and decomposing azodicarbonamide. The addition of zinc acetate causes the decomposition temperature of the reaction to drop from 200°C to 130°C, and its decomposition products contain nitrogen, carbon dioxide and ammonia. The addition of sodium bicarbonate greatly slows down the decomposition rate of the system. When the temperature reaches 130°C, the decomposition speed becomes faster, which overall delays the gasification and energy enhancement time of the high-temperature azo modified gasifier system.

[0033] Example 4: As an optimization of the above example, in the medium-temperature gas generating agent system, the mass ratio of sodium nitrite to ammonium chloride is 1:1.

[0034] In the present invention, the medium-temperature gasifier system is energized and gasified for about 10 days.

[0035] Example 5: As an optimization of the above example, a modified nano-silicon dioxide foam stabilizing material is prepared according to the following steps:

[0036] S1, dispersing a required amount of nano-silicon dioxide in anhydrous ethanol, stirring at room temperature until it forms a vortex, to obtain a first mixed solution, wherein the mass ratio of nano-silicon dioxide to anhydrous ethanol is 1:20;

[0037] S2, mixing perfluorododecyltriethoxysilane and water in a volume ratio of 1:2 and stirring to obtain a second mixed solution;

[0038] S3, mixing the first mixed solution and the second mixed solution in a volume ratio of 3.5 to 5.5:1, stirring and reacting at 70° C. for 3 hours to obtain a modified nano-silica foam-stabilizing material.

[0039] In the present invention, a modified nano-silica foam-stabilizing material with controllable wettability is prepared by using a dealcoholization condensation technology with perfluorododecyltriethoxysilane and nano-silica, wherein the obtained modified nano-silica foam-stabilizing material effectively prevents the agglomeration of nano-silica and improves its dispersibility. The dealcoholization condensation reaction mechanism of perfluorododecyltriethoxysilane and nano-silica is as follows:

[0040]

[0041]

[0042] .

[0043] Example 6: As an optimization of the above example, in step S3, the reaction temperature is 65°C to 75°C, and the reaction time is 2.5h to 3.5h.

[0044] Embodiment 7: As an optimization of the above embodiment, the oligomer has a number average molecular weight of 1500 to 3000.

[0045] Example 8: As an optimization of the above example, in the high-efficiency foaming agent system, the mass ratio of any four substances among lauramidopropyl hydroxysulfobetaine (LHSB), cocoamidopropyl hydroxysulfobetaine (CHSB), lauramidopropyl amine oxide (LAO), alkylphenol polyoxyethylene ether (APEO) and lauryl glucoside (APG1214) is 1:1:1:1.

[0046] Example 9: As an optimization of the above examples, the stirring speed is 100 rpm to 500 rpm.

[0047] Example 10: The preparation method of the nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells is carried out according to the following steps:

[0048] First, a high-temperature azo modified foaming agent system, a medium-temperature foaming agent system, and a modified nano-silica foam stabilizing material are sequentially added to a required amount of water, and stirred and dissolved to obtain a mixed solution; then, a high-efficiency foaming agent system and an oligomer are sequentially added to the mixed solution, and stirred and dispersed to obtain a nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells.

[0049] The present invention adopts a high-temperature azo modified gas generating agent system and a medium-temperature gas generating agent system to form a composite energizer system with an ultra-high temperature of less than 220°C; adopts a modified nano-silicon dioxide foam stabilizing material to significantly enhance the number of fine active droplets contained in a unit droplet and a nano-silicon oxide stable skeleton structure, improves the liquid film strength, and enhances its high temperature resistance and condensate resistance. At the same time, the modified nano-silicon dioxide foam stabilizing material contacts the modified sandstone skeleton to cause a wetting angle of 55° to 112° to reverse the wetting angle, further promoting the return of high-temperature wellbore accumulating liquid; adopts a low polymer with a molecular weight between 1500 and 3000 to increase the viscosity of the foam liquid film to improve the liquid film strength; adopts a high-efficiency foaming agent system to form a high-quality low-density foam fluid. And through the above chemical synthesis and functional combination methods, active groups such as energizing, foaming, and foam stabilization are introduced to form an energizing foaming agent for ultra-high temperature and high condensate oil and gas wells with excellent performance, which solves the technical difficulties of low foam liquid carrying rate under the conditions of low reservoir pressure, high temperature deep layer, and high condensate oil content, and has strong research value.

[0050] Compared with the prior art, the beneficial effects of the nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells of the present invention are:

[0051] (1) The enclosed energy increase is 1.5MPa to 3.5MPa;

[0052] (2) Temperature resistance ≥130℃;

[0053] (3) Condensate oil resistance ≥ 35%;

[0054] (4) The liquid carrying rate of the nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells of the present invention at 220°C, 35% condensate oil content, and 0.3% filling amount is ≥80%;

[0055] (5) The contact angle ranges from 55° to 112°.

[0056] Example 11: The nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells is prepared according to the following steps:

[0057] First, according to the mass percentage, the remaining water is placed in a stirring device, the stirring device is started to make it vortex-shaped, 35% of the high-temperature azo modified gasifier system, 12% of the medium-temperature gasifier system, and 8% of the modified nano-silica foam stabilizing material are sequentially added to the water, and stirred (speed 350rpm), and after the added materials are completely dissolved, a mixed solution is obtained; then, 35% of the high-efficiency foaming agent system and 12% of the oligomer are sequentially added to the mixed solution, and stirred (speed 350rpm) until the liquid is transparent and uniformly dispersed, and a nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells is obtained, wherein the high-efficiency foaming agent system is prepared by mixing lauramidopropyl hydroxysulfobetaine (LHSB), cocoamidopropyl hydroxysulfobetaine (CHSB), lauramidopropyl amine oxide (LAO) and lauryl glucoside (APG1214) in a mass ratio of 1:1:1:1.

[0058] The Wushi Banner oil and gas producing area of ​​the Sulige gas field is a low-quality tight sandstone gas reservoir. The Sulige gas field is a high-water-content tight sandstone gas reservoir. The water problem seriously restricts the gas well production capacity. This is particularly evident in the Sulige cooperative development block. Blocks Su77, ​​Zhao51, and Su19 are located in the Sulige gas-water layer area, which is a typical high-water-content tight sandstone gas reservoir. Gas wells generally produce water, with an average water-gas ratio of 2.3 cubic meters per 10,000 cubic meters, and a maximum of 12 cubic meters per 10,000 cubic meters, which is much higher than the average water-gas ratio of 0.75 cubic meters per 10,000 cubic meters in the Sulige gas field. The high temperature of formation water (130°C) and high condensate oil (up to 38%) seriously affect the drainage and gas production effect of the foaming agent, resulting in low production or even shutdown of about 23% of the gas wells, which seriously restricts the stable production of the block.

[0059] Well Su19-xx-xx has stopped production due to liquid accumulation since 2023. The low pressure in the wellbore is not enough to drain water and produce gas. After the nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells obtained in Example 11 with an injection volume of 0.3% was used on site, the liquid carrying rate reached 85%, the energy was increased by 1.5MPa to 3.5MPa, the oil-casing pressure difference phenomenon disappeared after drainage, and the average daily gas production reached 2100m 3 / d, implement intermittent production.

[0060] The production curve changes before and after using the nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells of the present invention are as follows: Figure 1 shown. Figure 1It can be seen that before the use of the nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells of the present invention, the large oil-casing pressure difference indicates that the oil pipe is seriously filled with liquid. After the use of the nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells of the present invention, the shut-in oil-casing pressure difference is quickly restored, and the oil-casing pressure difference is significantly reduced, indicating that the wellbore liquid accumulation phenomenon is significantly improved; after the use of the nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells of the present invention, the oil pressure and casing pressure are reduced compared with those before the test, indicating that the nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells has an obvious energy-enhancing effect, and can still cooperate with the intermittent recovery of production under lower oil-casing pressure conditions.

[0061] In summary, the present invention introduces active groups such as energy enhancement, foaming and foam stabilization through chemical synthesis and functional combination of a high-temperature azo modified gas generating agent system, a medium-temperature gas generating agent system, a modified nano-silica foam stabilizing material and an oligomer, thereby forming a nano-energy enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells with excellent performance, which has the characteristics of high temperature resistance, high resistance to condensate oil and high foam liquid carrying rate.

[0062] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells, characterized in that The raw material composition is 30% to 40% by mass of a high-temperature azo modified gasifier system, 10% to 20% by mass of a medium-temperature gasifier system, 5% to 10% by mass of a modified nano-silica foam stabilizing material, 10% to 15% by mass of an oligomer, and 30% to 50% by mass of a high-efficiency foaming agent system, and the balance is water, wherein the high-temperature azo modified gasifier system is composed of zinc acetate, azodicarbonamide, sodium bicarbonate and water, the medium-temperature gasifier system is composed of sodium nitrite and ammonium chloride, the oligomer is a polyacrylamide oligomer, and the high-efficiency foaming agent system is a mixture of any four substances selected from lauroamidopropyl hydroxysulfobetaine, cocoamidopropyl hydroxysulfobetaine, lauroamidopropyl amine oxide, alkylphenol polyoxyethylene ether and lauryl glucoside. The modified nano-silica foam stabilizing material is prepared according to the following steps: S1, dispersing a required amount of nano-silicon dioxide in anhydrous ethanol to obtain a first mixed solution; S2, mixing perfluorododecyltriethoxysilane and water in a volume ratio of 1:2 and stirring to obtain a second mixed solution; S3, mixing the first mixed liquid and the second mixed liquid in a volume ratio of 3.5 to 5.5:1 and reacting them to obtain a modified nano-silicon dioxide foam stabilizing material.

2. The nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells according to claim 1, characterized in that Prepared according to the following steps: First, a high-temperature azo modified foaming agent system, a medium-temperature foaming agent system, and a modified nano-silica foam stabilizing material are sequentially added to a required amount of water, and stirred and dissolved to obtain a mixed solution; then, a high-efficiency foaming agent system and an oligomer are sequentially added to the mixed solution, and stirred and dispersed to obtain a nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells.

3. The nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells according to claim 1 or 2, characterized in that In the high-temperature azo modified gasifier system, the mass ratio of zinc acetate, azodicarbonamide, sodium bicarbonate and water is 0.8:1:0.5:

2.

4. The nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells according to claim 3, characterized in that In the medium-temperature gasifier system, the mass ratio of sodium nitrite to ammonium chloride is 1:

1.

5. The nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells according to claim 2 or 4, characterized in that In step S3, the reaction temperature is 65° C. to 75° C., and the reaction time is 2.5 h to 3.5 h.

6. The nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells according to claim 5, characterized in that The oligomer has a number average molecular weight of 1500 to 3000.

7. The nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells according to claim 1, 2, 4 or 6, characterized in that The mass ratio of any four substances in the high-efficiency foaming agent system is 1:1:1:

1.

8. The nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells according to claim 7, characterized in that The stirring speed is 100 rpm to 500 rpm.

9. A method for preparing a nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells according to any one of claims 1 or 3 to 8, characterized in that Follow the steps below: First, a high-temperature azo modified foaming agent system, a medium-temperature foaming agent system, and a modified nano-silica foam stabilizing material are sequentially added to a required amount of water, and stirred and dissolved to obtain a mixed solution; then, a high-efficiency foaming agent system and an oligomer are sequentially added to the mixed solution, and stirred and dispersed to obtain a nano-energy-enhancing foaming agent for ultra-high temperature and high condensate oil and gas wells.

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