A blowing agent system, its preparation method and use

Abstract

The present application provides a foaming agent system, its preparation method and application, solves the problems of insufficient carrying and suspending capacity, large and unstable foam size in the current foam drilling fluid system, and can well meet the requirements of complex formation drilling operation. The foaming agent is composed of 20-45% main foaming agent, 5-20% auxiliary foaming agent and the balance of water; the main foaming agent is a carboxylate anionic surfactant containing alkyl glucoside structure; the auxiliary foaming agent is a non-ionic surfactant containing fatty acyl alcohol amine structure. The foaming agent system prepared by the present application has small foam size, salt resistance of 70000mg / L (Ca 2+ 2000mg / L), good foaming effect, good lubricity and reservoir protection effect, and can still maintain good foam stability under complex bottom hole conditions.

Description

Technical Field

[0001] This invention belongs to the field of drilling fluid technology, specifically relating to a foaming agent system, its preparation method, and its application. Background Technology

[0002] The current trend towards low-cost development is driving continuous optimization (simplification) of wellbore structures, leading to the widespread drilling of large-diameter, ultra-long open-hole sections. However, these sections often involve multiple pressure systems and complex formation lithology, increasing wellbore stability risks, narrowing the safe drilling window, and placing higher demands on drilling fluid performance. The task of reinforcing the wellbore (preventing leakage and collapse) is also crucial. Furthermore, as horizontal wells extend, cuttings bed problems become more prominent, posing a significant challenge to safe drilling and placing even higher demands on the cuttings-carrying capacity of drilling fluids.

[0003] Current foam drilling fluid systems produce large-sized foams that are prone to breakage, exhibit poor stability, and have limited functionality, failing to meet the requirements of complex well conditions. This necessitates the addition of other functional additives, further complicating the system. Alkyl glycoside surfactants, however, reduce water activity and alter the flow state of shale pore fluids, exhibiting a certain inhibitory effect. They also possess good lubrication, strong anti-fouling capabilities, and excellent reservoir protection, while being biodegradable, thus contributing to environmental protection. Therefore, a smaller-sized foam drilling fluid system can be prepared using alkyl glycoside surfactants. Due to the smaller foam size and lower gas content compared to ordinary foams, the bubbles are encapsulated by multiple liquid films, effectively preventing adjacent bubbles from merging and improving foam stability. Furthermore, the small size, high strength, and good stability of the bubbles provide a certain degree of leak prevention and plugging effect. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, this invention proposes a foaming agent system, its preparation method, and its application.

[0005] In a first aspect, the present invention provides a foaming agent system comprising: 20-45 wt% of a primary foaming agent, 5-20 wt% of a secondary foaming agent, and the balance being water;

[0006] The main foaming agent is a carboxylate-type anionic surfactant containing an alkyl glycoside structure;

[0007] The secondary foaming agent is a nonionic surfactant containing a fatty acyl alcohol amine structure;

[0008] The foam size of the foaming agent system is 97–124 μm.

[0009] As a specific embodiment of the present invention, the structure of the alkyl glycoside anionic surfactant is as follows:

[0010]

[0011] Where R is selected from C8-C 16 Alkyl groups, preferably C 12 -C 16 For example, selected from C 12 H 25 C 14 H 29 C 16 H 33 .

[0012] As a specific embodiment of the present invention, the structure of the nonionic surfactant with the fatty acyl alcohol amine structure is as follows:

[0013]

[0014] Where R is selected from C 10 -C 18 Alkyl, preferably C 11 -C 17 For example, selected from C 11 H 23 C 13 H 27 C 17 H 35 .

[0015] As a specific embodiment of the present invention, the preparation method of the main foaming agent is to use C8-C16 alkyl glycosides as raw materials, and after alkalization under the first solvent conditions, react with sodium chloroacetate to obtain the alkyl glycoside carboxylic acid sodium anionic surfactant.

[0016] In a specific embodiment of the present invention, the first solvent is xylene; the alkalization includes the use of sodium hydroxide; and the molar ratio of the alkyl glycoside to sodium chloroacetate is 1:(1.05-1.2).

[0017] As a specific embodiment of the present invention, the secondary foaming agent is prepared by condensing laurylamide, myristamide or stearamide with diethanolamine.

[0018] As a specific embodiment of the present invention, the molar ratio of laurylamide, myristamide or stearamide to diethanolamine is 1:(1.2-1.8); the condensation reaction temperature is 150-190°C; and the condensation reaction time is 2-5 h.

[0019] All of the above-mentioned raw materials used in this invention can be prepared in-house or purchased commercially; this invention does not impose any particular limitations on them.

[0020] Secondly, the present invention provides a method for preparing the foaming agent system, comprising: mixing 20-45 wt% of a primary foaming agent, 5-20 wt% of a secondary foaming agent, and the remainder water.

[0021] Thirdly, the present invention provides the application of the foaming agent system in the field of water-based drilling fluids.

[0022] As a specific embodiment of the present invention, the foaming agent system has a mass fraction of 0.5%-3% in the drilling fluid.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. The foaming agent system of this invention has small foam size and is resistant to salt concentrations of 70,000 mg / L (Ca). 2+ With a concentration of 2000 mg / L, it exhibits excellent foaming effect, good lubricity, and reservoir protection. Compared with existing technologies, this provides a foaming agent system for foam drilling with superior overall performance, maintaining good foaming properties even under complex formation conditions.

[0025] 2. This invention significantly improves the rolling recovery rate of rock cuttings compared to clear water and has a good effect on inhibiting rock cuttings hydration.

[0026] 3. This invention uses alkyl glycoside surfactants as the main foaming agent, which not only have excellent surface activity and good biodegradability, but are also non-toxic and harmless to the environment. Detailed Implementation

[0027] The present invention will be further described below with reference to specific embodiments, but this does not constitute any limitation on the present invention.

[0028] Example 1

[0029] This embodiment provides a primary foaming agent and its preparation method, with specific details as follows:

[0030] S1: With C 12 H 25 Using alkyl glycosides as raw materials, and xylene as solvent, the mixture was alkalized with sodium hydroxide at 40°C for 2 hours to obtain a mixture;

[0031] S2: The mixture obtained in step S1 is reacted with sodium chloroacetate at a molar ratio of 1:1.1 to prepare sodium alkyl glycoside carboxylate, an anionic surfactant and main foaming agent, with the following structural formula:

[0032]

[0033] The molecular weight is 405.

[0034] Example 2

[0035] With C 14 H 29 Using alkyl glycosides as raw materials, and prepared in the same manner as in Example 1, an alkyl glycoside sodium carboxylate anionic surfactant main foaming agent was obtained, with the structural formula as follows:

[0036]

[0037] The molecular weight is 433.

[0038] Example 3

[0039] With C 16 H 33 Using alkyl glycosides as raw materials, and prepared in the same manner as in Example 1, a sodium carboxylate anionic surfactant primary foaming agent of alkyl glycosides was obtained, with the structural formula as follows:

[0040]

[0041] The molecular weight is 461.

[0042] Example 4

[0043] This embodiment provides a secondary foaming agent and its preparation method, the details of which are as follows:

[0044] S1: Mix laurylamide and diethanolamine in a molar ratio of 1:1.4;

[0045] S2: A condensation reaction was carried out at 160℃ for 4 hours to obtain a nonionic surfactant, a fatty acyl alcohol amine; its structural formula is:

[0046]

[0047] The molecular weight is 287.

[0048] Example 5

[0049] Myristamide and diethanolamine were mixed at a molar ratio of 1:1.8 and subjected to a condensation reaction at 160℃ for 4 hours to obtain a nonionic surfactant, a fatty acyl alcohol amine; its structural formula is:

[0050]

[0051] The molecular weight is 315.

[0052] Example 6

[0053] Stearamide and diethanolamine were mixed at a molar ratio of 1:1.5 and subjected to a condensation reaction at 160℃ for 4 hours to obtain a nonionic surfactant, a fatty acyl alcohol amine; the structural formula is:

[0054]

[0055] The molecular weight is 371.

[0056] Example 7

[0057] This embodiment provides a foaming agent system and its preparation method, with specific details as follows:

[0058] Place 60g of water in a beaker and slowly add sodium alkyl glycoside carboxylate (R=C) prepared in Example 1 while stirring at 300rpm. 12 H 25 20g, and the auxiliary foaming agent fatty acyl alcohol amine (R=C) prepared in Example 4. 11 H 23 Add 20g of foaming agent and slowly heat to 40℃. Continue stirring at 200rpm until homogeneous to obtain foaming agent system 1.

[0059] Weigh 1g of the foaming agent system 1 obtained in Example 7, and add it to a solution with a mineralization of 70000mg / L (Ca). 2+ In simulated water (2000 mg / L), foam performance was tested using the Waring Blender method. The particle size of the foam of the prepared foaming agent was measured using a microscope, and its ability to inhibit shale hydration was determined. The data are shown in Tables 1-3.

[0060] Example 8

[0061] This embodiment provides a foaming agent system and its preparation method, with specific details as follows:

[0062] Place 65g of water in a beaker and slowly add sodium alkyl glycoside carboxylate (R=C), the main foaming agent from Example 1, while stirring at 300rpm. 12 H 25 20g, Example 5: Sub-foaming agent fatty acyl alcohol amine (R=C) 13 H 27 Add 15g of foaming agent to a slowly heated container and stir at 200 rpm until homogeneous to obtain foaming agent system 2.

[0063] Weigh 1g of the foaming agent system 2 obtained in Example 8 and add it to a solution with a mineralization of 70000mg / L (Ca). 2+ In simulated water (2000 mg / L), foam performance was tested using the Waring Blender method. The particle size of the foam of the prepared foaming agent was measured using a microscope, and its ability to inhibit shale hydration was determined. The data are shown in Tables 1-3.

[0064] Example 9

[0065] This embodiment provides a foaming agent system and its preparation method, with specific details as follows:

[0066] Place 70g of water in a beaker, and slowly add sodium alkyl glycoside carboxylate (R=C) as the main foaming agent from Example 2 while stirring. 14 H 29 20g, Example 4: Fatty acyl alcohol amine (R=C 11 H 23 Add 10g of the foaming agent and slowly heat it to 40℃ while stirring until homogeneous to obtain foaming agent system 3.

[0067] Weigh 1g of the foaming agent system 3 from Example 9 and add it to a solution with a mineralization of 70000mg / L (Ca). 2+ In simulated water (2000 mg / L), foam performance was tested using the Waring Blender method. The particle size of the foam of the prepared foaming agent was measured using a microscope, and its ability to inhibit shale hydration was determined. The data are shown in Tables 1-3.

[0068] Example 10

[0069] This embodiment provides a foaming agent system and its preparation method, with specific details as follows:

[0070] Place 50g of water in a beaker, and slowly add sodium alkyl glycoside carboxylate (R=C) as the main foaming agent from Example 1 while stirring. 12 H 25 30g, Example 4: Fatty acyl alcohol amine (R=C 11 H 23 Add 20g of the foaming agent and slowly heat it to 40℃ while stirring until homogeneous to obtain foaming agent system 4.

[0071] Weigh 1g of the foaming agent system 4 from Example 10 and add it to a solution with a mineralization of 70000mg / L (Ca). 2+ In simulated water (2000 mg / L), foam performance was tested using the Waring Blender method. The particle size of the foam of the prepared foaming agent was measured using a microscope, and its ability to inhibit shale hydration was determined. The data are shown in Tables 1-3.

[0072] Example 11

[0073] This embodiment provides a foaming agent system and its preparation method, with specific details as follows:

[0074] Place 45g of water in a beaker, and slowly add sodium alkyl glycoside carboxylate (R=C) as the main foaming agent from Example 1 while stirring. 12 H 25 45g, Example 4: Fatty acyl alcohol amine (R=C 11 H 23Add 10g of the foaming agent and slowly heat it to 40℃ while stirring until homogeneous to obtain foaming agent system 5.

[0075] Weigh 1g of the foaming agent system 5 from Example 11 and add it to a solution with a mineralization of 70000mg / L (Ca). 2+ In simulated water (2000 mg / L), foam performance was tested using the Waring Blender method. The particle size of the foam of the prepared foaming agent was measured using a microscope, and its ability to inhibit shale hydration was determined. The data are shown in Tables 1-3.

[0076] Example 12

[0077] This embodiment provides a foaming agent system and its preparation method, with specific details as follows:

[0078] Place 50g of water in a beaker, and slowly add sodium alkyl glycoside carboxylate (R=C) as the main foaming agent from Example 1 while stirring. 12 H 25 40g, Example 6 Fatty acyl alcohol amine (R=C 17 H 35 Add 10g of the foaming agent and slowly heat it to 40℃ while stirring until homogeneous to obtain foaming agent system 6.

[0079] Weigh 1g of the foaming agent system 6 from Example 12 and add it to a solution with a mineralization of 70000mg / L (Ca). 2+ In simulated water (2000 mg / L), foam performance was tested using the Waring Blender method. The particle size of the foam of the prepared foaming agent was measured using a microscope, and its ability to inhibit shale hydration was determined. The data are shown in Tables 1-3.

[0080] Example 13

[0081] This embodiment provides a foaming agent system and its preparation method, with specific details as follows:

[0082] Place 50g of water in a beaker, and slowly add sodium alkyl glycoside carboxylate (R=C) as the main foaming agent from Example 3 while stirring. 16 H 33 45g, Example 4: Fatty acyl alcohol amine (R=C 11 H 23 Add 5g of the foaming agent and slowly heat it to 40℃ while stirring until homogeneous to obtain foaming agent system 7.

[0083] Weigh 1g of the foaming agent system 7 from Example 13 and add it to a solution with a mineralization of 70000mg / L (Ca). 2+In simulated water (2000 mg / L), foam performance was tested using the Waring Blender method. The particle size of the foam of the prepared foaming agent was measured using a microscope, and its ability to inhibit shale hydration was determined. The data are shown in Tables 1-3.

[0084] Comparative Example 1

[0085] This comparative example provides a foaming agent system and its preparation method, with specific details as follows:

[0086] Place 55g of water in a beaker and slowly add sodium alkyl glycoside carboxylate (R=C) from Example 1 while stirring. 12 H 25 Add 45g of the foaming agent and slowly heat it to 40℃ while stirring until homogeneous to obtain foaming agent system D1.

[0087] Weigh 1g of the foaming agent system obtained in Comparative Example 1 and add it to a solution with a mineralization of 70000mg / L (Ca). 2+ In simulated water (2000 mg / L), foam performance was tested using the Waring Blender method. The particle size of the foam of the prepared foaming agent was measured using a microscope, and its ability to inhibit shale hydration was determined. The data are shown in Tables 1-3.

[0088] Comparative Example 2

[0089] This comparative example provides a foaming agent system and its preparation method, with specific details as follows:

[0090] Place 55g of water in a beaker, and slowly add the fatty acylamine (R=C) from Example 4 while stirring. 11 H 23 Add 5g of the foaming agent and slowly heat it to 40℃ while stirring until homogeneous to obtain foaming agent system D2.

[0091] Weigh 1g of the foaming agent system obtained in Comparative Example 2 and add it to a solution with a mineralization of 70000mg / L (Ca). 2+ In simulated water (2000 mg / L), foam performance was tested using the Waring Blender method. The particle size of the foam of the prepared foaming agent was measured using a microscope, and its ability to inhibit shale hydration was determined. The data are shown in Tables 1-3.

[0092] Comparative Example 3

[0093] This embodiment provides a foaming agent system and its preparation method, with specific details as follows:

[0094] Place 35g of water in a beaker, and slowly add sodium alkyl glycoside carboxylate (R=C) as the main foaming agent from Example 1 while stirring. 12 H 25 60g, Example 6 Fatty acyl alcohol amine (R=C17 H 35 Add 5g of the foaming agent and slowly heat to 40℃ while stirring until homogeneous to obtain foaming agent system D3.

[0095] Weigh 1g of the foaming agent system obtained in Comparative Example 3 and add it to a solution with a mineralization of 70000mg / L (Ca). 2+ In simulated water (2000 mg / L), foam performance was tested using the Waring Blender method. The particle size of the foam of the prepared foaming agent was measured using a microscope, and its ability to inhibit shale hydration was determined. The data are shown in Tables 1-3.

[0096] Comparative Example 4

[0097] This embodiment provides a foaming agent system and its preparation method, with specific details as follows:

[0098] Place 45g of water in a beaker, and slowly add sodium alkyl glycoside carboxylate (R=C) as the main foaming agent from Example 1 while stirring. 12 H 25 15g, Example 4: Fatty acyl alcohol amine (R=C 11 H 23 Add 40g of the foaming agent and slowly heat to 40℃ while stirring until homogeneous to obtain foaming agent system D4.

[0099] Weigh 1g of the foaming agent system from Comparative Example 4 and add it to a solution with a mineralization of 70000mg / L (Ca). 2+ In simulated water (2000 mg / L), foam performance was tested using the Waring Blender method. The particle size of the foam of the prepared foaming agent was measured using a microscope, and its ability to inhibit shale hydration was determined. The data are shown in Tables 1-3.

[0100] Comparative Example 5

[0101] This comparative example provides a commercially available drilling foaming agent with the code WD-18.

[0102] Test case

[0103] The foaming agent systems prepared in Examples 7-13 and the foaming agent systems in Comparative Examples 1-5 were subjected to foam diameter measurement, microfoam performance testing, and shale hydration inhibition performance testing. The test results are shown in Tables 1-3.

[0104] Table 1. Evaluation of the microfoam performance of the foaming agent systems obtained in Examples 7-13 and Comparative Examples 1-3.

[0105] Foaming System 1 545 32 196 Foaming System 2 560 28 214 Foaming System 3 550 24 186 Foaming system 4 565 36 165 Foaming system 5 520 29 208 Foaming system 6 565 24 234 Foaming System 7 550 26 196 Comparative Example 1 510 21 164 Comparative Example 2 500 18 138 Comparative Example 3 505 17 152 Comparative Example 4 495 22 135 Comparative Example 5 490 15 127

[0106] Table 2. Foam particle size of the foaming agent systems obtained in Examples 7-13 and Comparative Examples 1-5

[0107]

[0108]

[0109] Table 3 shows the shale hydration inhibition performance of the foaming agent systems obtained in Examples 7-13 and Comparative Examples 1-5.

[0110]

[0111] As can be seen from the test data of Examples 7-13 and Comparative Examples 1-4 in Tables 1-3, the microfoam foaming system of the present invention has small foam size, good foam stability, good shale hydration inhibition performance, and strong salt resistance. Considering all performance data, the preferred combination of the present invention is 30-40 wt% main foaming agent, 10-20 wt% secondary foaming agent, and the balance being water. Compared with Comparative Example 5, the foaming agent system of the present invention in Examples 7-13 has better performance than the commercially available product in Comparative Example 5.

[0112] Application examples

[0113] A drilling company reported severe cuttings hydration during foam drilling, causing a rapid increase in foam base fluid viscosity, slow drilling speed, and high on-site water consumption. In contrast, another well in the same block used foaming agent 4 as described in Example 10 of this invention. With the same 1% foaming agent dosage, this well showed less increase in foam base fluid viscosity compared to the adjacent well, a 47.62% increase in drilling speed, and a significant reduction in on-site water consumption. This demonstrates that the product of this invention has a good effect on inhibiting cuttings hydration and can significantly improve drilling speed.

[0114] Any numerical value mentioned in this invention, if there is only a two-unit interval between any minimum and any maximum value, includes all values ​​that increase by one unit each time from the minimum to the maximum value. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, or time, is stated as 50-90, in this specification it means specifically listing values ​​such as 51-89, 52-88… and 69-71 and 70-71, etc. For non-integer values, it may be appropriately considered that a unit is 0.1, 0.01, 0.001, or 0.0001. These are merely some specifically specified examples. In this application, in a similar manner, all possible combinations of numerical values ​​between the listed minimum and maximum values ​​are considered to have been disclosed.

[0115] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A foaming agent system, characterized in that, The foaming agent system includes: 20~45wt% of main foaming agent, 5~20wt% of secondary foaming agent, and the balance being water; The main foaming agent includes a carboxylate-type anionic surfactant containing an alkyl glycoside structure; The secondary foaming agent includes a nonionic surfactant containing a fatty acyl alcohol amine structure; The foam size of the foaming agent system is 97~124μm; The structure of the carboxylate-type anionic surfactant containing an alkyl glycoside structure is as follows: Where R is selected from C8-C 16 Alkyl groups; The structure of the nonionic surfactant containing a fatty acyl alcohol amine structure is as follows: Where R is selected from C 10 -C 18 alkyl.

2. The foaming agent system according to claim 1, characterized in that, In the structure of carboxylate-type anionic surfactants containing alkyl glycoside structures, R is selected from C 12 -C 16 ; And / or, in the nonionic surfactant containing a fatty acylamine structure, R is selected from C 11 -C 17 .

3. The foaming agent system according to claim 1, characterized in that, In the structure of the carboxylate-type anionic surfactant containing an alkyl glycoside structure, R is selected from C. 12 H 25 C 14 H 29 C 16 H 33 Any one of them; And / or, in the nonionic surfactant containing a fatty acylamine structure, R is selected from C 11 H 23 C 13 H 27 C 17 H 35 Any one of them.

4. The foaming agent system according to any one of claims 1-3, characterized in that, The preparation method of the main foaming agent includes: using C8-C 16 Using alkyl glycosides as raw materials, the surfactant is prepared by alkalization under the first solvent condition and then reacting with sodium chloroacetate to obtain the carboxylate-type anionic surfactant containing the alkyl glycoside structure.

5. The foaming agent system according to claim 4, characterized in that, The first solvent is xylene; the alkalization includes alkalization with sodium hydroxide; the molar ratio of the alkyl glycoside to sodium chloroacetate is 1:(1.05~1.2).

6. The foaming agent system according to any one of claims 1-3, characterized in that, The preparation method of the secondary foaming agent includes condensation reaction of lauryl amide, myristamide or stearamide with diethanolamine.

7. The foaming agent system according to claim 6, characterized in that, The molar ratio of laurylamide, myristamide or stearamide to diethanolamine is 1:(1.2~1.8). The condensation reaction temperature is 150~190℃; the condensation reaction time is 2~5h.

8. A method for preparing the foaming agent system according to any one of claims 1-7, characterized in that, include: Mix 20-45 wt% of the main foaming agent, 5-20 wt% of the secondary foaming agent, and the remainder water.

9. The application of the foaming agent system according to any one of claims 1-7 or the foaming agent system prepared by the preparation method according to claim 8 in the field of water-based drilling fluids.

10. The application according to claim 9, characterized in that, The foaming agent system has a mass fraction of 0.5%-3% in the drilling fluid.

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