A flocculant, its preparation method and application

Abstract

The present application relates to a kind of flocculants and its preparation method and application, the preparation raw material of the flocculants includes saturated fatty acid dimer, polyol amine and polyene polyamine.In the present application, the flocculants has good flocculation effect for oil-based drilling fluid, and has less influence on the rheological property of drilling fluid.

Description

Technical Field

[0001] This invention relates to the field of drilling fluid technology, and in particular to a flocculant, its preparation method, and its application. Background Technology

[0002] Oil-based drilling fluids offer good resistance to high temperatures, lubrication, and inhibition, making them commonly used in drilling challenging formations such as shale. However, with increasing drilling time, the content of inferior solid phases in repeatedly used oil-based drilling fluids increases, and these solid particles are small and difficult to remove with solids control equipment. These inferior solid phases not only increase the viscosity and shear stress of the drilling fluid, deteriorating its rheological properties, but also slow down the rate of penetration (ROP) due to increased internal friction, reducing drilling efficiency. In severe cases, they can render the drilling fluid unusable, thereby increasing drilling costs.

[0003] CN115322757A discloses a method for external phase conversion and recovery of shale gas oil-based drilling fluid, including the following steps: S1, pumping the old oil-based drilling fluid to be converted into a circulation tank, and after natural sedimentation, vibration, and desanding treatment, the low-density solid content of the old oil-based drilling fluid is ≤10%, thus obtaining the slurry to be converted; S2, cleaning the mixing tank, adding base oil equivalent to 80% of the tank volume by mass percentage, leaving 20% ​​space for adding the following treatment agent for stirring treatment; S3, pumping the slurry to be converted into the bottom of the well and entering the large circulation, while simultaneously replenishing the oil-based adhesive in the on-site mixing tank, and slowly replenishing the slurry to be converted with the oil-based adhesive at a ratio of 1:4 according to the circulation cycle, so as to carry out external phase conversion of the slurry to be converted and obtain a stable converted slurry.

[0004] Currently, existing technologies generally treat inferior solid phases in oil-based drilling fluids that are reused multiple times by methods such as demulsification and separation, but these are all secondary treatments.

[0005] Flocculants can increase the particle size of inferior solids through flocculation, making them meet the processing conditions of solids control equipment and thus remove them.

[0006] CN114989793A discloses a self-removing oil-based drilling fluid system for nano- and micron-sized inferior solid phases, its preparation method, and its application. The disclosed oil-based drilling fluid system contains an oil-soluble selective flocculant, which is prepared by graft polymerization of cationic monomers grafted with silica, methacrylate monomers, and maleic anhydride; the content of the oil-soluble selective flocculant in the oil-based drilling fluid system is 0.1-2 wt%.

[0007] In the existing technology, almost all flocculants are used in water-based drilling fluids and few are used in oil-based drilling fluids. Flocculants suitable for oil-based drilling fluids are difficult to achieve good flocculation effects while having little impact on the rheological properties of the drilling fluid.

[0008] Therefore, it is necessary to develop a flocculant suitable for oil-based drilling fluids that can overcome the above-mentioned defects. Summary of the Invention

[0009] In view of the shortcomings of the prior art, the purpose of this invention is to provide a flocculant, its preparation method and application. The flocculant has a good flocculation effect on oil-based drilling fluids and has little impact on the rheological properties of drilling fluids.

[0010] To achieve this objective, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides a flocculant, wherein the raw materials for preparing the flocculant include saturated fatty acid dimers, polyol amines, and polyene polyamines.

[0012] In this invention, saturated fatty acid dimers, polyol amines, and polyene polyamines are used as the main raw materials to form a flocculant suitable for oil-based drilling fluids. This flocculant exhibits good flocculation effects on oil-based drilling fluids and has minimal impact on the rheological properties of the drilling fluid. Specifically, the saturated fatty acid dimers provide lipophilic groups, giving the resulting flocculant lipophilic properties; the polyol amines provide hydrophilic groups, giving the resulting flocculant hydrophilic properties; and the polyene polyamines provide adsorption groups, giving the resulting flocculant flocculation ability in oil-based drilling fluids. These three components work synergistically to form a flocculant suitable for oil-based drilling fluids.

[0013] Preferably, the saturated fatty acid dimer includes any one or a combination of at least two of octadecenoic acid dimer, hexadecenoic acid dimer, or dodecenoic acid dimer, wherein typical but non-limiting combinations include: a combination of octadecenoic acid dimer and hexadecenoic acid dimer, a combination of hexadecenoic acid dimer and dodecenoic acid dimer, a combination of octadecenoic acid dimer, hexadecenoic acid dimer, and dodecenoic acid dimer, etc., and octadecenoic acid dimer is more preferred.

[0014] In this invention, the saturated fatty acid dimer is preferably an octadecenoic acid dimer because its hydrocarbon chain is longer, which gives the resulting flocculant better lipophilicity.

[0015] Preferably, the polyol amine includes diethanolamine and / or triethanolamine.

[0016] In this invention, the polyol amine is preferably diethanolamine, which produces a flocculant with better flocculation effect.

[0017] Preferably, the polyene polyamine includes any one or a combination of at least two of diethylenetriamine, triethylenediamine, or tetraethylenediamine, with diethylenetriamine being more preferred.

[0018] In this invention, the polyene polyamine is preferably a flocculant generated from diethylenetriamine, which has a better flocculation effect and a smaller impact on the apparent viscosity of oil-based drilling fluid.

[0019] Preferably, based on 100 parts by weight of the saturated fatty acid dimer, the polyol amine is 30-50 parts by weight, such as 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, 48 ​​parts, etc.

[0020] In this invention, the weight percentage of polyol amine is preferably in the range of 30-50 parts. If the amount added is too high, the product viscosity will be too high, which will seriously affect the rheological properties of the drilling fluid; if the amount added is too low, the product will be too small.

[0021] Preferably, based on 100 parts by weight of the saturated fatty acid dimer, the polyene polyamine is 20-30 parts by weight, such as 22 parts, 24 parts, 26 parts, 28 parts, etc.

[0022] In this invention, the weight percentage of polyene polyamine is preferably in the range of 20-30 parts. If the amount added is too high, the product viscosity will be too high, which will seriously affect the rheological properties of the drilling fluid; if the amount added is too low, the product will be too small.

[0023] Preferably, the raw materials for preparation further include a solubilizer and / or an initiator.

[0024] Preferably, the solubilizer includes any one or a combination of at least two of ethanol, isopropanol, or ethylene glycol monobutyl ether.

[0025] Preferably, based on 100 parts by weight of the saturated fatty acid dimer, the solubilizer is 80-120 parts by weight, such as 90 parts, 100 parts, 110 parts, etc.

[0026] Preferably, the initiator comprises cyclohexanone peroxide.

[0027] Preferably, based on 100 parts by weight of the saturated fatty acid dimer, the initiator is 2-4 parts by weight, such as 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3 parts, 3.2 parts, 3.6 parts, 3.8 parts, etc.

[0028] In a second aspect, the present invention provides a method for preparing the flocculant described in the first aspect, the method comprising the following steps:

[0029] The flocculant is obtained by mixing saturated fatty acid dimers, polyol amines, and polyene polyamines and carrying out a polymerization reaction.

[0030] Preferably, the preparation method specifically includes: first mixing saturated fatty acid dimers, polyol amines and polyene polyamines in a solubilizer, removing oxygen, then mixing with an initiator, and finally carrying out a polymerization reaction.

[0031] For example, in this invention, the deoxygenation method includes passing nitrogen gas.

[0032] Preferably, the polymerization reaction temperature is 80-95℃, such as 82℃, 84℃, 86℃, 88℃, 90℃, 92℃, 94℃, etc.

[0033] Preferably, the polymerization reaction takes 1-5 hours, for example, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, etc.

[0034] Preferably, the polymerization reaction speed is ≤300 r / min, such as 250 r / min, 200 r / min, 150 r / min, 100 r / min, 50 r / min, etc.

[0035] Preferably, when the polymerization reaction lasts for ≤0.5h, the stirring speed is 50-150 r / min, such as 60 r / min, 80 r / min, 100 r / min, 120 r / min, 140 r / min, etc.

[0036] Preferably, when the polymerization reaction is >0.5h, the stirring speed is 200-300r / min, such as 220r / min, 240r / min, 260r / min, 280r / min, etc.

[0037] Preferably, the polymerization reaction is followed by cooling.

[0038] Preferably, the temperature is reduced to ≤60℃, such as 55℃, 50℃, 45℃, 40℃, etc.

[0039] As a preferred technical solution, the preparation method includes the following steps:

[0040] (1) Mix saturated fatty acid dimer, polyol amine and polyene polyamine in a solubilizer and remove oxygen to obtain the first solution;

[0041] (2) Mix the first solution with the initiator to obtain the second solution;

[0042] (3) The second solution is subjected to polymerization reaction at 80-95℃ for 1-5 hours. During the first 0.5 hours of polymerization reaction, the mixture is stirred at 50-150 r / min. Then the stirring speed is adjusted to 200-300 r / min for the remaining reaction time. After the reaction is completed, the mixture is cooled to ≤60℃ and discharged to obtain the flocculant.

[0043] Thirdly, the present invention provides a drilling fluid comprising the flocculant described in the first aspect.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] (1) In this invention, the flocculant has a good flocculation effect on oil-based drilling fluid and has little impact on the rheological properties of drilling fluid.

[0046] (2) In this invention, the flocculant reduces the solid content of oil-based drilling fluid by 11%-20% and the apparent viscosity changes by -5% to -26%. Detailed Implementation

[0047] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0048] Example 1

[0049] This embodiment provides a flocculant, the raw materials for preparing the flocculant comprising the following components in parts by weight:

[0050]

[0051] Among them, the saturated fatty acid dimer was purchased from Guangzhou Yuanda New Materials Co., Ltd., with the grade name 61788-89-4.

[0052] The flocculant is obtained by the following preparation method, which includes the following steps:

[0053] (1) Mix saturated fatty acid dimer, polyol amine and polyene polyamine in a solubilizer, and stir under nitrogen at 600 r / min for 20 min to remove oxygen, to obtain the first solution;

[0054] (2) Mix the first solution with the initiator to obtain the second solution;

[0055] (3) The second solution is subjected to polymerization reaction at 85°C for 3 hours. During the first 0.5 hours of polymerization reaction, the mixture is stirred at low speed. Then the stirring speed is adjusted to 250 r / min for the remaining reaction time. After the reaction is completed, the mixture is cooled to 60°C and discharged to obtain the flocculant.

[0056] Example 2

[0057] This embodiment provides a flocculant, the raw materials for preparing the flocculant comprising the following components in parts by weight:

[0058]

[0059]

[0060] Among them, the saturated fatty acid dimer was purchased from Guangzhou Yuanda New Materials Co., Ltd., with the grade name 61788-89-4.

[0061] The flocculant is obtained by the following preparation method, which includes the following steps:

[0062] (1) Mix saturated fatty acid dimer, polyol amine and polyene polyamine in a solubilizer, and stir under nitrogen at 600 r / min for 20 min to remove oxygen, to obtain the first solution;

[0063] (2) Mix the first solution with the initiator to obtain the second solution;

[0064] (3) The second solution is subjected to polymerization reaction at 80°C for 5 hours. During the first hour of polymerization reaction, the mixture is stirred at low speed. Then the stirring speed is adjusted to 2000 r / min for the remaining reaction time. After the reaction is completed, the mixture is cooled to 50°C and discharged to obtain the flocculant.

[0065] Example 3

[0066] This embodiment provides a flocculant, the raw materials for preparing the flocculant comprising the following components in parts by weight:

[0067]

[0068] Among them, the saturated fatty acid dimer was purchased from Guangzhou Yuanda New Materials Co., Ltd., with the grade name 61788-89-4.

[0069] The flocculant is obtained by the following preparation method, which includes the following steps:

[0070] (1) Mix saturated fatty acid dimer, polyol amine and polyene polyamine in a solubilizer, and stir under nitrogen at 600 r / min for 20 min to remove oxygen, to obtain the first solution;

[0071] (2) Mix the first solution with the initiator to obtain the second solution;

[0072] (3) The second solution is subjected to polymerization reaction at 95°C for 2 hours. During the first 0.5 hours of polymerization reaction, the mixture is stirred at low speed. Then the stirring speed is adjusted to 300 r / min for the remaining reaction time. After the reaction is completed, the mixture is cooled to 60°C and discharged to obtain the flocculant.

[0073] Example 4

[0074] The difference between this embodiment and Example 1 is that the saturated fatty acid dimer is replaced by an equal mass of hexadecenoic acid dimer (purchased from Hubei Guangao Biotechnology Co., Ltd., brand name 629-56-1), while the rest is the same as in Example 1.

[0075] Example 5

[0076] The difference between this embodiment and Embodiment 1 is that the polyol amine is replaced by an equal mass of triethanolamine instead of diethanolamine; otherwise, they are the same as in Embodiment 1.

[0077] Example 6

[0078] The difference between this embodiment and Embodiment 1 is that the weight of the polyol amine is 55 parts, while the rest are the same as in Embodiment 1.

[0079] Example 7

[0080] The difference between this embodiment and Embodiment 1 is that the polyene polyamine is replaced by an equal mass of tetraethylenediamine instead of diethylenetriamine; otherwise, they are the same as in Embodiment 1.

[0081] Example 8

[0082] The difference between this embodiment and Embodiment 1 is that the weight of the polyene polyamine is 35 parts, while the rest are the same as in Embodiment 1.

[0083] Comparative Example 1

[0084] The difference between this comparative example and Example 1 is that it does not include polyol amines; otherwise, it is the same as Example 1.

[0085] Comparative Example 2

[0086] The difference between this comparative example and Example 1 is that it does not include polyene polyamines; otherwise, they are the same as in Example 1.

[0087] Performance testing

[0088] The flocculants described in Examples 1-8 and Comparative Examples 1-2 were added at a ratio of 1% to the oil-based drilling fluid (density 1.67 g / cm³). 3 In a solution with a solid content of 30%, the following tests were performed:

[0089] (1) Percentage decrease in solid content in oil-based drilling fluid: Comply with GB / T 16783.2 Field testing of drilling fluids for petroleum and natural gas industry - Part 2: Oil-based drilling fluids.

[0090] (2) Percentage decrease in apparent viscosity of oil-based drilling fluid: Comply with GB / T 16783.2 Field test of drilling fluids for petroleum and natural gas industry - Part 2: Oil-based drilling fluids.

[0091] The test results are summarized in Table 1.

[0092] Table 1

[0093]

[0094]

[0095] Analysis of the data in Table 1 shows that the flocculant described in this invention reduces the solid content of oil-based drilling fluid by 11%-20%, and the apparent viscosity changes by a percentage within -5% to -26%. The flocculant described in this invention has a good flocculation effect on oil-based drilling fluid and has little impact on the rheological properties of the drilling fluid.

[0096] Analysis of Comparative Examples 1-2 and Example 1 shows that the performance of Comparative Examples 1-2 is not as good as that of Example 1, proving that the flocculant described in this invention has better performance.

[0097] Analysis of Example 4 and Example 1 shows that the performance of Example 4 is not as good as that of Example 1, proving that the flocculant formed by the preferred saturated fatty acid dimer, octadecenoic acid dimer, has better performance.

[0098] Analysis of Example 5 and Example 1 shows that the performance of Example 5 is not as good as that of Example 1, proving that the flocculant formed by the preferred polyol amine, diethanolamine, has better performance.

[0099] Analysis of Example 6 and Example 1 shows that the performance of Example 6 is not as good as that of Example 1, proving that the flocculant formed by 30-50 parts by weight of the polyol amine is worse than that formed by 100 parts by weight of the saturated fatty acid dimer.

[0100] Analysis of Example 7 and Example 1 shows that the performance of Example 7 is not as good as that of Example 1, proving that the flocculant formed by the preferred polyene polyamine is better.

[0101] Analysis of Example 8 and Example 1 shows that the performance of Example 8 is not as good as that of Example 1, proving that the flocculant formed by 20-30 parts by weight of the polyene polyamine is worse than that formed by 100 parts by weight of the saturated fatty acid dimer.

[0102] The present invention has been illustrated with the above embodiments to explain the detailed method of the present invention. However, the present invention is not limited to the detailed method described above, that is, it does not mean that the present invention must rely on the detailed method described above to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A flocculating agent, characterized by, The raw materials for preparing the flocculant include saturated fatty acid dimers, polyol amines, and polyene polyamines; The method for preparing the flocculant includes: (1) Mix saturated fatty acid dimer, polyol amine and polyene polyamine in a solubilizer and remove oxygen to obtain the first solution; (2) Mix the first solution with the initiator to obtain the second solution; (3) The second solution is subjected to polymerization reaction at 80-95℃ for 1-5 h. During the first 0.5 h of polymerization reaction, the mixture is stirred at 50-150 r / min. Then the stirring speed is adjusted to 200-300 r / min for the remaining reaction time. After the reaction is completed, the mixture is cooled to ≤60℃ and discharged to obtain the flocculant.

2. The flocculating agent according to claim 1, characterized by The saturated fatty acid dimer includes any one or a combination of at least two of the following: octadecenoic acid dimer, hexadecenoic acid dimer, or dodecenoic acid dimer.

3. The flocculating agent according to claim 1, characterized by The polyol amines include diethanolamine and / or triethanolamine.

4. The flocculating agent according to claim 1, characterized by The polyene polyamine includes any one or a combination of at least two of diethylenetriamine, triethylenediamine, or tetraethylenediamine.

5. The flocculating agent of claim 1, wherein Based on 100 parts by weight of the saturated fatty acid dimer, the polyol amine is 30-50 parts by weight.

6. The flocculating agent of claim 1, wherein Based on 100 parts by weight of the saturated fatty acid dimer, the polyene polyamine is 20-30 parts by weight.

7. The flocculating agent of claim 1, wherein The solubilizer includes any one or a combination of at least two of ethanol, isopropanol, or ethylene glycol monobutyl ether.

8. The flocculating agent of claim 1, wherein Based on 100 parts by weight of the saturated fatty acid dimer, the solubilizer comprises 80-120 parts by weight.

9. The flocculating agent of claim 1, wherein The initiator includes cyclohexanone peroxide.

10. The flocculating agent of claim 1, wherein Based on 100 parts by weight of the saturated fatty acid dimer, the initiator comprises 2-4 parts by weight.

11. A process for the preparation of the flocculating agent according to any one of claims 1 to 10, characterized in that, The preparation method includes the following steps: (1) Mix saturated fatty acid dimer, polyol amine and polyene polyamine in a solubilizer and remove oxygen to obtain the first solution; (2) Mix the first solution with the initiator to obtain the second solution; (3) The second solution is subjected to polymerization reaction at 80-95℃ for 1-5 h. During the first 0.5 h of polymerization reaction, the mixture is stirred at 50-150 r / min. Then the stirring speed is adjusted to 200-300 r / min for the remaining reaction time. After the reaction is completed, the mixture is cooled to ≤60℃ and discharged to obtain the flocculant.

12. A drilling fluid, characterized by, The drilling fluid includes the flocculant according to any one of claims 1-10.

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