Shear improving agent, preparation method thereof and drilling fluid

Abstract

The invention provides a shear strength improving agent, a preparation method thereof and a drilling fluid, the shear strength improving agent comprises the following raw materials: an unsaturated fatty acid dimer, a polyol amine compound and a polyethylene polyamine compound, the shear strength improving agent has a good shear strength improving effect on the oil-based drilling fluid, and the influence on the rheological property of the drilling fluid is small. The shear strength improving agent has a good shear strength improving effect on the oil-based drilling fluid, and the dynamic shear force can be increased by 8-30% by adding 0.2% by mass of the shear strength improving agent; the shear strength improving agent enables the plastic viscosity change percentage of the oil-based drilling fluid to be within 12-26%.

Description

Technical Field

[0001] The invention belongs to the technical field of drilling fluids and relates to a shearing agent and a preparation method thereof and drilling fluid. Background Art

[0002] Traditional oil-based drilling fluids use organic soil as a viscosity enhancer and oxidized asphalt or organic lignite materials as a fluid loss reducer, which has played an important role in the development of drilling engineering and is still widely used in the drilling of complex formations, deep / ultra-deep formations and complex structure wells. However, traditional oil-based drilling fluids have the following disadvantages: organic soil and oxidized asphalt-based colloid materials are not conducive to drilling speed, and are prone to thickening of drilling fluids after aging; colloid materials are not conducive to reservoir protection; and the high colloid content makes it difficult to increase the density of drilling fluids to a higher density. Therefore, oil-based drilling fluids with low colloid content have been widely used, but the shear force of oil-based drilling fluids at low colloid content is insufficient, and the wellbore cleaning effect is not ideal.

[0003] In order to solve the above problems, the main research direction at home and abroad is to develop an oil-based drilling fluid cutting agent to replace organic soil. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a cutting agent and a preparation method thereof and a drilling fluid. The cutting agent has a good cutting effect on the oil-based drilling fluid and has little effect on the rheological properties of the drilling fluid.

[0005] In order to achieve the above technical effects, the present invention adopts the following technical solutions:

[0006] One of the purposes of the present invention is to provide a shearing agent, the raw materials of which include unsaturated fatty acid dimer, polyol amine compounds and polyethylene polyamine compounds;

[0007] In the polyol amine compound, the number of hydroxyl groups is ≥2;

[0008] In the polyethylene polyamine compound, the number of ethylene groups is ≥2, and the number of nitrogen atoms is ≥2.

[0009] Among them, the number of hydroxyl groups in the polyol amine compounds can be 2, 3, 4 or 5, the number of ethylene groups in the polyethylene polyamine compounds can be 2, 3, 4 or 5, and the number of nitrogen atoms can be 2, 3, 4 or 5, but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0010] In the present invention, the role of the unsaturated fatty acid dimer is to provide a lipophilic group, so that the generated fluid loss additive has lipophilicity; the role of the polyolamine is to provide a hydrophilic group, so that the generated fluid loss additive has hydrophilicity; the role of the polyethylenepolyamine is to provide an adsorption group, so that the generated fluid loss additive has the ability to increase the gel strength in the oil-based drilling fluid; the three cooperate synergistically to form a fluid loss additive suitable for the oil-based drilling fluid.

[0011] As a preferred technical solution of the present invention, based on 100 parts by weight of the unsaturated fatty acid dimer, the weight of the polyolamine compound is 30-50 parts, such as 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, 45 parts, 48 parts or 50 parts, etc., but not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0012] In the present invention, if the addition amount of the polyolamine is too high, the viscosity of the product will be too large, seriously affecting the rheology of the drilling fluid; if the addition amount is too low, the amount of the product will be insufficient.

[0013] Preferably, based on 100 parts by weight of the unsaturated fatty acid dimer, the weight of the polyethylenepolyamine compound is 20-30 parts, such as 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts or 30 parts, etc., but not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0014] In the present invention, if the addition amount of the polyethylenepolyamine is too high, the viscosity of the product will be too large, seriously affecting the rheology of the drilling fluid; if the addition amount is too low, the amount of the product will be insufficient.

[0015] As a preferred technical solution of the present invention, the unsaturated fatty acid dimer includes any one or a combination of at least two of the oleic acid dimer, palmitoleic acid dimer or lauroleic acid dimer. Typical but non-limiting examples of the combination include: the combination of oleic acid dimer and palmitoleic acid dimer, the combination of palmitoleic acid dimer and lauroleic acid dimer, the combination of oleic acid dimer, palmitoleic acid dimer and lauroleic acid dimer, etc. Further preferably, it is the oleic acid dimer.

[0016] In the present invention, the unsaturated fatty acid dimer is preferably the oleic acid dimer because its hydrocarbon chain is longer, so that the generated fluid loss additive has better lipophilicity.

[0017] Preferably, the polyolamine compound includes diethanolamine and / or triethanolamine. Diethanolamine is preferably used.

[0018] Preferably, the polyethylenepolyamine compound includes any one or a combination of at least two of diethylenetriamine, triethylenediamine or tetraethylenetriamine. Preferably it is diethylenetriamine, which has a relatively small impact on the apparent viscosity of the oil-based drilling fluid.

[0019] As a preferred technical solution of the present invention, the raw materials of the gel strength enhancer further include a solubilizer and / or an initiator.

[0020] Preferably, the solubilizer includes any one or a combination of at least two of ethanol, isopropanol or ethylene glycol monobutyl ether.

[0021] Preferably, the initiator includes cyclohexanone peroxide.

[0022] In the present invention, based on 100 parts by weight of the unsaturated fatty acid dimer, the weight parts of the solubilizer can be 80-120 parts, such as 80 parts, 85 parts, 90 parts, 95 parts, 100 parts, 105 parts, 110 parts, 115 parts or 120 parts, etc.; the weight parts in the initiator can be 2-4 parts, such as 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts, 3.2 parts, 3.5 parts, 3.8 parts or 4 parts, etc., but are not limited to the listed values, and other unlisted values within the above numerical ranges are equally applicable.

[0023] The second object of the present invention is to provide a preparation method of the gel strength enhancer provided in the first object, and the preparation method includes:

[0024] Mix the unsaturated fatty acid dimer, polyolamine compound and polyethylenepolyamine compound and carry out a polymerization reaction to obtain the gel strength enhancer.

[0025] As a preferred technical solution of the present invention, the preparation method includes:

[0026] Mix the unsaturated fatty acid dimer, polyolamine compound, polyethylenepolyamine compound and solubilizer, and perform deoxygenation treatment to obtain a first mixed solution;

[0027] Mix the first mixed solution with the initiator to obtain a second solution;

[0028] Perform a polymerization reaction on the second solution to obtain the gel strength enhancer.

[0029] In the present invention, exemplarily, the deoxygenation method can be to introduce nitrogen into the reaction system to displace air.

[0030] As a preferred technical solution of the present invention, the temperature of the polymerization reaction is 85 to 95 °C, such as 85 °C, 86 °C, 87 °C, 88 °C, 89 °C, 90 °C, 91 °C, 92 °C, 93 °C, 94 °C or 95 °C, etc., but not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0031] Preferably, the time of the polymerization reaction is 2 to 4 h, such as 2 h, 2.2 h, 2.5 h, 2.8 h, 3 h, 3.2 h, 3.5 h, 3.8 h or 4 h, etc., but not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0032] As a preferred technical solution of the present invention, the polymerization reaction is carried out under stirring.

[0033] Preferably, the rotation speed of the stirring is ≤ 300 r / min, such as 300 r / min, 250 r / min, 200 r / min, 150 r / min, 100 r / min or 50 r / min, etc., but not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0034] Preferably, when the polymerization reaction is ≤ 0.5 h, the rotation speed of the stirring is 50 to 150 r / min; when the polymerization reaction > 0.5 h, the rotation speed of the stirring is 200 to 300 r / min.

[0035] As a preferred technical solution of the present invention, cooling treatment is carried out after the polymerization reaction;

[0036] Preferably, the end temperature of the cooling treatment is ≤ 60 °C, such as 60 °C, 55 °C, 50 °C, 45 °C, 40 °C, 35 °C, 30 °C, 25 °C or 20 °C, etc., but not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0037] The third object of the present invention is to provide a drilling fluid, and the drilling fluid includes the thickening agent provided by the first object.

[0038] Compared with the prior art, the present invention has at least the following beneficial effects:

[0039] (1) The present invention provides a thickening agent, and the thickening agent has a good thickening effect on oil-based drilling fluids. Adding a thickening agent with a mass fraction of 0.2% can increase the yield point by 8 to 30%;

[0040] (2) The present invention provides a thickening agent, and the percentage change in the plastic viscosity of the oil-based drilling fluid caused by the thickening agent is within 12% to 26%. Detailed implementation manners

[0041] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0042] Example 1

[0043] This embodiment provides a shearing agent, and the raw materials for preparing the shearing agent include the following components in parts by weight:

[0044]

[0045] Among them, unsaturated fatty acid dimer: purchased from Guangzhou Yuanda New Materials Co., Ltd., brand number 61788-89-4.

[0046] The shearing agent is obtained by the following preparation method, which comprises the following steps:

[0047] (1) mixing unsaturated fatty acid dimer, polyol amine and polyethylene polyamine in a solubilizing agent, stirring at 600 r / min for 20 min to remove oxygen through nitrogen, to obtain a first solution;

[0048] (2) mixing the first solution with an initiator to obtain a second solution;

[0049] (3) subjecting the second solution to a polymerization reaction at 85° C. for 3 h, wherein low-speed stirring is performed within 0.5 h of the polymerization reaction, and then the rotation speed is adjusted to 250 r / min for the remaining reaction time, and after the reaction is completed, the temperature is lowered to 60° C. for discharging to obtain the shearing agent.

[0050] Example 2

[0051] This embodiment provides a shearing agent, and the raw materials for preparing the shearing agent include the following components in parts by weight:

[0052]

[0053] Among them, unsaturated fatty acid dimer: purchased from Guangzhou Yuanda New Materials Co., Ltd., brand number 61788-89-4.

[0054] The shearing agent is obtained by the following preparation method, which comprises the following steps:

[0055] (1) mixing unsaturated fatty acid dimer, polyol amine and polyethylene polyamine in a solubilizing agent, stirring at 600 r / min for 20 min to remove oxygen through nitrogen, to obtain a first solution;

[0056] (2) mixing the first solution with an initiator to obtain a second solution;

[0057] (3) Polymerize the second solution at 87 °C for 4 h. During the polymerization reaction for 1 h, perform low-speed stirring, then adjust the rotation speed to 2000 r / min for the remaining reaction time. After the reaction ends, cool down to 50 °C and discharge to obtain the viscosifier.

[0058] Example 3

[0059] This example provides a viscosifier. The raw materials for preparing the viscosifier include the following components by weight:

[0060]

[0061] Among them, the unsaturated fatty acid dimer: purchased from Guangzhou Yuanda New Materials Co., Ltd., with the product number 61788-89-4.

[0062] The viscosifier is obtained by the following preparation method. The preparation method includes the following steps:

[0063] (1) Mix the unsaturated fatty acid dimer, polyolamine, and polyethylenepolyamine in a solubilizer, and stir under nitrogen at 600 r / min for 20 min to remove oxygen to obtain the first solution;

[0064] (2) Mix the first solution with an initiator to obtain the second solution;

[0065] (3) Polymerize the second solution at 95 °C for 2 h. During the polymerization reaction for 0.5 h, perform low-speed stirring, then adjust the rotation speed to 300 r / min for the remaining reaction time. After the reaction ends, cool down to 60 °C and discharge to obtain the viscosifier.

[0066] Example 4

[0067] The difference between this example and Example 1 is that the unsaturated fatty acid dimer is replaced with an equal mass of hexadecenoic acid dimer (purchased from Hubei Guangao Biotech Co., Ltd.), and the rest are the same as in Example 1.

[0068] Example 5

[0069] The difference between this example and Example 1 is that the polyolamine is replaced with an equal mass of triethanolamine, and the rest are the same as in Example 1.

[0070] Example 6

[0071] The difference between this example and Example 1 is that the weight of the polyolamine is 55 parts, and the rest are the same as in Example 1.

[0072] Example 7

[0073] The difference between this embodiment and Embodiment 1 is that the polyalkylene polyamine is replaced with tetraethylene triamine of equal mass, and the rest are the same as those in Embodiment 1.

[0074] Embodiment 8

[0075] The difference between this embodiment and Embodiment 1 is that the weight fraction of the polyalkylene polyamine is 35 parts, and the rest are the same as those in Embodiment 1.

[0076] Comparative Example 1

[0077] The difference between this comparative example and Embodiment 1 is that no polyol amine is added, and the rest are the same as those in Embodiment 1.

[0078] Comparative Example 2

[0079] The difference between this comparative example and Embodiment 1 is that no polyalkylene polyamine is added, and the rest are the same as those in Embodiment 1.

[0080] Comparative Example 3

[0081] The difference between this comparative example and Embodiment 1 is that the dimer of octadecenoic acid is replaced with octadecenoic acid of equal mass, and the rest are the same as those in Embodiment 1.

[0082] Performance Test

[0083] Add the viscosifiers described in Embodiments 1-8 and Comparative Examples 1-3 to the oil-based drilling fluid (density 1.67 g / cm 3 , oil-water ratio 80:20, formula: 3# white oil + 3% emulsifier + 3% organic clay + 3% quicklime + calcium chloride solution + 3% oxidized asphalt filtration reducer + 0.2% wetting agent + barite) at a ratio of 0.2%, and conduct the following tests:

[0084] Percentage change in plastic viscosity and yield point in the oil-based drilling fluid: Implement "GB / T 16783.2 Petroleum and natural gas industries - Drilling fluids - Field testing - Part 2: Oil-based drilling fluids".

[0085] The test results are shown in Table 1.

[0086] Table 1

[0087] Percentage change in yield point (%) Percentage change in plastic viscosity (%) Example 1 20 23 Example 2 30 12 Example 3 15 18 Example 4 11 25 Example 5 13 20 Example 6 28 26 Example 7 16 19 Example 8 8 17 Comparative Example 1 3 26 Comparative Example 2 8 44 Comparative Example 3 9 40

[0088] Analyzing the data in Table 1, it can be seen that the viscosifier described in the present invention has a good effect on increasing the yield point and plastic viscosity of the oil-based drilling fluid. Adding a viscosifier with a mass fraction of 0.2% can increase the yield point by 8-30%, and the percentage change in plastic viscosity is within 12%-26%; the viscosifier described in the present invention has a good effect on increasing the yield point and plastic viscosity of the oil-based drilling fluid, and has little influence on the rheological properties of the drilling fluid.

[0089] Analysis of comparative examples 1-3 and example 1 shows that the performance of comparative examples 1-3 is not as good as that of example 1, which proves that the performance of the shearing agent of the present invention is better.

[0090] Analysis of Example 4 and Example 1 shows that the performance of Example 4 is not as good as that of Example 1, which proves that the shearing agent formed by the saturated fatty acid dimer, preferably octadecenoic acid dimer, has better performance.

[0091] Analysis of Example 5 and Example 1 shows that the performance of Example 5 is not as good as that of Example 1, which proves that the shearing agent formed by the polyol amine, preferably diethanolamine, has better performance.

[0092] Analysis of Example 6 and Example 1 shows that the performance of Example 6 is not as good as that of Example 1, which proves that the performance of the shearing agent formed by 30 to 50 parts by weight of the polyol amine, based on 100 parts by weight of the saturated fatty acid dimer, is better.

[0093] Analysis of Example 7 and Example 1 shows that the performance of Example 7 is not as good as that of Example 1, which proves that the shearing agent formed by the polyethylene polyamine, preferably diethylenetriamine, has better performance.

[0094] Analysis of Example 8 and Example 1 shows that the performance of Example 8 is not as good as that of Example 1, which proves that the performance of the shearing agent formed by 20 to 30 parts by weight of the polyethylene polyamine, based on 100 parts by weight of the saturated fatty acid dimer, is better.

[0095] The applicant declares that the present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various 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 viscosifier, characterized in that, the raw materials of the viscosifier include unsaturated fatty acid dimers, polyolamine compounds and polyethylenepolyamine compounds; in the polyolamine compounds, the number of hydroxyl groups ≥ 2; in the polyethylenepolyamine compounds, the number of ethylene groups ≥ 2 and the number of nitrogen atoms ≥ 2.

2. The viscosifier according to claim 1, characterized in that, taking the weight portion of the unsaturated fatty acid dimer as 100 parts, the weight portion of the polyolamine compounds is 30 - 50 parts; preferably, taking the weight portion of the unsaturated fatty acid dimer as 100 parts, the weight portion of the polyethylenepolyamine compounds is 20 - 30 parts.

3. The viscosifier according to claim 1 or 2, characterized in that, the unsaturated fatty acid dimer includes any one or a combination of at least two of octadecenoic acid dimer, hexadecenoic acid dimer or dodecenoic acid dimer; preferably, the polyolamine compounds include diethanolamine and / or triethanolamine; preferably, the polyethylenepolyamine compounds include any one or a combination of at least two of diethylenetriamine, triethylenediamine or tetraethylenetriamine.

4. The viscosifier according to any one of claims 1 - 3, characterized in that, the raw materials of the viscosifier further include a solubilizer and / or an initiator; preferably, the solubilizer includes any one or a combination of at least two of ethanol, isopropanol or ethylene glycol monobutyl ether; preferably, the initiator includes cyclohexanone peroxide.

5. A preparation method of the viscosifier according to any one of claims 1 - 4, characterized in that, the preparation method includes: mixing the unsaturated fatty acid dimer, polyolamine compounds and polyethylenepolyamine compounds for a polymerization reaction to obtain the viscosifier.

6. The preparation method according to claim 5, characterized in that, the preparation method includes: mixing the unsaturated fatty acid dimer, polyolamine compounds, polyethylenepolyamine compounds and a solubilizer, and performing deoxygenation treatment to obtain a first mixed solution; mixing the first mixed solution with an initiator to obtain a second solution; performing a polymerization reaction on the second solution to obtain the viscosifier.

7. The preparation method according to claim 5 or 6, characterized in that, the temperature of the polymerization reaction is 85 - 95 °C; preferably, the time of the polymerization reaction is 2 - 4 h.

8. The preparation method according to any one of claims 5 - 7, characterized in that, the polymerization reaction is carried out under stirring; preferably, the rotation speed of the stirring ≤ 300 r / min; preferably, when the polymerization reaction ≤ 0.5 h, the rotation speed of the stirring is 50 - 150 r / min; when the polymerization reaction > 0.5 h, the rotation speed of the stirring is 200 - 300 r / min.

9. The preparation method according to any one of claims 5 - 8, characterized in that, performing a cooling treatment after the polymerization reaction; preferably, the end temperature of the cooling treatment ≤ 60 °C.

10. A drilling fluid, characterized in that, the drilling fluid includes the viscosifier according to any one of claims 1 - 4.

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