Retarder for palm oil-based drilling fluid as well as preparation method and application of retarder

Abstract

The invention provides a palm oil-based retarder for drilling fluid as well as a preparation method and application of the palm oil-based retarder. The preparation method comprises the following steps: S1, preparing a porous micro-carrier; s2, loading tea polyphenol palmitate on the porous micro-carrier obtained in the step S1 to obtain composite microspheres; s3, acidizing the composite microspheres obtained in the step S2 to obtain the retarder for palm oil. According to the retarder, the tea polyphenol palmitate serves as an effective component, crystallization and condensation of palm oil in a low-temperature environment can be effectively avoided, the release rate of the tea polyphenol palmitate is greatly slowed down through the porous structure of the porous micro-carrier, the slow-release and long-acting effects are achieved, an acid environment is built on the surface of the porous micro-carrier, and the slow-release and long-acting effects are achieved. The stability of the tea polyphenol palmitate is enhanced. After the retarder is added into the palm oil-based drilling fluid, the anti-freezing property of the drilling fluid is greatly improved, and the rheological property of the drilling fluid is not obviously changed in an environment of 4 DEG C.

Description

Technical Field

[0001] The invention belongs to the technical field of oil-based drilling fluid treating agents, and in particular relates to a retarder for palm oil-based drilling fluid and a preparation method and application thereof. Background Art

[0002] With the rapid development of the economy and society, the demand for oil and gas resources has increased significantly, and exploration and development operations have begun to turn to oil and gas resources in complex strata on land and deep-water oceans. Complex stratum drilling and deep-water drilling have strict requirements on the performance of drilling fluids. Drilling fluids will face a series of problems such as well wall stability, lubricity, high temperature resistance, and environmental protection. Oil-based drilling fluids have natural advantages in these aspects, but traditional oil-based drilling fluids are seriously polluting to the environment. Palm oil not only has the basic functions of oil-based drilling fluids, but also has the advantages of strong biodegradability, low cost, and environmental friendliness. However, as a vegetable oil, palm oil has a large gap in structural components compared with diesel and white oil. It has a high freezing point and is easy to crystallize or even solidify in a low-temperature environment, thus affecting the performance of drilling fluids. At present, there are only a few related research reports on drilling fluids with palm oil as the liquid phase.

[0003] The patent with publication number CN105385425A provides a palm oil-based drilling fluid and a preparation method thereof. The drilling fluid includes organic soil, fluid loss reducer, primary emulsifier, auxiliary emulsifier, aqueous phase and oil phase, wherein the oil phase is palm oil. In the patent, only the rheological properties of the drilling fluid system at high temperature (150°C) are evaluated, and its rheological properties at low temperature are not tested. This is because the drilling fluid uses palm oil as the oil phase, and palm oil is easy to crystallize and solidify at low temperatures, resulting in poor rheological properties of the drilling fluid. In drilling construction, especially in blocks with complex strata on land (for example, abnormally low-temperature strata) or in deep-water marine blocks, low-temperature environments are often encountered. At this time, ordinary palm oil as oil will affect the performance of the drilling fluid. Therefore, how to keep palm oil-based drilling fluids still have good rheological properties in low-temperature environments is a problem that needs to be solved in this field. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a retarder for palm oil-based drilling fluid, by loading tea polyphenol palmitate on a porous microcarrier, the release rate of tea polyphenol palmitate is slowed down, and a slow-release and long-acting effect is achieved.

[0005] Another object of the present invention is to provide a retarder for palm oil-based drilling fluid, which can effectively prevent palm oil from crystallizing and condensing in a low temperature environment.

[0006] Another object of the present invention is to provide an application of a retarder for palm oil-based drilling fluid, so that the antifreeze performance of the palm oil-based drilling fluid is greatly improved, and the rheological properties do not change significantly in an environment of 4°C.

[0007] To this end, the technical solution provided by the present invention is as follows: A method for preparing a palm oil-based retarder for drilling fluid comprises the following steps: Step 1) preparing a porous microcarrier; Step 2) loading tea polyphenol palmitate onto a porous microcarrier to obtain composite microspheres; Step 3) Acidification treatment is performed on the composite microspheres to obtain.

[0008] Step 1) The method for preparing the porous microcarrier is as follows: (1) Pour 40-46 parts by weight of dimethyldichlorosilane into a container, then add 12-14 parts by weight of 40wt% concentrated hydrochloric acid, and stir for 30-40 minutes at 40-50°C to obtain oily octamethylcyclotetrasiloxane; (2) 32-35 parts by weight of octamethylcyclotetrasiloxane and 11-13 parts by weight of 30 wt% ammonia water were mixed, heated and stirred for 25-30 min, filtered, and washed with anhydrous ethanol to obtain octamethylcyclotetrasiloxane polymer microspheres; (3) calcining the obtained octamethylcyclotetrasiloxane polymer microspheres at a temperature of 650-750° C. for 60-70 min, taking out and cooling naturally to obtain the microspheres.

[0009] The preparation process of the composite microspheres in step 2) is as follows: (1) adding tea polyphenol palmitate and iron powder to palm oil and stirring to obtain a treated liquid, wherein the mass ratio of tea polyphenol palmitate: palm oil: iron powder is 1: (5.4-5.8): (0.3-0.5); (2) placing the porous microcarrier in a treatment solution, applying power, and soaking the porous microcarrier. The power-on time is 30-50 minutes, and the soaking time is 22-24 hours. The power-on voltage is 6-9V. (3) Filter out the porous micro-carrier after electrification and soaking, and dry it to obtain the product.

[0010] The process of acidification treatment in step 3) is as follows: (1) Prepare a basic glue solution by mixing polyacrylamide and water in a mass ratio of 1:(2.4-2.8); (2) Add acetic acid to the base glue solution, with the mass ratio of base glue solution to acetic acid = 1: (0.06-0.08), and stir evenly to obtain an acidic glue solution; (3) Immerse the composite microspheres in the acidic glue solution for 100-120 minutes to complete the acidification.

[0011] The porous micro-carrier in step 2) is a porous micro-carrier with a particle size of 0.1-0.2 mm sieved through a sieve.

[0012] A retarder for palm oil based drilling fluid.

[0013] The invention discloses an application of a palm oil-based retarder for drilling fluid in preparing drilling fluid.

[0014] The particle size of the retarder for palm oil based drilling fluid is 2-4 mm.

[0015] The prepared drilling fluid comprises the following substances in parts by weight: 100 parts of palm oil, 2-4 parts of bentonite, 2.2-2.6 parts of sodium carboxymethyl cellulose, 1.2-1.4 parts of Span 80, 0.3-0.5 parts of calcium oxide, 4-6 parts of water and 4-5 parts of a palm oil-based drilling fluid retarder.

[0016] The beneficial effects of the present invention are: The retarder provided by the present invention uses tea polyphenol palmitate as an effective ingredient, which can effectively prevent palm oil from crystallizing and condensing in a low-temperature environment. The porous structure of the porous micro-carrier greatly slows down the release rate of tea polyphenol palmitate, achieving a sustained-release and long-acting effect, and creates an acidic environment on the surface of the porous micro-carrier, thereby enhancing the stability of tea polyphenol palmitate.

[0017] After the retarder was added to the palm oil-based drilling fluid, the antifreeze performance of the drilling fluid was greatly improved, and the rheological properties did not change significantly in an environment of 4°C. DETAILED DESCRIPTION

[0018] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0019] Now, exemplary embodiments of the present invention are introduced. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments are not intended to limit the present invention.

[0020] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0021] Example 1 This embodiment provides a method for preparing a palm oil-based retarder for drilling fluid, comprising the following steps: Step 1) preparing a porous microcarrier; Step 2) loading tea polyphenol palmitate onto a porous microcarrier to obtain composite microspheres; Step 3) Acidification treatment is performed on the composite microspheres to obtain.

[0022] Step 1) The method for preparing the porous microcarrier is as follows: (1) Pour 40-46 parts by weight of dimethyldichlorosilane into a container, then add 12-14 parts by weight of 40wt% concentrated hydrochloric acid, and stir for 30-40 minutes at 40-50°C to obtain oily octamethylcyclotetrasiloxane; (2) 32-35 parts by weight of octamethylcyclotetrasiloxane and 11-13 parts by weight of 30 wt% ammonia water were mixed, heated and stirred for 25-30 min, filtered, and washed with anhydrous ethanol to obtain octamethylcyclotetrasiloxane polymer microspheres; (3) calcining the obtained octamethylcyclotetrasiloxane polymer microspheres at a temperature of 650-750° C. for 60-70 min, taking out and cooling naturally to obtain the microspheres.

[0023] The preparation process of the composite microspheres in step 2) is as follows: (1) adding tea polyphenol palmitate and iron powder to palm oil and stirring to obtain a treated liquid, wherein the mass ratio of tea polyphenol palmitate: palm oil: iron powder is 1: (5.4-5.8): (0.3-0.5); (2) placing the porous microcarrier in a treatment solution, applying power, and soaking the porous microcarrier. The power-on time is 30-50 minutes, and the soaking time is 22-24 hours. The power-on voltage is 6-9V. (3) Filter out the porous micro-carrier after electrification and soaking, and dry it to obtain the product.

[0024] The process of acidification treatment in step 3) is as follows: (1) Prepare a basic glue solution by mixing polyacrylamide and water in a mass ratio of 1:(2.4-2.8); (2) Add acetic acid to the base glue solution, with the mass ratio of base glue solution to acetic acid = 1: (0.06-0.08), and stir evenly to obtain an acidic glue solution; (3) Immerse the composite microspheres in the acidic glue solution for 100-120 minutes to complete the acidification.

[0025] Principle of the invention: The retarder for palm oil provided by the present invention uses tea polyphenol palmitate as an effective ingredient. The phenolic hydroxyl groups of the tea polyphenol palmitate molecules are connected to the carbonyl groups in the palm oil (mainly triglyceride) molecules through intermolecular hydrogen bonds, which hinders the movement of the oil molecules and thus slows down the growth of the oil crystals, thereby achieving the purpose of retarding the coagulation of palm oil in a low temperature environment.

[0026] When preparing the palm oil retarder of the present invention, a porous medium is used as a carrier, so that tea polyphenol palmitate can be slowly released. When loading, an electric current is applied and iron powder is used as a medium, so that tea polyphenol palmitate is stably loaded inside the pores and on the surface of the porous medium in a manner of electrostatic adsorption. In addition, a layer of weakly acidic film is also provided on the surface of the porous medium. This is because tea polyphenol palmitate is easily degraded in an alkaline environment. The use of polyacrylamide in the form of a gel film, supplemented with acetic acid, can prevent a large amount of tea polyphenol palmitate from being degraded in the initial stage of the palm oil retarder being added to the drilling fluid.

[0027] Example 2 On the basis of Example 1, this example provides a method for preparing a palm oil-based retarder for drilling fluid, comprising the following steps: Step 1) preparing a porous microcarrier; Using dimethyldichlorosilane as a raw material, silicon-containing porous microspheres are prepared, that is, porous microcarriers, as follows: S11, pouring 43 parts by weight of dimethyldichlorosilane into a beaker, adding 13 parts by weight of 40 wt% concentrated hydrochloric acid into the beaker, stirring at 45° C. for 35 min to obtain oily octamethylcyclotetrasiloxane; S12, taking 33 parts by weight of the octamethylcyclotetrasiloxane obtained in step S11, mixing it with 12 parts by weight of 30 wt% ammonia water, heating and stirring for 28 min, filtering, and washing with anhydrous ethanol to obtain octamethylcyclotetrasiloxane polymerized microspheres; S13, calcining the octamethylcyclotetrasiloxane polymerized microspheres obtained in step S12 at a temperature of 700° C. for 65 min, taking out and cooling naturally to obtain a porous microcarrier; S14. Use a sieve to select porous micro-carriers with a particle size of 0.1-0.2 mm and keep them for later use.

[0028] Step 2) loading tea polyphenol palmitate onto a porous microcarrier to obtain composite microspheres; S21, adding tea polyphenol palmitate and iron powder to palm oil, stirring to obtain a treated liquid, wherein the mass ratio of tea polyphenol palmitate: palm oil: iron powder is 1:5.6:0.4; S22, placing the porous microcarrier obtained in step 1) in the treatment solution obtained in step S21, energizing, and soaking, the energizing device is a laboratory student power supply, and the positive and negative electrodes are respectively led out with wires and placed in the treatment solution, the energizing voltage is 7.5V, the energizing time is 40 minutes, and the soaking time is 23 hours; S23, filtering out the porous microcarrier after soaking in step S22, and drying at 50°C to obtain composite microspheres.

[0029] Step 3) Acidification treatment is performed on the composite microspheres to obtain; S31, preparing a basic glue solution by mixing polyacrylamide and water in a mass ratio of 1:2.6; S32, adding acetic acid to the base glue solution, in a mass ratio of base glue solution: acetic acid = 1:0.07, and stirring evenly to obtain an acidic glue solution; S33, immersing the composite microspheres obtained in step 2) in the acidic colloid obtained in step S32, filtering out after 110 minutes, drying at 50°C, grinding and sieving, and taking out particles of 2-4 mm, which are the retarder A1 for palm oil-based drilling fluid.

[0030] Example 3 On the basis of Example 1, this example provides a method for preparing a palm oil-based retarder for drilling fluid, comprising the following steps: S1, preparing porous microcarriers; Using dimethyldichlorosilane as a raw material, silicon-containing porous microspheres are prepared, that is, porous microcarriers, as follows: S11, pouring 40 parts by weight of dimethyldichlorosilane into a beaker, adding 12 parts by weight of 40 wt% concentrated hydrochloric acid into the beaker, stirring at 40° C. for 30 minutes to obtain oily octamethylcyclotetrasiloxane; S12, taking 32 parts by weight of the octamethylcyclotetrasiloxane obtained in step S11, mixing it with 11 parts by weight of 30 wt% ammonia water, heating and stirring for 25 min, filtering, and washing with anhydrous ethanol to obtain octamethylcyclotetrasiloxane polymerized microspheres; S13, calcining the octamethylcyclotetrasiloxane polymerized microspheres obtained in step S12 at a temperature of 650° C. for 60 min, taking out and cooling naturally to obtain a porous microcarrier; S14, using a sieve to sieve out the porous micro-carriers with a particle size of 0.1-0.2 mm and keep them for later use; S2, loading tea polyphenol palmitate onto the porous microcarrier obtained in step S1 to obtain composite microspheres; S21, adding tea polyphenol palmitate and iron powder to palm oil, stirring to obtain a treated liquid, wherein the mass ratio of tea polyphenol palmitate: palm oil: iron powder is 1:5.4:0.3; S22, placing the porous microcarrier obtained in step S1 in the treatment solution obtained in step S21, energizing, and soaking, the energizing device is a laboratory student power supply, and the positive and negative electrodes are respectively led out with wires and placed in the treatment solution, the energizing voltage is 6V, the energizing time is 30 minutes, and the soaking time is 22 hours; S23, filtering out the porous micro-carriers soaked in step S22, and drying them to obtain composite microspheres; S3, acidifying the composite microspheres obtained in step S2 to obtain a palm oil-based retarder for drilling fluid; S31, preparing a basic glue solution by mixing polyacrylamide and water in a mass ratio of 1:2.4; S32, adding acetic acid to the base glue solution, in a mass ratio of base glue solution: acetic acid = 1:0.06, and stirring evenly to obtain an acidic glue solution; S33, immersing the composite microspheres obtained in step S2 in the acidic colloid obtained in step S32, filtering out after 100 minutes, drying, grinding and sieving, and taking out particles of 2-4 mm, which are the retarder A2 for palm oil-based drilling fluid.

[0031] Example 4 On the basis of Example 1, this example provides a method for preparing a palm oil-based retarder for drilling fluid, comprising the following steps: S1, preparing porous microcarriers; Using dimethyldichlorosilane as a raw material, silicon-containing porous microspheres are prepared, that is, porous microcarriers, as follows: S11, pouring 46 parts by weight of dimethyldichlorosilane into a beaker, adding 14 parts by weight of 40 wt% concentrated hydrochloric acid into the beaker, stirring at 50° C. for 40 min, to obtain oily octamethylcyclotetrasiloxane; S12, taking 35 parts by weight of the octamethylcyclotetrasiloxane obtained in step S11, mixing it with 13 parts by weight of 30 wt% ammonia water, heating and stirring for 30 min, filtering, and washing with anhydrous ethanol to obtain octamethylcyclotetrasiloxane polymerized microspheres; S13, calcining the octamethylcyclotetrasiloxane polymerized microspheres obtained in step S12 at a temperature of 750° C. for 70 min, taking out and cooling naturally to obtain porous micro-carriers; S14, using a sieve to sieve out the porous micro-carriers with a particle size of 0.1-0.2 mm and keep them for later use; S2, loading tea polyphenol palmitate onto the porous microcarrier obtained in step S1 to obtain composite microspheres; S21, adding tea polyphenol palmitate and iron powder to palm oil, stirring to obtain a treated liquid, wherein the mass ratio of tea polyphenol palmitate: palm oil: iron powder is 1:5.8:0.5; S22, placing the porous microcarrier obtained in step S1 in the treatment solution obtained in step S21, energizing, and soaking, the energizing device is a laboratory student power supply, and the positive and negative electrodes are respectively led out with wires and placed in the treatment solution, the energizing voltage is 9V, the energizing time is 50 minutes, and the soaking time is 24 hours; S23, filtering out the porous micro-carriers soaked in step S22, and drying them to obtain composite microspheres; S3, acidifying the composite microspheres obtained in step S2 to obtain a palm oil-based retarder for drilling fluid; S31, preparing a basic glue solution by mixing polyacrylamide and water in a mass ratio of 1:2.8; S32, adding acetic acid to the base glue solution, in a mass ratio of base glue solution: acetic acid = 1:0.08, and stirring evenly to obtain an acidic glue solution; S33, immersing the composite microspheres obtained in step S2 in the acidic colloid obtained in step S32, filtering out after 120 minutes, drying, grinding and sieving, and taking out particles of 2-4 mm, which are the retarder A3 for palm oil-based drilling fluid.

[0032] Example 5 This embodiment provides an application of a palm oil-based retarder for drilling fluid in preparing drilling fluid.

[0033] 400 g of palm oil was added to an enamel measuring cup, and then 12 g of bentonite, 9.6 g of sodium carboxymethyl cellulose, 5.2 g of Span 80, 1.6 g of calcium oxide, 20 g of water and 18 g of the palm oil-based drilling fluid retarder A1 prepared in Example 2 were added in sequence under stirring to finally obtain palm oil-based drilling fluid B1.

[0034] Example 6 This embodiment provides an application of a palm oil-based retarder for drilling fluid in preparing drilling fluid.

[0035] The difference from Example 5 is that the palm oil-based drilling fluid retarder A1 prepared in Example 2 is replaced by the palm oil-based drilling fluid retarder A2 prepared in Example 3, and finally the palm oil-based drilling fluid B2 is obtained.

[0036] Example 7 This embodiment provides an application of a palm oil-based retarder for drilling fluid in preparing drilling fluid.

[0037] The difference from Example 5 is that the palm oil-based drilling fluid retarder A1 prepared in Example 2 is replaced by the palm oil-based drilling fluid retarder A3 prepared in Example 4, and finally the palm oil-based drilling fluid B3 is obtained.

[0038] Comparative Example 1 The difference from Example 5 is that: palm oil retarder A1 is not added, and finally palm oil-based drilling fluid D1 is obtained.

[0039] Comparative Example 2 The difference from Example 5 is that the palm oil-based drilling fluid prepared in Example 2 is replaced with an equal amount of tea polyphenol palmitate by retarder A1, and finally palm oil-based drilling fluid D2 is obtained.

[0040] Rheology The palm oil-based drilling fluids prepared in Examples 5-7 and Comparative Examples 1-2 were placed at room temperature (25°C), high temperature (150°C), and low temperature (4°C) for 2 hours, then taken out and stirred for 3 minutes, and their rheological properties were measured. The rheological properties were measured in accordance with the national standard GB / T 29170-2012, and the experimental results are shown in Table 1. AV is the apparent viscosity, PV is the plastic viscosity, and YP is the dynamic shear force, all in mPa·s.

[0041] Table 1 Rheological properties of palm oil-based drilling fluid

[0042] As can be seen from the data in Table 1, the palm oil-based drilling fluid retarder of the present invention, after being added to the palm oil-based drilling fluid, greatly improves the antifreeze performance of the drilling fluid, and the rheological properties do not change significantly under a 4°C environment. However, in Comparative Example D1, since no retarder for palm oil-based drilling fluid is added, the palm oil-based drilling fluid crystallizes after being treated at a low temperature of 4°C, making the liquid viscous and turbid, thereby affecting its rheological properties, especially the dynamic shear force YP. Comparative Example D2 uses tea polyphenol palmitate as a retarder, which has a certain retarding effect, so the rheological properties are slightly better than D1. However, due to long-term (2 hours) contact with alkaline drilling fluid, it is partially degraded, so its rheological properties are poorer than those of B1-B3 under a 4°C environment.

[0043] B1 and D2 were used as experimental objects, respectively, and stored at 4°C. They were taken out at 0h, 1h, 2h, 3h, 4h, and 5h, respectively, and their rheological properties were measured after stirring for 3 minutes. The experimental results are shown in Table 2.

[0044] Table 2 Rheological properties of palm oil-based drilling fluid at 4°C

[0045] As can be seen from Table 2, B1 uses the slow-release and long-acting retarder for palm oil provided by the present invention, in which the effective retarding ingredient tea polyphenol palmitate slowly escapes from the porous medium and is slowly released over a long period of time, thereby ensuring that it has a long-term retarding effect. D2 uses tea polyphenol palmitate directly as a retarder, which has a good retarding effect at the beginning of the experiment. However, as time goes on, tea polyphenol palmitate is gradually degraded in an alkaline environment, thereby failing, which in turn leads to crystallization in the drilling fluid, which is manifested as a deterioration in the rheological properties of the drilling fluid.

[0046] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. All designs that are the same or similar to the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a palm oil-based retarder for drilling fluid, characterized in that: The following steps are involved: Step 1) preparing a porous microcarrier; Step 2) loading tea polyphenol palmitate onto a porous microcarrier to obtain composite microspheres; Step 3) Acidification treatment is performed on the composite microspheres to obtain.

2. The method for preparing a palm oil-based retarder for drilling fluid according to claim 1, characterized in that: Step 1) The method for preparing the porous microcarrier is as follows: (1) Pour 40-46 parts by weight of dimethyldichlorosilane into a container, then add 12-14 parts by weight of 40wt% concentrated hydrochloric acid, and stir for 30-40 minutes at 40-50°C to obtain oily octamethylcyclotetrasiloxane; (2) 32-35 parts by weight of octamethylcyclotetrasiloxane and 11-13 parts by weight of 30 wt% ammonia water were mixed, heated and stirred for 25-30 min, filtered, and washed with anhydrous ethanol to obtain octamethylcyclotetrasiloxane polymer microspheres; (3) calcining the obtained octamethylcyclotetrasiloxane polymer microspheres at a temperature of 650-750° C. for 60-70 min, taking out and cooling naturally to obtain the microspheres.

3. The method for preparing a palm oil-based retarder for drilling fluid according to claim 1, characterized in that: The preparation process of the composite microspheres in step 2) is as follows: (1) adding tea polyphenol palmitate and iron powder to palm oil and stirring to obtain a treated liquid, wherein the mass ratio of tea polyphenol palmitate: palm oil: iron powder is 1: (5.4-5.8): (0.3-0.5); (2) placing the porous microcarrier in a treatment solution, applying power, and soaking the porous microcarrier. The power-on time is 30-50 minutes, and the soaking time is 22-24 hours. The power-on voltage is 6-9V. (3) Filter out the porous micro-carrier after electrification and soaking, and dry it to obtain the product.

4. The method for preparing a palm oil-based retarder for drilling fluid according to claim 1, characterized in that: The process of acidification treatment in step 3) is as follows: (1) Prepare a basic glue solution by mixing polyacrylamide and water in a mass ratio of 1:(2.4-2.8); (2) Add acetic acid to the base glue solution, with the mass ratio of base glue solution to acetic acid = 1: (0.06-0.08), and stir evenly to obtain an acidic glue solution; (3) Immerse the composite microspheres in the acidic glue solution for 100-120 minutes to complete the acidification.

5. The method for preparing a palm oil-based retarder for drilling fluid according to claim 1, characterized in that: The porous micro-carrier in step 2) is a porous micro-carrier with a particle size of 0.1-0.2 mm sieved through a sieve.

6. A retarder for palm oil-based drilling fluid prepared by the preparation method according to any one of claims 1 to 5.

7. Use of a palm oil-based retarder for drilling fluid according to claim 6 in preparing drilling fluid.

8. The use of a palm oil-based retarder for drilling fluid according to claim 7 in preparing drilling fluid, characterized in that: The particle size of the retarder for palm oil based drilling fluid is 2-4 mm.

9. The use of a palm oil-based retarder for drilling fluid according to claim 7 in preparing drilling fluid, characterized in that: The prepared drilling fluid comprises the following substances in parts by weight: 100 parts of palm oil, 2-4 parts of bentonite, 2.2-2.6 parts of sodium carboxymethyl cellulose, 1.2-1.4 parts of Span 80, 0.3-0.5 parts of calcium oxide, 4-6 parts of water and 4-5 parts of a palm oil-based drilling fluid retarder.

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