Preparation method and application of granular temporary plugging agent

Abstract

The invention discloses a preparation method and application of a granular temporary plugging agent. The temporary plugging agent is prepared from the following raw materials in parts by weight: 10-15 parts of a biodegradable polymer temporary plugging material, 10-12 parts of a polyester material, 7-10 parts of maleic anhydride, 5-6 parts of sodium p-toluenesulfonate, 3-4 parts of betaine and 1-2 parts of alkylphenol polyoxyethylene ether. According to the invention, through strictly controlled molding and drying processes, the obtained particles are uniform and firm, and the particle shape and size are optimized, so that the particles can better fill and leak stoppage in practical application, and the use efficiency is improved. In the reaction process, ethanol is used for cooling and diluting, so that the operation safety is relatively high, and risks possibly existing in the production process are reduced. According to the invention, the temporary plugging rate is 99.02%-99.47%, the dissolving property of the temporary plugging particles is uniform and transparent, no precipitate is generated, and the temporary plugging particles are obviously superior to a contrast.

Description

Technical Field

[0001] This invention belongs to the field of oilfield chemical technology, specifically relating to a method for preparing and applying a particulate temporary plugging agent. Background Technology

[0002] Well leakage is a common and serious problem in oil and gas field drilling and completion operations. It causes drilling fluid or cement slurry to leak into the formation, wasting significant amounts of materials and potentially leading to serious well control issues, impacting drilling progress and safety. Therefore, developing an efficient temporary plugging agent to address well leakage is of great importance. In recent years, biodegradable materials have gained increasing attention. These materials can naturally degrade after fulfilling their function, reducing environmental pollution and aligning with green environmental protection principles. In temporary plugging applications in oil and gas fields, biodegradable materials not only achieve excellent plugging results but also decompose naturally after application, avoiding long-term impacts on the formation and environment.

[0003] Traditional temporary plugging agents come in various forms, including fiber-based, particulate, and chemical-based agents. Each has its advantages and disadvantages. Fiber-based agents can form a network structure in lost circulation channels, thus blocking pores; particulate agents can block pores through physical filling; and chemical-based agents generate solid substances through chemical reactions, forming a stable plugging layer in the lost circulation area. However, these agents also have some problems. For example, fiber-based agents may fail under high temperature and pressure conditions; particulate agents may be ineffective in high-porosity or high-permeability formations; and the reaction of chemical-based agents is difficult to control and may cause environmental pollution. Summary of the Invention

[0004] 1. Technical problems to be solved

[0005] In view of the problems existing in the prior art, the purpose of this invention is to provide a method for preparing and applying a particulate temporary plugging agent. It can improve the uniformity and stability of the particles through an optimized preparation process, and has a high temporary plugging rate and usage efficiency.

[0006] 2. Technical Solution

[0007] To solve the above problems, the present invention adopts the following technical solution.

[0008] A granular temporary plugging agent is composed of the following raw materials in parts by weight: 10-15 parts of biodegradable polymer temporary plugging material, 10-12 parts of polyester material, 7-10 parts of maleic anhydride, 5-6 parts of sodium p-toluenesulfonate, 3-4 parts of betaine, and 1-2 parts of alkylphenol polyoxyethylene ether.

[0009] Furthermore, the granular temporary plugging agent is composed of the following raw materials in parts by weight: 13 parts of biodegradable polymer temporary plugging material, 11 parts of polyester material, 8.5 parts of maleic anhydride, 5.5 parts of sodium p-toluenesulfonate, 3.5 parts of betaine, and 1.5 parts of alkylphenol polyoxyethylene ether.

[0010] The preparation method of the granular temporary plugging agent includes the following steps:

[0011] 1) Mixing: Weigh all raw materials according to the above proportions. Place the biodegradable polymer temporary plugging material and polyester material into a dry mixing tank, add xylene, start the stirring device, control the stirring speed at 50-100 RPM, and stir for 10-20 minutes. Then add maleic anhydride, sodium p-toluenesulfonate, betaine and alkylphenol polyoxyethylene ether in sequence, and continue stirring for 5-10 minutes to mix evenly, ensuring that the raw materials are evenly distributed.

[0012] 2) Heating: Heat the mixture to 80-100°C, maintain heating and continuous stirring for 50-100 RPM to ensure that all components are fully mixed. The heating time is 10-15 minutes to ensure that all components are fully mixed and that the reaction begins, to obtain reactant Q;

[0013] 3) Reaction: Slowly add reactant Q to the prepared ethanol for cooling and dilution. The ethanol temperature is controlled at 0-10℃. Stirring is maintained during the addition process for 8-10 minutes. Keep the temperature constant and continue stirring and react for 1-2 hours.

[0014] 4) Cooling: After the reaction is complete, cool the mixture to room temperature (20-25°C). During the cooling process, keep stirring from time to time at a speed of 30-60 RPM to prevent particles from clumping.

[0015] 5) Molding and drying: After cooling to room temperature, the mixture is shaped using a pelletizing device. The shaped pellets are then placed in a vacuum dryer and dried at 60-80°C for 50-60 minutes to ensure that the moisture inside the pellets is completely evaporated. The molding process is controlled at a pressure of 10-20 MPa and a molding time of 5-10 seconds.

[0016] 6) Screening: Use screening equipment to screen the dried particles. The screen mesh size is controlled between 0.5 and 2 mm to remove unqualified particles and ensure that the product has a uniform particle size.

[0017] 7) Packaging: Pack the sieved granular temporary plugging agent, seal it, and store it to prevent moisture and contamination.

[0018] Preferably, the application method is used in oil and gas field drilling and completion operations as a temporary plugging material.

[0019] 3. Beneficial effects

[0020] Compared with the prior art, the advantages of this invention are:

[0021] 1) This invention utilizes a scientifically proportioned mixture of biodegradable polymer temporary plugging material, polyester material, maleic anhydride, sodium p-toluenesulfonate, betaine, and alkylphenol polyoxyethylene ether. This temporary plugging agent can rapidly produce a good plugging effect, effectively preventing leakage during oil and gas field drilling and completion. The application of biodegradable polymer material allows the temporary plugging agent to degrade naturally after completing its plugging task, without causing long-term environmental pollution, thus meeting the requirements of green environmental protection.

[0022] 2) This invention, through a strictly controlled molding and drying process, produces uniform and robust particles. The optimized particle morphology and size enable them to better fill and seal leaks in practical applications, improving efficiency. The prepared granular temporary plugging agent exhibits good stability under certain temperature and pressure conditions, adapting to the application requirements of different environmental conditions, such as high-temperature and high-pressure environments, ensuring its effectiveness in various complex working conditions.

[0023] 3) The preparation method of this invention has clear and specific steps, and the required equipment and operating conditions are simple and easy to implement, facilitating large-scale production. In addition, through reasonable heating, cooling, stirring and drying processes, the full mixing and reaction of each raw material are ensured, improving preparation efficiency and product consistency.

[0024] 4) The present invention uses ethanol for cooling and dilution during the reaction process, which ensures high operational safety and reduces potential hazards during production. The temporary plugging rate in the present invention is 99.02%–99.47%, and the temporarily plugging particles are uniformly transparent with no precipitation, which is significantly better than the comparative example. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] A granular temporary plugging agent is composed of the following raw materials in parts by weight: 10 parts of biodegradable polymer temporary plugging material, 10 parts of polyester material, 7 parts of maleic anhydride, 5 parts of sodium p-toluenesulfonate, 3 parts of betaine, and 1 part of alkylphenol polyoxyethylene ether.

[0028] The preparation method of the granular temporary plugging agent includes the following steps:

[0029] 1) Mixing: Weigh all raw materials according to the above proportions. Place the biodegradable polymer temporary plugging material and polyester material into a dry mixing tank, add xylene, start the stirring device, control the stirring speed at 50 RPM, and stir for 10 minutes. Then add maleic anhydride, sodium p-toluenesulfonate, betaine and alkylphenol polyoxyethylene ether in sequence, and continue stirring for 5 minutes to mix evenly, ensuring that the raw materials are evenly distributed.

[0030] 2) Heating: Heat the mixture to 80°C and maintain heating and stirring at 50 RPM to ensure that all components are fully mixed. The heating time is 10 minutes to ensure that all components are fully mixed and that the reaction begins, yielding reactant Q;

[0031] 3) Reaction: Slowly add reactant Q to the prepared ethanol for cooling and dilution. The ethanol temperature is controlled at 2°C. Stirring is maintained during the addition process for 8 minutes. Keep the temperature constant, continue stirring and react for 1 hour.

[0032] 4) Cooling: After the reaction is complete, cool the mixture to room temperature (20°C). During the cooling process, keep stirring from time to time at a speed of 30 RPM to prevent particles from clumping.

[0033] 5) Molding and drying: After cooling to room temperature, the mixture is shaped using a pelletizing device. The shaped pellets are then placed in a vacuum dryer and dried at 60°C for 50 minutes to ensure that all moisture inside the pellets is completely evaporated. The molding process is controlled at a pressure of 10 MPa and a molding time of 5 seconds.

[0034] 6) Screening: Use screening equipment to screen the dried particles. The screen mesh size is controlled at 0.5 mm to remove unqualified particles and ensure that the product has a uniform particle size.

[0035] 7) Packaging: Pack the sieved granular temporary plugging agent, seal it, and store it to prevent moisture and contamination.

[0036] The application method described herein is used in oil and gas field drilling and completion operations as a temporary plugging material.

[0037] Example 2

[0038] A granular temporary plugging agent is composed of the following raw materials in parts by weight: 12 parts of biodegradable polymer temporary plugging material, 11 parts of polyester material, 8.5 parts of maleic anhydride, 5.5 parts of sodium p-toluenesulfonate, 3.5 parts of betaine, and 1.5 parts of alkylphenol polyoxyethylene ether.

[0039] The preparation method of the granular temporary plugging agent includes the following steps:

[0040] 1) Mixing: Weigh all raw materials according to the above proportions. Place the biodegradable polymer temporary plugging material and polyester material into a dry mixing tank, add xylene, start the stirring device, control the stirring speed at 75 RPM, and stir for 15 minutes. Then add maleic anhydride, sodium p-toluenesulfonate, betaine and alkylphenol polyoxyethylene ether in sequence, and continue stirring for 8 minutes to mix evenly, ensuring that the raw materials are evenly distributed.

[0041] 2) Heating: Heat the mixture to 90°C and maintain heating and stirring at 75 RPM to ensure that all components are fully mixed. The heating time is 12 minutes to ensure that all components are fully mixed and that the reaction begins, yielding reactant Q;

[0042] 3) Reaction: Slowly add reactant Q to the prepared ethanol for cooling and dilution. The ethanol temperature is controlled at 7°C. Stirring is maintained during the addition process for 9 minutes. The temperature is kept constant, and stirring is continued for 1.5 hours.

[0043] 4) Cooling: After the reaction is complete, cool the mixture to room temperature (23°C). During the cooling process, keep stirring from time to time at a speed of 45 RPM to prevent particles from clumping.

[0044] 5) Molding and drying: After cooling to room temperature, the mixture is shaped using a pelletizing device. The shaped pellets are then placed in a vacuum dryer and dried at 70°C for 55 minutes to ensure that all moisture inside the pellets is completely evaporated. The molding process is controlled at a pressure of 15 MPa and a molding time of 7 seconds.

[0045] 6) Screening: Use screening equipment to screen the dried particles. The screen mesh size is controlled at 1 mm to remove unqualified particles and ensure that the product has a uniform particle size.

[0046] 7) Packaging: Pack the sieved granular temporary plugging agent, seal it, and store it to prevent moisture and contamination.

[0047] The application method described herein is used in oil and gas field drilling and completion operations as a temporary plugging material.

[0048] Example 3

[0049] A granular temporary plugging agent is composed of the following raw materials in parts by weight: 15 parts of biodegradable polymer temporary plugging material, 12 parts of polyester material, 10 parts of maleic anhydride, 6 parts of sodium p-toluenesulfonate, 4 parts of betaine, and 2 parts of alkylphenol polyoxyethylene ether.

[0050] The preparation method of the granular temporary plugging agent includes the following steps:

[0051] 1) Mixing: Weigh all raw materials according to the above proportions. Place the biodegradable polymer temporary plugging material and polyester material into a dry mixing tank, add xylene, start the stirring device, control the stirring speed at 100 RPM, and stir for 20 minutes. Then add maleic anhydride, sodium p-toluenesulfonate, betaine and alkylphenol polyoxyethylene ether in sequence, and continue stirring for 10 minutes to mix evenly, ensuring that the raw materials are evenly distributed.

[0052] 2) Heating: Heat the mixture to 100°C and maintain heating and stirring at 100 RPM to ensure that all components are fully mixed. The heating time is 15 minutes to ensure that all components are fully mixed and that the reaction begins, yielding reactant Q;

[0053] 3) Reaction: Slowly add reactant Q to the prepared ethanol for cooling and dilution. The ethanol temperature is controlled at 10℃. Stirring is maintained during the addition process for 10 minutes. Keep the temperature constant, continue stirring and react for 2 hours.

[0054] 4) Cooling: After the reaction is complete, cool the mixture to room temperature (25°C). During the cooling process, keep stirring from time to time at a speed of 60 RPM to prevent particles from clumping.

[0055] 5) Molding and drying: After cooling to room temperature, the mixture is shaped using a pelletizing device. The shaped pellets are then placed in a vacuum dryer and dried at 80°C for 60 minutes to ensure that all moisture inside the pellets is completely evaporated. The molding process is controlled at a pressure of 20 MPa and a molding time of 10 seconds.

[0056] 6) Screening: Use screening equipment to screen the dried particles. The screen mesh size is controlled at 2 mm to remove unqualified particles and ensure that the product has a uniform particle size.

[0057] 7) Packaging: Pack the sieved granular temporary plugging agent, seal it, and store it to prevent moisture and contamination.

[0058] The application method described herein is used in oil and gas field drilling and completion operations as a temporary plugging material.

[0059] Experimental Example

[0060] The performance of the granular temporary plugging agent described in this embodiment was tested indoors, using the paper "Preparation and Performance Study of a Temperature-Sensitive Gel Temporary Plugging Agent Particles" published by Zhao Wenjin, Zhang Dingjun, Wu Yanfei, Xian Yanbo, Chen Zhenbin, et al. as a comparative example. The quality and technical tests of the granular temporary plugging agent are shown in Table 1.

[0061]

[0062] As shown in Table 1, the temporary plugging rate in this invention is 99.02% to 99.47%, and the temporary plugging particles have uniform and transparent dissolution properties with no precipitation, which is significantly better than the comparative example.

[0063] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A granular temporary plugging agent, characterized in that... It is composed of the following raw materials in parts by weight: 10-15 parts of biodegradable polymer temporary plugging material, 10-12 parts of polyester material, 7-10 parts of maleic anhydride, 5-6 parts of sodium p-toluenesulfonate, 3-4 parts of betaine, and 1-2 parts of alkylphenol polyoxyethylene ether.

2. The granular temporary plugging agent according to claim 1, characterized in that... It is composed of the following raw materials in parts by weight: 13 parts of biodegradable polymer temporary plugging material, 11 parts of polyester material, 8.5 parts of maleic anhydride, 5.5 parts of sodium p-toluenesulfonate, 3.5 parts of betaine, and 1.5 parts of alkylphenol polyoxyethylene ether.

3. A method for preparing a particulate temporary plugging agent according to claim 1 or 2, characterized in that... Includes the following steps: 1) Mixing: Weigh all raw materials according to the above proportions. Place the biodegradable polymer temporary plugging material and polyester material into a dry mixing tank, add xylene, start the stirring device, control the stirring speed at 50-100 RPM, and stir for 10-20 minutes. Then add maleic anhydride, sodium p-toluenesulfonate, betaine and alkylphenol polyoxyethylene ether in sequence, and continue stirring for 5-10 minutes to mix evenly, ensuring that the raw materials are evenly distributed. 2) Heating: Heat the mixture to 80-100°C, maintain heating and continuous stirring for 50-100 RPM to ensure that all components are fully mixed. The heating time is 10-15 minutes to ensure that all components are fully mixed and that the reaction begins, to obtain reactant Q; 3) Reaction: Slowly add reactant Q to the prepared ethanol for cooling and dilution. The ethanol temperature is controlled at 0-10℃. Stirring is maintained during the addition process for 8-10 minutes. Keep the temperature constant and continue stirring and react for 1-2 hours. 4) Cooling: After the reaction is complete, cool the mixture to room temperature (20-25°C). During the cooling process, keep stirring from time to time at a speed of 30-60 RPM to prevent particles from clumping. 5) Molding and drying: After cooling to room temperature, the mixture is shaped using a pelletizing device. The shaped pellets are then placed in a vacuum dryer and dried at 60-80°C for 50-60 minutes to ensure that the moisture inside the pellets is completely evaporated. The molding process is controlled at a pressure of 10-20 MPa and a molding time of 5-10 seconds. 6) Screening: Use screening equipment to screen the dried particles. The screen mesh size is controlled between 0.5 and 2 mm to remove unqualified particles and ensure that the product has a uniform particle size. 7) Packaging: Pack the sieved granular temporary plugging agent, seal it, and store it to prevent moisture and contamination.

4. The application of a granular temporary plugging agent according to any one of claims 1 to 3, characterized in that: The application method described herein is used in oil and gas field drilling and completion operations as a temporary plugging material.

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