Gel plugging agent for oil-based drilling fluid and application thereof
By using gel slug plugs for oil-based drilling fluids, which utilize thermoplastic oleophilic polymers, rigid particles, and flexible fibers to form slugs, the problem of leakage and spillage of oil-based drilling fluids in complex formations has been solved, achieving efficient plugging and isolation effects and ensuring drilling safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SINOPEC OILFIELD SERVICE CORPORATION
- Filing Date
- 2022-07-12
- Publication Date
- 2026-07-03
AI Technical Summary
Existing oil-based drilling fluids are prone to leakage when encountering complex formations, especially fractured formations, and it is difficult to effectively seal complex downhole situations where leakage and overflow coexist, especially in well sections with multi-pressure systems, where existing plugging materials are not effective.
The oil-based drilling fluid gel slug plugging agent is composed of thermoplastic oleophilic polymers, rigid particles and flexible fibers. After mixing, it forms a slug with strong viscosity at formation temperature, which seals formation pores and fractures and isolates the oil-based drilling fluid from the formation fluid.
It effectively seals oil-based drilling fluid leakage, isolates spills from the formation, improves the safety and reliability of downhole operations, and is made from abundant raw materials and is easy to prepare, making it suitable for large-scale production.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of oilfield chemical technology, and particularly relates to a gel slug plugging agent for oil-based drilling fluids and its application. Background Technology
[0002] When oil-based drilling fluids encounter complex formations, such as fractured and porous formations, leakage is prone to occur. Existing oil-based drilling fluid plugging materials are limited and have poor sealing effects, resulting in low success rates. This difficulty is exacerbated when encountering formations where both leakage and overflow coexist. When multiple pressure systems are encountered in the same open-hole section, the limitations of the wellbore structure make it difficult to separate high- and low-pressure zones, easily leading to complex downhole situations where leakage and overflow coexist. This is particularly true in wells with multiple pressure systems in fractured formations, where the good conductivity of fractures makes formation pressure balancing difficult, making leakage and overflow hard to avoid. For example, in the Sichuan Basin of my country, the terrain is steep, the formation is fractured, faulted, and fractured, with significant differences in pressure coefficients between the upper and lower formations in the same open-hole section. The coexistence of multiple pressure systems easily leads to complex situations where leakage and overflow coexist during oil-based drilling. Therefore, it is necessary to develop a gel slug plugging agent for oil-based drilling fluid that can both seal formation pores and fractures and isolate formation gas, while simultaneously meeting the need to plug leaks in oil-based drilling fluids that coexist with leakage and overflow. Summary of the Invention
[0003] In view of this, the purpose of the present invention is to provide a gel slug plugging agent for oil-based drilling fluid and its application. The gel slug plugging agent for oil-based drilling fluid provided by the present invention can effectively solve the problem of oil-based drilling fluid leakage, especially the problem of sealing the formation where leakage and spillage coexist.
[0004] This invention provides a gel slug plugging agent for oil-based drilling fluids, comprising, by weight:
[0005] 30-60 parts by weight of thermoplastic lipophilic polymer;
[0006] 30-60 parts by weight of rigid granules;
[0007] 10 to 30 parts by weight of flexible fiber.
[0008] Preferably, the thermoplastic oleophilic polymer is prepared from materials comprising amorphous oleophilic materials, crystalline oleophilic materials, and reinforcing agents.
[0009] Preferably, the particle size of the thermoplastic oleophilic polymer is 0.1 to 3 mm.
[0010] Preferably, the amorphous oleophilic material is selected from one or more of polyethylene-vinyl acetate, polyethylene-butyl acrylate, polystyrene-butadiene-styrene, saturated SBS, ethylene propylene diene monomer (EPDM) rubber, and styrene-butadiene rubber.
[0011] Preferably, the crystalline oleophilic material is selected from one or more of polyethylene, polypropylene, and polyamide.
[0012] Preferably, the reinforcing agent is selected from one or more of heavy calcium carbonate and talc.
[0013] Preferably, the rigid particles are selected from one or more of calcium carbonate, silicon dioxide, quartz sand, and shell materials.
[0014] Preferably, the rigid particles have a particle size of 0.1 to 5 mm.
[0015] Preferably, the flexible fiber is selected from one or more of silicate fiber, sepiolite fiber, polypropylene fiber, and polyester fiber.
[0016] This invention provides a method for plugging leaks using oil-based drilling fluid, comprising:
[0017] Mix oil-based drilling fluid and oil-based drilling fluid with a gel slug plugging agent;
[0018] The mass of the gel slug plugging agent for the oil-based drilling fluid is 20-40% of the mass of the oil-based drilling fluid;
[0019] The gel slug plugging agent for oil-based drilling fluid is the same as the gel slug plugging agent for oil-based drilling fluid described in the above technical solution.
[0020] The oil-based drilling fluid gel slug plugging agent provided by this invention is a composite of thermoplastic oleophilic polymers, rigid particles, and flexible fibers in a certain proportion. The thermoplastic oleophilic polymers have low oil absorption capacity at room temperature and minimal impact on the viscosity of oil-based drilling fluids, meeting the requirements for plugging slurry preparation and pumping. After entering the lost circulation zone, under the influence of formation temperature, the oil absorption capacity significantly increases, forming a polymer slug with a certain viscosity. The combination of rigid particles and flexible fiber materials further improves the pressure-bearing performance of the gel slug. The formed gel slug can effectively seal pores or fractures, preventing oil-based drilling fluid loss. When encountering complex situations such as drilling losses accompanied by formation gas outbursts, it can form an oil- and gas-isolated slug above the high-pressure gas-producing layer, preventing formation fluid overflow and ensuring the safety of subsequent operations such as tripping in and out of the drill string. The plugging agent provided by this invention has widely available raw materials, a simple and safe preparation process, and is conducive to large-scale production and application. Attached Figure Description
[0021] Figure 1 This is a schematic diagram illustrating the preparation of the thermoplastic lipophilic polymer in this invention;
[0022] Figure 2 This is a schematic diagram of the visible sand bed structure during the detection process in an embodiment of the present invention;
[0023] Figure 3This is a visual simulation diagram of the sand bed experiment during the detection process in an embodiment of the present invention;
[0024] Figure 4 This is an image of the sealing layer obtained during the detection process in an embodiment of the present invention. 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0026] This invention provides a gel slug plugging agent for oil-based drilling fluids, comprising, by weight:
[0027] 30-60 parts by weight of thermoplastic lipophilic polymer;
[0028] 30-60 parts by weight of rigid granules;
[0029] 10 to 30 parts by weight of flexible fiber.
[0030] The gel slug plugging agent for oil-based drilling fluid provided by this invention can solve the problem of poor leakage sealing effect of existing oil-based drilling fluids, especially the difficulty in sealing when encountering formations where leakage and spillage coexist. The gel slug plugging agent for oil-based drilling fluid provided by this invention can not only seal formation pores and fractures, but also isolate oil from formation fluids, thus meeting the sealing requirements of formations where leakage and spillage coexist.
[0031] In this invention, the thermoplastic oleophilic polymer is preferably 40 to 50 parts by weight, more preferably 45 parts.
[0032] In this invention, the thermoplastic oleophilic polymer is preferably prepared from materials comprising amorphous oleophilic materials, crystalline oleophilic materials and reinforcing agents.
[0033] In this invention, the method for preparing the thermoplastic lipophilic polymer preferably includes:
[0034] A thermoplastic oleophilic polymer is obtained by mixing and granulating amorphous oleophilic materials, crystalline oleophilic materials and reinforcing agents.
[0035] In this invention, the amorphous oleophilic material is preferably selected from one or more of polyethylene-vinyl acetate (EVA), polystyrene-butadiene-styrene (SBS), saturated SBS (SEBS), etc.
[0036] In this invention, the crystalline oleophilic material is preferably selected from one or more of polyethylene (PE), polypropylene (PP), etc.
[0037] In this invention, the reinforcing agent is preferably selected from one or more of calcium carbonate, calcite powder, mineral oil, etc.
[0038] In this invention, the mass ratio of the amorphous oleophilic material, the crystalline oleophilic material and the reinforcing agent is preferably (45-50):(30-40):(10-15), more preferably (46-49):(32-38):(11-14), and most preferably (47-48):(34-36):(12-13).
[0039] In this invention, the mixing temperature is preferably 150-180°C, more preferably 160-170°C, and most preferably 165°C.
[0040] In this invention, the preparation of the thermoplastic lipophilic polymer is as follows: Figure 1 As shown, cubes represent crystal lattice structures with a regular arrangement; lines represent irregular amorphous portions. In this invention, the preferred method for preparing the thermoplastic oleophilic polymer includes:
[0041] Add the amorphous oleophilic material, crystalline oleophilic material, and reinforcing agent to a container in a certain proportion; stir thoroughly; and mix at 150℃~180℃.
[0042] After being mixed evenly, the mixture is granulated to obtain a thermoplastic oleophilic polymer for oil-based drilling fluid gel slugs.
[0043] In this invention, the particle size of the thermoplastic oleophilic polymer is preferably 0.1-3 mm, more preferably 0.1-1 mm or 1-3 mm, even more preferably 0.5-2.5 mm, even more preferably 1-2 mm, and most preferably 1.5 mm.
[0044] In this invention, the rigid particles are preferably 35 to 50 parts by weight, more preferably 40 to 45 parts by weight.
[0045] In this invention, the rigid particles can serve as rigid bridging and filling agents, and the scratch shadow is preferably 2 to 3, with a density preferably of 1.7 to 2.7 g / cm³. 3 .
[0046] In this invention, the rigid particles are preferably selected from mineral particles or shell materials, such as calcium carbonate particles, silicon dioxide, quartz sand particles, shell materials, etc., one or more of which are preferred, and more preferably shell residue and / or oyster shells.
[0047] In this invention, the particle size of the rigid particles is preferably 0.1-5 mm, more preferably 0.5-3 mm, even more preferably 1-3 mm, and most preferably 2 mm.
[0048] In this invention, the weight percentage of the flexible fiber is preferably 15 to 25 parts, more preferably 20 parts.
[0049] In this invention, the flexible fiber is preferably selected from one or more of mineral fibers and synthetic fibers, such as one or more of silicate fibers, sepiolite fibers, polypropylene fibers, and polyester fibers, and more preferably selected from one or more of sepiolite fibers and silicate fibers.
[0050] In this invention, it is preferable to pulverize the flexible fiber. In this invention, the length of the flexible fiber is preferably 0.05–5 mm, more preferably 0.1–4 mm, even more preferably 0.5–3 mm, even more preferably 1–3 mm, and most preferably 2 mm.
[0051] In this invention, the preferred method for preparing the gel slug plugging agent for oil-based drilling fluid includes:
[0052] A polymer gel slub plug for oil-based drilling fluids is obtained by mixing thermoplastic oleophilic polymers, rigid particles, and flexible fibers.
[0053] In this invention, the mixing is preferably carried out using a mixing device to achieve uniform mixing.
[0054] This invention provides a method for plugging leaks using oil-based drilling fluid, comprising:
[0055] Mix oil-based drilling fluid and oil-based drilling fluid with a gel slug plugging agent;
[0056] The mass of the gel slug plugging agent for the oil-based drilling fluid is 20-40% of the mass of the oil-based drilling fluid;
[0057] The gel slug plugging agent for oil-based drilling fluid is the same as the gel slug plugging agent for oil-based drilling fluid described in the above technical solution.
[0058] The gel slug plug provided by this invention, when added to oil-based drilling fluid, can form a slug that isolates the oil-based drilling fluid from the formation fluid under the action of formation temperature. This can both seal the leakage channel and prevent the formation fluid from overflowing, thereby ensuring the safety of subsequent operations such as tripping in and out of the well.
[0059] In this invention, the mass of the gel slug plugging agent for oil-based drilling fluid is preferably 25-35% of the mass of the oil-based drilling fluid, more preferably 30%.
[0060] In this invention, compared with water-based drilling fluids, oil-based drilling fluids have advantages such as resistance to high temperatures and salt-calcium corrosion, which is beneficial to wellbore stability, good lubrication, and less damage to oil and gas reservoirs. In this invention, the oil-based drilling fluid preferably comprises:
[0061] Diesel fuel, organic clay, primary emulsifier, secondary emulsifier, CaCl2 solution, barite.
[0062] In this invention, the diesel fuel content in the oil-based drilling fluid is preferably 60-80% by mass, more preferably 65-75%, and most preferably 70%; the primary emulsifier content in the oil-based drilling fluid is preferably 3-5% by mass, more preferably 3.5-4.5%, and most preferably 4%; the auxiliary emulsifier content in the oil-based drilling fluid is preferably 1-3% by mass, more preferably 1.5-2.5%, and most preferably 2%; the CaCl2 solution content in the oil-based drilling fluid is preferably 4-16% by mass, more preferably 5-15%, more preferably 8-12%, and most preferably 10%; the CaCl2 solution concentration is preferably 15-25%, more preferably 18-22%, and most preferably 20%; the amount of barite can be adjusted according to the density of the oil-based drilling fluid to be obtained. In this invention, the density of the oil-based drilling fluid is preferably 1-2 g / cm³. 3 More preferably 1.5 g / cm³ 3 .
[0063] The plugging agent provided by this invention, when added to oil-based drilling fluid, enables the oil-based drilling fluid to be cured at 120°C for 4–168 hours; after curing at 120°C for 168 hours, the viscosity change is not significant, demonstrating good high-temperature resistance. This invention evaluates the sealing and gas reverse breakthrough aspects of the gel slug plugging agent. The results show that the gel slug plugging agent provided by this invention can effectively seal pores and isolate oil-based drilling fluid from formation fluids. It can be used to seal oil-based drilling fluid losses, particularly addressing the problem of simultaneous overflow and leakage during oil-based drilling.
[0064] The lipophilic polymer contained in the gel slub plug for oil-based drilling fluid provided by this invention, after being pumped into the lost circulation zone, can form a slub with strong viscosity under the action of formation temperature and oil-based drilling fluid. The compounded rigid particles and flexible fibers can seal formation pores and fractures on the one hand, and synergistically improve the pressure-bearing capacity of the gel slub with the lipophilic polymer on the other hand. The formed slub plug can effectively seal the lost circulation zone of oil-based drilling fluid and isolate the oil-based drilling fluid from the formation fluid, thereby achieving effective sealing of the formation where leakage and spillage coexist. The gel slub formed by the plugging agent of this invention has an effective period of more than 7 days at 120°C, and the raw materials are abundant, the preparation process is simple, and it is easy to carry out large-scale production and application.
[0065] The crystalline oleophilic materials used in the following embodiments of the present invention are polyethylene (produced by Shanghai Petrochemical), polypropylene (produced by Yangzi Petrochemical), and amorphous materials are polyethylene-vinyl acetate (produced by Formosa Plastics), polystyrene-butadiene-styrene (PSB) and saturated SBS (produced by Baling Petrochemical). Calcium carbonate, talc, silicate fiber, shell residue, oyster shell, and sepiolite powder are all industrial products. Shell residue and oyster shell were purchased from Tianjin Oyster Shell Powder Factory, and calcium carbonate, talc, silicate fiber, and sepiolite powder were purchased from Lingshou County Ore Factory.
[0066] Example 1
[0067] By weight, 45 parts of a thermoplastic oleophilic polymer product with a particle size of 0.1-3 mm, 40 parts of shell residue with a particle size of 0.5-3 mm, and 15 parts of silicate fiber with a length of 1-3 mm are placed in a mixing device and mixed evenly to obtain an oil-based drilling fluid gel slug plugging agent.
[0068] Preparation of thermoplastic oleophilic polymer: 600g of polyethylene-vinyl acetate (EVA) powder, 100g of calcium carbonate powder and 300g of polyethylene (PE) were vacuum dried at 80℃, thoroughly stirred and mixed, kneaded at 180℃, extruded, cooled and granulated, with a particle size of 0.1-3mm.
[0069] Example 2
[0070] By weight, 50 parts of a thermoplastic oleophilic polymer product with a particle size of 0.1-1 mm, 40 parts of oyster shells with a particle size of 0.5-3 mm, and 10 parts of sepiolite fibers with a length of 1-3 mm are placed in a mixing device and mixed evenly to obtain an oil-based drilling fluid gel slug plugging agent.
[0071] Preparation of thermoplastic oleophilic polymer: 600g SEBS powder, 100g talc powder and 300g polypropylene (PP) were vacuum dried at 80℃, thoroughly stirred and mixed, kneaded at 200℃, extruded, cooled and granulated, with a particle size of 0.1~3mm.
[0072] Example 3
[0073] By weight, 45 parts of a thermoplastic oleophilic polymer with a particle size of 0.1-3 mm, 40 parts of oyster shells with a particle size of 0.5-3 mm, and 10 parts of silicate fibers with a length of 1-3 mm are placed in a mixing device and mixed evenly to obtain an oil-based drilling fluid gel slug plugging agent.
[0074] Preparation of thermoplastic oleophilic polymer: 600g SBS, 100g ultrafine calcium carbonate powder and 300g polypropylene (PP) were vacuum dried at 80℃, thoroughly stirred and mixed, kneaded at 200℃, cooled and granulated, with a particle size of 0.1~3mm.
[0075] Performance testing
[0076] The performance of the gel-segment plugging agent prepared in the embodiments of the present invention was evaluated:
[0077] (1) Evaluation of temperature resistance
[0078] The density of the solution is 1.5 g / cm³. 3 Oil-based drilling fluid: diesel oil (oil-water ratio = 8:2) + 20wt% CaCl2 solution + 3wt% organic clay + 3wt% main emulsifier + 3wt% auxiliary emulsifier + barite (all the above materials are industrial products, purchased from Sinopec Nanjing Chemical Research Institute). The gel slug plug prepared in the embodiments of the present invention was added to the oil-based drilling fluid in different amounts. After curing at 120°C for different times, the oil-based drilling fluid gel slug was obtained.
[0079] The viscosity of the prepared oil-based drilling fluid gel slug was tested using a DV-II type cloth viscometer. The results are shown in Table 1. Table 1 is the evaluation result of the high-temperature resistance of the gel slug plugging agent prepared in the embodiment of the present invention.
[0080] Table 1 Evaluation of High Temperature Resistance
[0081]
[0082] As shown in Table 1, after adding the gel slug plugging agent prepared in the embodiments of the present invention, the viscosity of the drilling fluid increased significantly, forming a slug. Moreover, after curing at 120°C for 168 hours, the viscosity change was not significant, indicating that the plugging agent prepared in the embodiments of the present invention has good high-temperature resistance.
[0083] (2) Evaluation of sealing performance
[0084] The visual sandbed filtration meter test method is used to evaluate sealing performance. This is a newly established experimental method for evaluating drilling fluid leakage, based on the API filtration loss test method. An acrylic glass cylinder is used as the transparent drilling fluid test container. Its advantages include: even if the filtration loss measured within the specified time is zero, the entire experimental process can be observed, and the progress of fluid intrusion into the sandstone can be monitored. A visual sandbed structure diagram is shown below. Figure 2 As shown, 300g of river sand with a particle size of 0.83-1.7mm was added to the visible sand bed to simulate a lost circulation zone. Then, 300mL of the above-mentioned drilling fluid product with added plugging agent, which had been cured at 120℃ for 24 hours, was poured in. Using nitrogen as the pressure source, the pressure was increased to 0.69MPa at the air inlet (e.g., Figure 3 As shown in Table 2, the leakage layer simulated by the gel plug sealing in sand with a particle size of 0.83-1.7 mm was observed; the test results are shown in Table 2.
[0085] Table 2. Evaluation of Blocking Performance
[0086] formula Visual sand bed evaluation results Oil-based drilling fluid Complete omission Oil-based drilling fluid + 25% Example 1 product No leakage / material penetration depth into the sand bed: 7.5cm Oil-based drilling fluid + 30% Example 2 product No leakage / material penetration depth into the sand bed: 10.1cm Oil-based drilling fluid + 35% Example 2 product No leakage / material penetration depth into the sand bed: 7.3cm Oil-based drilling fluid + 40% Example 2 product No leakage / material penetration depth into the sand bed was 4.5cm. Oil-based drilling fluid + 35% Example 3 product No leakage / material penetration depth into the sand bed: 7.2cm
[0087] As shown in Table 2, the plugging agent prepared in the example can effectively seal the pores in the sand bed, with good sealing effect and significantly improve the formation's bearing capacity. The formed sealing layer is as follows: Figure 4 As shown.
[0088] (3) Sealing performance evaluation
[0089] The sealing performance was evaluated using a visible sand bed filtration meter test method. 300g of river sand with a particle size of 0.83–1.7mm was poured into the bottom of an acrylic glass tube to simulate formation pore channels. Then, oil-based drilling fluid aged at 120℃ for 24h and the plugging agent prepared in the example were injected into the acrylic glass tube to form a slug. 100mL of oil-based drilling fluid was added to the top of the slug, and finally, a nitrogen source was connected to the gas outlet (e.g., ...). Figure 3 (As shown in the figure) Simulate formation fluid, pressurize from the gas outlet, and the gas enters the interface with the slug through the sand layer. The effect of the slug in isolating oil-based drilling fluid and gas can be observed. The results are shown in Table 3.
[0090] Table 3. Sealing Performance Evaluation
[0091] formula Visual sand bed evaluation results Oil-based drilling fluid + 25% Example 1 product Pressurized to 0.69 MPa, the gas did not break through the slug. Oil-based drilling fluid + 30% Example 2 product Pressurized to 0.69 MPa, the gas did not break through the slug. Oil-based drilling fluid + 35% Example 2 product Pressurized to 0.69 MPa, the gas did not break through the slug. Oil-based drilling fluid + 40% Example 2 product Pressurized to 0.69 MPa, the gas did not break through the slug. Oil-based drilling fluid + 35% Example 3 product Pressurized to 0.69 MPa, the gas did not break through the slug.
[0092] It can be seen that when the pressure is reversed to 0.69 MPa, the gas does not break through the slug formed by the plugging agent prepared in each embodiment and enter the oil-based drilling fluid. The dense isolation slug formed by the plugging agent provided by the present invention in the oil-based drilling fluid has a good effect of isolating the oil-based drilling fluid from the formation fluid.
[0093] The lipophilic polymer contained in the gel slub plug for oil-based drilling fluid provided by this invention, after being pumped into the lost circulation zone, can form a slub with strong viscosity under the action of formation temperature and oil-based drilling fluid. The compounded rigid particles and flexible fibers can seal formation pores and fractures on the one hand, and synergistically improve the pressure-bearing capacity of the gel slub with the lipophilic polymer on the other hand. The formed slub plug can effectively seal the lost circulation zone of oil-based drilling fluid and isolate the oil-based drilling fluid from the formation fluid, thereby achieving effective sealing of the formation where leakage and spillage coexist. The gel slub formed by the plugging agent of this invention has an effective period of more than 7 days at 120°C, and the raw materials are abundant, the preparation process is simple, and it is easy to carry out large-scale production and application.
[0094] While the invention has been described and illustrated with reference to specific embodiments thereof, such description and illustration are not intended to limit the invention. It will be readily understood by those skilled in the art that various changes may be made to suit particular circumstances, materials, compositions, substances, methods, or processes to the objectives, spirit, and scope of this application without departing from the true spirit and scope of the invention as defined by the appended claims. All such modifications are intended to be within the scope of the appended claims. Although the methods disclosed herein have been described with reference to specific operations performed in a particular order, it should be understood that these operations may be combined, subdivided, or reordered to form equivalent methods without departing from the teachings of the invention. Therefore, unless specifically indicated herein, the order and grouping of operations are not a limitation of this application.
Claims
1. A gel slug plugging agent for oil-based drilling fluids, comprising, by weight: 30-60 parts by weight of thermoplastic lipophilic polymer; The thermoplastic oleophilic polymer has a particle size of 0.1~3mm; 30-60 parts by weight of rigid granules; 10-30 parts by weight of flexible fiber; The thermoplastic lipophilic polymer is prepared from materials including amorphous lipophilic material, crystalline lipophilic material and reinforcing agent; the mass ratio of amorphous lipophilic material, crystalline lipophilic material and reinforcing agent is (45~50):(30~40):(10~15); The amorphous oleophilic material is selected from one or more of polyethylene-vinyl acetate, polystyrene-butadiene-styrene, and saturated SBS; the reinforcing agent is selected from one or more of heavy calcium carbonate and talc. The crystalline oleophilic material is selected from one or more of polyethylene and polypropylene.
2. The gel slug plugging agent for oil-based drilling fluid according to claim 1, characterized in that, The rigid particles are selected from one or more of calcium carbonate, silicon dioxide, quartz sand, and shell materials.
3. The gel slug plugging agent for oil-based drilling fluid according to claim 1, characterized in that, The rigid particles have a particle size of 0.1~5mm.
4. The gel slug plugging agent for oil-based drilling fluid according to claim 1, characterized in that, The flexible fiber is selected from one or more of silicate fiber, sepiolite fiber, polypropylene fiber, and polyester fiber.
5. A method for plugging leaks using oil-based drilling fluid, comprising: Mix oil-based drilling fluid and oil-based drilling fluid with a gel slug plugging agent; The mass of the gel slug plugging agent for oil-based drilling fluid is 20-40% of the mass of the oil-based drilling fluid; The gel slug plugging agent for oil-based drilling fluid is the gel slug plugging agent for oil-based drilling fluid as described in claim 1.