Multifunctional plugging anti-collapse agent and preparation method thereof
By preparing a multifunctional sealing and anti-collapse agent, the problems of easy failure and poor sealing effect of existing sealing and anti-collapse agents at high temperatures were solved, achieving stable sealing effect and environmental performance at high temperatures, and improving the density and lubricity of the mud cake.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-19
- Publication Date
- 2026-04-07
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing sealing and anti-collapse agents are prone to agglomeration and failure at high temperatures, have insufficient temperature resistance, cannot effectively seal micron-level formation pores, have poor environmental performance, and have limited functionality.
This multifunctional sealing and anti-collapse agent is composed of cosmetic-grade mineral oil, composite emulsifier, amide-based thickening polymer or polysaccharide thickening polymer, nano-silica, graphite powder, polyethylene glycol and defoamer. It is prepared by high-speed shearing and fine grinding to form a submicron to micron wide particle size distribution. It has anti-collapse, filtration loss reduction and lubrication functions, and can withstand temperatures up to 220℃.
It achieves stable sealing effect at high temperatures, effectively sealing micron-level formation fractures, improving the density and toughness of the mud cake, reducing friction, preventing rock cuttings adhesion, and improving the environmental performance of drilling fluid.
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Figure CN121801549A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of oil drilling, in particular to a multifunctional plugging anti-sloughing agent and a preparation method thereof. BACKGROUND
[0002] The performance of the conventional water-based drilling fluid system at the present stage cannot meet the drilling construction requirements of complex structure wells, and in order to meet the well wall stability requirements of complex shale formations, a plugging anti-sloughing agent is generally added to improve the plugging anti-sloughing performance of the water-based drilling fluid. At present, the most commonly used plugging anti-sloughing agent is a bitumen plugging anti-sloughing agent such as sulfonated bitumen, cationic bitumen and emulsified bitumen, which mainly deforms by softening at high temperature, effectively plugs the micro cracks of the well wall, forms a thin and tough mud cake, and at the same time forms a hydrophobic film on the surface of the clay mineral to block the penetration of water molecules to the clay mineral.
[0003] However, the existing plugging anti-sloughing agent has the following defects: (1) easy to aggregate and fail at high temperature, insufficient temperature resistance (usually below 180℃); (2) unable to effectively plug micron-sized formation pores, limited anti-sloughing effect; (3) poor environmental performance, containing fluorescent substances; (4) single product function. SUMMARY
[0004] The present application aims to provide a multifunctional plugging anti-sloughing agent and a preparation method thereof. The prepared plugging anti-sloughing agent has the functions of anti-sloughing, filtration loss reduction and lubrication, has a temperature resistance of up to 220℃, does not contain fluorescent substances, has a sub-micron-micron wide particle size distribution, and can plug micron-sized formation cracks.
[0005] The technical solution adopted by the present application is as follows: A multifunctional plugging anti-sloughing agent, comprising the following raw materials in a total of 100% by weight: cosmetic grade mineral oil, 35%-45%; composite emulsifier, 8%-12%; amide thickening polymer or polysaccharide thickening polymer, 3%-8%; nanometer silicon dioxide, 3%-5%; graphite powder, 1%-3%; polyethylene glycol, 2%-3%; defoaming agent, 1-2%; water, the balance.
[0006] Further, the cosmetic grade mineral oil is one or more of 5# white oil, 10# white oil and 15# white oil.
[0007] Further, the composite emulsifier is a mixture of span 60 (span 60) and tween 60 (tween 60).
[0008] Furthermore, the weight ratio of span 60 to tween 60 is 1:(0.8~1.2).
[0009] Furthermore, the amide-based thickening polymer is polyacrylamide; The polysaccharide thickening polymer is one or more of modified starch, guar gum, modified guar gum or their derivatives.
[0010] Furthermore, the defoamer is an organosilicon defoamer.
[0011] Furthermore, the nano-silica, the graphite powder, and the polyethylene glycol are first subjected to dry grinding before being mixed with the remaining raw materials; wherein, the grinding time is... ; In the formula, T is the base time, ranging from 40 to 60 minutes. Generally, for laboratory preparation, T ranges from 40 to 50 minutes; for factory-scale preparation, T ranges from 50 to 60 minutes. m1 is the weight of the polyethylene glycol. m2 is the weight of the nano-silica. m3 is the weight of the graphite powder. k is a time correction factor related to the total weight of the nano-silica, the graphite powder, and the polyethylene glycol, with a value ranging from 0.8 to 1.2. Generally, the larger the total weight of the nano-silica, graphite powder, and polyethylene glycol, the larger the value of k. For example, in small-scale laboratory preparation, the k value is generally between 0.8 and 0.9; in pilot-scale laboratory preparation, the k value is generally between 0.9 and 1.0; and in large-scale factory preparation, the k value is generally between 1.0 and 1.2.
[0012] Based on the same inventive concept, the present invention also provides a method for preparing a multifunctional sealing and anti-collapse agent, comprising the following steps: Step S1: In a high-speed shear press, add water, amide-based thickening polymer or polysaccharide-based thickening polymer in proportion and stir at low speed. Step S2: Add composite emulsifier and cosmetic-grade mineral oil, and shear pre-emulsify at 8000~12000 rpm; In step S3, add nano-silica, graphite powder, polyethylene glycol, and defoamer, and emulsify and shear again at a speed of 8000~12000 rpm; Step S4: The product from step S3 is added to a colloid mill for fine grinding. The gap is 0.8~1 mm, the rotation speed is 2000~3000 rpm, and the cycle is 3~5 times to obtain a uniform emulsion, which is a multifunctional sealing and anti-collapse agent.
[0013] The beneficial effects of this invention are: This invention provides a multifunctional sealing and anti-collapse agent and its preparation method, comprising cosmetic-grade mineral oil, a composite emulsifier, an amide-based thickening polymer or a polysaccharide-based thickening polymer, nano-silica, graphite powder, polyethylene glycol, an antifoaming agent, and water. The cosmetic-grade mineral oil is environmentally friendly and non-fluorescent; the composite emulsifier is a mixture of Span 60 and Tween 60 in a specific ratio, enhancing the thermal stability of the emulsion; the amide-based or polysaccharide-based thickening polymer can improve emulsion stability and enhance sealing toughness; the nano-silica can form a protective layer on the surface of emulsion droplets by adsorption, delaying aggregation and filling the pores of the mud cake, improving the density of the mud cake; the graphite powder can reduce frictional resistance, improve lubricity, and enhance temperature resistance; the polyethylene glycol can improve the high-temperature stability of the emulsion and prevent emulsion stratification; and the antifoaming agent can be used for defoaming. Through the synergistic effect of the above raw materials, the multifunctional sealing and anti-collapse agent prepared in this invention has the following characteristics: (1) The multifunctional sealing and anti-collapse agent contains cosmetic-grade white oil, which is environmentally friendly and fluorescent. (2) The raw materials work together to resist temperature, which improves the stability and temperature resistance of the emulsion system (temperature resistance can reach 220℃). (3) The multifunctional sealing and anti-collapse agent has a wide particle size distribution from submicron to micron, which can seal micron-level formation cracks, effectively prevent filtrate from entering the formation, and prevent the collapse of hard, brittle, and fractured mudstone and shale; (4) Under the action of high temperature and pressure difference downhole, some components of the multifunctional plugging and anti-collapse agent soften and adhere tightly to the well wall, plugging formation micro-fractures, forming a dense film, participating in mud cake formation, improving mud cake density and toughness, and improving mud cake quality; high-quality mud cake prevents pressure difference transmission between wellbore and formation, while improving mud cake surface properties, reducing friction, and forming a protective film on metal surface, effectively preventing drill bit mud packing, preventing rock cuttings from adhering to centralizers and drill pipes, and improving anti-sticking ability. Attached Figure Description
[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0015] Figure 1 This is a particle size distribution diagram of the multifunctional sealing and anti-collapse agent sample in Example 3 at room temperature.
[0016] Figure 2 This is a particle size distribution diagram of the multifunctional sealing and anti-collapse agent sample in Example 3 after aging at 220°C. Detailed Implementation
[0017] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, these are merely examples and are not intended to limit the present invention.
[0018] The embodiments of the invention will now be described in detail with reference to the accompanying drawings.
[0019] Example 1
[0020] A method for preparing a multifunctional sealing and anti-collapse agent, the preparation process of which is as follows: Step S1: In a high-speed shearing machine, add 44 kg of water and 3 kg of polyacrylamide in proportion, stir at low speed of 300 rpm to dissolve, and allow to swell for 30 min. Step S2: Add 10 kg of composite emulsifier (span 60 and tween 60 in a weight ratio of 1:1.2) and 35 kg of No. 10 white oil, and shear pre-emulsify at 8000 rpm for 10 min; In step S3, add 3 kg of nano-silica (300 nm particle size), 2 kg of graphite powder (1.3 μm particle size), 2 kg of polyethylene glycol (PEG-400), and 1 kg of defoamer (organic silicone defoamer TYXP produced by Korla Tongyi Industry and Trade Co., Ltd.). Emulsify and shear again at 8000 rpm for 20 min. Step S4: The above product is added to a colloid mill for fine grinding (gap 0.8 mm, 2000 rpm, 3 cycles) to obtain a uniform emulsion, i.e., a multifunctional sealing and anti-collapse agent.
[0021] Example 2
[0022] A method for preparing a multifunctional sealing and anti-collapse agent, the preparation process of which is as follows: Step S1: In a high-speed shearing machine, add 35 kg of water and 5 kg of modified starch in proportion, stir at low speed of 300 rpm to dissolve, and swell for 30 min. Step S2: Add 12 kg of composite emulsifier (span 60 and tween 60 in a weight ratio of 1:0.8) and 40 kg of No. 10 white oil, and shear pre-emulsify at 10,000 rpm for 15 min; In step S3, add 4 kg of nano silica (300 nm particle size), 1 kg of graphite powder (1.3 μm particle size), 2 kg of polyethylene glycol (PEG-400), and 1 kg of defoamer (organic silicone defoamer TYXP produced by Korla Tongyi Industry and Trade Co., Ltd.). Emulsify and shear again at 10,000 rpm for 20 min. Step S4: The above product is added to a colloid mill for fine grinding (gap 0.8 mm, 2000 rpm, 3 cycles) to obtain a uniform emulsion, i.e., a multifunctional sealing and anti-collapse agent.
[0023] Example 3
[0024] A method for preparing a multifunctional sealing and anti-collapse agent, the preparation process of which is as follows: Step S1: In a high-speed shearing machine, add 32 kg of water and 6 kg of guar gum in proportion, stir at low speed of 300 rpm to dissolve, and swell for 30 min; Step S2: Add 10 kg of composite emulsifier (span 60 and tween 60 in a weight ratio of 1:1) and 40 kg of 10# white oil, and shear pre-emulsify at 12000 rpm for 15 min; In step S3, add 4 kg of nano silica (300 nm particle size), 2 kg of graphite powder (1.3 μm particle size), 3 kg of polyethylene glycol (PEG-400), and 1 kg of defoamer (organic silicone defoamer TYXP produced by Korla Tongyi Industry and Trade Co., Ltd.). Emulsify and shear again at 12000 rpm for 30 min. Step S4: The above product is added to a colloid mill for fine grinding (gap 0.8 mm, 2000 rpm, 3 cycles) to obtain a uniform emulsion, i.e., a multifunctional sealing and anti-collapse agent.
[0025] Example 4
[0026] To improve the dispersion of nano-silica and graphite powder, surface modification with coupling agents or alteration of shear emulsification process conditions (such as increasing the shear emulsification speed) are commonly employed. However, surface modification with coupling agents places relatively stringent requirements on the storage conditions of the nano-silica and graphite powder. This embodiment, through extensive testing, innovatively discovers that dry grinding of nano-silica, graphite powder, and polyethylene glycol before adding the ground mixture to the mixing system improves the dispersibility of nano-silica and graphite powder, enhances the effectiveness of the multifunctional sealing and anti-collapse agent, and eliminates the need for stringent storage conditions. The applicant believes this may be because some molecular chains of polyethylene glycol break during grinding, allowing them to adsorb onto the surfaces of nano-silica and graphite powder, or because polyethylene glycol may coat the surfaces of nano-silica and graphite powder during grinding, thereby improving the dispersion effect. Meanwhile, based on extensive test results, the applicant discovered that the effectiveness of the multifunctional sealing and anti-collapse agent is significantly related to the dry grinding time and the weight of the grinding mixture. Therefore, further research into the dry grinding process of a large quantity of nano-silica, graphite powder, and polyethylene glycol, and its innovative findings regarding the effectiveness of the multifunctional sealing and anti-collapse agent, revealed that when the grinding time t meets the following specific conditions, under specific raw material compositions and with corresponding shear emulsification process conditions, the effectiveness of nano-silica, graphite powder, and the multifunctional sealing and anti-collapse agent can be further improved. Among these conditions, the grinding time... In the formula, T is the base time, ranging from 40 to 60 minutes; generally, in laboratory preparation, T ranges from 40 to 50 minutes; in factory-scale preparation, T ranges from 50 to 60 minutes; m1 is the weight of polyethylene glycol, m2 is the weight of nano-silica, m3 is the weight of graphite powder, and k is a time correction coefficient related to the total weight of the nano-silica, graphite powder, and polyethylene glycol, ranging from 0.8 to 1.2. Generally, the larger the total weight of nano-silica, graphite powder, and polyethylene glycol, the larger the value of k. For example, in small-scale laboratory preparation, the value of k is generally 0.8 to 0.9; in pilot-scale laboratory preparation, the value of k is generally 0.9 to 1.0; and in factory-scale preparation, the value of k is generally 1.0 to 1.2.
[0027] A method for preparing a multifunctional sealing and anti-collapse agent, the preparation process of which is as follows: Step S1: In a high-speed shearing machine, add 32 kg of water and 6 kg of guar gum in proportion, stir at low speed of 300 rpm to dissolve, and swell for 30 min; Step S2: Add 10 kg of composite emulsifier (span 60 and tween 60 in a weight ratio of 1:1) and 40 kg of 10# white oil, and shear pre-emulsify at 12000 rpm for 15 min; In step S3, add 4 kg of nano-silica (300 nm particle size), 2 kg of graphite powder (1.3 μm particle size), 3 kg of polyethylene glycol (PEG-400), and 1 kg of defoamer (TYXP silicone defoamer produced by Korla Tongyi Industry and Trade Co., Ltd.). Emulsify and shear again at 12000 rpm for 10 min. The nano-silica, graphite powder, and polyethylene glycol are first dry-ground before being mixed with the remaining raw materials. ; Step S4: The above product is added to a colloid mill for fine grinding (gap 0.8 mm, 2000 rpm, 3 cycles) to obtain a uniform emulsion, i.e., a multifunctional sealing and anti-collapse agent.
[0028] Comparative Example 1 A method for preparing a multifunctional sealing and anti-collapse agent, the preparation process of which is as follows: Step S1: In a high-speed shearing machine, add 41g of water and 6kg of guar gum in proportion, stir at low speed to dissolve, and swell for 30 minutes; Step S2: Add 10 kg of composite emulsifier (span 60 and tween 60 in a weight ratio of 1:1) and 40 kg of 10# white oil, and shear pre-emulsify at 12000 rpm for 15 min; Step S3: Add 1 kg of defoamer (TYXP silicone defoamer produced by Korla Tongyi Industry and Trade Co., Ltd.) and emulsify and shear again at 12000 rpm for 30 min. Step S4: The above product is added to a colloid mill for fine grinding (gap 0.8 mm, 2000 rpm, 3 cycles) to obtain an emulsion, namely a multifunctional sealing and anti-collapse agent.
[0029] Experimental Method 1: Particle Size Analysis Measure 300 mL of distilled water and add 3 g of the sample prepared in the example. Stir at 11000 rpm for 10 min, then ultrasonically disperse for 5 min on an ultrasonic disperser. Prepare 3 portions; measure the particle size of one portion using a laser particle size analyzer at room temperature; place the other two portions into aging tanks with liners, one portion aged at 140 °C for 8 h and the other portion aged at 220 °C for 8 h. After the aging time is up, stop heating and allow to cool naturally; then stir at high speed for 10 min, ultrasonically disperse for 5 min on an ultrasonic disperser, and then measure the particle size again using a laser particle size analyzer.
[0030] Table 1. Particle size test results
[0031] Figure 1 and Figure 2This is a particle size distribution diagram of the multifunctional sealing and anti-collapse agent sample in Example 3 after aging at room temperature and 220°C. (See Table 1 for details.) Figure 1 , Figure 2 As can be seen from the above results, the particle size distribution of the sealing and anti-collapse agent invented in the examples is in the submicron to micron range; after high-temperature aging, the emulsion did not agglomerate, and the emulsion droplet size was less than 15 μm. This indicates that the sealing and anti-collapse agent has good emulsification and dispersion stability and can withstand temperatures up to 220℃.
[0032] Experimental Method 2: Drilling Fluid Performance Testing Four percent of the example sample and the comparative sample were added to the water-based drilling fluid of a well at the site, and various properties were tested. At the same time, 50g of air-dried rock cuttings from Da'anzhai (particle size 1.63mm~3.86mm, single-roll recovery rate of 30% in clean water) were weighed, added to the drilling fluid, rolled and aged at 77℃ for 16h, filtered through a 0.44mm standard sieve, dried at 105℃, and the mass of rock cuttings was weighed. The rolling recovery rate of rock cuttings was calculated, and the results are shown in Table 2.
[0033] Table 2 Drilling fluid performance test results
[0034] The experimental results in Table 2 above show that when the plugging and anti-collapse agent invented in the examples is added to water-based drilling fluid, the viscosity increases slightly, the medium-pressure filtration loss and high-temperature and high-pressure filtration loss decrease significantly, the mud cake thickness decreases, the mud cake viscosity coefficient decreases, and the cuttings recovery rate increases. After adding the comparative sample, the filtration loss remains basically unchanged, the mud cake thickness does not decrease significantly, and the mud cake viscosity coefficient remains unchanged. The analysis results indicate that the plugging and anti-collapse agent invented in the examples participates in mud cake formation, improves mud cake density and toughness, improves mud cake quality, reduces filtration loss, and improves lubricity and inhibition properties.
Claims
1. A multifunctional sealing and anti-collapse agent, characterized in that, The ingredients comprise, by weight percentage, totaling 100%, as follows: Cosmetic-grade mineral oil, 35%~45%; Compound emulsifier, 8%~12%; Amide-based thickening polymers or polysaccharide-based thickening polymers, 3%~8%; Nano-silica, 3%~5%; Graphite powder, 1%~3%; Polyethylene glycol, 2%~3%; Defoamer, 1-2%; Water, remaining amount.
2. The multifunctional sealing and anti-collapse agent according to claim 1, characterized in that, The cosmetic-grade mineral oil is one or more of 5# white oil, 10# white oil, and 15# white oil.
3. The multifunctional sealing and anti-collapse agent according to claim 1, characterized in that, The composite emulsifier is a mixture of span 60 and tween 60.
4. The multifunctional sealing and anti-collapse agent according to claim 1, characterized in that, The weight ratio of span 60 to tween 60 is 1:(0.8~1.2).
5. The multifunctional sealing and anti-collapse agent according to claim 1, characterized in that, The amide-based thickening polymer is polyacrylamide; The polysaccharide thickening polymer is one or more of modified starch, guar gum, modified guar gum or their derivatives.
6. The multifunctional sealing and anti-collapse agent according to claim 1, characterized in that, The defoamer is an organosilicon defoamer.
7. The multifunctional sealing and anti-collapse agent according to any one of claims 1 to 6, characterized in that, The nano-silica, graphite powder, polyethylene glycol, and other raw materials are first subjected to dry grinding before being mixed; wherein, the grinding time is... ; In the formula, T is the base time, and its value ranges from 40 to 60 minutes; m1 is the weight of the polyethylene glycol. m2 is the weight of the nano-silica. m3 is the weight of the graphite powder. k is a time correction factor related to the total weight of the nano-silica, the graphite powder, and the polyethylene glycol, and its value ranges from 0.8 to 1.
2.
8. A method for preparing a multifunctional sealing and anti-collapse agent, characterized in that, Includes the following steps: Step S1: In a high-speed shear press, add water, amide-based thickening polymer or polysaccharide-based thickening polymer in proportion and stir at low speed. Step S2: Add composite emulsifier and cosmetic-grade mineral oil, and shear pre-emulsify at 8000~12000 rpm; In step S3, add nano-silica, graphite powder, polyethylene glycol, and defoamer, and emulsify and shear again at a speed of 8000~12000 rpm; Step S4: The product from step S3 is added to a colloid mill for fine grinding. The gap is 0.8~1 mm, the rotation speed is 2000~3000 rpm, and the cycle is 3~5 times to obtain a uniform emulsion, which is a multifunctional sealing and anti-collapse agent.