WO2024046265A1

WO2024046265A1 - Ultrahigh-temperature-resistant filtrate reducer and preparation thereof, oil-based drilling fluid and oil field drilling method

Info

Publication number: WO2024046265A1
Application number: PCT/CN2023/115248
Authority: WO
Inventors: 陶怀志; 艾加伟; 陈俊斌; 舒小波; 明显森; 周杨; 袁志平; 景岷嘉
Original assignee: 中国石油天然气集团有限公司; 中国石油集团川庆钻探工程有限公司
Priority date: 2022-08-29
Filing date: 2023-08-28
Publication date: 2024-03-07
Also published as: CN117659313A

Abstract

An ultrahigh-temperature-resistant filtrate reducer and the preparation thereof, an oil-based drilling fluid and an oil field drilling method. The ultrahigh-temperature-resistant filtrate reducer is prepared by reacting a lithium magnesium silicate with an alkenyl-containing silane coupling agent to prepare an alkenyl-containing silane-modified lithium magnesium silicate, and then subjecting the alkenyl-containing silane-modified lithium magnesium silicate to a copolymerization reaction with isoprene, 4-vinylbenzenesulfonic acid-tetrabutylphosphonium salt, styrene and vinylimidazole. The ultrahigh-temperature-resistant filtrate reducer is low in terms of an addition amount, has an obvious filtrate reduction effect, and also has the characteristics of resistance to ultrahigh temperatures, little influence on the rheology of an oil-based drilling fluid, etc.

Description

Ultra-high temperature resistant fluid loss agent and its preparation, oil-based drilling fluid and oilfield drilling method

This application is required to be submitted to the China Patent Office on August 29, 2022. The application number is 2022110388272 and the invention is a Chinese patent titled "A fluid loss agent resistant to ultra-high temperature and its preparation, oil-based drilling fluid and oilfield drilling method" claim of priority, the entire contents of which are incorporated herein by reference.

Technical field

The invention relates to an ultra-high temperature resistant fluid loss agent and its preparation, an oil-based drilling fluid and an oilfield drilling method, and belongs to the technical field of oilfield drilling fluids.

Background technique

Oil-based drilling fluids are widely used in oilfield drilling processes because of their advantages such as good inhibition, resistance to salt erosion, and good lubricity. Fluid loss additives can block micro-nano pores in oil-based drilling fluids and reduce the fluid loss of drilling fluids. At present, conventional fluid loss additives for oil-based drilling fluids are generally natural asphalt or oxidized asphalt with different softening points, including a small amount of sulfonated asphalt and modified humic acid fluid loss additives. During operations, these conventional oil-based drilling fluid fluid loss additives generally add too much and affect the rheology of the drilling fluid, causing problems such as loss of control under high and ultra-high temperature conditions.

Asphalt fluid loss additives often only work near their softening point. When the formation temperature is much higher than the asphalt softening point, the asphalt softens, dissolves, and decomposes into small particles at the molecular level, losing the function of blocking and reducing fluid loss; while when the formation temperature is much lower than the asphalt softening point, asphalt-based fluid loss reduction The agent often exists in the drilling fluid in the form of large solid particles, which not only greatly reduces the filter loss effect, but also increases the solid content in the drilling fluid, resulting in excessively high viscosity of the drilling fluid.

In recent years, with the continuous deepening of exploration and development, the temperature of operating wells has continued to rise. The temperature of many wells has reached above 205°C, with the highest reaching 260°C. Under ultra-high temperature (205-260℃) or extremely high temperature (≥260℃) conditions, modified humic acid fluid loss additives, conventional polymers and other fluid loss additives have become ineffective. In order to control the fluid loss, during on-site drilling operations, a large amount of asphalt fluid loss additive is often added. In many cases, the dosage of asphalt fluid loss additive exceeds 8% (the dosage is the mass-to-volume ratio, For example, if 1 ton of treatment agent is added to ^100m3 of drilling fluid or base slurry, the amount of treatment agent added is 1%), or even more than 10%. Even so, the fluid loss is still difficult to control. Since asphalt contains oil-soluble colloids and asphaltenes, the addition of a large amount of fluid loss reducer will cause the liquid viscosity of the oil-based drilling fluid to be extremely high, making the fluid loss difficult to control and often leading to changes in its rheology. out of control. In addition, the fluorescence characteristics of asphalt-based fluid loss agents will also affect the accuracy of geological logging.

Furthermore, asphalt can easily cause environmental pollution, so how to reduce the use of this type of fluid loss agent and improve the product's resistance to Temperature effect has become an important problem in oil fields.

Therefore, providing a new ultra-high temperature resistant fluid loss agent and its preparation, oil-based drilling fluids and oilfield drilling methods have become technical problems that need to be solved urgently in this field.

Contents of the invention

In order to solve the problem of oil-based drilling fluid fluid loss additives such as asphalt, which are currently the most widely used, they have a large amount of addition, a large increase in solid phase, and insufficient temperature resistance. They are prone to failure under ultra-high temperature conditions and have insufficient fluid loss effects at low temperatures. Problems such as affecting the rheology of drilling fluids, one purpose of the present invention is to provide a fluid loss agent that resists ultra-high temperatures.

Another object of the present invention is to provide a method for preparing the above-mentioned ultra-high temperature resistant fluid loss reducer.

Another object of the present invention is to provide an oil-based drilling fluid, which contains the above-mentioned ultra-high temperature resistant fluid loss agent.

Another object of the present invention is to provide an oilfield drilling method, which is achieved by using the above-mentioned oil-based drilling fluid.

In order to achieve the above object, on the one hand, the present invention provides a fluid loss agent resistant to ultra-high temperature, wherein the fluid loss agent resistant to ultra-high temperature is first coupled with lithium magnesium silicate and a silane containing an alkenyl group. The agent reacts to generate alkenyl-containing silane-modified magnesium lithium silicate, and then the alkenyl-containing silane-modified magnesium lithium silicate is reacted with isoprene and 4-vinylbenzenesulfonic acid-tetrabutyl The quaternary phosphonium salt, styrene and vinylimidazole are subjected to a copolymerization reaction, and after the reaction is completed, the ultra-high temperature resistant fluid loss agent is obtained.

As a specific embodiment of the above-mentioned ultra-high temperature resistant fluid loss agent of the present invention, the ultra-high temperature resistant fluid loss agent is prepared by a preparation method including the following steps:

S1: Add 19.5-58.6 parts by weight (preferably 39.1 parts by weight) of lithium magnesium silicate to 1000 parts by weight of deionized water to obtain a dispersion of lithium magnesium silicate, and then let the dispersion stand still hydration;

S2: Under stirring conditions, add 14.8-28.0 parts by weight of the alkenyl-containing silane coupling agent to the solution obtained in S1, then adjust the pH value of the system to 4-6, and let the alkenyl-containing silane coupling agent Fully react with lithium magnesium silicate to obtain a silane-modified aqueous solution of magnesium lithium silicate containing alkenyl groups, and then dry the aqueous solution and then cool it naturally;

S3: Add the alkenyl-containing silane-modified lithium magnesium silicate obtained in S2 to 500 parts by weight of deionized water and mix it evenly, and then heat the system temperature to 40-50°C by heating in a water bath;

S4: Add 60-80 parts by weight of surfactant, 22.1-44.2 parts by weight of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 4.7-22.2 parts by weight of vinylimidazole to the solution obtained in S3. And fully dissolve 4-vinyl benzene sulfonic acid-tetrabutyl quaternary phosphine salt and vinyl imidazole; then react the resulting solution in the absence of oxygen at a constant temperature of 70-75°C for 30-40 minutes; after the reaction is completed, add to the obtained solution Add 13.6-20.4 parts by weight of isoprene and 5.2-15.6 parts by weight into the solution parts of styrene to form a microemulsion; then add 0.5-1.5 parts by weight of oil-soluble initiator to the microemulsion and then heat it to 75±2°C to react for 1-3 hours. After the reaction is completed, the ultrahigh temperature resistant Fluid loss reducer.

As a specific embodiment of the above ultra-high temperature resistant fluid loss agent of the present invention, the preparation method further includes:

S5: Dry the polymer emulsion obtained in S4, add the dried product to an aqueous solution containing ethanol to adjust it into a turbid liquid, stir the turbid liquid and let it stand to allow the solid phase to fully precipitate. ;

S6: Pour off the supernatant liquid in the system obtained in S5, add deionized water to adjust the precipitate to a turbid liquid, and then dry the turbid liquid to a constant weight to obtain the ultra-high temperature resistant fluid loss agent. .

As a specific embodiment of the above ultra-high temperature resistant fluid loss agent of the present invention, the silane coupling agent containing an alkenyl group includes a silane coupling agent containing a vinyl group, a propenyl group or an allyl group;

Preferably, the alkenyl-containing silane coupling agent includes vinyltriethoxysilane (A-151), vinyltrimethoxysilane (A-171), vinyltris(2-methoxyethoxy silane (A-172) and vinylmethyldimethoxysilane (A-2171), or a combination of several. The alkenyl group-containing silane coupling agent used in the present invention is a commercially available conventional product, for example, the corresponding product purchased from Compton International Chemical Company of the United States.

As a specific embodiment of the above ultra-high temperature resistant fluid loss agent of the present invention, the magnesium lithium silicate has a nanosheet structure, with a particle size of 30-70 nm and a thickness of 5-15 nm.

As a specific embodiment of the above ultra-high temperature resistant fluid loss agent of the present invention, the vinylimidazole includes one of 1-vinylimidazole and vinylimidazole having the structure shown in the following formula I, etc. or a combination of several;

In formula I, R ₂ includes methyl, ethyl, n-propyl, isopropyl or butyl, etc., X ^- includes tetrafluoroborate, chloride ion or bromide ion, etc.;

Preferably, the vinylimidazole includes 1-vinyl-3-ethylimidazole tetrafluoroborate, 1-vinyl-3-ethylimidazole bromide, 1-vinylimidazole and 1-vinyl-3 -One or a combination of several of butylimidazole chloride salts, etc.

As a preferred embodiment of the above ultra-high temperature resistant fluid loss agent of the present invention, the vinylimidazole is 1-vinylimidazole.

As a specific embodiment of the above ultra-high temperature resistant fluid loss agent of the present invention, the molar ratio between the lithium magnesium silicate and the silane coupling agent containing an alkenyl group is 1:1, wherein the lithium magnesium silicate The molecular weight is based on 361g/mol.

As a specific embodiment of the above ultra-high temperature resistant fluid loss agent of the present invention, wherein, alkenyl-containing silane coupling agent, isoprene, styrene, 4-vinylbenzenesulfonic acid-tetrabutyl The molar ratio between quaternary phosphonium salt and vinylimidazole is 2:5:2:1:2.

The lithium magnesium silicate, styrene, isoprene, vinylimidazole, 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt, etc. used in the present invention are all commercially available conventional products; for example: the silicic acid Magnesium and lithium were purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd., the vinylimidazole can be the corresponding product purchased from Shanghai Chengjie Chemical Co., Ltd., and the 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt was purchased from Southwest Petroleum University, its relative molecular mass is 442g/mol.

As a specific embodiment of the above ultra-high temperature resistant fluid loss agent of the present invention, the surfactant includes sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfate (AS), A combination of any two of octylphenol polyoxyethylene ether (OP-10) and cardanol polyoxyethylene ether (BGF-10). The above-mentioned surfactant products used in the present invention are all commercially available conventional products.

As a specific embodiment of the above ultra-high temperature resistant fluid loss agent of the present invention, the surfactant includes sodium dodecyl benzene sulfonate and octylphenol polyoxyethylene ether, and the mass ratio of the two It is 3:2, or sodium dodecyl sulfate and octylphenol polyoxyethylene ether, the mass ratio of the two is 7:3, or sodium dodecyl benzene sulfonate and cardanol polyoxyethylene ether, the two The mass ratio is 4:1.

As a specific embodiment of the above ultra-high temperature resistant fluid loss agent of the present invention, the oil-soluble initiator includes azobisisobutyronitrile, azobisisoheptanitrile, azobisisovaleronitrile or Any of azodicyclohexylcarbonitrile, etc.

The ultra-high temperature resistant fluid loss agent provided by the present invention needs to have a suitable molecular weight. If the molecular weight is too small, it will not be able to form multi-point adsorption. If the molecular weight is too large, it will easily lead to drilling fluid conditioning. Considering that the product needs to have high temperature resistance to prevent excessive degradation at high temperatures, it also needs to prevent the product from having an excessive impact on the viscosity of the drilling fluid. As a specific embodiment of the above-mentioned ultra-high temperature resistant fluid loss agent of the present invention, the molecular weight of the ultra-high temperature resistant fluid loss agent is 10,000-50,000.

As a specific embodiment of the above-mentioned ultra-high temperature resistant fluid loss agent of the present invention, the average particle size of the ultra-high temperature resistant fluid loss agent is 50-150 nm, preferably 70-100 nm.

On the other hand, the present invention also provides a method for preparing the above-mentioned ultra-high temperature resistant fluid loss reducer, wherein the preparation method includes:

First, lithium magnesium silicate is reacted with a silane coupling agent containing an alkenyl group to generate a silane-modified lithium magnesium silicate containing an alkenyl group, and then the silane-modified lithium magnesium silicate containing an alkenyl group is reacted with a different Pentadiene, 4-vinylbenzenesulfonic acid-tetrabutylquaternary The phosphonate salt, styrene and vinylimidazole undergo a copolymerization reaction, and after the reaction is completed, the ultra-high temperature resistant fluid loss agent is obtained.

As a specific embodiment of the above preparation method of the present invention, the preparation method specifically includes:

S1: Add 19.5-58.6 parts by weight of lithium magnesium silicate to 1000 parts by weight of deionized water to obtain a dispersion of magnesium lithium silicate, and then allow the said dispersion of magnesium lithium silicate to stand and hydrate;

S2: Under stirring conditions, add 14.8-28.0 parts by weight of the alkenyl-containing silane coupling agent to the solution obtained in S1, then adjust the pH value of the system to 4-6, and let the alkenyl-containing silane coupling agent Fully react with lithium magnesium silicate to obtain a silane-modified aqueous solution of magnesium lithium silicate containing an alkenyl group, and then dry the aqueous solution and then cool it naturally;

S4: Add 60-80 parts by weight of surfactant, 22.1-44.2 parts by weight of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 4.7-22.2 parts by weight of vinylimidazole to the solution obtained in S3. And fully dissolve 4-vinyl benzene sulfonic acid-tetrabutyl quaternary phosphine salt and vinyl imidazole; then react the resulting solution in the absence of oxygen at a constant temperature of 70-75°C for 30-40 minutes; after the reaction is completed, add to the obtained solution Add 13.6-20.4 parts by weight of isoprene and 5.2-15.6 parts by weight of styrene to the solution to form a microemulsion; then add 0.5-1.5 parts by weight of an oil-soluble initiator to the microemulsion and heat it to 75 The reaction is carried out at ±2°C for 1-3 hours, and after the reaction is completed, the ultra-high temperature resistant fluid loss agent is obtained.

As a specific embodiment of the above preparation method of the present invention, the preparation method further includes:

In S2, after adjusting the pH value of the system to 4-6, add the alcohol solvent produced when the alkenyl-containing silane coupling agent is hydrolyzed into the system, so that the alkenyl-containing silane coupling agent and silicic acid Magnesium and lithium react fully; wherein, the addition amount of the alcohol solvent is 3-30%, where 3-30% is the mass-volume ratio. For example: 1000 parts by weight of deionized water is used in S1, then S2 is added The mass of alcohol solvent is 3-30g.

As a specific embodiment of the above preparation method of the present invention, in S1, 19.5-58.6 parts by weight of magnesium lithium silicate is added to 1000 parts by weight of deionized water, and stirred at a high speed of 12000±1000 rpm for 20-30 min. , to form a magnesium lithium silicate dispersion. Among them, the purpose of S1 medium-high speed stirring is to fully disperse magnesium lithium silicate into nanometer-sized particles, and magnesium lithium silicate needs to be fully hydrated to disperse into nanometer-sized flake particles, exposing the hydroxyl groups on its surface.

As a specific embodiment of the above preparation method of the present invention, in S2, a silane coupling agent containing an alkenyl group It needs to be hydrolyzed before the coupling reaction can occur with the hydroxyl groups on the surface of magnesium lithium silicate. Taking vinyl silane coupling agent as an example, the reaction process is as shown in the following formula II:

In formula II, R ₁ varies according to the vinyl silane coupling agent, for example, it can be methyl or ethyl, etc.

For alkenyl-containing silane coupling agents (such as A151) whose own groups have a weak impact on the pH value of the aqueous solution, the pH value of the aqueous solution can be adjusted by adding acetic acid, ammonia and other substances to the system to make the alkenyl-containing silane coupling agent The coupling agent is easier to hydrolyze. Add acetic acid to the system to adjust the pH value of the aqueous solution to weak acidity (4-6) before hydrolyzing A151. The hydrolysis speed will be significantly improved. In addition, when a silane coupling agent containing an alkenyl group is hydrolyzed, a certain amount of alcohol solvents such as methanol and ethanol that can be freely miscible with water will be produced. This is determined by the R ₁ group in the silane structure. If in S1 Preliminarily adding the alcohol solvent produced when the alkenyl group-containing silane coupling agent is hydrolyzed to the obtained aqueous solution will make the alkenyl group-containing silane coupling agent more fully dispersed in the aqueous solution, thereby making the hydrolyzate more stable. For example, if a small amount of ethanol is added to the aqueous solution obtained in S1 before hydrolysis of A151 is carried out, the oily A151 will be miscible with the aqueous solution faster and will not easily condense and precipitate. In addition, sufficient stirring is required when the alkenyl-containing silane coupling agent is hydrolyzed, so that the alkenyl-containing silane coupling agent can more fully contact with water and reduce the occurrence of contact between the alkenyl-containing silane coupling agents. In the condensation polymerization reaction, once the silane coupling agent containing alkenyl groups is polycondensed, it will be difficult to hydrolyze.

As a specific embodiment of the above preparation method of the present invention, in S4, isoprene and styrene are hydrophobic monomers (oil-soluble monomers). According to the principle of similarity and compatibility, isoprene is easily soluble in hydrocarbons. At the same time, styrene containing benzene rings is easily soluble in oil-soluble substances containing aromatic rings. Through the introduction of the above two monomers, the dispersion performance of synthetic products in oil can be enhanced.

In addition, in order to prevent high-temperature degradation, the present invention selects isoprene containing C=C unsaturated double bonds for polymerization reaction to obtain a polymer with C-C single bonds. Since the C-C bond energy is very large, it is not prone to high-temperature degradation, which can improve the temperature resistance of the resulting polymer. At the same time, after isoprene is polymerized, a double bond structure will be formed on the side chain of the polymer, further ensuring the hydrophobicity of the product. sex.

The present invention also introduces two hydrophilic monomers, 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and vinylimidazole, which are ionic liquid monomers that can be polymerized and have good temperature resistance properties. , 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and styrene monomer both have benzene ring structures. The combination of the two improves the rigidity of the polymer molecular chain, thus It can improve the product's temperature resistance. In addition, the five-membered ring structure contained in vinylimidazole also has a certain degree of rigidity, which can further improve the product's temperature resistance. At the same time, due to the presence of the tetrabutyl quaternary phosphonium salt group, the dipole moment of the 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphonium salt monomer is enhanced, making the monomer have a certain polarity, thus making the polymer The adsorption capacity of the product is improved, and the introduction of the imidazole structure can further enhance the adsorption effect of the resulting polymer product.

In the present invention, alkenyl-containing silane-modified magnesium lithium silicate (taking vinylsilane-modified magnesium lithium silicate as an example) is combined with isoprene, styrene, 4-vinylbenzenesulfonic acid-tetrabutyl The reaction process of quaternary phosphonium salt and vinylimidazole (taking vinylimidazole with the structure shown in the above formula I as an example) is as shown in the following formula III:

In formula III, the molar ratio of x, y, z, m and n is 1-3:1-3:1-3:4-6:1-1.5, preferably 2:2:2:5:1.

As a specific embodiment of the above preparation method of the present invention, in S5 and S6, the drying can be performed in a spray dryer. Spray drying is one of the commonly used drying methods for emulsion products and cloudy liquid products. Actual operations require reasonable adjustments to the spray drying temperature and time, as long as the drying purpose can be achieved.

In S5, an aqueous solution containing ethanol is added to the dried product to adjust it into a turbid liquid, in order to make the polymer complex precipitate more easily. At the same time, the purpose of leaving the turbid liquid to stand is mainly to allow the water-soluble surfactant to enter the upper water phase and be washed away, thereby reducing the synthesis reaction when the ultra-high temperature resistant fluid loss agent is added to the oil-based drilling fluid later. Negative effects of surfactants used in oil-based drilling fluids.

In another aspect, the present invention also provides an oil-based drilling fluid, wherein the oil-based drilling fluid contains the ultra-high temperature resistant fluid loss agent described above.

As a specific embodiment of the above-mentioned oil-based drilling fluid of the present invention, the added amount of the ultra-high temperature resistant fluid loss agent is 1-3%, where 1-3% is the mass to volume ratio, such as : Add 1g of ultra-high temperature resistant fluid loss agent to 100 mL of drilling fluid or base slurry. At this time, the added amount of ultra-high temperature resistant fluid loss agent is 1%.

In yet another aspect, the present invention also provides an oilfield drilling method, wherein the oilfield drilling method is implemented using the above-mentioned oil-based drilling fluid.

Compared with the existing technology, the beneficial technical effects achieved by the present invention include:

The present invention synthesizes an ultra-high temperature resistant plugging oil-based drilling fluid fluid loss agent through organic and inorganic composite modification. When preparing the ultra-high temperature resistant fluid loss agent, a monomer with silane coupling effect, that is, a silane coupling agent containing an alkenyl group, is first used to react with lithium magnesium silicate to convert the nanoscale lithium magnesium silicate into The particles are modified into nanoparticles with polymerization activity, and then the oil-soluble monomers, namely styrene, isoprene and hydrophilic monomers, namely 4-vinylbenzenesulfonic acid- Tetrabutyl quaternary phosphine salt and vinyl imidazole polymerize with alkenyl-containing active lithium magnesium silicate to finally form an organic-inorganic polymer complex, that is, an organic-inorganic nanocomposite fluid loss agent. The present invention makes the hydrophilic lithium magnesium silicate have a certain degree of hydrophobicity through hydrophobic modification, thereby solving the problem of lipophilic dispersion of the lithium magnesium silicate. At the same time, the ultra-high temperature resistant fluid loss agent obtained by the present invention is an inorganic-organic polymer composite. While the inorganic part plays a blocking role, the organic polymer chain can play a certain role in "stretching and bridging". function, further enhancing the sealing and filter loss reducing effects of the product.

The present invention synthesizes the ultra-high temperature resistant fluid loss agent through microemulsion polymerization, effectively controls the particle size of the product, keeps the synthesized composite particles at the nanometer level, and solves the problem of conventional modification of inorganic-organic nanocomposite materials. Problems such as agglomeration and difficulty in controlling particle size are prone to occur during the process.

The present invention effectively controls the chain length of the polymer by controlling the amount of initiator, so that the polymer chain of the product has good filter loss reduction and self-dispersion capabilities; further, the synthesized product has excellent blocking and reduction properties. Under the premise of filter loss performance, it does not affect the rheology of drilling fluid.

By using monomers containing rigid groups and temperature-resistant groups and adjusting the proportion of each monomer, the invention greatly improves the temperature resistance of the product, and the temperature resistance can reach 260°C.

By optimizing hydrophilic monomers and hydrophobic monomers and adjusting their ratio with hydrophilic magnesium lithium silicate, the invention makes the synthesized product have a certain degree of amphiphilicity and can assist emulsification in oil-based drilling fluids. function, which can further improve the emulsification stability of oil-based drilling fluid, increase the demulsification voltage, and reduce filter loss.

By using the two monomers of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and vinylimidazole, the present invention not only greatly enhances the temperature resistance effect of the product, but also improves the stability of the product in clay, barite, etc. The adsorption capacity on the particles greatly improves the product's temperature resistance and filter loss reduction capabilities.

In summary, the ultra-high temperature resistant fluid loss agent provided by the present invention not only has a small amount of addition and obvious fluid loss reducing effect, but also has the characteristics of resisting ultra-high temperatures and having little impact on the rheology of oil-based drilling fluids.

Detailed ways

It should be noted that the term "comprise" and any variations thereof in the description and claims of the present invention are intended to cover non-exclusive inclusion, for example, a process, method, system, product or product that includes a series of steps or units. Apparatus are not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such processes, methods, products or devices.

The "ranges" disclosed herein are given in terms of lower and upper limits. It can be one or more lower bounds, and one or more upper bounds. A given range is limited by selecting a lower limit and an upper limit. The selected lower and upper bounds define the boundaries of the particular range. All ranges defined in this way are combinable, that is, any lower limit can be combined with any upper limit to form a range. For example, where ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that ranges of 60-110 and 80-120 are also to be expected. Furthermore, if the minimum range values listed are 1 and 2, and the maximum range values listed are 3, 4, and 5, then the following ranges are all expected: 1-3, 1-4, 1-5, 2- 3, 2-4 and 2-5.

In the present invention, unless otherwise stated, the numerical range "a-b" represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in the present invention, and "0-5" is just an abbreviation of these numerical combinations.

In the present invention, unless otherwise specified, all embodiments and preferred embodiments mentioned in the present invention can be combined with each other to form new technical solutions.

In the present invention, unless otherwise specified, all technical features and preferred features mentioned in the present invention can be combined with each other to form new technical solutions.

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the appendix and examples. The embodiments described below are part of the embodiments of the present invention, not all of them. They are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. If the specific conditions are not specified in the examples, the conditions should be carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not indicated, they are all conventional products that can be purchased commercially.

Example 1

This embodiment provides an ultra-high temperature resistant fluid loss agent, which is prepared by a preparation method including the following specific steps:

S1: Add 36.1g magnesium lithium silicate (purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd., which has a nanosheet structure, particle size is 30-70nm, thickness is 5-15nm) into 1000mL deionized water, at 12000±1000rpm Stir for 30 minutes under high-speed conditions. After the magnesium lithium silicate dispersion is formed, let it stand for 1 hour to hydrate.

S2: Under stirring conditions, first add 14.8g of vinyl trimethoxysilane (A-171, purchased from Compton International Chemical Company, USA) to the magnesium lithium silicate solution prepared in S1, and then add acetic acid. Adjust the pH value of the solution to 4-6, then add 3.2g of methanol and stir at a speed of 3000±100rpm for 1 hour to fully react with vinyltrimethoxysilane and lithium magnesium silicate to obtain vinyltrimethoxysilane. A natural aqueous solution of magnesium lithium silicate; the aqueous solution is dried at a temperature of 105°C, and then naturally cooled to room temperature after drying.

S3: Add the vinyltrimethoxysilane-modified lithium magnesium silicate obtained in S2 to 500 mL of deionized water, stir at high speed for 30 minutes, then transfer it to a 2L glass reactor, turn on the water bath heating device, and adjust the temperature to 45°C.

S4: Add 80g of surfactant composition (including 64.0g of SDBS and 16.0g of BGF-10), 22.1g of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 9.4 to the glass reactor. g of 1-vinylimidazole, then add a certain amount of deionized water and stir to dissolve 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 1-vinylimidazole and mix evenly; after flowing nitrogen for 30 minutes, After the system is heated to 70°C, it is maintained at a constant temperature and reacts at this temperature for 30 minutes. After the reaction is completed, the remaining lipophilic monomer mixture (including 17.0g of isoprene and 10.4g of styrene) is added dropwise to the system, and stirring is continued for 30 minutes. A microemulsion was formed, and 1.0 g of azobisisobutyronitrile initiator was added to the microemulsion, and the system was heated to 75°C and reacted for 1 hour.

S5: Place the polymer emulsion obtained in S4 into a spray dryer for drying. Add the dried product to an aqueous solution containing ethanol to adjust it into a turbid liquid. Stir the turbid liquid at low speed for 1 hour. , let stand for 2 hours until the solid phase is fully precipitated.

S6: Pour off the supernatant liquid in the system obtained in S5, and then add deionized water to adjust the precipitate to a turbid liquid. Place the turbid liquid in a spray dryer for drying. After drying to constant weight, the anti-supernatant is obtained. The high-temperature fluid loss additive has a molecular weight of 20,000 and an average particle size of 100nm.

Example 2

S1: Add 36.1g of lithium magnesium silicate (purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd., which has a nanosheet structure, a particle size of 30-70nm, and a thickness of 5-15nm) into 1000mL of deionized water. Stir for 30 minutes at a high speed of 1000 rpm. After the magnesium lithium silicate dispersion is formed, let it stand for 1 hour to hydrate.

S2: Under stirring conditions, first add 19.0g of vinyltriethoxysilane (A-151, purchased from Compton International Chemical Company, USA) to the magnesium lithium silicate dispersion prepared in S1, and then add Acetic acid, adjust the pH value of the solution to 4-6, then add 4.6g of ethanol and stir at a speed of 3000±100rpm for 1 hour to fully react between vinyltriethoxysilane and lithium magnesium silicate to obtain vinyltriethoxysilane. Aqueous solution of magnesium lithium silicate modified with silane; the aqueous solution is dried at a temperature of 105°C, and then naturally cooled to room temperature after drying.

S3: Add the vinyltriethoxysilane-modified lithium magnesium silicate obtained in S2 to 500 mL of deionized water, stir at high speed for 30 minutes, then transfer it to a 2L glass reactor, turn on the water bath heating device, and adjust the temperature to 45°C .

S4: Add 80g of surfactant composition (including 48.0g of SDBS and 32.0g of OP-10), 22.1g of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 9.4 to the glass reactor in sequence. g of 1-vinylimidazole, then add a certain amount of deionized water and stir to dissolve 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 1-vinylimidazole and mix them evenly. uniform; after flowing nitrogen for 30 minutes, heat the system to 70°C and maintain a constant temperature and react at this temperature for 30 minutes. After the reaction is completed, the remaining lipophilic monomer mixture (including 17.0g of isoprene and styrene) is added dropwise to the system. 10.4g), continue stirring for 30 minutes to form a microemulsion; then add 1.0g of azobisisobutyronitrile initiator to the microemulsion, and heat the system to 75°C and react for 1 hour.

Example 3

S1: Add 36.1g of magnesium lithium silicate (purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd., which has a nanosheet structure, a particle size of 30-70nm, and a thickness of 5-15nm) into 1000mL of deionized water. Stir for 30 minutes at a high speed of ±1000 rpm. After the magnesium lithium silicate dispersion is formed, let it stand for 1 hour to hydrate.

S2: Under stirring conditions, first add 19.0g of vinyltriethoxysilane (A-151, purchased from Compton International Chemical Company, USA) to the prepared magnesium lithium silicate dispersion in S1, and then add acetic acid , adjust the pH value of the solution to 4-6, then add 4.6g of ethanol and stir at a speed of 3000±100rpm for 1 hour to fully react between vinyltriethoxysilane and magnesium lithium silicate to obtain vinyltriethoxysilane. Silane-modified magnesium lithium silicate aqueous solution; dry the aqueous solution at a temperature of 105°C, and then naturally cool to room temperature after drying.

S4: Add 80g of surfactant composition (including 48.0g of SDBS and 32.0g of OP-10), 22.1g of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 9.4 to the glass reactor in sequence. g of 1-vinylimidazole, then add a certain amount of deionized water and stir to dissolve 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 1-vinylimidazole and mix evenly; after flowing nitrogen for 30 minutes, After the system is heated to 70°C, it is maintained at a constant temperature and reacts at this temperature for 30 minutes. After the reaction is completed, the remaining lipophilic monomer mixture (including 17.0g of isoprene and 10.4g of styrene) is added dropwise to the system, and stirring is continued for 30 minutes. A microemulsion was formed; then 0.5g of azobisisobutyronitrile initiator was added to the microemulsion, and the system was heated to 75°C and reacted for 1 hour.

S5: Place the polymer emulsion obtained in S4 into a spray dryer for drying, and add the dried product to Pour into an aqueous solution containing ethanol to adjust it into a turbid liquid, stir the turbid liquid at a low speed for 1 hour, and let it stand for 2 hours until the solid phase is fully precipitated.

S6: Pour off the supernatant liquid in the system obtained in S5, and then add deionized water to adjust the precipitate to a turbid liquid. Place the turbid liquid in a spray dryer for drying. After drying to constant weight, the anti-supernatant is obtained. The high-temperature fluid loss additive has a molecular weight of 50,000 and an average particle size of 140nm.

Example 4

S4: Add 80g of surfactant composition (including 48.0g of SDBS and 32.0g of OP-10), 22.1g of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 9.4 to the glass reactor in sequence. g of 1-vinylimidazole, then add a certain amount of deionized water and stir to dissolve 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 1-vinylimidazole and mix evenly; after flowing nitrogen for 30 minutes, After the system is heated to 70°C, it is maintained at a constant temperature and reacts at this temperature for 30 minutes. After the reaction is completed, the remaining lipophilic monomer mixture (including 17.0g of isoprene and 10.4g of styrene) is added dropwise to the system, and stirring is continued for 30 minutes. A microemulsion was formed; then 1.5g of azobisisobutyronitrile initiator was added to the microemulsion, and the system was heated to 75°C and reacted for 1 hour.

S6: Pour off the supernatant liquid in the system obtained in S5, and then add deionized water to adjust the precipitate to a turbid liquid. Place the turbid liquid in a spray dryer for drying. After drying to constant weight, the anti-supernatant is obtained. The high-temperature fluid loss additive has a molecular weight of 10,000 and an average particle size of 60nm.

Example 5

S2: Under stirring conditions, first add 22.2g of vinyl trimethoxysilane (A-171, purchased from Compton International Chemical Company, USA) to the magnesium lithium silicate solution prepared in S1, and then add acetic acid. Adjust the pH value of the solution to 4-6, and then stir for 1 hour at a speed of 3000±100 rpm to fully react between vinyltrimethoxysilane and lithium magnesium silicate to obtain vinyltrimethoxysilane-modified lithium magnesium silicate. Aqueous solution; dry the aqueous solution at a temperature of 105°C, and then naturally cool to room temperature after drying.

S4: Add 80g of surfactant composition (including 48.0g of SDBS and 32.0g of OP-10), 22.1g of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 9.4 to the glass reactor in sequence. g of 1-vinylimidazole, then add a certain amount of deionized water and stir to dissolve 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 1-vinylimidazole and mix evenly; after flowing nitrogen for 30 minutes, After the system is heated to 70°C, it is maintained at a constant temperature and reacts at this temperature for 30 minutes. After the reaction is completed, the remaining lipophilic monomer mixture (including 17.0g of isoprene and 10.4g of styrene) is added dropwise to the system, and stirring is continued for 30 minutes. A microemulsion was formed, and 1.0 g of azobisisobutyronitrile initiator was added to the microemulsion, and the system was heated to 75°C and reacted for 1 hour.

Comparative example 1

This comparative example provides a fluid loss reducer, which is prepared by a preparation method including the following specific steps:

S4: Add 80g of surfactant composition (including 64.0g of SDBS and 16.0g of BGF-10) into the glass reactor. After flowing nitrogen for 30 minutes, heat the system to 70°C and maintain a constant temperature and react at this temperature. 30 min. After the reaction is completed, the remaining lipophilic monomer mixture (including 17.0 g of isoprene and 10.4 g of styrene) is added dropwise to the system. Continue stirring for 30 min to form a microemulsion. Then add 1.0 g to the microemulsion. azobisisobutyronitrile initiator, and the system was heated to 75°C and reacted for 1 hour.

S6: Pour off the supernatant liquid in the system obtained in S5, then add deionized water to adjust the precipitate to a turbid liquid, place the turbid liquid in a spray dryer for drying, and dry to constant weight to obtain the above Fluid loss additive has a molecular weight of 20,000 and an average particle size of 100nm.

Comparative example 2

S4: Add 40g of surfactant composition (including 32.0g of SDBS and 8.0g of BGF-10), 22.1g of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 9.4g of 1-vinylimidazole, then add a certain amount of deionized water and stir to make the 4-vinylbenzenesulfonate Dissolve the acid-tetrabutyl quaternary phosphonium salt and 1-vinylimidazole and mix them evenly; after flowing nitrogen for 30 minutes, heat the system to 70°C and maintain a constant temperature and react at this temperature for 30 minutes. After the reaction is completed, the remaining residue is added dropwise to the system. of lipophilic monomer mixture (including 17.0g of isoprene and 10.4g of styrene), continue stirring for 30 minutes to form an emulsion, then add 1.0g of azobisisobutyronitrile initiator to the emulsion, and mix the system Raise the temperature to 75°C and react for 1 hour.

S6: Pour off the supernatant liquid in the system obtained in S5, then add deionized water to adjust the precipitate to a turbid liquid, place the turbid liquid in a spray dryer for drying, and dry to constant weight to obtain the above Fluid loss additive has a molecular weight of 40,000 and an average particle size of 220nm.

Comparative example 3

S4: Add 80g of surfactant composition (including 64.0g of SDBS and 16.0g of BGF-10), 22.1g of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 9.4 to the glass reactor. g of 1-vinylimidazole, then add a certain amount of deionized water and stir to dissolve 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 1-vinylimidazole and mix evenly; after flowing nitrogen for 30 minutes, After the system is heated to 70°C, maintain a constant temperature and react at this temperature for 30 minutes. After the reaction is completed, the remaining lipophilic monomer mixture (6.8g of isoprene and 26g of styrene) is added dropwise to the system, and stirring is continued for 30 minutes to form Microemulsion, then add 1.0g of azobisisobutyronitrile initiator to the microemulsion, heat the system to 75°C, and react for 1 hour.

S6: Pour off the supernatant liquid in the system obtained in S5, then add deionized water to adjust the precipitate to a turbid liquid, place the turbid liquid in a spray dryer for drying, and dry to constant weight to obtain the above Fluid loss additive has a molecular weight of 12,000 and an average particle size of 80nm.

Comparative example 4

S4: Add 80g of surfactant composition (including 64.0g of SDBS and 16.0g of BGF-10), 22.1g of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 9.4 to the glass reactor. g of 1-vinylimidazole, then add a certain amount of deionized water and stir to dissolve 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 1-vinylimidazole, and mix evenly. After 30 minutes of nitrogen, After the system is heated to 70°C, maintain a constant temperature and react at this temperature for 30 minutes. After the reaction is completed, the remaining lipophilic monomer mixture (including 12.9g of methyl acrylate and 10.4g of styrene) is added dropwise to the system, and the mixture is continued to stir for 30 minutes to form Microemulsion, then add 1.0g of azobisisobutyronitrile initiator to the microemulsion, heat the system to 75°C, and react for 1 hour.

S6: Pour off the supernatant liquid in the system obtained in S5, then add deionized water to adjust the precipitate to a turbid liquid, place the turbid liquid in a spray dryer for drying, and dry to constant weight to obtain the above Fluid loss additive has a molecular weight of 20,000 and an average particle size of 105nm.

Comparative example 5

S4: Add 80g of surfactant composition (including 64.0g of SDBS and 16.0g of BGF-10), 10.3g of sodium styrene sulfonate and 9.4g of 1-vinylimidazole into the glass reactor, and then Add a certain amount of deionized water and stir to dissolve 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 1-vinylimidazole and mix them evenly; after flowing nitrogen for 30 minutes, heat the system to 70°C and maintain constant temperature. React at this temperature for 30 minutes. After the reaction is completed, drop the remaining lipophilic monomer mixture (including 17.0g of isoprene and 10.4g of styrene) into the system, continue stirring for 30 minutes to form a microemulsion, and then add it to the microemulsion. Add 1.0g of azobisisobutyronitrile initiator to the emulsion, heat the system to 75°C, and react for 1 hour.

Comparative example 6

S2: Under stirring conditions, first add 14.8g of vinyltrimethoxy to the magnesium lithium silicate solution prepared in S1. Silane (A-171, purchased from Compton International Chemical Company, USA), then add acetic acid, adjust the pH value of the solution to 4-6, then add 3.2g of methanol and stir for 1 hour at a speed of 3000±100rpm. Vinyltrimethoxysilane and lithium magnesium silicate react fully to obtain a vinyltrimethoxysilane-modified magnesium lithium silicate aqueous solution; the aqueous solution is dried at a temperature of 105°C, and then naturally cooled to room temperature.

S4: Add 80g of surfactant composition (including 64.0g of SDBS and 16.0g of BGF-10) and 22.1g of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt into the glass reactor in sequence, and then Add a certain amount of deionized water and stir to dissolve the 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and mix evenly; after flowing nitrogen for 30 minutes, heat the system to 70°C, maintain a constant temperature, and react at this temperature for 30 minutes. , after the reaction is completed, the remaining lipophilic monomer mixture (including 17.0g of isoprene and 10.4g of styrene) is added dropwise to the system, and stirring is continued for 30 minutes to form a microemulsion, and then 1.0g of Azobisisobutyronitrile initiator was used, and the system was heated to 75°C and reacted for 1 hour.

Comparative example 7

This comparative example provides an ultra-high temperature resistant fluid loss agent, which is prepared by a preparation method including the following specific steps:

S4: Add 80g of surfactant composition (including 48.0g of SDBS and 32.0g of OP-10), 22.1g of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 9.4 to the glass reactor in sequence. g of 1-vinylimidazole, then add a certain amount of deionized water and stir to dissolve 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 1-vinylimidazole and mix evenly; after flowing nitrogen for 30 minutes, After the system is heated to 70°C, it is maintained at a constant temperature and reacts at this temperature for 30 minutes. After the reaction is completed, the remaining lipophilic monomer mixture (including 17.0g of isoprene and 10.4g of styrene) is added dropwise to the system, and stirring is continued for 30 minutes. A microemulsion was formed; then 0.1g of azobisisobutyronitrile initiator was added to the microemulsion, and the system was heated to 75°C and reacted for 1 hour.

S6: Pour off the supernatant liquid in the system obtained in S5, and then add deionized water to adjust the precipitate to a turbid liquid. Place the turbid liquid in a spray dryer for drying. After drying to constant weight, the anti-supernatant is obtained. The high-temperature fluid loss additive has a molecular weight of 120,000 and an average particle size of 280nm.

Comparative example 8

S4: Add 80g of surfactant composition (including 48.0g of SDBS and 32.0g of OP-10), 44.2g of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 18.8 g of tetrabutyl quaternary phosphine salt into the glass reactor in sequence. g of 1-vinylimidazole, then add a certain amount of deionized water and stir to dissolve 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 1-vinylimidazole and mix evenly; after flowing nitrogen for 30 minutes, After the system is heated to 70°C, maintain a constant temperature and react at this temperature for 30 minutes. After the reaction is completed, the remaining lipophilic monomer mixture (including 17.0g of isoprene and 10.4g of styrene) is added dropwise to the system and continues. Stir for 30 minutes to form a microemulsion; then add 1.0g of azobisisobutyronitrile initiator to the microemulsion, heat the system to 75°C, and react for 1 hour.

S6: Pour off the supernatant liquid in the system obtained in S5, and then add deionized water to adjust the precipitate to a turbid liquid. Place the turbid liquid in a spray dryer for drying. After drying to constant weight, the anti-supernatant is obtained. The high-temperature fluid loss additive has a molecular weight of 20,000 and an average particle size of 106nm.

Test example 1

This test example tests the fluid loss reducing performance, temperature resistance, etc. of the ultra-high temperature resistant fluid loss agents provided in Examples 1 to 5 and the fluid loss reducing agents provided in Comparative Examples 1 to 8. The above test includes the following specific steps:

1) Sample slurry preparation:

Preparation of base slurry: Take 240mL of 3# white oil, add 21.0g of emulsifier-modified rosinate (CQ-NT) for oil-based drilling fluids, and 9.0g of co-emulsifier low-molecular polymer for oil-based drilling fluids. Amide (CQ-GC), stir at a high speed of 11000r/min for 20 minutes, then add the oil-based drilling fluid viscosity stabilizer modified silicate (CQNZC-Ⅱ) and stir at a high speed for 10 minutes. Under high-speed stirring conditions, slowly add 60mL Calcium chloride brine with a mass fraction of 25.0%, stir at high speed for 20 minutes after adding, then add 12.0g of calcium oxide, stir at high speed for 30 minutes, then add 3.0g of oil-based drilling fluid sealing agent YX-40, 3.0 g of oil-based drilling fluid sealing agent YX-120. After adding, stir at high speed for 10 minutes. Then add 388 g of barite and stir at high speed for 30 minutes to obtain the base slurry.

Among them, the 3# white oil is the 3# white oil taken from the Changning block in Sichuan Province;

The emulsifier-modified rosinate (CQ-NT) used in oil-based drilling fluids was obtained from Chuanqing Drilling and Production Engineering Technology Research Institute;

The co-emulsifier low molecular polyamide (CQ-GC) used in oil-based drilling fluids was obtained from Chuanqing Drilling and Drilling Engineering Technology Research Institute;

The oil-based drilling fluid viscosity-increasing stabilizer modified silicate (CQNZC-Ⅱ) was obtained from Chuanqing Drilling and Drilling Engineering Technology Research Institute;

The calcium chloride used is of analytical grade;

The sealing agent YX-40 for oil-based drilling fluid was obtained from Chuanqing Drilling and Production Engineering Technology Research Institute;

The sealing agent YX-120 for oil-based drilling fluid was obtained from Chuanqing Drilling and Production Engineering Technology Research Institute;

Barite was obtained from Chuanqing Drilling and Mining Engineering Technology Research Institute.

Preparation of sample slurry: Add the target mass of fluid loss agent to 300 mL of base slurry according to the design proportion shown in Table 1 below, and stir at high speed for 10 minutes to obtain the sample slurry.

Wherein, the fluid loss agents are the ultra-high temperature resistant fluid loss agents provided in Examples 1 to 5 and the comparative fluid loss agents respectively. Example 1 - The fluid loss agent provided in Comparative Example 8 and the commercially available fluid loss agent. The commercially available fluid loss agent includes commercially available fluid loss agent No. 1, commercially available fluid loss agent No. 2, and commercially available fluid loss agent No. 2. Fluid loss agent No. 3 and commercially available ordinary oxidized asphalt;

Among them, the commercially available fluid loss agent No. 1 is an asphalt fluid loss agent produced by a manufacturer in Chengdu, and the commercially available fluid loss agent No. 2 is a humic acid-modified fluid loss agent produced by a manufacturer in Hubei. Fluid loss agent No. 3 is a polymer fluid loss agent produced by a manufacturer in Shandong and the parameters of ordinary oxidized asphalt on the market are as follows: the softening point of the asphalt is 180-220°C, and the weight content of toluene insoluble matter is 25-35%. The weight content of quinoline insoluble matter is 10-12%, the coking value is 30-50%, and the volatile content is 45%-55%.

2) Test methods and experimental results obtained:

Put the sample slurry prepared above into a roller furnace respectively, roll it for 16 hours at a temperature of (260±2)°C, take it out to cool, open the can, and observe the water and oil precipitation of the sample slurry in the aging tank. Situation: Pour out the upper chromatographic liquid, measure the volume of the chromatographic liquid with a measuring cylinder, pour the upper chromatographic liquid and the lower slurry back into the high stirring cup, stir for 20 minutes at high speed, then pour it into the thermostatic cup, according to GB/T 16783.2 According to the regulations in -2012, the AV, PV, YP value, ES value of the sample slurry at (50±1)℃ and the HTHP filter loss value at the temperature of 220℃ were measured. The test results obtained are shown in Table 1 below. .

Table 1 Performance comparison of different fluid loss additives after aging at 260°C in white oil-based drilling fluids

Note: The asphalt in Table 1 is commercially available ordinary oxidized asphalt.

The percentage content in Table 1 is the mass-to-volume ratio, which is calculated based on the total volume of the base slurry. For example: add 24g of asphalt to 300mL of base slurry. At this time, the amount of asphalt added is 8%.

As can be seen from Table 1 above, the ultra-high temperature resistant fluid loss agent provided by the embodiment of the present invention has a temperature resistance of up to 260°C in oil-based drilling fluids, and the ultra-high temperature resistant fluid loss agent product has the ability to The rheology of oil-based drilling fluid has little impact, and its own fluid loss reducing effect is outstanding. It has good compatibility with fluid loss reducing agents for oil-based drilling fluids such as asphalt, humic acid, and conventional polymers, and has strong synergistic effect. It can also significantly improve the characteristics of oil-based drilling fluid such as demulsification voltage.

Comparing the data of Example 1 and Example 2 shown in Table 1 and combining Example 1 and Example 2, it can be seen that for silane coupling agents containing alkenyl groups, whether vinylmethoxysilane or vinylethylene is used, Oxysilane, the ultra-high temperature resistant fluid loss additives prepared have good fluid loss effects, with very little difference, which shows that the coupling of alkenyl-containing silane The type of agent has little impact on the performance of the produced ultra-high temperature resistant fluid loss reducer product.

Comparing the data of Example 2 to Example 4 and Comparative Example 7 shown in Table 1 and combining the data of Example 2 to Example 4 and Comparative Example 7, it can be seen that the amount of initiator added will significantly affect the filtration reduction against ultra-high temperature. The fluid loss reduction effect of loss agent products. If the amount of initiator is small, the polymer chain in the product will be longer, which will make the product thicker. The increase in molecular weight within a certain range will help reduce the filter loss of the product; on the contrary, if the amount of initiator is large, the product will have a thickening effect. There are many active points for the reaction, which in turn shortens the polymer chain in the product and reduces the viscosity-increasing effect. At the current addition amount, compare the ultra-high temperature resistant fluid loss agent provided in Example 3 and the fluid loss agent provided in Example 2 and Example 4. Although the fluid loss of the ultra-high temperature resistant fluid loss reducer has increased, the increase is not obvious. Comparing Examples 2 to 4 and 7, it can be seen that when the usage amount of the initiator is greatly reduced, the molecular weight of the product increases and the particle size becomes larger. As a result, the fluid loss agent product increases. The viscosity effect is obvious, and the filtration loss increases instead. Analysis suggests that this may be due to the increase in product particle size, which makes the system particle size gradation unreasonable.

Comparing the data of Example 1 and Comparative Example 1 shown in Table 1 and combining Example 1 and Comparative Example 1, it can be seen that the fluid loss agent prepared when no hydrophilic monomer is used in the preparation of the fluid loss agent has a As the fluid loss increases, the product's effect on improving the emulsion stability of oil-based drilling fluids is significantly reduced. Analysis shows that compared with Example 1, only hydrophobic monomers were used to prepare the fluid loss agent in Comparative Example 1, and the hydrophilic property of the obtained fluid loss agent product was significantly reduced. At this time, the fluid loss reducer in oil-based drilling fluid is more dispersed in the oil phase, and the adsorption amount at the emulsion interface is reduced, so its stabilizing effect on the emulsion as a solid particle is reduced. On the contrary, the presence of appropriate amounts of hydrophilic monomers, namely 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 1-vinylimidazole, enables the product to be adsorbed at the oil-water interface, and its stabilizing effect on the emulsion is enhanced. ; In addition, the styrene monomer used has a benzene ring, which increases the rigidity of the resulting polymer chain, thereby improving the product's temperature resistance.

Comparing the data of Example 1 and Comparative Example 2 shown in Table 1 and combining Example 1 and Comparative Example 2, it can be seen that when the amount of emulsifier added is insufficient, the fluid loss of the obtained fluid loss reducer becomes significantly larger. And during the actual reaction, the translucency and transparency of the microemulsion did not appear. The analysis may be because the amount of emulsifier added is insufficient to form a microemulsion system, but only an ordinary emulsion system. The droplet size in the ordinary emulsion system is larger than the droplet size in the microemulsion, thus forming a product The particle size will also increase accordingly, losing the nano-blocking effect. At the same time, the polymer chain will also become longer, affecting the viscosity effect of the product.

Comparing the data of Example 1 and Comparative Example 3 shown in Table 1 and combining Example 1 and Comparative Example 3, it can be seen that compared with Example 1, the proportion of the lipophilic monomer used in Comparative Example 3 has changed significantly. Afterwards, the fluid loss reducing and plugging ability of the resulting product decreases. Analysis shows that in Comparative Example 3, the proportion of isoprene decreases and the proportion of styrene increases significantly. Although the rigidity of the product is improved and the temperature resistance of the product is improved, due to the addition of styrene containing benzene rings, the If the amount is too large, the steric hindrance in the reaction system will also increase, the polymerization reaction will be hindered, and the polymer will actually participate in the reaction to form polymerization. The monomers in the material chain are less than the theoretical ones, and the molecular weight of the product becomes smaller, which makes the product's filter loss reduction effect at high temperatures weaker.

Comparing the data of Example 1 and Comparative Example 4 shown in Table 1 and combining Example 1 and Comparative Example 4, it can be seen that in Comparative Example 4, the isoprene monomer used in Example 1 is replaced with an acrylate monomer. , the fluid loss of the resulting product becomes larger, and the fluid loss reduction effect is weakened. Analysis suggests that the main reason is that acrylate has insufficient temperature resistance and decomposes under high temperature conditions of 260°C.

Comparing the data of Example 1 and Comparative Example 5 shown in Table 1 and combining Example 1 and Comparative Example 5, it can be seen that in Comparative Example 5, the 4-vinylbenzenesulfonic acid-tetrabutyl quaternary acid used in Example 1 is used. The phosphonate salt monomer was replaced by sodium styrene sulfonate, and the filter loss of the resulting product increased. Analysis suggests that the reason may be: the 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphonium salt monomer used in Example 1 contains a quaternary phosphonium salt structure, which enhances the polarity and adsorption capacity of the obtained product, helping to improve The adsorption capacity of the product on clay and barite, in turn, helps to reduce the filter loss of the product.

Comparing the data of Example 1 and Comparative Example 6 shown in Table 1 and combining Example 1 and Comparative Example 6, it can be seen that compared with Example 1, Comparative Example 6 does not use 1-vinylimidazole monomer, and the resulting product The filter loss increases. Analysis suggests that the reason is: In Example 1, 1-vinylimidazole monomer is used to prepare the fluid loss agent. The introduction of the 1-vinylimidazole structure increases the rigidity of the product on the one hand, and improves the adsorption capacity of the product on the other. When 1-vinylimidazole monomer is not used in Comparative Example 6, the high-temperature adsorption resistance of the resulting product is reduced, so the filter loss is increased.

Comparing the data of Example 2 and Comparative Example 8 shown in Table 1 and combining Example 2 and Comparative Example 8, it can be seen that when the monomer ratio exceeds a certain range, the molecular weight of the product does not change significantly, and the particle size does not change significantly. , but the fluid loss of the fluid loss reducer product increases. Analysis suggests that this should be caused by the unreasonable ratio between the lipophilic monomer and the hydrophilic monomer used in the preparation of the fluid loss reducer in Comparative Example 8. The hydrophilic and lipophilic properties of the product have changed. Specifically, the hydrophilicity of the product has increased and the lipophilicity has decreased.

It can be known from the above experimental results that there is a synergistic effect between the monomer components used in the present invention to prepare the ultra-high temperature resistant fluid loss agent, and a certain monomer component is missing or the monomer component is replaced. Other monomer components commonly used in the cost field are used to prepare fluid loss agents. The fluid loss properties, high temperature resistance and other properties of the prepared fluid loss agents are inferior to the corresponding properties of the fluid loss agent provided by the present invention. .

The above are only specific embodiments of the present invention and cannot be used to limit the scope of the invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the patent protection scope of the present invention, should still be covered by this patent. category. In addition, the technical features in the present invention can be freely combined with each other, between technical features and technical inventions, and between technical inventions and technical inventions.

Claims

An anti-ultra-high temperature fluid loss agent, wherein the anti-ultra-high temperature fluid loss agent first reacts lithium magnesium silicate with a silane coupling agent containing an alkenyl group to generate a modified silane containing an alkenyl group. lithium magnesium silicate, and then the alkenyl-containing silane-modified lithium magnesium silicate is reacted with isoprene, 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt, styrene and vinylimidazole Obtained from copolymerization reaction.
The ultra-high temperature resistant fluid loss agent according to claim 1, wherein the ultra-high temperature resistant fluid loss agent is prepared by a preparation method including the following steps:

S1: Add 19.5-58.6 parts by weight of lithium magnesium silicate to 1000 parts by weight of deionized water to obtain a dispersion of magnesium lithium silicate, and then allow the said dispersion of magnesium lithium silicate to stand and hydrate;

S2: Under stirring conditions, add 14.8-28.0 parts by weight of the alkenyl-containing silane coupling agent to the solution obtained in S1, then adjust the pH value of the system to 4-6, and let the alkenyl-containing silane coupling agent Fully react with lithium magnesium silicate to obtain a silane-modified aqueous solution of magnesium lithium silicate containing alkenyl groups, and then dry the aqueous solution and then cool it naturally;

S3: Add the alkenyl-containing silane-modified lithium magnesium silicate obtained in S2 to 500 parts by weight of deionized water and mix it evenly, and then heat the system temperature to 40-50°C by heating in a water bath;

S4: Add 60-80 parts by weight of surfactant, 22.1-44.2 parts by weight of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 4.7-22.2 parts by weight of vinylimidazole to the solution obtained in S3. And fully dissolve 4-vinyl benzene sulfonic acid-tetrabutyl quaternary phosphine salt and vinyl imidazole; then react the resulting solution in the absence of oxygen at a constant temperature of 70-75°C for 30-40 minutes; after the reaction is completed, add to the obtained solution Add 13.6-20.4 parts by weight of isoprene and 5.2-15.6 parts by weight of styrene to the solution to form a microemulsion; then add 0.5-1.5 parts by weight of an oil-soluble initiator to the microemulsion and heat it to 75 The reaction is carried out at ±2°C for 1-3 hours, and after the reaction is completed, the ultra-high temperature resistant fluid loss agent is obtained.
The ultra-high temperature resistant fluid loss agent according to claim 2, wherein the preparation method further includes:

S5: Dry the polymer emulsion obtained in S4, add the dried product to an aqueous solution containing ethanol to adjust it into a turbid liquid, stir the turbid liquid and let it stand to allow the solid phase to fully precipitate. ;

S6: Pour off the supernatant liquid in the system obtained in S5, add deionized water to adjust the precipitate to a turbid liquid, and then dry the turbid liquid to a constant weight to obtain the ultra-high temperature resistant fluid loss agent. .
The ultra-high temperature resistant fluid loss agent according to any one of claims 1 to 3, wherein the alkenyl-containing silane coupling agent includes a vinyl, propenyl or allyl-containing silane coupling agent;

Preferably, the alkenyl-containing silane coupling agent includes vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris(2-methoxyethoxy)silane, vinylmethyldimethyl One or a combination of several oxysilanes.
The ultra-high temperature resistant fluid loss agent according to any one of claims 1 to 3, wherein the magnesium lithium silicate is sodium Rice flake structure, particle size is 30-70nm, thickness is 5-15nm.
The ultra-high temperature resistant fluid loss agent according to any one of claims 1 to 3, wherein the vinylimidazole includes one of 1-vinylimidazole and vinylimidazole having the structure shown in the following formula I or a combination of several;

In formula I, R 2 includes methyl, ethyl, n-propyl, isopropyl or butyl, and X - includes tetrafluoroborate, chloride ion or bromide ion;

Preferably, the vinylimidazole includes 1-vinyl-3-ethylimidazole tetrafluoroborate, 1-vinyl-3-ethylimidazole bromide, 1-vinylimidazole and 1-vinyl-3 -One or a combination of several butylimidazole chloride salts.
The ultra-high temperature resistant fluid loss agent according to any one of claims 1 to 3, wherein the molar ratio between lithium magnesium silicate and the alkenyl-containing silane coupling agent is 1:1, wherein the magnesium silicate The molecular weight of lithium is 361g/mol.
The ultra-high temperature resistant fluid loss agent according to any one of claims 1 to 3, wherein the alkenyl-containing silane coupling agent, isoprene, styrene, 4-vinylbenzenesulfonic acid-tetrabutyl The molar ratio between quaternary phosphonium salt and vinylimidazole is 2:5:2:1:2.
The ultra-high temperature resistant fluid loss agent according to claim 2 or 3, wherein the surfactant includes sodium dodecyl benzene sulfonate, sodium lauryl sulfate, octylphenol polyoxyethylene ether and A combination of any two of cardanol polyoxyethylene ethers.
The ultra-high temperature resistant fluid loss agent according to claim 9, wherein the surfactant includes sodium dodecyl benzene sulfonate and octylphenol polyoxyethylene ether, and the mass ratio of the two is 3:2. , or sodium dodecyl sulfate and octylphenol polyoxyethylene ether, the mass ratio of the two is 7:3, or sodium dodecylbenzene sulfonate and cardanol polyoxyethylene ether, the mass ratio of the two is 4:1.
The ultra-high temperature resistant fluid loss agent according to claim 2 or 3, wherein the oil-soluble initiator includes azobisisobutyronitrile, azobisisoheptanitrile, azobisisovaleronitrile or azobisisobutyronitrile. Any of dicyclohexylcarbonitrile.
The ultra-high temperature resistant fluid loss agent according to any one of claims 1 to 3, wherein the molecular weight of the ultra-high temperature resistant fluid loss agent is 10,000-50,000.
The ultra-high temperature resistant fluid loss agent according to any one of claims 1 to 3, wherein the ultra-high temperature resistant fluid loss agent The average particle size of the fluid loss agent is 50-150 nm, preferably 70-100 nm.
The preparation method of the ultra-high temperature resistant fluid loss agent according to any one of claims 1 to 13, wherein the preparation method includes:

First, lithium magnesium silicate is reacted with a silane coupling agent containing an alkenyl group to generate a silane-modified lithium magnesium silicate containing an alkenyl group, and then the silane-modified lithium magnesium silicate containing an alkenyl group is reacted with a different Pentadiene, 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt, styrene and vinylimidazole are copolymerized, and after the reaction is completed, the ultra-high temperature resistant fluid loss agent is obtained.
The preparation method according to claim 14, wherein the preparation method specifically includes:

S1: Add 19.5-58.6 parts by weight of lithium magnesium silicate to 1000 parts by weight of deionized water to obtain a dispersion of magnesium lithium silicate, and then allow the said dispersion of magnesium lithium silicate to stand and hydrate;

S2: Under stirring conditions, add 14.8-28.0 parts by weight of the alkenyl-containing silane coupling agent to the solution obtained in S1, then adjust the pH value of the system to 4-6, and let the alkenyl-containing silane coupling agent Fully react with lithium magnesium silicate to obtain a silane-modified aqueous solution of magnesium lithium silicate containing alkenyl groups, and then dry the aqueous solution and then cool it naturally;

S3: Add the alkenyl-containing silane-modified lithium magnesium silicate obtained in S2 to 500 parts by weight of deionized water and mix it evenly, and then heat the system temperature to 40-50°C by heating in a water bath;

S4: Add 60-80 parts by weight of surfactant, 22.1-44.2 parts by weight of 4-vinylbenzenesulfonic acid-tetrabutyl quaternary phosphine salt and 4.7-22.2 parts by weight of vinylimidazole to the solution obtained in S3. And fully dissolve 4-vinyl benzene sulfonic acid-tetrabutyl quaternary phosphine salt and vinyl imidazole; then react the resulting solution in the absence of oxygen at a constant temperature of 70-75°C for 30-40 minutes; after the reaction is completed, add to the obtained solution Add 13.6-20.4 parts by weight of isoprene and 5.2-15.6 parts by weight of styrene to the solution to form a microemulsion; then add 0.5-1.5 parts by weight of an oil-soluble initiator to the microemulsion and heat it to 75 The reaction is carried out at ±2°C for 1-3 hours, and after the reaction is completed, the ultra-high temperature resistant fluid loss agent is obtained.
The preparation method according to claim 15, wherein the preparation method further includes:

S5: Dry the polymer emulsion obtained in S4, add the dried product to an aqueous solution containing ethanol to adjust it into a turbid liquid, stir the turbid liquid and let it stand to allow the solid phase to fully precipitate. ;

S6: Pour off the supernatant liquid in the system obtained in S5, add deionized water to adjust the precipitate to a turbid liquid, and then dry the turbid liquid to a constant weight to obtain the ultra-high temperature resistant fluid loss agent. .
The preparation method according to claim 15 or 16, wherein the preparation method further includes:

In S2, after adjusting the pH value of the system to 4-6, add the alcohol solvent produced when the alkenyl-containing silane coupling agent is hydrolyzed into the system, so that the alkenyl-containing silane coupling agent and silicic acid Magnesium and lithium react fully; wherein, the addition amount of the alcohol solvent is 3-30%.
An oil-based drilling fluid, wherein the oil-based drilling fluid contains the ultra-high temperature resistant fluid loss agent according to any one of claims 1 to 13.
The oil-based drilling fluid according to claim 18, wherein the added amount of the ultra-high temperature resistant fluid loss agent is 1-3%.
An oilfield drilling method, wherein the oilfield drilling method is implemented using the oil-based drilling fluid according to claim 18 or 19.