Low-temperature fast-curing slow-release solid tracer and preparation method thereof

Abstract

The invention discloses a low-temperature fast-curing slow-release solid tracer and a preparation method thereof, and belongs to the technical field of oil and gas field tracing. The sustained-release solid tracer comprises the following raw materials in percentage by mass: 30-80% of bisphenol A epoxy resin, 5-60% of a tracer, 5-20% of a curing agent, 0-10% of a catalyst and 0.5-15% of a diluent. The low-boiling-point tracer agent is coated in a cured material of epoxy resin, so that loss caused by intensified evaporation of the tracer agent due to high curing reaction temperature and too long curing time is avoided, and the tracer agent in a solid tracer agent product is ensured to reach an expected effective concentration. The preparation method is simple to operate, mild in process condition, short in curing time, high in production efficiency and easy to realize large-scale production.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field tracing, and in particular relates to a low-temperature fast-curing sustained-release solid tracer and a preparation method thereof. Background Art

[0002] Tracer technology is a technology that injects tracers from injection wells, produces them from production wells, and determines reservoir parameters based on information such as the concentration of the injected and produced tracers. With the development of tertiary oil recovery technology, inter-well tracer technology has been widely used in oil and gas field production sites. Since this technology can accurately provide the flow direction and flow characteristics of the injected fluid, and then determine the heterogeneous characteristics of the inter-well oil layer, it has become a recognized reservoir engineering method.

[0003] In order to improve the on-site construction performance and extend the effective action time of the tracer in the well, more applications are to add the active ingredients of the tracer into epoxy resin, and solidify and shape it after the epoxy resin and curing agent react chemically. This type of solid tracer has good sustained release performance and the theoretical action time in the well can reach half a year or even longer, thereby reducing the construction workload and reducing the overall cost.

[0004] The epoxy resin curing reaction generally needs to be at a certain temperature to occur, and the curing reaction process is usually accompanied by heat release. Some oil phase tracers (such as perfluorobutyl ethyl acrylate) or gas phase tracers (such as perfluoropentane, perfluorohexane, perfluorocyclohexane, perfluoromethylcyclopentane, etc.) commonly used in production sites have very low boiling points (below 60°C). The market price of this type of tracer per kilogram is generally several thousand to tens of thousands of yuan. If the temperature of the curing reaction is too high, the tracer will evaporate, so the effective component of the tracer cannot be completely coated in the epoxy resin, which ultimately leads to the tracer content in the cured product not reaching the expected concentration, and the expensive tracer raw materials are wasted. Therefore, the difficulty of the curing process of this type of low-boiling point tracer is how to quickly complete the curing reaction at a temperature below room temperature, so that the effective component of the tracer is quickly coated in the epoxy resin cured product, avoiding the evaporation loss of the tracer due to the high curing temperature.

[0005] At present, most of the sustained-release long-acting resin-type solid tracers use bisphenol A epoxy resin with good heat resistance as the base, and obtain solid tracers through curing reaction. However, these curing processes or methods list a large number of tracers and curing agents, but do not optimize the boiling point characteristics of the tracers, resulting in the temperature of the curing reaction in actual production being higher than the boiling point of the tracer, causing the loss of expensive tracers. For example, the Chinese patent "A sustained-release long-acting tracer and its preparation method" (publication number: CN 113653486A) with application number 202111034040.4 mentions that Example 1 is cured at 80°C for 2h, Example 2 is cured at 65°C for 4h, Example 3 is cured at 100°C for 2h, Example 4 is cured at 80°C for 3h, and so on. Obviously, the method of the prior art is not suitable for the curing of low-boiling point tracers, and there are no other reports or patents specifically for the curing process of low-boiling point tracers. Summary of the invention

[0006] The purpose of the present application is to overcome at least one of the shortcomings of the prior art. To this end, the first aspect of the present application provides a slow-release solid tracer that solidifies rapidly at low temperature (30° C. or below).

[0007] The second aspect of the present application provides a method for preparing the sustained-release solid tracer.

[0008] The technical solution adopted in this application is:

[0009] According to the first aspect of the present application, a sustained-release tracer is provided, comprising the following raw materials in percentage by mass: 30%-80% bisphenol A epoxy resin, 5%-60% tracer, 5%-20% curing agent, 0%-10% catalyst, and 0.5%-15% diluent, wherein the curing agent is one of polythiol and polyisocyanate, and the tracer is one or more of perfluorobutyl ethyl acrylate, perfluoropentane, perfluorohexane, perfluorocyclopentane, perfluorocyclohexane, and perfluoromethylcyclopentane.

[0010] In some embodiments, the bisphenol A epoxy resin is selected from at least one of the bisphenol A epoxy resins with models of E-54, E-51, E-44, E-42, E-35, E-31, E-20, E-14, E-12, E-10, and E-06.

[0011] In some embodiments, when the bisphenol A epoxy resin is a type of bisphenol A epoxy resin, the type is selected from E-54, E-51, E-44, E-42, E-35, and E-31.

[0012] In some of the embodiments, when the bisphenol A epoxy resin is a mixture of two, three, four or five types of bisphenol A epoxy resins, based on the mass of the mixture as 100%, the sum of the masses of the bisphenol A epoxy resins selected from the types E-54, E-51, E-44, E-42, E-35 and / or E-31 accounts for greater than or equal to 25% (≥25%) of the mass of the mixture; the rest are selected from the types E-20, E-14, E-12, E-10 and / or E-06 bisphenol A epoxy resins.

[0013] In some of the embodiments, when the curing agent is polythiol, a catalyst needs to be added, and the catalyst is at least one of a linear tertiary amine, pyridine, and 2-(dimethylaminomethyl)phenol.

[0014] In some embodiments, when the curing agent is polyisocyanate, no catalyst needs to be added, and the mass percentage of the catalyst in the sustained-release solid tracer is 0%.

[0015] In some embodiments, the diluent is one or more of dibutyl phthalate, dioctyl phthalate, acetone, turpentine, xylene, ethanol, toluene, furfuryl alcohol, and ethyl acetate.

[0016] In some preferred embodiments, a sustained-release tracer comprises the following raw materials in percentage by mass: 50%-80% bisphenol A epoxy resin, 8%-40% tracer, 8.5%-15% curing agent, 0%-5% catalyst, and 0.5%-10% diluent.

[0017] According to the second aspect of the present application, a method for preparing a sustained-release solid tracer is provided, comprising the following steps:

[0018] (1) weighing the raw materials according to any of the above items,

[0019] (2) adding a diluent to the bisphenol A epoxy resin, stirring at a speed of 200 rpm to 500 rpm for 10 to 30 min to uniformly mix the bisphenol A epoxy resin and the diluent to obtain slurry A;

[0020] (3) adding a tracer to slurry A and stirring the mixture to obtain slurry B;

[0021] (4) Add a catalyst to slurry B, and then add a curing agent, and stir rapidly at a temperature not higher than 30°C (30°C or below) to allow the catalyst and curing agent to be evenly mixed in slurry B. Continue to stand at a temperature not higher than 30°C to allow the slurry to undergo a curing reaction. When the slurry is completely hardened, a solid tracer is obtained.

[0022] Among them, RPM is the abbreviation of revolutions per minute, which represents the number of times the device rotates per minute.

[0023] In some of the embodiments, when the bisphenol A epoxy resin is selected from bisphenol A epoxy resins with models of E-20, E-14, E-12, E-10 and / or E-06, the bisphenol A epoxy resin is solid at room temperature and needs to be heated and softened before adding a diluent.

[0024] In some preferred embodiments, the heating and softening is heating to 65-110° C. and softening for 8-15 min.

[0025] In some of the embodiments, when the bisphenol A epoxy resin is selected from bisphenol A epoxy resins with models of E-54, E-51, E-44, E-42, E-35 and / or E-31, the bisphenol A epoxy resin is liquid at room temperature and the diluent is directly added.

[0026] In some embodiments, steps (1), (2), (3) of the reaction are carried out at room temperature, which is usually in the range of 10-30°C.

[0027] The beneficial effects of the embodiments of the present application are:

[0028] The sustained-release solid tracer of the present application is a solid tracer with bisphenol A epoxy resin as the sustained-release matrix, and the effective component is a low-boiling-point tracer such as perfluorobutyl ethyl acrylate, perfluoropentane, perfluorohexane, perfluorocyclopentane, perfluorocyclohexane, and perfluoromethylcyclopentane. By optimizing the curing agent and the catalyst, the distribution ratio of each component of the system is adjusted to make the curing temperature low and the time short, and the effective concentration retention rate of the tracer component in the obtained sustained-release solid tracer is high. As in Example 5, the content of the initially added tracer is 30%, and the tracer content in the obtained sustained-release solid tracer is 29.6%.

[0029] The present application provides a low-temperature curing method (process) for low-boiling oil phase or gas phase tracers for oil and gas fields. Through this preparation method, the curing reaction of epoxy resin can be quickly completed at a condition not higher than 30°C, which is conducive to the low-boiling point tracer being coated in the cured product of epoxy resin, avoiding the loss caused by the evaporation of the tracer due to the high curing reaction temperature and too long curing time, thereby ensuring that the tracer in the solid tracer product reaches the expected effective concentration. The preparation method is simple to operate, has mild process conditions, short curing time, high production efficiency, and is easy to achieve large-scale production.

[0030] The technical solution of the present application can prepare solid tracers in various shapes such as strips, blocks, and rods. It has mild process conditions, low equipment requirements, high production efficiency, and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1This is a comparison chart of curing time of Examples 1-9 of the present application when cured at 25°C.

[0032] Figure 2 The following is a comparison chart of the curing temperature, curing time and tracer component content in the cured product of Examples 3 to 6 of the present application and Comparative Examples 1 to 4. The tracer component content in the cured product is calculated by thermogravimetric analysis. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application is clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Therefore, the following detailed description of the embodiments of the present application is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0034] The terms "including" and "having" and any variations thereof of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, device, product or equipment comprising a series of steps is not limited to the listed steps or modules, but may optionally include steps not listed, or may optionally include other steps inherent to these processes, methods, products or equipment.

[0035] In the present invention, the term "multiple" refers to two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0036] It is well known to those skilled in the art of epoxy resin that epoxy curing is classified into four conditions: 1) low temperature curing: 30°C or below; 2) room temperature curing: 30-50°C; 3) medium temperature curing: 50-100°C; 4) high temperature curing: 100°C or above. The technical solution of this application is a slow-release solid tracer cured at low temperature (30°C or below) and its preparation method and application.

[0037] A sustained-release (long-acting) solid tracer (composite material), comprising a polymer matrix (having a three-dimensional network structure) and a tracer coated therein, wherein the polymer matrix is ​​obtained by a curing reaction of a bisphenol A epoxy resin, a diluent, and a curing agent under a catalyst or without a catalyst at a low temperature (30°C or below).

[0038] The sustained-release solid tracer (composite material) comprises the following raw materials in percentage by mass: 30%-80% of bisphenol-A epoxy resin, 5%-60% of tracer, 5%-20% of curing agent, 0%-10% of catalyst, and 0.5%-15% of diluent, wherein the curing agent is one of polythiol and polyisocyanate.

[0039] The function of the curing agent is to react with the epoxy resin to form a three-dimensional cross-linked network structure, generate a polymer, that is, to cure and obtain a cured product. There are many types of curing agents, and the properties vary greatly. This application requires that the curing reaction be initiated at no more than 30°C and the reaction be completed quickly, and there are fewer curing agents that can achieve this effect. In addition, it is necessary to consider that the curing agent itself cannot react with the low-boiling point tracers involved, and there are even fewer curing agents that can meet the requirements. For example, the inventor used diethylenetriamine, triethylenetetramine, tetraethylenepentamine and other fatty amine curing agents to react with epoxy resin. Due to the severe heat release of the curing reaction, the low-boiling point tracer in the slurry evaporated, and a large amount of white smoke appeared during the stirring of the slurry. The loss rate of the tracer effective component in the formed epoxy cured product reached up to 93%. After a large number of experiments, the inventor finally confirmed that polythiols and polyisocyanates were the curing agents that met the conditions and had the best effect.

[0040] The tracer of the present application is one or more of perfluorobutyl ethyl acrylate, perfluoropentane, perfluorohexane, perfluorocyclopentane, perfluorocyclohexane, and perfluoromethylcyclopentane. The tracer is a low boiling point tracer and does not react with the other four components. After the bisphenol A type epoxy resin reacts with the curing agent and other components, the epoxy resin forms a three-dimensional network structure, which has many pores. The tracer component is embedded in the pores to form a slow-release long-acting solid tracer.

[0041] In some embodiments, the bisphenol-A epoxy resin is selected from at least one of the bisphenol-A epoxy resins with models of E-54, E-51, E-44, E-42, E-35, E-31, E-20, E-14, E-12, E-10, and E-06.

[0042] The model numbers mentioned above are all national standard numbers for bisphenol A epoxy resin. For details, please refer to "Bisphenol A Epoxy Resin", standard number is GB / T 13657-2011.

[0043] Epoxy resin refers to resin compounds that contain at least two reactive epoxy groups in the molecule. After curing, epoxy resin has many outstanding excellent properties, such as strong adhesion to various materials, especially metals, strong chemical corrosion resistance, high mechanical strength, good electrical insulation, corrosion resistance, etc. In addition, epoxy resin can be cured in a fairly wide temperature range, and the volume shrinkage is small during curing.

[0044] Bisphenol A epoxy resin is the most widely used and produced type of epoxy resin because of its high transparency. It is produced by the reaction of bisphenol A and epichlorohydrin in the presence of sodium hydroxide. According to the relative molecular weight, bisphenol A epoxy resin can be divided into various types.

[0045] The bisphenol A epoxy resin types and epoxy values ​​mentioned in this application are shown in Table 1.

[0046] Table 1

[0047] Domestic models Epoxy value / (eq / 100g) E-54 0.52-0.56 E-51 0.48-0.54 E-44 0.41-0.47 E-42 0.38-0.45 E-35 0.30-0.40 E-31 0.23-0.38 E-20 0.18-0.22 E-14 0.10-0.18 E-12 0.09-0.14 E-10 0.08-0.12 E-06 0.04-0.07

[0048] Among them, the bisphenol A epoxy resin with a large epoxy value has a relatively small viscosity, while the bisphenol A epoxy resin with a small epoxy value has a relatively large viscosity, and they need to be used in combination.

[0049] In some embodiments, when the bisphenol A epoxy resin is a type of bisphenol A epoxy resin, the type is selected from E-54, E-51, E-44, E-42, E-35, and E-31.

[0050] In some of the embodiments, when the bisphenol A epoxy resin is a mixture of two, three, four or five types of bisphenol A epoxy resins, based on the mass of the mixture as 100%, the sum of the masses of the bisphenol A epoxy resins selected from the types E-54, E-51, E-44, E-42, E-35 and / or E-31 accounts for greater than or equal to 25% (≥25%) of the (total) mass of the mixture; the rest are selected from the bisphenol A epoxy resins of types E-20, E-14, E-12, E-10 and / or E-06 (i.e., ≤75%).

[0051] In some preferred embodiments, one or two bisphenol A epoxy resins are selected.

[0052] In some of the embodiments, the tracer is a low-boiling point oil phase tracer or a gas phase tracer; the low-boiling point oil phase tracer is perfluorobutyl ethyl acrylate; the low-boiling point gas phase tracer is one or more of perfluoropentane, perfluorohexane, perfluorocyclopentane, perfluorocyclohexane, and perfluoromethylcyclopentane.

[0053] The boiling points of the above compounds are shown in Table 2, and the boiling point information of the compounds is derived from Baidu search.

[0054] Table 2

[0055]

[0056] When the tracer is a mixture of multiple tracers, a person skilled in the art can adjust the ratio as needed. Because the six low-boiling point tracers preferred in this application do not react with the other four components, and the six low-boiling point tracers do not react with each other. After the bisphenol A type epoxy resin reacts with raw materials such as a curing agent, the epoxy resin forms a three-dimensional network structure with many gaps in the three-dimensional network structure, and the tracer is distributed in the gaps to form a slow-release solid tracer.

[0057] In some of the embodiments, when the curing agent is polythiol, a catalyst needs to be added, and the catalyst is at least one of a linear tertiary amine, pyridine, and 2-(dimethylaminomethyl)phenol.

[0058] In some embodiments, when the curing agent is polyisocyanate, no catalyst needs to be added, and the mass percentage of the catalyst in the sustained-release solid tracer is 0%.

[0059] The catalyst is used in combination with the polythiol curing agent. Without the catalyst, polythiol as a curing agent can also undergo a curing reaction with epoxy, but the reaction time will be prolonged and the curing temperature will be increased; adding a catalyst can accelerate the curing reaction and react at room temperature or even below room temperature.

[0060] In some embodiments, the diluent is one or more of dibutyl phthalate, dioctyl phthalate, acetone, turpentine, xylene, ethanol, toluene, furfuryl alcohol, and ethyl acetate.

[0061] The diluent can appropriately reduce the viscosity of the epoxy resin and also disperse the tracer in the slurry well.

[0062] In some preferred embodiments, a sustained-release tracer comprises the following raw materials in percentage by mass: 50%-80% bisphenol A epoxy resin, 8%-40% tracer, 8.5%-15% curing agent, 0%-5% catalyst, and 0.5%-10% diluent.

[0063] A method for preparing a sustained-release solid tracer comprises the following steps:

[0064] (1) weighing the raw materials according to any of the above items,

[0065] (2) adding a diluent to the bisphenol A epoxy resin, stirring at a speed of 200 rpm to 500 rpm for 10 to 30 min to uniformly mix the bisphenol A epoxy resin and the diluent to obtain slurry A;

[0066] (3) adding a tracer to slurry A and stirring the mixture to obtain slurry B;

[0067] (4) Add a catalyst to slurry B, and then add a curing agent, and stir rapidly at a temperature not higher than 30° C. to allow the catalyst and the curing agent to be evenly mixed in the slurry. Continue to allow the slurry to stand at a temperature not higher than 30° C. to allow the slurry to undergo a curing reaction. When the slurry is completely hardened, a solid tracer is obtained.

[0068] The steps (1), (2) and (3) of the reaction are carried out at room temperature, which is usually between 10 and 30° C. That is, the reaction temperature range of the steps (2) and (3) of the reaction is relatively wide, and there is no need to perform additional temperature increase treatment for the reaction even in winter, and there is no need to perform temperature reduction treatment in summer.

[0069] In some of the embodiments, bisphenol A epoxy resins of models E-20, E-14, E-12, E-10 and / or E-06 are solid (paste) at room temperature and need to be heated to soften before adding a diluent.

[0070] In some preferred embodiments, the heating and softening is heating to 65-110° C. and softening for 8-15 min.

[0071] In some of the embodiments, the bisphenol A epoxy resin with models E-54, E-51, E-44, E-42, E-35 and / or E-31 is liquid at room temperature and can be directly added with a diluent.

[0072] The bisphenol A epoxy resin with a low epoxy value in the bisphenol A epoxy resin series has a high viscosity. After adding a diluent, the viscosity of the bisphenol A epoxy resin can be reduced. Therefore, the stirring speed and stirring time of step (2) are limited. After the bisphenol A epoxy resin and the diluent are evenly mixed, slurry A is obtained.

[0073] RPM is the abbreviation for revolutions per minute, which represents the number of times the device rotates per minute.

[0074] In some embodiments, the solid tracer has certain morphological requirements. Those skilled in the art can make adjustments as needed, such as preparing solid tracers in various shapes such as granules, strips, blocks, and rods. In step (4), the slurry can be directly placed in a mold and stirred and mixed, or after adding a catalyst and a curing agent, it can be quickly stirred at a temperature not higher than 30° C. so that the catalyst and the curing agent are evenly mixed in the slurry, and then immediately poured into the mold.

[0075] In some of the embodiments, the stirring time is controlled within 1 minute, because the subsequent curing time is very short (the shortest is 5 minutes in the embodiment), and the material needs to be allowed to stand as soon as possible for the curing reaction.

[0076] The criterion for judging the curing reaction molding in the embodiment is that the slurry is completely hardened.

[0077] The slow-release solid tracer of this application can be used in the development of oil field production wells (efficient and accurate) and the water search process of fracturing wells. The specific method of use is: the slow-release solid tracer is dropped into the well from the wellhead and pressed into the specified formation by pressure. Samples are taken at the wellhead to detect the concentration of various tracer components to determine the water production in each formation.

[0078] The sustained-release solid tracer of the present application can also be applied to other fields, and those skilled in the art can use it as needed.

[0079] The experimental methods in the following examples of this application that do not specify specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various commonly used chemical reagents used in the examples are all commercially available products.

[0080] The content of the tracer component in the solidified material in the embodiment is measured and calculated by a thermogravimetric analyzer.

[0081] The following is a description with reference to specific embodiments.

[0082] Embodiment 1:

[0083] (1) Add 6 g of toluene to 100 g of E-42 (epoxy value 0.38-0.45 eq / 100 g) at room temperature, and stir at 200 rpm for 10 min to obtain slurry A;

[0084] (2) adding 12 g of perfluorobutyl ethyl acrylate to slurry A at room temperature, and stirring at 300 rpm for 30 min to obtain slurry B;

[0085] (3) Add 1 g of a linear tertiary amine and 15 g of polythiol to slurry B at room temperature, stir rapidly and evenly at 25°C, and place in a 25°C thermostat to stand until the slurry is completely hardened, thereby obtaining a solid tracer.

[0086] Embodiment 2:

[0087] (1) To a mixture of 35 g of E-12 (epoxy value: 0.09-0.14 eq / 100 g) and 65 g of E-31 (epoxy value: 0.23-0.38 eq / 100 g) were added 3 g of dibutyl phthalate and 3 g of dioctyl phthalate, respectively, at room temperature, and stirred at 300 rpm for 5 min to obtain slurry A;

[0088] (2) adding 35 g of perfluorobutyl ethyl acrylate to slurry A at room temperature, and stirring at 400 rpm for 20 min to obtain slurry B;

[0089] (3) Add 2 g of pyridine and 20 g of polythiol to slurry B in sequence at room temperature, keep stirring rapidly at 25°C, and place in a 25°C thermostat to stand until the slurry is completely hardened, thereby obtaining a solid tracer.

[0090] Embodiment 3:

[0091] (1) Add 2 g of acetone and 5 g of xylene to a mixture of 25 g of E-44 (epoxy value: 0.41-0.47 eq / 100 g) and 75 g of E-20 (epoxy value: 0.18-0.22 eq / 100 g) at room temperature, and stir at 400 rpm for 30 min to obtain slurry A;

[0092] (2) adding 56 g of perfluoropentane to slurry A at room temperature, stirring at 500 rpm for 10 min, to obtain slurry B;

[0093] (3) Add 3 g of 2-(dimethylaminomethyl)phenol and 20 g of polythiol to slurry B in sequence at room temperature, keep stirring rapidly at 25°C, and place in a 25°C thermostat to stand until the slurry is completely hardened, thereby obtaining a solid tracer.

[0094] Embodiment 4:

[0095] (1) Add 5 g of ethyl acetate to 100 g of E-54 (epoxy value 0.52-0.56 eq / 100 g) at room temperature, and stir at 500 rpm for 20 min to obtain slurry A;

[0096] (2) adding 55 g of perfluorohexane to slurry A at room temperature, stirring at 200 rpm for 30 min, to obtain slurry B;

[0097] (3) Add 20 g of polythiol to slurry B at room temperature, keep it at 25°C and stir it quickly and evenly, then place it in a 25°C thermostat and let it stand until the slurry is completely hardened to obtain a solid tracer.

[0098] Embodiment 5:

[0099] (1) Add 7 g of dibutyl phthalate to a mixture of 60 g of E-51 (epoxy value: 0.48-0.54 eq / 100 g) and 40 g of E-14 (epoxy value: 0.10-0.18 eq / 100 g) at room temperature, and stir at 200 rpm for 10 min to obtain slurry A;

[0100] (2) adding 55 g of perfluorocyclopentane to slurry A at room temperature, stirring at 400 rpm for 30 min, to obtain slurry B;

[0101] (3) Add 20 g of polyisocyanate to slurry B at room temperature, keep it at 25°C and stir it quickly and evenly, then place it in a 25°C thermostat and let it stand until the slurry is completely hardened to obtain a solid tracer.

[0102] Embodiment 6:

[0103] (1) Add 5 g of dioctyl phthalate to a mixture of 30 g of E-54 (epoxy value: 0.52-0.56 eq / 100 g) and 70 g of E-10 (epoxy value: 0.08-0.12 eq / 100 g) at room temperature, and stir at 300 rpm for 10 min to obtain slurry A;

[0104] (2) adding 55 g of perfluoromethylcyclopentane to slurry A at room temperature, and stirring at 300 rpm for 20 min to obtain slurry B;

[0105] (3) Add 20 g of polyisocyanate to slurry B at room temperature, keep it at 25°C and stir it quickly and evenly, then place it in a 25°C thermostat and let it stand until the slurry is completely hardened to obtain a solid tracer.

[0106] Embodiment 7:

[0107] (1) Add 5 g of ethyl acetate to 100 g of E-54 (epoxy value 0.52-0.56 eq / 100 g) at room temperature, and stir at 500 rpm for 20 min to obtain slurry A;

[0108] (2) adding 55 g of perfluorohexane to slurry A at room temperature, stirring at 200 rpm for 30 min, to obtain slurry B;

[0109] (3) Add 1 g of a linear tertiary amine and 20 g of polythiol to slurry B at room temperature, stir rapidly and evenly at 25°C, and place in a 25°C thermostat to stand until the slurry is completely hardened, thereby obtaining a solid tracer.

[0110] Embodiment 8:

[0111] (1) Add 6 g of toluene to 70 g of E-44 (epoxy value: 0.41-0.47 eq / 100 g), 20 g of E-35 (epoxy value: 0.26-0.40 eq / 100 g) and 10 g of E-20 (epoxy value: 0.18-0.22 eq / 100 g, softened at 65° C. for 10 min) at room temperature, and stir at 200 rpm for 10 min to obtain slurry A;

[0112] (2) adding 12 g of perfluorobutyl ethyl acrylate to slurry A at room temperature, and stirring at 300 rpm for 30 min to obtain slurry B;

[0113] (3) Add 1 g of a linear tertiary amine and 15 g of polythiol to slurry B at room temperature, stir rapidly and evenly at 25°C, and place in a 25°C thermostat to stand until the slurry is completely hardened, thereby obtaining a solid tracer.

[0114] Embodiment 9:

[0115] (1) Add 6 g of toluene to 100 g of E-42 (epoxy value 0.38-0.45 eq / 100 g) at room temperature, and stir at 200 rpm for 10 min to obtain slurry A;

[0116] (2) adding 12 g of perfluorobutyl ethyl acrylate and 42 g of perfluorocyclohexane to slurry A at room temperature, and stirring at 300 rpm for 30 min to obtain slurry B;

[0117] (3) Add 1 g of a linear tertiary amine and 15 g of polythiol to slurry B at room temperature, stir rapidly and evenly at 25°C, and place in a 25°C thermostat to stand until the slurry is completely hardened, thereby obtaining a solid tracer.

[0118] Figure 1 This is a comparison chart of curing time of Examples 1-9 of the present application when cured at 25°C.

[0119] Figure 1 It is shown in the figure: Examples 1-4 all use polythiol as a curing agent. The difference between Example 1-3 and Example 4 is that a catalyst is added to Example 1-3, so that the curing reaction time is shortened from 18 minutes without a catalyst to 5-13 minutes, indicating that the catalyst can effectively shorten the curing reaction time and allow the tracer to be coated in the epoxy resin in a shorter time; Example 5-6 uses polyisocyanate as a curing agent, and can also perform a curing reaction at 25°C without applying a catalyst, and the curing time is 9-10 minutes, and the curing speed is faster than that of the example with a single polythiol curing agent; Example 7 is different from Example 4 in that, under the same other conditions, Example 7 adds 1g of straight-chain tertiary amine as a catalyst, while Example 4 does not add a catalyst, and the curing times of Example 4 and Example 7 are 18 minutes and 14 minutes respectively, indicating that the catalyst can shorten the curing reaction time; Example 8 is based on Example 1, and other conditions remain unchanged, and one epoxy resin is changed to three; Example 9 is based on Example 1, and other conditions remain unchanged, and two tracer components are added.

[0120] In order to compare the effect of curing agent types on curing reaction temperature and time, as well as the difference in the content of effective tracer components in the cured products obtained under different curing conditions, based on Examples 3-6, corresponding epoxy resins and tracers were selected, and the corresponding component ratios were the same as in Examples 3-6. The initial amount of tracer raw materials was kept at 30% by mass of the total slurry system, and four comparative examples were carried out.

[0121] Comparative Example 1:

[0122] (1) Add 2 g of acetone and 5 g of xylene to a mixture of 25 g of E-44 and 75 g of E-20 at room temperature, and stir at 400 rpm for 3 min to obtain slurry A;

[0123] (2) adding 56 g of perfluoropentane to slurry A at room temperature, stirring at 500 rpm for 10 min, to obtain slurry B;

[0124] (3) Add 23 g of diethylenetriamine to slurry B at room temperature, stir quickly and evenly, and place in a 25°C constant temperature box to stand and solidify. When the slurry is completely hardened, a solid tracer is obtained. The results are shown in Table 3.

[0125] The difference between Example 3 and Comparative Example 1 is that, in Example 3, polythiol is selected as a curing agent, and an appropriate amount of 2-(dimethylaminomethyl)phenol is added as a catalyst. After being placed in a 25°C thermostat in step (3), the temperature of the reaction slurry system is always maintained at 25°C for curing reaction. After 5 minutes, the slurry is completely hardened and the curing reaction is completed; Comparative Example 1 selects diethylenetriamine, a typical fatty amine, as a curing agent. After the curing agent is added to slurry B in step (3), the slurry quickly becomes hot and emits white smoke. The temperature of the slurry system is monitored during the static process of being placed in a 25°C thermostat. The temperature of the slurry system is maintained at about 100°C. After 56 minutes of curing reaction, the slurry is completely cured and formed. The results are shown in Table 3.

[0126] The results in Table 3 show that, compared with Example 3 and Comparative Example 1, the curing reaction of Comparative Example 1 is very intense, the reaction temperature is much higher than the boiling point (29° C.) of the tracer perfluoropentane, and the curing reaction time is about 10 times that of Example 3. After analyzing the proportion of the tracer component in the cured product, it is found that the tracer content in the cured product of Example 3 is 29.8%, which is very close to the initial addition ratio of the tracer; the tracer content in the cured product of Comparative Example 1 is only 10.7%, indicating that the tracer component is seriously lost during the curing reaction.

[0127] Table 3

[0128] Curing temperature(℃) Curing reaction time (min) Tracer content in solidified material (%) Example 3 25 5 29.8 Comparative Example 1 100 56 10.7

[0129] Comparative Example 2:

[0130] (1) Add 5 g of ethyl acetate to 100 g of E-54 at room temperature, and stir at 500 rpm for 2 min to obtain slurry A;

[0131] (2) adding 55 g of perfluorohexane to slurry A at room temperature, stirring at 200 rpm for 30 min, to obtain slurry B;

[0132] (3) Add 20 g of menthane diamine to slurry B at room temperature, stir quickly and evenly, and place in a 25°C constant temperature box to stand and solidify to obtain a solid tracer.

[0133] The difference between Example 4 and Comparative Example 2 is that Example 4 uses polythiol as a curing agent. After being placed in a 25°C thermostat in step (3), the temperature of the reaction slurry system is always maintained at 25°C for curing reaction. After 18 minutes, the slurry is completely hardened and the curing reaction is completed; Comparative Example 2 uses a typical alicyclic amine such as menthane diamine as a curing agent. After the curing agent is added to slurry B in step (3), the slurry quickly becomes hot and emits white smoke. The temperature of the slurry system is monitored during the static process of being placed in a 25°C thermostat. The temperature of the slurry system is maintained at about 130°C. After 45 minutes of curing reaction, the slurry is completely cured and formed. The results are shown in Table 4.

[0134] The results in Table 4 show that, compared with Example 4 and Comparative Example 2, the curing reaction of Comparative Example 2 is very intense, the reaction temperature is much higher than the boiling point of the tracer perfluorohexane (57.8°C), and the curing reaction time is nearly 3 times that of Example 4. After analyzing the proportion of the tracer component in the cured product, it was found that the tracer content in the cured product of Example 4 was 28.9%, which was very close to the initial addition ratio of the tracer; the tracer content in the cured product of Comparative Example 2 was only 6.1%, indicating that the tracer component was seriously lost during the curing reaction.

[0135] Table 4

[0136] Curing temperature(℃) Curing reaction time (min) Tracer content in solidified material (%) Example 4 25 18 28.9 Comparative Example 2 130 45 6.1

[0137] For example, to produce 1 kg of sustained-release solid perfluorohexane tracer (all raw materials add up to 1 kg), epoxy cured product is synthesized according to 30% mass percentage of tracer effective components. A total of 30% × 1kg = 0.3kg of tracer is added to the initial raw materials. Due to the violent curing reaction, the tracer is volatilized and lost, resulting in the actual tracer content in the epoxy cured product being 6.1% × 1kg = 0.061kg, and the tracer loss rate reaches (0.3-0.061) / 0.3 × 100% = 79.7%; if the selling price of this tracer is 10,000 yuan / kg, then the loss is 79.7% × 1kg × 10,000 yuan / kg = 7967 yuan.

[0138] Comparative Example 3:

[0139] (1) Add 7 g of dibutyl phthalate to a mixture of 60 g of E-51 and 40 g of E-14 at room temperature, and stir at 200 rpm for 10 min to obtain slurry A;

[0140] (2) adding 55 g of perfluorocyclopentane to slurry A at room temperature, stirring at 400 rpm for 30 min, to obtain slurry B;

[0141] (3) Add 20 g of diaminodiphenylmethane to slurry B at room temperature, stir quickly and evenly, and place in a 25°C constant temperature box to stand and solidify to obtain a solid tracer.

[0142] The difference between Example 5 and Comparative Example 3 is that Example 5 uses polyisocyanate as a curing agent. After being placed in a 25°C thermostat in step (3), the temperature of the reaction slurry system is always maintained at 25°C for curing reaction. After 10 minutes, the slurry is completely hardened and the curing reaction is completed; Comparative Example 3 uses diaminodiphenylmethane as a curing agent. After the curing agent is added to slurry B in step (3), the slurry quickly becomes hot. The temperature of the slurry system is monitored during the static process of being placed in a 25°C thermostat. The temperature of the slurry system is always maintained at about 150°C. After 240 minutes of curing reaction, the slurry is completely cured and formed. The results are shown in Table 5.

[0143] The results in Table 5 show that, compared with Example 5 and Comparative Example 3, the curing reaction of Comparative Example 3 is violent, the reaction temperature is much higher than the boiling point (55°C) of the tracer perfluorocyclopentane, and the curing reaction time is 24 times that of Example 5. After analyzing the proportion of the tracer component in the cured product, it is found that the tracer content in the cured product of Example 5 is 29.6%, which is very close to the initial addition ratio of the tracer; the tracer content in the cured product of Comparative Example 3 is only 4.8%, indicating that the tracer component is seriously lost during the curing reaction.

[0144] Table 5

[0145] Curing temperature(℃) Curing reaction time (min) Tracer content in solidified material (%) Example 5 25 10 29.6 Comparative Example 3 150 240 4.8

[0146] For example, to produce 1 kg of sustained-release solid perfluorocyclopentane tracer (all raw materials add up to 1 kg), epoxy cured product is synthesized according to 30% mass percentage of tracer effective components. A total of 30% × 1 kg = 0.3 kg of tracer is added to the initial raw materials. Due to the violent curing reaction, the tracer is volatilized and lost, resulting in an actual tracer content in the epoxy cured product of 4.8% × 1 kg = 0.048 kg, and the tracer loss rate reaches (0.3-0.048) / 0.3 × 100% = 84.0%; if the selling price of this tracer is 10,000 yuan / kg, then the loss is 84.0% × 1 kg × 10,000 yuan / kg = 8,400 yuan.

[0147] Comparative Example 4:

[0148] (1) Add 5 g of dioctyl phthalate to a mixture of 30 g of E-54 and 70 g of E-10 at room temperature, and stir at 300 rpm for 10 min to obtain slurry A;

[0149] (2) adding 55 g of perfluoromethylcyclopentane to slurry A at room temperature, and stirring at 300 rpm for 20 min to obtain slurry B;

[0150] (3) Add 20 g of diaminodiphenyl sulfone to slurry B at room temperature, stir quickly and evenly, and place in a 25°C constant temperature box to stand and solidify to obtain a solid tracer.

[0151] The difference between Example 6 and Comparative Example 4 is that Example 6 uses polyisocyanate as a curing agent. After being placed in a 25°C thermostat in step (3), the temperature of the reaction slurry system is always maintained at 25°C for curing reaction. After 9 minutes, the slurry is completely hardened and the curing reaction is completed; Comparative Example 4 uses diaminodiphenyl sulfone as a curing agent. After the curing agent is added to slurry B in step (3), the slurry quickly becomes hot. The temperature of the slurry system is monitored during the static process of being placed in a 25°C thermostat. The temperature of the slurry system is always maintained at about 200°C. After 240 minutes of curing reaction, the slurry is completely cured and formed. The results are shown in Table 6.

[0152] The results in Table 6 show that, compared with Example 6 and Comparative Example 4, the curing reaction of Comparative Example 4 is violent, the reaction temperature is much higher than the boiling point (48° C.) of the tracer perfluoromethylcyclopentane, and the curing reaction time is 26.7 times that of Example 6. After analyzing the proportion of the tracer component in the cured product, it is found that the tracer content in the cured product of Example 6 is 29.6%, which is very close to the initial addition ratio of the tracer; the tracer content in the cured product of Comparative Example 4 is only 4.8%, indicating that the tracer component is seriously lost during the curing reaction.

[0153] Table 6

[0154] Curing temperature(℃) Curing reaction time (min) Tracer content in solidified material (%) Example 6 25 10 29.6 Comparative Example 4 200 240 4.8

[0155] Figure 2 It is a comparison chart of the curing temperature, curing time and the content of the tracer component in the cured product of Examples 3-6 of the present application and Comparative Examples 1-4.

[0156] Figure 2 It shows that: the curing temperature of Examples 3-6 of the present application can be stabilized at 25°C, the curing time is less than 20 minutes, the curing reaction is mild, and the content of the tracer component in the cured product is very close to the initial amount of the tracer raw material (30%); the curing temperature of Comparative Examples 1-4 is greater than 100°C, even reaching 200°C, and the curing time is significantly longer than that of the embodiments. The content of the tracer component in the cured product is less than 11%, and compared with the initial amount of the tracer, the tracer component loss is very large.

[0157] Application Example 1

[0158] The time is: September 2023-March 2024.

[0159] The oil-gas phase slow-release tracer prepared in the embodiment of the present application was used for the downhole operation of No. XXX in the Southwest Oil and Gas Field. Before the downhole operation, the mass percentage of the tracer effective component in the slow-release tracer was 30%. The tracer was extracted half a year after the downhole operation. It was found through measurement that the mass percentage of the tracer effective component in the solid tracer still reached 25-27%.

[0160] The present application provides a low-temperature curing process for low-boiling oil phase or gas phase tracers for oil and gas fields. Through this preparation method, the curing reaction of epoxy resin can be quickly completed at a condition not higher than 30°C, which is conducive to the low-boiling point tracer being coated in the cured product of epoxy resin, avoiding the loss caused by the evaporation of the tracer due to the high curing reaction temperature and too long curing time, thereby ensuring that the tracer in the sustained-release solid tracer product reaches the expected effective concentration. The preparation method is simple to operate, has mild process conditions, short curing time, high production efficiency, and is easy to achieve large-scale production.

[0161] The above is a further detailed description of the present invention, which should not be regarded as a limitation on the specific implementation of the present invention. For ordinary technicians in the technical field to which the present invention belongs, simple deduction or replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A sustained-release solid tracer, characterized in that: The invention comprises the following raw materials in percentage by weight: 30%-80% of bisphenol A epoxy resin, 5%-60% of tracer, 5%-20% of curing agent, 0%-10% of catalyst and 0.5%-15% of diluent, wherein the curing agent is one of polythiol and polyisocyanate, and the tracer is one or more of perfluorobutyl ethyl acrylate, perfluoropentane, perfluorohexane, perfluorocyclopentane, perfluorocyclohexane and perfluoromethylcyclopentane.

2. The sustained-release solid tracer according to claim 1, characterized in that: The bisphenol A epoxy resin is selected from at least one of the bisphenol A epoxy resins with models of E-54, E-51, E-44, E-42, E-35, E-31, E-20, E-14, E-12, E-10, and E-06.

3. The sustained-release solid tracer according to claim 2, characterized in that: When the bisphenol A epoxy resin is a type of bisphenol A epoxy resin, the type is selected from E-54, E-51, E-44, E-42, E-35, and E-31.

4. The sustained-release solid tracer according to claim 2, characterized in that: When the bisphenol A epoxy resin is a mixture of two, three, four or five types of bisphenol A epoxy resins, based on the mass of the mixture as 100%, the sum of the masses of the bisphenol A epoxy resins selected from the types E-54, E-51, E-44, E-42, E-35 and / or E-31 accounts for greater than or equal to 25% of the mass of the mixture; the rest are selected from the bisphenol A epoxy resins of types E-20, E-14, E-12, E-10 and / or E-06.

5. The sustained-release solid tracer according to claim 1, characterized in that: When the curing agent is polythiol, the catalyst is at least one of linear tertiary amine, pyridine and 2-(dimethylaminomethyl)phenol.

6. The sustained-release solid tracer according to claim 1, characterized in that: When the curing agent is polyisocyanate, the mass percentage of the catalyst in the sustained-release solid tracer is 0%.

7. The sustained-release solid tracer according to claim 1, characterized in that: The diluent is one or more of dibutyl phthalate, dioctyl phthalate, acetone, turpentine, xylene, ethanol, toluene, furfuryl alcohol, and ethyl acetate.

8. The method for preparing a sustained-release solid tracer according to any one of claims 1 to 7, characterized in that: The following steps are involved: Weigh the raw materials according to any one of claims 1 to 7, Adding a diluent to the bisphenol A epoxy resin, stirring at a speed of 200 rpm to 500 rpm for 10 to 30 minutes, to obtain slurry A; Adding a tracer to slurry A and stirring evenly to obtain slurry B; Add a catalyst to slurry B, and then add a curing agent, and stir rapidly at a temperature not higher than 30°C to allow the catalyst and curing agent to be evenly mixed in slurry B. Continue to stand at a temperature not higher than 30°C to allow the slurry to undergo a curing reaction. When the slurry is completely hardened, a slow-release solid tracer is obtained.

9. The preparation method according to claim 8, characterized in that: When the bisphenol A epoxy resin is selected from bisphenol A epoxy resins with models of E-20, E-14, E-12, E-10 and / or E-06, the bisphenol A epoxy resin needs to be heated and softened first.

Images