Room temperature curing slow release type solid tracer agent and preparation method thereof

Abstract

The invention discloses a room-temperature 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: 20-80% of bisphenol A epoxy resin, 5-30% of a tracer, 5-60% of a curing agent, 0-25% of an accelerant and 1-15% of a diluent. The sustained-release solid tracer obtained by curing under the condition of 30-50 DEG C is excellent in heat resistance, and the tracer content loss in a cured product is less, so that the softening temperature of the solid tracer is increased to 80 DEG C or above while the tracer in a sustained-release solid tracer product reaches the expected effective concentration, and the use requirements of oil and gas field production sites are met.

Description

Technical Field

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

[0002] Oil and gas field tracer technology refers to the technology of adding easily identifiable or easily monitored tracers to the substances or fluids to be traced, and studying the existence, movement state and change law of the substances or fluids to be traced by monitoring the properties and concentration changes of the tracers, so as to solve the problems of oil and gas field development and production. Tracer technology has a wide range of applications in oil and gas fields and has become an important means of oil and gas reservoir engineering.

[0003] In order to make full use of the expensive tracer and extend its service life, the tracer is usually mixed into epoxy resin, and a solid tracer with a slow-release effect is formed after the epoxy resin is cured. This type of solid tracer can slowly release the tracer component underground, has a long service life, can reduce the number of dosing and the amount of dosing, and thus significantly save production costs.

[0004] The curing reaction of epoxy resin is generally accompanied by exothermic phenomena. Some curing reactions are very violent, and the reaction temperature can reach above 100°C. A considerable number of commonly used oil-phase and gas-phase tracers have boiling points below 80°C. If these tracers are cured at a temperature higher than their own boiling points, they will be lost due to evaporation, thereby reducing the effective concentration of tracers in epoxy cured products. Therefore, for specific tracers, epoxy resins need to be cured at appropriate reaction temperatures.

[0005] Epoxy resin itself is very stable, but it is brittle, has poor performance, and has no application value. After adding curing agent and auxiliary agent to epoxy resin, the cross-linking network of epoxy resin changes, so that the mechanical properties, thermal stability and chemical stability of epoxy resin cured product change significantly. The curing agent in the epoxy resin system has a great influence on the curing reaction temperature and the heat resistance of the cured product. Generally, when the curing temperature is high, the more thorough the curing reaction of the epoxy groups in the epoxy resin, the better the cross-linking of the three-dimensional network structure of the epoxy resin formed, and the better the performance of the obtained epoxy resin cured product, such as better heat resistance, chemical resistance, acid and alkali resistance. It can be seen that the solid tracer prepared at a higher curing temperature can better adapt to the production environment of the oil and gas field site. Generally speaking, the production environment of oil and gas fields varies according to the depth and location of the well. The temperature of shallow wells is 60-80℃, and the temperature of deep wells can reach above 160℃. However, for tracers with lower boiling points, it is necessary to consider that the curing reaction occurs at an appropriate temperature to avoid evaporation loss of the tracer. Therefore, for low-boiling point tracers, the epoxy resin curing process should be optimized to ensure that the tracer evaporation loss is avoided while the heat resistance of the epoxy cured product is improved as much as possible to meet the requirements for the use of solid tracers in oil and gas field production sites.

[0006] At present, there are no reports or patents specifically targeting at the preparation of oil and gas phase tracers with boiling points in the range of 60-90°C. Summary of the invention

[0007] The purpose of the present application is to overcome at least one shortcoming of the prior art. In a first aspect, the present application provides a room temperature curing (30-50° C. curing) sustained-release solid tracer.

[0008] The second aspect of the present application provides a method for preparing the sustained-release solid tracer.

[0009] The technical solution adopted in this application is:

[0010] According to the first aspect of the present application, a sustained-release solid tracer is provided, comprising the following raw materials in percentage by mass: 20%-80% of bisphenol A epoxy resin, 5%-30% of tracer, 5%-60% of curing agent, 0%-25% of accelerator, and 1%-15% of diluent, wherein the tracer is at least one of methyl perfluoroformate, methyl perfluoroacetate, methyl perfluorobutyrate, methyl perfluorononanoate, perfluoroheptyl ethyl acrylate, perfluorooctyl ethyl acrylate, perfluoroheptane, and perfluorobenzene; and the curing agent is one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyamide, N-aminoethylpiperazine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiroundecane adduct, and meta-xylylenediamine.

[0011] In some embodiments, the bisphenol A epoxy resin is one or more of E-51, E-42, E-35, E-20, E-12, E-10, and E-06.

[0012] In some embodiments, when the bisphenol A epoxy resin is a type of bisphenol A epoxy resin, the type is selected from E-51, E-42, and E-35.

[0013] 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 with types E-51, E-42 and / or E-35 in the mixture is greater than or equal to 30% by mass; the rest are bisphenol A epoxy resins with types E-20, E-12, E-10 and / or E-06.

[0014] In some embodiments, the promoter is one or more of phenol, o-cresol, nonylphenol, resorcinol, 2,4,6-tris(dimethylaminomethyl)phenol, and triethanolamine.

[0015] In some embodiments, the diluent is one or more of dibutyl 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 weight: 40%-70% bisphenol A epoxy resin, 10%-25% tracer, 10%-50% curing agent, 0%-10% accelerator, and 1%-10% diluent.

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

[0018] (1) Weigh the raw materials according to the above ratio,

[0019] (2) adding a diluent to the bisphenol A epoxy resin and stirring at a speed of 100 rpm to 500 rpm for 5 to 20 min to obtain slurry A;

[0020] (3) adding a tracer to slurry A and stirring at a speed of 100 rpm to 500 rpm for 5 to 30 min to obtain slurry B;

[0021] (4) Add a curing agent to slurry B, and then add an accelerator, stir evenly, and let stand at 30-50° C. to cure and form, thereby preparing a sustained-release solid tracer.

[0022] In some embodiments, when the bisphenol A epoxy resin is selected from bisphenol A epoxy resins of types E-20, E-12, E-10 and / or E-6, the bisphenol A epoxy resin needs to be heated and softened first.

[0023] 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.

[0024] The beneficial effects of this application are:

[0025] The present application is applicable to the preparation method of room temperature curing of oil phase and gas phase tracers with boiling points in the range of 60-90°C, which can resolve the contradiction between the poor heat resistance of epoxy cured products obtained by low temperature curing and the large loss of tracers caused by high temperature curing. By adjusting the distribution ratio of each component of the system and the process parameters, the curing reaction can be controlled to proceed at a suitable temperature to prepare a solid tracer with excellent heat resistance. The preparation method is simple to operate, has mild process conditions, and is easy to achieve large-scale production.

[0026] The present application uses bisphenol A epoxy resin as a sustained-release matrix of a solid tracer, and achieves a curing reaction at 30-50° C. by selecting a room temperature curing agent and an accelerator to prepare a solid tracer.

[0027] The preparation method of the present application can prepare solid tracers in various shapes such as strips, blocks, and rods, with mild process conditions, low equipment requirements, and the ability to achieve large-scale production.

[0028] The sustained-release solid tracer obtained in the present application has excellent heat resistance and less tracer content loss in the solidified product, thereby ensuring that the tracer in the sustained-release solid tracer product reaches the expected effective concentration and meets the use requirements of the production site. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a comparison chart of the softening temperatures of the solid tracers prepared by curing at 50° C. in Examples 1-7 of the present application. DETAILED DESCRIPTION

[0030] 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.

[0031] 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.

[0032] The term "multiple" in the present invention 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.

[0033] 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 room temperature curing (30-50°C curing) sustained-release solid tracer and its preparation method and application.

[0034] A sustained-release 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 bisphenol A epoxy resin, a diluent, and a curing agent at room temperature (30-50°C) with or without an accelerator.

[0035] The sustained-release solid tracer (composite material) comprises the following raw materials in percentage by mass: 20%-80% of bisphenol A epoxy resin, 5%-30% of tracer, 5%-60% of curing agent, 0%-25% of accelerator, and 1%-15% of diluent.

[0036] In some of the embodiments, the tracer is an oil phase tracer or a gas phase tracer with a boiling point in the range of 60-90°C; the oil phase tracer is one or two of methyl perfluoroformate, methyl perfluoroacetate, methyl perfluorobutyrate, methyl perfluorononanoate, perfluoroheptyl ethyl acrylate, and perfluorooctyl ethyl acrylate; the gas phase tracer is one or two of perfluoroheptane and perfluorobenzene.

[0037] Generally speaking, when tracers are mixed, tracers of the same type are used.

[0038] The boiling points of the above compounds are shown in Table 1, and the boiling point information of the compounds is derived from Baidu search.

[0039] Table 1

[0040]

[0041]

[0042] In some embodiments, the curing agent is one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyamide, N-aminoethylpiperazine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiroundecane adduct, and m-xylylenediamine. The plurality of curing agents is preferably two.

[0043] 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, and cure to obtain a cured product. There are many types of curing agents, and their properties vary greatly.

[0044] In order to avoid or reduce the evaporation loss of tracers with boiling points in the range of 60-90°C due to high curing temperatures, the present application prefers 7 curing agents of four types, namely aromatic amines, alicyclic polyamines, aliphatic polyamines, and polyamides. The 7 curing agents can all undergo curing reactions with the preferred bisphenol A epoxy resin in the range of 30-50°C. Many properties of epoxy resin cured products, such as heat resistance and chemical stability, depend on the extent of the curing reaction. Generally, the higher the curing temperature, the more thorough the curing reaction, the greater the cross-linking density of the formed cured product, and the more conducive to the improvement of various physical and chemical properties of the epoxy resin cured product. In addition, the addition of an accelerator can accelerate the curing reaction rate on the one hand, and promote the extent of the curing reaction on the other hand.

[0045] Generally speaking, the heat resistance of epoxy resin cured products formed by curing at room temperature of 30-50°C in the prior art is poorer than that of medium temperature (50-100°C) and high temperature (greater than 100°C) cured products. In order to improve the heat resistance of room temperature cured products and meet the requirements of the production environment for the heat resistance of solid tracers, this application adopts measures such as optimizing curing agents and epoxy resins, compounding accelerators, etc., to maintain the curing temperature at 30-50°C, avoid volatilization of tracer components, and improve the heat resistance of the cured product.

[0046] The present application measures the heat resistance of the cured product by its softening temperature. The lower the softening temperature, the worse the heat resistance of the product.

[0047] In the early stage of the research, the inventor used divinyl propylamine and menthane diamine as curing agents and cured at 50°C. The softening temperatures of the obtained solid tracers were 38°C and 46°C respectively, which did not meet the requirements of the working environment of 60°C and above in the production wells of oil and gas fields. After a large number of experiments, the inventors screened out suitable epoxy resins and room temperature curing agents, and by optimizing the proportion of accelerators, when the curing reaction occurred at 30-50°C, the softening temperature of the obtained epoxy cured products was higher than 80°C, which could meet the production requirements of oil and gas fields in subsequent applications.

[0048] In some embodiments, the bisphenol A epoxy resin is one or more of E-51, E-42, E-35, E-20, E-12, E-10, and E-06.

[0049] 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.

[0050] Epoxy resin refers to a resin compound containing 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.

[0051] 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.

[0052] The bisphenol A epoxy resin models and epoxy values ​​mentioned in this application are shown in Table 2.

[0053] Table 2

[0054] Domestic models Epoxy value / (eq / 100g) E-51 0.48-0.54 E-42 0.38-0.45 E-35 0.30-0.40 E-20 0.18-0.22 E-12 0.09-0.14 E-10 0.08-0.12 E-06 0.04-0.07

[0055] In order to ensure that the curing reaction of the epoxy resin is carried out at room temperature of 30-50°C, and the obtained cured product has good heat resistance (softening temperature is higher than 80°C), and meet the use requirements of the sustained-release solid tracer at the oil and gas field production site, the epoxy resin must be screened, and the room temperature curing agent compatible with the epoxy resin is preferably selected. After systematic experimental research, the inventors have selected E-51, E-42, E-35, E-20, E-12, E-10, and E-06 as epoxy resins suitable for the technical solution of the present application.

[0056] In some embodiments, when the bisphenol A epoxy resin is a type of bisphenol A epoxy resin, the type is selected from E-51, E-42, and E-35.

[0057] 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-51, E-42, and E-35 accounts for greater than or equal to 30% (≥30%) of the (total) mass of the mixture; the rest are selected from the bisphenol A epoxy resins of types E-20, E-12, E-10, and E-06 (i.e., ≤70%).

[0058] The ratio is based on an epoxy value of 0.3. The ratio of epoxy resins with an epoxy value greater than or equal to 0.3 should be greater than or equal to 30%, and can reach up to 100%; the ratio of epoxy resins with an epoxy value less than 0.3 should be less than or equal to 70%.

[0059] In some preferred embodiments, one or two bisphenol A epoxy resins are selected.

[0060] In some embodiments, the promoter is one or more of phenol, o-cresol, nonylphenol, resorcinol, 2,4,6-tris(dimethylaminomethyl)phenol, and triethanolamine.

[0061] The functions of accelerators mainly include:

[0062] Accelerate the curing reaction: The accelerator can reduce the activation energy of the reaction between the epoxy resin and the curing agent, thereby accelerating the curing reaction, shortening the curing time, and making the curing reaction more thorough.

[0063] Improve thermal stability: Accelerators help improve the thermal stability of cured epoxy resins, allowing them to maintain good performance at high temperatures.

[0064] The preferred accelerator of the present application is used in combination with an aliphatic polyamine curing agent, and the accelerator participates in the curing reaction.

[0065] In some embodiments, the diluent is one or more of dibutyl phthalate, acetone, turpentine, xylene, ethanol, toluene, furfuryl alcohol, and ethyl acetate.

[0066] The diluent can appropriately reduce the viscosity of the bisphenol A epoxy resin and can also disperse the tracer in the slurry well. The diluent in the embodiment of the present application does not participate in the curing reaction.

[0067] There is no specific requirement for the ratio of diluents, as long as the epoxy resin and tracer can be fully dispersed. When multiple diluents are used, add one diluent at a time, stir evenly, then add another diluent and stir evenly again.

[0068] In some preferred embodiments, a sustained-release tracer comprises the following raw materials in percentage by weight: 40%-70% bisphenol A epoxy resin, 10%-25% tracer, 10%-50% curing agent, 0%-10% accelerator, and 1%-10% diluent.

[0069] The method for preparing the sustained-release solid tracer comprises the following steps:

[0070] (1) Weigh the raw materials according to the above ratio,

[0071] (2) adding a diluent to the bisphenol A epoxy resin and stirring at a speed of 100 rpm to 500 rpm for 5 to 20 min to obtain slurry A;

[0072] (3) adding a tracer to slurry A and stirring at a speed of 100 rpm to 500 rpm for 5 to 30 min to obtain slurry B;

[0073] (4) Add an accelerator to slurry B, then add a curing agent, stir evenly, and allow to stand at 30-50° C. to cure and form, thereby preparing a sustained-release solid tracer.

[0074] 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.

[0075] In some of the embodiments, the bisphenol A epoxy resin of model E-20, E-12, E-10 and / or E-06 is solid (paste) at room temperature and needs to be heated to soften before adding a diluent.

[0076] In some embodiments, the heating to soften is heating to 65-110° C. for 8-15 min.

[0077] In some of the embodiments, bisphenol A epoxy resins of models E-51, E-42, and E-35 are liquid at room temperature and are directly added to the diluent.

[0078] 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.

[0079] RPM is the abbreviation for revolutions per minute, which represents the number of times the device rotates per minute.

[0080] In some embodiments, the solid tracer has certain morphological requirements. Those skilled in the art can adjust it as needed. In step (4), the slurry can be directly placed in the mold and stirred and mixed, or after adding the accelerator and the curing agent, stir evenly and then pour into the mold.

[0081] In some embodiments, the device for the material to be left to stand for curing reaction is a thermostat, which can be adjusted by those skilled in the art as needed.

[0082] The reagents in the following examples are derived from commercially available products.

[0083] In the examples, the softening temperature of the cured product is used to measure its heat resistance. The lower the softening temperature, the worse the heat resistance of the product. The softening temperature of the cured product in the examples is determined by the ring and ball method. The specific operation method is based on the national standard GB / T12007.6-1989 "Method for Determining the Softening Point of Epoxy Resins".

[0084] The bisphenol A epoxy resins of type E-20, E-12, E-10 and / or E-06 in the embodiments are heated to 65-110° C. and softened for 8-15 minutes before use.

[0085] When multiple diluents are selected in the embodiments, "sequentially" does not limit the order of adding the diluents. Each time a diluent is added, stir evenly, and then add another diluent and stir evenly.

[0086] The following is a description with reference to specific embodiments.

[0087] Embodiment 1:

[0088] (1) After 60 g of E-51 and 40 g of softened E-10 were mixed uniformly at room temperature, 2 g of acetone and 4 g of toluene were added in sequence, and the mixture was stirred at 200 rpm for 5 min to obtain slurry A;

[0089] (2) adding 31 g of methyl perfluorobutyrate to slurry A at room temperature, and stirring at 500 rpm for 30 min to obtain slurry B;

[0090] (3) Add 70 g of polyamide to slurry B at room temperature, stir evenly, and place in a 50° C. constant temperature box to stand and solidify to obtain a sustained-release solid tracer.

[0091] Embodiment 2:

[0092] (1) After 35 g of E-42 and 65 g of softened E-06 were mixed uniformly at room temperature, 3 g of dibutyl phthalate and 3 g of ethanol were added in sequence, and the mixture was stirred at 300 rpm for 2 min to obtain slurry A;

[0093] (2) adding 24 g of methyl perfluoroacetate to slurry A at room temperature, stirring at 400 rpm for 20 min, to obtain slurry B;

[0094] (3) Add 2 g of o-cresol and 24 g of diethylenetriamine to slurry B at room temperature, stir evenly, and place in a 50°C constant temperature box to solidify and form, thereby obtaining a sustained-release solid tracer.

[0095] Embodiment 3:

[0096] (1) After 35 g of E-42 and 65 g of softened E-06 were mixed uniformly at room temperature, 3 g of dibutyl phthalate and 3 g of ethanol were added in sequence, and the mixture was stirred at 300 rpm for 2 min to obtain slurry A;

[0097] (2) adding 24 g of methyl perfluoroacetate to slurry A at room temperature, stirring at 400 rpm for 20 min, to obtain slurry B;

[0098] (3) Add 24 g of diethylenetriamine to slurry B at room temperature, stir evenly, and place in a 50°C constant temperature box to stand and solidify to obtain a sustained-release solid tracer.

[0099] Embodiment 4:

[0100] (1) After 40 g of E-35 and 60 g of softened E-20 were mixed uniformly at room temperature, 1 g of turpentine and 5 g of ethyl acetate were added in sequence, and the mixture was stirred at 100 rpm for 1 min to obtain slurry A;

[0101] (2) adding 20 g of methyl perfluorononanoate and 10 g of perfluorooctyl ethyl acrylate to slurry A in sequence at room temperature, and stirring at 300 rpm for 30 min to obtain slurry B;

[0102] (3) Add 24 g of N-aminoethylpiperazine to slurry B at room temperature, stir evenly, and place in a 50° C. constant temperature box to stand and solidify to obtain a sustained-release solid tracer.

[0103] Embodiment 5:

[0104] (1) After 55 g of E-51 and 45 g of softened E-12 were mixed uniformly at room temperature, 2 g of furfuryl alcohol and 4 g of ethyl acetate were added in sequence, and the mixture was stirred at 200 rpm for 10 min to obtain slurry A;

[0105] (2) adding 30 g of perfluoroheptane to slurry A at room temperature, stirring at 200 rpm for 10 min, to obtain slurry B;

[0106] (3) Add 24 g of 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiroundecane adduct to slurry B at room temperature, stir evenly, and place in a 50° C. constant temperature box to allow for curing and forming, thereby obtaining a sustained-release solid tracer.

[0107] Embodiment 6:

[0108] (1) After 30 g of E-35 and 70 g of softened E-10 were mixed uniformly at room temperature, 2 g of turpentine and 4 g of toluene were added in sequence, and the mixture was stirred at 300 rpm for 1 min to obtain slurry A;

[0109] (2) adding 30 g of perfluorobenzene to slurry A at room temperature, stirring at 100 rpm for 20 min, to obtain slurry B;

[0110] (3) Add 24 g of m-xylylenediamine to slurry B at room temperature, stir evenly, and place in a 50° C. constant temperature box to allow to solidify and form, thereby obtaining a sustained-release solid tracer.

[0111] Embodiment 7:

[0112] (1) Add 2 g of turpentine and 4 g of toluene to 100 g of E-35 at room temperature, and stir at 300 rpm for 1 min to obtain slurry A;

[0113] (2) adding 30 g of perfluorobenzene to slurry A at room temperature, stirring at 100 rpm for 20 min, to obtain slurry B;

[0114] (3) Add 24 g of m-xylylenediamine to slurry B at room temperature, stir evenly, and place in a 50° C. constant temperature box to allow to solidify and form, thereby obtaining a sustained-release solid tracer.

[0115] The present application measures the heat resistance of the cured product by its softening temperature. The lower the softening temperature, the worse the heat resistance of the product.

[0116] Figure 1 This is a comparison chart of the softening temperatures of the sustained-release solid tracers prepared by curing at 50° C. in Examples 1-7 of the present application.

[0117] Figure 1It is shown in the figure: Example 1 is a polyamide curing agent, Examples 2-3 are aliphatic polyamine curing agents, Examples 4-5 are alicyclic polyamine curing agents, and Examples 6-7 are aromatic amine curing agents. The softening temperature of the cured products of all examples is greater than 80°C. By comparing the influence of the four types of curing agents on the softening temperature of the cured products, it can be seen that under the same curing conditions, the heat resistance of the cured products is: aromatic amine curing agent> alicyclic polyamine curing agent> aliphatic polyamine curing agent> polyamide curing agent; Examples 2 and 3 are both aliphatic polyamine curing agents, the difference is that Example 2 adds o-cresol as an accelerator, so that the softening temperature of the cured product is increased from 84°C without an accelerator to 94°C, indicating that the addition of an accelerator can improve the heat resistance of the cured product; the difference between Examples 6 and 7 is that Example 6 prefers a mixture of epoxy resins E-35 and E-10, while Example 7 only uses one epoxy resin, E-35. The softening temperatures of the cured products of Examples 6 and 7 are 121° C. and 130° C., respectively. Increasing the amount of resin with a large epoxy value will improve the heat resistance of the cured product.

[0118] In order to compare the influence of curing agent and curing reaction temperature on the softening point of epoxy cured product and the effective component content of tracer in the obtained cured product, four comparative examples were conducted with Example 2 and Example 4 as the benchmark, corresponding epoxy resin and tracer were selected, and the proportions of other corresponding components were the same as those in Example 2 or 4. The content of tracer component in the cured product in the examples and comparative examples was measured and calculated by thermogravimetric analyzer.

[0119] Comparative Example 1:

[0120] (1) After 35 g of E-42 and 65 g of softened E-06 were mixed uniformly at room temperature, 3 g of dibutyl phthalate and 3 g of ethanol were added in sequence, and the mixture was stirred at 300 rpm for 2 min to obtain slurry A;

[0121] (2) adding 24 g of methyl perfluoroacetate to slurry A at room temperature, stirring at 400 rpm for 20 min, to obtain slurry B;

[0122] (3) 2 g of o-cresol and 24 g of divinylpropylamine were added to slurry B at room temperature, stirred evenly, and placed in a 50°C constant temperature box for curing to obtain a sustained-release solid tracer. The results are shown in Table 3.

[0123] The curing temperatures of Example 2 and Comparative Example 1 are both 50° C., the difference being that Example 2 uses diethylenetriamine as a curing agent, while Comparative Example 1 uses divinylpropylamine as a curing agent.

[0124] The results in Table 3 show that the softening point of the solidified product of Example 2 is 94°C, and the softening point of the solidified product of Comparative Example 1 is 38°C, indicating that under the same curing conditions, the heat resistance of the solidified products is quite different due to the different curing agents. The solidified product obtained in Comparative Example 1 does not meet the use environment of more than 60°C in oil and gas fields; because the curing reaction is carried out below the boiling point (68°C) of the perfluoroacetic acid methyl ester tracer, the tracer content in the cured products of Example 2 and Comparative Example 1 is 14.9%, which is very close to the initial addition ratio of the tracer, indicating that the curing conditions will not cause serious loss of the tracer.

[0125] Table 3

[0126]

[0127] Comparative Example 2:

[0128] (1) After 40 g of E-35 and 60 g of softened E-20 were mixed uniformly at room temperature, 1 g of turpentine and 5 g of ethyl acetate were added in sequence, and the mixture was stirred at 100 rpm for 1 min to obtain slurry A;

[0129] (2) adding 20 g of methyl perfluorononanoate and 10 g of perfluorooctyl ethyl acrylate to slurry A in sequence at room temperature, and stirring at 300 rpm for 30 min to obtain slurry B;

[0130] (3) Add 24 g of menthane diamine to slurry B at room temperature, stir evenly, and place in a 50°C constant temperature box to solidify and form, thereby obtaining a sustained-release solid tracer. The results are shown in Table 4.

[0131] The curing temperatures of Example 4 and Comparative Example 2 are both 50° C., the difference being that Example 4 uses N-nitroethylpiperazine as a curing agent, while Comparative Example 2 uses menthanediamine as a curing agent.

[0132] The results in Table 4 show that the softening point of the solidified product of Example 4 is 94°C, and the softening point of the solidified product of Comparative Example 1 is 46°C, indicating that under the same curing conditions, the heat resistance of the solidified products is quite different due to different curing agents. The solidified product obtained in Comparative Example 2 does not meet the use environment of more than 60°C in oil and gas fields; the tracer content in the cured products of Example 4 and Comparative Example 2 is 18.6%, which is very close to the initial addition ratio of the tracer, indicating that the curing conditions will not cause serious loss of the tracer.

[0133] Table 4

[0134]

[0135] Comparative Example 3:

[0136] (1) After 35 g of E-42 and 65 g of softened E-06 were mixed uniformly at room temperature, 3 g of dibutyl phthalate and 3 g of ethanol were added in sequence, and the mixture was stirred at 300 rpm for 2 min to obtain slurry A;

[0137] (2) adding 24 g of methyl perfluoroacetate to slurry A at room temperature, stirring at 400 rpm for 20 min, to obtain slurry B;

[0138] (3) 2 g of o-cresol and 24 g of divinylpropylamine were added to slurry B at room temperature, stirred evenly, and placed in a 100°C constant temperature box for curing to obtain a sustained-release solid tracer. The results are shown in Table 5.

[0139] The difference between Comparative Example 1 and Comparative Example 3 is the curing temperature. The curing temperature of Comparative Example 1 is 50°C, and the curing temperature of Comparative Example 3 is 100°C. The difference between Example 2 and Comparative Example 3 is that Example 2 uses diethylenetriamine as a curing agent and the curing temperature is 50°C, while Comparative Example 3 uses divinylpropylamine as a curing agent and the curing temperature is 100°C.

[0140] The results in Table 5 show that, since Comparative Example 3 adopts a relatively high curing temperature (100° C.), the softening point of the cured product thereof is increased from 38° C. in Comparative Example 1 to 65° C., which can basically meet the production environment requirement of 60° C. for oil and gas field production wells. However, since the curing reaction is carried out at 100° C., the perfluoroacetic acid methyl ester tracer with a boiling point of 68° C. evaporates during the curing reaction, and therefore, the tracer content in the cured product of Comparative Example 3 is only 7.6%, which is a serious loss.

[0141] For example, to produce 1 kg of sustained-release solid methyl perfluoroacetate tracer (all raw materials add up to 1 kg), the epoxy cured product is synthesized according to the mass percentage of the tracer effective component of 15%. A total of 15%×1kg=0.15kg of tracer is added to the initial raw materials. Since the curing reaction temperature is much higher than the boiling point of the tracer, the actual tracer content in the epoxy cured product in Comparative Example 3 is 7.6%×1kg=0.076kg, and the tracer loss rate reaches (0.15-0.076) / 0.15×100%=49.3%; if the selling price of this tracer is 10,000 yuan / kg, then the loss is 49.3%×1kg×10,000 yuan / kg=4933 yuan.

[0142] Therefore, although the epoxy cured product that basically meets the requirements of the production site can be obtained by increasing the curing temperature, the high curing temperature leads to large economic losses caused by the loss of tracer raw materials. Therefore, it is necessary to use a suitable temperature and preferably a suitable curing agent to meet the requirements of the sustained-release solid tracer product.

[0143] Table 5

[0144]

[0145] Comparative Example 4:

[0146] (1) After 35 g of E-42 and 65 g of softened E-06 were mixed uniformly at room temperature, 3 g of dibutyl phthalate and 3 g of ethanol were added in sequence, and the mixture was stirred at 300 rpm for 2 min to obtain slurry A;

[0147] (2) adding 24 g of methyl perfluoroacetate to slurry A at room temperature, stirring at 400 rpm for 20 min, to obtain slurry B;

[0148] (3) 2 g of o-cresol and 24 g of divinylpropylamine were added to slurry B at room temperature, stirred evenly, and placed in a 25°C constant temperature box for curing to obtain a sustained-release solid tracer. The results are shown in Table 6.

[0149] Comparative Example 1 is different from Comparative Example 4 in terms of curing temperature. The curing temperature of Comparative Example 1 is 50° C., and the curing temperature of Comparative Example 4 is 25° C. The difference between Example 2 and Comparative Example 4 is that Example 2 uses diethylenetriamine as a curing agent and the curing temperature is 50° C., while Comparative Example 4 uses divinylpropylamine as a curing agent and the curing temperature is 25° C.

[0150] The results in Table 6 show that Comparative Example 4 uses a curing temperature lower than that of the present invention for the curing reaction, and the softening point of the cured product is reduced from 38°C in Comparative Example 1 to 28°C, which cannot meet the production environment requirements of 60°C and above for oil and gas field production wells. Comparing Comparative Example 1 with Comparative Example 4, it can be seen that the reduction in curing temperature will lead to a reduction in the softening point of the epoxy cured product; since the curing reaction is carried out below the boiling point (68°C) of the perfluoroacetic acid methyl ester tracer, the tracer content in the cured products of Example 2 and Comparative Example 4 is 14.9%, which is very close to the initial addition ratio of the tracer, indicating that the curing conditions will not cause serious loss of the tracer.

[0151] Table 6

[0152]

[0153] Application Example 1

[0154] The time is: September 2023-March 2024.

[0155] 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 15%. 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 13.5-14.5%.

[0156] 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 mass: 20%-80% of bisphenol A epoxy resin, 5%-30% of tracer, 5%-60% of curing agent, 0%-25% of accelerator and 1%-15% of diluent, wherein the tracer is at least one of methyl perfluoroformate, methyl perfluoroacetate, methyl perfluorobutyrate, methyl perfluorononanoate, perfluoroheptyl ethyl acrylate, perfluorooctyl ethyl acrylate, perfluoroheptane and perfluorobenzene; and the curing agent is one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyamide, N-aminoethylpiperazine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiroundecane adduct and meta-phenylenediamine.

2. The sustained-release solid tracer according to claim 1, characterized in that: The bisphenol A type epoxy resin is one or more of E-51, E-42, E-35, E-20, 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-51, E-42, and E-35.

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 of types E-51, E-42 and / or E-35 in the mixture is greater than or equal to 30% by mass; the rest are bisphenol A epoxy resins of types E-20, E-12, E-10 and / or E-06.

5. The sustained-release solid tracer according to claim 1, characterized in that: The accelerator is one or more of phenol, o-cresol, nonylphenol, resorcinol, 2,4,6-tris(dimethylaminomethyl)phenol and triethanolamine.

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

7. The method for preparing a sustained-release solid tracer according to any one of claims 1 to 6, characterized in that: The following steps are involved: Weigh the raw materials according to any one of claims 1 to 6, Add a diluent to the bisphenol A epoxy resin, and stir at a speed of 100 rpm to 500 rpm for 5 to 20 minutes to obtain slurry A; Add a tracer to slurry A, and stir at a speed of 100 rpm to 500 rpm for 5 to 30 min to obtain slurry B; Add a curing agent to slurry B, then add an accelerator, stir evenly, and let stand at 30-50° C. to cure and form, thereby preparing a sustained-release solid tracer.

8. The preparation method according to claim 7, characterized in that: When the bisphenol A epoxy resin is selected from bisphenol A epoxy resins with models of E-20, E-12, E-10 and / or E-6, the bisphenol A epoxy resin needs to be heated and softened first.

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