Medium-temperature cured slow-release solid tracer agent and preparation method thereof

Abstract

The invention discloses a medium-temperature cured 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: 20-70% of bisphenol A epoxy resin, 5-40% of a tracer, 5-35% of a curing agent, 0-15% of an accelerant and 1-20% of a diluent. Bisphenol A type epoxy resin is used as a slow-release matrix of the solid tracer, an oil-phase tracer or a gas-phase tracer with the boiling point ranging from 90 DEG C to 150 DEG C is used as an effective component, a curing agent and an accelerant are optimized, and the slow-release solid tracer is rapidly prepared at the temperature lower than 100 DEG C; and the curing time is shortened to dozens of minutes from the original several hours or days. The preparation method is relatively mild in process condition, relatively low in equipment requirement, short in curing time, high in production efficiency and suitable for 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 medium-temperature solidified slow-release solid tracer and a preparation method thereof. Background Art

[0002] With the application of tertiary oil recovery technology in oil fields and the need to adjust and tap the potential of oil fields, tracer technology has been widely used and has achieved good results. The key to the application of tracer technology lies in the effective time of the tracer in underground operations. In order to achieve the purpose of long-term tracer effect, the tracer is usually prepared into a solid with a slow-release effect and put into underground use, so that the active ingredients of the tracer are slowly released and the service life of the tracer is extended.

[0003] The common method for preparing slow-release solid tracers is to mix the tracer active component into epoxy resin, and form a cured product by reacting the epoxy resin with a curing agent, so that the tracer is coated in the epoxy cured product. The epoxy cured product slowly releases the tracer active component in the downhole environment, thereby achieving the purpose of long-term effect. There are many types of tracers commonly used in oil and gas fields with boiling points in the range of 90-150°C. For example, the boiling point of methyl perfluoropropionate is 95°C, and the boiling point of methyl perfluorohexanoate is 122°C. If this type of tracer is prepared by a high-temperature curing process, although the curing time during the preparation process is relatively short, the high temperature of the curing process will accelerate the volatilization of the tracer, resulting in the loss of the active component of the tracer; if a low-temperature curing (curing at 30°C or below) or room temperature curing (curing at 30-50°C) process is used, although the curing process temperature is relatively low and the tracer is not easy to evaporate, the curing time is as long as several hours or even days due to the low curing temperature, which is not conducive to industrial production.

[0004] At present, most of the sustained-release solid tracers use bisphenol A epoxy resin with good heat resistance as the base, and the solid tracers are prepared by optimizing the curing agent and other additives. However, these curing processes or methods list a large number of tracers and curing agents, but they are not optimized according to the boiling point characteristics of the tracers, and are not necessarily suitable for application in actual industrial production. For example, the Chinese patent "A sustained-release long-acting tracer and its preparation method" (publication number: CN 113653486 A) with application number 202111034040.4 mentions that Example 1 is cured at 80°C for 2h (120min), and the tracer used is methyl perfluorooctanoate with a boiling point of 158°C (760mmHg). Example 2 is cured at 65°C for 4h (240min), and the tracer used is perfluoromethylcyclopentane with a boiling point of 48°C.

[0005] So far, there are no reports or patents specifically for the rapid curing process of 90-150°C medium-temperature 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 medium-temperature curing (50-100° C.) sustained-release solid tracer.

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

[0008] The technical solution adopted by the present invention is:

[0009] According to the first aspect of the present application, a sustained-release tracer is provided, comprising the following raw materials in mass percentage: 20%-70% bisphenol A epoxy resin, 5%-40% tracer, 5%-35% curing agent, 0%-15% accelerator, and 1%-20% diluent, wherein the tracer is selected from an oil phase tracer or a gas phase tracer with a boiling point in the range of 90-150°C, and the curing agent is at least one of N,N-dimethylpiperazine, triethylenediamine, tetramethylamine, 2-methylimidazole, 2-phenylimidazole, boron trifluoride-monoethylamine, boron trifluoride-n-butylamine, and boron trifluoride-dimethylaniline; the sustained-release solid tracer is obtained by a curing reaction of the above raw materials under a temperature condition of 50-100°C.

[0010] In some embodiments, the bisphenol A epoxy resin is one or more of E-54, E-44, E-35, E-20, E-14, 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-20, E-14, E-10, and E-06.

[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-44, and E-35 accounts for less than or equal to 40% of the mass percentage of the mixture; the rest are selected from the bisphenol A epoxy resins of types E-20, E-14, E-10, and E-06.

[0013] In some embodiments, the oil phase tracer with a boiling point in the range of 90-150° C. is at least one of methyl perfluoropropionate, methyl perfluoropentanoate, methyl perfluorohexanoate, methyl perfluoroheptanoate, perfluorononyl ethyl acrylate, and perfluorodecyl ethyl acrylate.

[0014] In some embodiments, the gas phase tracer with a boiling point in the range of 90-150° C. is at least one of perfluorooctane, perfluorononane, perfluorodimethylcyclohexane, perfluorotoluene, and perfluoronaphthalene.

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

[0016] In some embodiments, the promoter is one or more of diethylamine, aniline, triethylamine, monoethylamine, and n-hexylamine.

[0017] In some preferred embodiments, a sustained-release tracer comprises the following raw materials in percentage by mass: 30%-60% bisphenol A epoxy resin, 8%-30% tracer, 10%-30% curing agent, 0%-10% accelerator, and 1%-15% diluent.

[0018] According to the second aspect of the present application, a method for preparing a sustained-release solid tracer is provided, comprising the following steps:

[0019] (1) weighing the raw materials according to any of the above items,

[0020] (2) adding a diluent to the bisphenol A epoxy resin, stirring at a speed of 100 rpm to 500 rpm for 1 to 30 min to obtain slurry A;

[0021] (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;

[0022] (4) Add an accelerator to slurry B, and then add a curing agent, and stir rapidly to allow the accelerator and curing agent to be evenly mixed in the slurry. Allow the slurry to stand at 50-100° C. to allow the slurry to undergo a curing reaction. When the slurry is completely hardened, a slow-release solid tracer is obtained.

[0023] Among them, RPM is the abbreviation of revolutions per minute, which represents the number of times the device rotates per minute.

[0024] In some embodiments, when the bisphenol A epoxy resin is selected from bisphenol A epoxy resins of types E-20, E-14, E-10 and / or E-6, the bisphenol A epoxy resin needs to be heated and softened first.

[0025] In some preferred embodiments, the heating and softening is heating to 65-110° C. and softening for 8-15 min.

[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 this application are:

[0028] The sustained-release solid tracer of the present application uses bisphenol A epoxy resin as the sustained-release matrix of the solid tracer, and the active ingredient is an oil phase tracer or a gas phase tracer with a boiling point in the range of 90-150°C. By optimizing the curing agent and the accelerator, the sustained-release solid tracer can be quickly prepared under conditions below 100°C, and the curing time is shortened from several hours or days to tens of minutes.

[0029] The rapid curing process of the medium-boiling oil phase or gas phase tracer for oil and gas fields of the present application can quickly complete the curing reaction of epoxy resin at a temperature below 100°C, which is beneficial to improving production efficiency while reducing energy consumption. The preparation method is simple to operate, has a relatively low curing temperature, a short curing time, and high production efficiency, and is suitable for industrial production.

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

[0031] Figure 1 This is a comparison chart of the curing time of Examples 1-9 of the present application when cured at 90°C. DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[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] 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.

[0036] It is well known to those skilled in the art of epoxy resin that epoxy resin curing reaction is divided into four situations: 1) low temperature curing: 30°C and below; 2) room temperature curing: 30-50°C; 3) medium temperature curing: 50-100°C; 4) high temperature curing: 100°C and above. The technical solution of this application is a medium temperature curing (50-100°C curing) sustained-release solid tracer 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 bisphenol A epoxy resin, a diluent, and a curing agent under the action of an accelerator or without the action of an accelerator, and curing at a medium temperature (curing at 50-100°C).

[0038] The sustained-release solid tracer (composite material) comprises the following raw materials in percentage by mass: 20%-70% of bisphenol A epoxy resin, 5%-40% of tracer, 5%-35% of curing agent, 0%-15% of accelerator and 1%-20% of diluent.

[0039] In some embodiments, the tracer is an oil phase tracer or a gas phase tracer with a boiling point in the range of 90-150°C; the oil phase tracer is one or more of methyl perfluoropropionate, methyl perfluoropentanoate, methyl perfluorohexanoate, methyl perfluoroheptanoate, perfluorononanyl ethyl acrylate, and perfluorodecanyl ethyl acrylate; the gas phase tracer is one or more of perfluorooctane, perfluorononane, perfluorodimethylcyclohexane, perfluorotoluene, and perfluoronaphthalene.

[0040] Generally speaking, when tracers are mixed, tracers of the same type are used.

[0041] The boiling points of the above compounds are shown in Table 1.

[0042] Table 1

[0043]

[0044] When the tracer is a mixture of multiple tracers, those skilled in the art can adjust the ratio as needed. Because the preferred tracer of the present application does not react with the other four components, and there is no reaction between the tracers. After the bisphenol A epoxy resin reacts with the raw materials such as the 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 sustained-release solid tracer.

[0045] In some embodiments, the curing agent is one or more of N,N-dimethylpiperazine, triethylenediamine, tetramethylamine, 2-methylimidazole, 2-phenylimidazole, boron trifluoride-monoethylamine, boron trifluoride-n-butylamine, and boron trifluoride-dimethylaniline.

[0046] The function of the curing agent is to react with the epoxy resin to form a three-dimensional cross-linked network structure and generate a polymer (cured product). There are many types of curing agents, and their properties vary greatly.

[0047] This application requires that the curing reaction of the epoxy resin be carried out in the range of 50-100°C, and that it be completely cured and formed within 90 minutes. Taking the commonly used medium-temperature curing agents piperidine and 2-heptadecylimidazole as examples, when the curing reaction is carried out at a temperature of 100°C, the curing time of the epoxy resin is 2-8h. Due to the addition of tracer components, the curing time of the epoxy resin is also extended, and some curing times reach more than 10h. The longer the curing time, the lower the production efficiency of the solid tracer, and it is bound to be necessary to shorten the curing time. In fact, the demand for tracers with a boiling point in the range of 90-150°C at the oil and gas field production site is very large. Due to the limitation of its boiling point, this type of tracer is more suitable for epoxy resin curing reaction at 50-100°C, and will not cause large evaporation losses of the effective components of the tracer due to excessively high curing temperature. However, according to the current epoxy curing material system, a curing time of several hours is not conducive to large-scale and efficient production. After a large number of experiments, the inventors screened out suitable epoxy resins and medium-temperature curing agents, and by optimizing the ratio of accelerators, controlled the curing time of the epoxy resin to be within 1.5 hours when the curing reaction occurred at 50-100°C, thereby greatly shortening the curing time and improving the production efficiency of the solid tracer.

[0048] In some embodiments, the diluent is one or more of dioctyl phthalate, acetone, turpentine, xylene, ethanol, and ethyl acetate.

[0049] The diluent can appropriately reduce the viscosity of the epoxy resin and also disperse the tracer in the slurry well.

[0050] When multiple diluents are selected, there is no specific requirement for the ratio of the diluents, as long as the epoxy resin and the tracer can be fully dispersed. Preferably, one or two diluents are selected, and one diluent is added each time, stirred evenly, and then another diluent is added and stirred evenly again.

[0051] In some embodiments, the bisphenol A epoxy resin is one or more of E-54, E-44, E-35, E-20, E-14, E-10, and E-06. The models are all national standard numbers of bisphenol A epoxy resins, see "Bisphenol A Epoxy Resin" for details, the standard number is GB / T 13657-2011.

[0052] 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.

[0053] 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.

[0054] The bisphenol A epoxy resin models and epoxy values ​​mentioned in this application are shown in Table 2.

[0055] Table 2

[0056] Domestic models Epoxy value / (eq / 100g) E-54 0.52-0.56 E-44 0.41-0.47 E-35 0.30-0.40 E-20 0.18-0.22 E-14 0.10-0.18 E-10 0.08-0.12 E-06 0.04-0.07

[0057] In order to ensure that the curing reaction of epoxy resin is accelerated under medium temperature conditions of 50-100°C and the curing time is shortened, the epoxy resin must be screened and a medium temperature curing agent compatible with the epoxy resin must be selected. After systematic experimental research, the inventors have selected E-54, E-44, E-35, E-20, E-14, E-10, and E-06 as epoxy resins suitable for the technical solution of the present application.

[0058] In some embodiments, when the bisphenol A epoxy resin is a type of bisphenol A epoxy resin, the type is selected from E-20, E-14, E-10, and E-06.

[0059] 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-44, and E-35 accounts for less than or equal to 40% (≤40%) of the (total) mass of the mixture; the remaining bisphenol A epoxy resins selected from the types E-20, E-14, E-10, and E-06 account for greater than or equal to 60% (i.e., ≥60%).

[0060] 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 less than or equal to 40%; the ratio of epoxy resins with an epoxy value less than 0.3 should be greater than or equal to 60%, and can reach up to 100%.

[0061] In some preferred embodiments, one or two bisphenol A epoxy resins are selected.

[0062] In some embodiments, the promoter is one or more of diethylamine, aniline, triethylamine, monoethylamine, and n-hexylamine.

[0063] In some preferred embodiments, a sustained-release tracer comprises the following raw materials in percentage by mass: 30%-60% bisphenol A epoxy resin, 8%-30% tracer, 10%-30% curing agent, 0%-10% accelerator, and 1%-15% diluent.

[0064] The core of the technical solution is to achieve rapid curing (curing time is less than 1.5h) at medium temperature (50-100°C). To achieve this goal, three aspects are mainly taken into consideration: 1) The preferred curing agent must be a compatible medium-temperature curing agent (i.e., it can undergo curing reaction in the range of 50-100°C). Therefore, N,N-dimethylpiperazine, triethylenediamine, tetramethylamine, 2-methylimidazole, 2-phenylimidazole, boron trifluoride-monoethylamine, boron trifluoride-n-butylamine, and boron trifluoride-dimethylaniline are screened out from four types of medium-temperature curing agents, namely, alicyclic polyamines, tertiary amines, imidazoles, and boron trifluoride complexes; 2) In order to further improve the curing rate of boron trifluoride complex curing agents, the matching accelerators, namely, diethylamine, aniline, triethylamine, monoethylamine, and n-hexylamine, are also optimized. The addition of accelerators can further shorten the curing time; 3) The optimization of epoxy resin also affects the curing rate, ensuring that the proportion of resin with low epoxy value (i.e. high molecular weight) is higher than that of resin with high epoxy value (with epoxy value of 0.3 as the limit).

[0065] The preparation method of the sustained-release solid tracer comprises the following steps:

[0066] (1) Weigh the raw materials according to the above-mentioned ratio,

[0067] (2) adding a diluent to the bisphenol A epoxy resin, stirring at a speed of 100 rpm to 500 rpm for 1 to 30 min to obtain slurry A;

[0068] (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;

[0069] (4) Add an accelerator to slurry B, and then add a curing agent, and stir rapidly to allow the accelerator and curing agent to be evenly mixed in slurry B. Allow the slurry to stand at 50-100° C. to allow the slurry to undergo a curing reaction. When the slurry is completely hardened, a slow-release solid tracer is obtained.

[0070] The steps (1), (2) and (3) of the reaction are carried out at room temperature, which is usually in the range of 10-30°C.

[0071] In some of the embodiments, the bisphenol A epoxy resins of models E-20, E-14, E-10, and E-06 are solid (paste) at room temperature and need to be heated and softened before adding a diluent.

[0072] In some embodiments, the heating to soften is heating to 65-110° C. for 8-15 min.

[0073] In some of the embodiments, bisphenol A epoxy resins of types E-54, E-44, and E-35 are in liquid state at room temperature and are directly added to the diluent.

[0074] In the bisphenol A epoxy resin series, bisphenol A epoxy resin with low epoxy value (i.e., large molecular weight) has high viscosity. After adding diluent, the viscosity of 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.

[0075] RPM is the abbreviation for revolutions per minute, which represents the number of times the device rotates per minute.

[0076] In some embodiments, the solid tracer has certain morphological requirements. Those skilled in the art can adjust it as needed, such as preparing solid tracers in various shapes such as granules, strips, blocks, rods, etc. 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, it can be quickly stirred evenly, and then the slurry can be transferred into the mold.

[0077] The criterion for judging the curing reaction molding in the embodiment is that the slurry is completely hardened.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] The content of the tracer component in the solidified material in the embodiment is measured and calculated by a thermogravimetric analyzer.

[0082] The bisphenol A epoxy resins of type E-20, E-14, E-10 and E-06 in the embodiments are heated to 65-110° C. and softened for 8-15 minutes before use.

[0083] The solidified material obtained in the examples or comparative examples is a sustained-release solid tracer.

[0084] The following is a description with reference to specific embodiments.

[0085] Embodiment 1:

[0086] (1) After 40 g of E-54 and 60 g of E-14 were mixed uniformly at room temperature, 5 g of dioctyl phthalate and 1 g of ethanol were added in sequence, and the mixture was stirred at 300 rpm for 8 min to obtain slurry A;

[0087] (2) adding 20 g of methyl perfluoropropionate and 20 g of methyl perfluorohexanoate to slurry A in sequence at room temperature, and stirring at 200 rpm for 20 min to obtain slurry B;

[0088] (3) Add 38 g of N,N-dimethylpiperazine to slurry B at room temperature, stir quickly and evenly, and place in a 90° C. constant temperature box to stand and solidify to obtain a sustained-release solid tracer.

[0089] Embodiment 2:

[0090] (1) After 35 g of E-44 and 65 g of E-10 were mixed uniformly at room temperature, 3 g of acetone and 3 g of ethyl acetate were added in sequence, and the mixture was stirred at 500 rpm for 5 min to obtain slurry A;

[0091] (2) adding 46 g of perfluorononyl ethyl acrylate to slurry A at room temperature, and stirring at 100 rpm for 10 min to obtain slurry B;

[0092] (3) Add 38 g of triethylenediamine to slurry B at room temperature, stir quickly and evenly, and place in a 90° C. constant temperature box to stand and solidify to obtain a sustained-release solid tracer.

[0093] Embodiment 3:

[0094] (1) After 40 g of E-35 and 60 g of E-06 were mixed uniformly at room temperature, 4 g of turpentine and 2 g of xylene were added in sequence, and stirred at 100 rpm for 5 min to obtain slurry A;

[0095] (2) adding 46 g of perfluorooctane to slurry A at room temperature, and stirring at 300 rpm for 15 min to obtain slurry B;

[0096] (3) Add 38 g of tetramethylamine to slurry B at room temperature, stir quickly and evenly, and place in a 90° C. constant temperature box to stand and solidify to obtain a sustained-release solid tracer.

[0097] Embodiment 4:

[0098] (1) After 25 g of E-35 and 75 g of E-14 were mixed uniformly at room temperature, 1 g of xylene and 5 g of ethyl acetate were added in sequence, and the mixture was stirred at 200 rpm for 3 min to obtain slurry A;

[0099] (2) adding 47 g of perfluorodimethylcyclohexane to slurry A at room temperature, and stirring at 400 rpm for 25 min to obtain slurry B;

[0100] (3) Add 40 g of 2-methylimidazole to slurry B at room temperature, stir quickly and evenly, and place in a 90° C. constant temperature box to stand and solidify to obtain a sustained-release solid tracer.

[0101] Embodiment 5:

[0102] (1) After 40 g of E-35 and 60 g of E-10 were mixed uniformly at room temperature, 1 g of dioctyl phthalate and 5 g of xylene were added in sequence, and the mixture was stirred at 400 rpm for 10 min to obtain slurry A;

[0103] (2) adding 48 g of perfluoronaphthalene to slurry A at room temperature, and stirring at 500 rpm for 30 min to obtain slurry B;

[0104] (3) Add 42 g of boron trifluoride-monoethylamine to slurry B at room temperature, stir quickly and evenly, and place in a 90° C. constant temperature box to stand and solidify to obtain a sustained-release solid tracer.

[0105] Embodiment 6:

[0106] (1) After 40 g of E-35 and 60 g of E-10 were mixed uniformly at room temperature, 1 g of dioctyl phthalate and 5 g of xylene were added in sequence, and the mixture was stirred at 400 rpm for 10 min to obtain slurry A;

[0107] (2) adding 48 g of perfluoronaphthalene to slurry A at room temperature, and stirring at 500 rpm for 30 min to obtain slurry B;

[0108] (3) 11 g of diethylamine and 42 g of boron trifluoride-monoethylamine were added to slurry B at room temperature, and the mixture was quickly stirred to be uniform. The mixture was then placed in a 90° C. thermostat to be cured and formed, thereby obtaining a sustained-release solid tracer.

[0109] Embodiment 7:

[0110] (1) Add 1 g of xylene and 5 g of ethyl acetate to 100 g of E-20 at room temperature, and stir at 200 rpm for 3 min to obtain slurry A;

[0111] (2) adding 47 g of perfluorodimethylcyclohexane to slurry A at room temperature, and stirring at 400 rpm for 25 min to obtain slurry B;

[0112] (3) Add 40 g of 2-methylimidazole to slurry B at room temperature, stir quickly and evenly, and place in a 90° C. constant temperature box to stand and solidify to obtain a sustained-release solid tracer.

[0113] Embodiment 8:

[0114] (1) After 40 g of E-35 and 60 g of E-10 were mixed uniformly at room temperature, 1 g of dioctyl phthalate and 5 g of xylene were added in sequence, and the mixture was stirred at 400 rpm for 10 min to obtain slurry A;

[0115] (2) adding 48 g of perfluoronaphthalene to slurry A at room temperature, and stirring at 500 rpm for 30 min to obtain slurry B;

[0116] (3) 5 g of diethylamine and 42 g of boron trifluoride-monoethylamine were added to slurry B in sequence at room temperature, and the mixture was quickly stirred to be uniform. The mixture was then placed in a 90° C. constant temperature box and allowed to stand and solidify to obtain a sustained-release solid tracer.

[0117] Embodiment 9:

[0118] (1) After 40 g of E-35 and 60 g of E-10 were mixed uniformly at room temperature, 1 g of dioctyl phthalate and 5 g of xylene were added in sequence, and the mixture was stirred at 400 rpm for 10 min to obtain slurry A;

[0119] (2) adding 48 g of perfluoronaphthalene to slurry A at room temperature, and stirring at 500 rpm for 30 min to obtain slurry B;

[0120] (3) 11 g of n-hexylamine and 42 g of boron trifluoride-monoethylamine were added to slurry B at room temperature, and the mixture was quickly stirred to be uniform. The mixture was then placed in a 90° C. thermostat to be cured and formed, thereby obtaining a sustained-release solid tracer.

[0121] Figure 1 This is a comparison chart of the curing time of Examples 1-9 of the present application when cured at 90°C.

[0122] Figure 1 It is shown in the figure that: Examples 1-2 are alicyclic polyamine curing agents, Example 3 is a tertiary amine curing agent, Examples 4 and 7 are imidazole curing agents, and Examples 5-6, 8-9 are boron trifluoride complex curing agents. By comparing the curing time of the examples, the influence of the type of curing agent on the curing time can be obtained, that is, under the same curing conditions and without adding an accelerator, the curing rate is: imidazole> alicyclic polyamine> tertiary amine> boron trifluoride complex; the difference between Examples 4 and 7 is that Example 4 preferably uses a mixture of epoxy resins E-35 and E-20, while Example 7 only uses one epoxy resin, E-20. The curing time of Examples 4 and 7 is 28 min and 24 min, respectively. By increasing the amount of resin with a small epoxy value, the curing time will be slightly shortened. The curing agents of Examples 5-6 are all boron trifluoride-monoethylamine. The difference is that 11 g of diethylamine is added as an accelerator in Example 6, so that the curing time is reduced from 87 min in Example 5 to 16 min in Example 6. The difference between Examples 6 and 8 is that the accelerator in Example 6 is 11 g of diethylamine, while the accelerator in Example 8 is 5 g of diethylamine. The curing times of Examples 6 and 8 are 16 min and 43 min, respectively, which are shorter than the curing time of Example 5 without adding an accelerator. However, reducing the amount of accelerator will lengthen the curing time. The difference between Example 6 and Example 9 is that the accelerator in Example 6 is 11 g of diethylamine, while the accelerator in Example 9 is 11 g of n-hexylamine. The curing times of Examples 6 and 9 are 16 min and 69 min, respectively, indicating that different types of accelerators have different effects on the curing reaction, and the promoting effect of some accelerators is more significant.

[0123] In order to optimize the compatible curing agent, the inventors conducted a large number of comparative experiments on four types of curing agents, namely, imidazoles, alicyclic polyamines, tertiary amines, and boron trifluoride complexes, and finally screened out the curing agent described in the present application. In order to illustrate the effect of the type of curing agent on the curing reaction time, 2-heptadecylimidazole (imidazoles), piperidine (alicyclic polyamines), 2-N,N-dimethylcyclohexylamine (tertiary amines), and boron trifluoride-benzylamine (boron trifluoride complexes) were used as comparative curing agents to compare the curing time at the same curing temperature.

[0124] Comparative Example 1:

[0125] (1) After 40 g of E-54 and 60 g of E-14 were mixed uniformly at room temperature, 5 g of dioctyl phthalate and 1 g of ethanol were added in sequence, and the mixture was stirred at 300 rpm for 8 min to obtain slurry A;

[0126] (2) adding 20 g of methyl perfluoropropionate and 20 g of methyl perfluorohexanoate to slurry A in sequence at room temperature, and stirring at 200 rpm for 20 min to obtain slurry B;

[0127] (3) Add 38 g of piperidine to slurry B at room temperature, stir quickly and evenly, and place in a 90°C constant temperature box to stand and solidify to obtain a solid tracer. The results are shown in Table 3.

[0128] The difference between Example 1 and Comparative Example 1 is that Example 1 uses N,N-dimethylpiperazine as a curing agent, while Comparative Example 1 uses piperidine as a curing agent. The results in Table 3 show that the curing reaction time of Example 1 is only 35 minutes, while the curing reaction time of Comparative Example 1 is as long as 480 minutes, which is not conducive to improving the efficiency of large-scale production. By comparing the tracer content in the obtained solidified material, it is found that the tracer content in the solidified material of Example 1 is 19.8%, which is very close to the initial concentration of the tracer raw material in the total slurry (20%), and the tracer content in the solidified material of Comparative Example 1 is 12.2%, which is lower than that of Example 1. This is because the curing time is too long, resulting in the loss of the tracer due to volatilization during the curing reaction.

[0129] Table 3

[0130]

[0131] Comparative Example 2:

[0132] (1) After 40 g of E-35 and 60 g of E-06 were mixed uniformly at room temperature, 4 g of turpentine and 2 g of xylene were added in sequence, and stirred at 100 rpm for 5 min to obtain slurry A;

[0133] (2) adding 46 g of perfluorooctane to slurry A at room temperature, and stirring at 300 rpm for 15 min to obtain slurry B;

[0134] (3) Add 38 g of 2-N,N-dimethylcyclohexylamine to slurry B at room temperature, stir quickly and evenly, and place in a 90°C constant temperature box to stand and solidify to obtain a solid tracer. The results are shown in Table 4.

[0135] The difference between Example 3 and Comparative Example 2 is that Example 3 uses tetramethylamine as a curing agent, while Comparative Example 2 uses 2-N,N-dimethylcyclohexylamine as a curing agent. The results in Table 4 show that the curing reaction time of Example 3 is only 35 minutes, while the curing reaction time of Comparative Example 2 is as long as 1800 minutes (30 hours), and the production efficiency is extremely low. By comparing the tracer content in the obtained solidified material, it is found that the tracer content in the solidified material of Example 3 is 23.8%, which is very close to the initial concentration (24%) of the tracer raw material in the total slurry, and the tracer content in the solidified material of Comparative Example 2 is 9.2%, which is much lower than the initial concentration. This is because the curing time is too long, resulting in serious loss of the tracer due to volatilization during the curing reaction.

[0136] Table 4

[0137]

[0138] Comparative Example 3:

[0139] (1) After 25 g of E-35 and 75 g of E-14 were mixed uniformly at room temperature, 1 g of xylene and 5 g of ethyl acetate were added in sequence, and the mixture was stirred at 200 rpm for 3 min to obtain slurry A;

[0140] (2) adding 47 g of perfluorodimethylcyclohexane to slurry A at room temperature, and stirring at 400 rpm for 25 min to obtain slurry B;

[0141] (3) Add 40 g of 2-heptadecylimidazole to slurry B at room temperature, stir quickly and evenly, and place in a 90°C constant temperature box to stand and solidify to obtain a solid tracer. The results are shown in Table 5.

[0142] The difference between Example 4 and Comparative Example 3 is that Example 4 uses 2-methylimidazole as a curing agent, while Comparative Example 3 uses 2-heptadecylimidazole as a curing agent. The results in Table 5 show that the curing reaction time of Example 4 is only 28 minutes, while the curing reaction time of Comparative Example 3 is as long as 300 minutes, which is not conducive to improving production efficiency. By comparing the tracer content in the obtained solidified material, it is found that the tracer content in the solidified material of Example 4 is 23.9%, which is very close to the initial concentration (24%) of the tracer raw material in the total slurry, and the tracer content in the solidified material of Comparative Example 3 is 14.6%, which is significantly lower than the initial concentration. This is because the curing time is too long, resulting in the loss of the tracer due to volatilization during the curing reaction.

[0143] Table 5

[0144]

[0145] Comparative Example 4:

[0146] (1) After 40 g of E-35 and 60 g of E-10 were mixed uniformly at room temperature, 1 g of dioctyl phthalate and 5 g of xylene were added in sequence, and the mixture was stirred at 400 rpm for 10 min to obtain slurry A;

[0147] (2) adding 48 g of perfluoronaphthalene to slurry A at room temperature, and stirring at 500 rpm for 30 min to obtain slurry B;

[0148] (3) Add 42 g of boron trifluoride-benzylamine to slurry B at room temperature, stir quickly and evenly, and place in a 90°C constant temperature box to stand and solidify to obtain a solid tracer. The results are shown in Table 6.

[0149] The difference between Example 5 and Comparative Example 4 is that Example 5 uses boron trifluoride-monoethylamine as a curing agent.

[0150] Comparative Example 4 uses boron trifluoride-benzylamine as a curing agent. The results in Table 6 show that the curing reaction time of Example 5 is only 87 minutes, while the curing reaction time of Comparative Example 4 is as long as 210 minutes, which is not conducive to improving production efficiency. By comparing the tracer content in the obtained solidified material, it is found that the tracer content in the solidified material of Example 5 is 23.7%, which is very close to the initial concentration (24%) of the tracer raw material in the total slurry, and the tracer content in the solidified material of Comparative Example 4 is 16.1%, which is lower than the initial concentration. This is because the curing time is too long, resulting in the loss of the tracer due to volatilization during the curing reaction.

[0151] Table 6

[0152]

[0153]

[0154] Comparative Example 5:

[0155] (1) After 40 g of E-35 and 60 g of E-10 were mixed uniformly at room temperature, 1 g of dioctyl phthalate and 5 g of xylene were added in sequence, and the mixture was stirred at 400 rpm for 10 min to obtain slurry A;

[0156] (2) adding 48 g of perfluoronaphthalene to slurry A at room temperature, and stirring at 500 rpm for 30 min to obtain slurry B;

[0157] (3) 11 g of diethylamine and 42 g of boron trifluoride-benzylamine were added to slurry B at room temperature, and the mixture was quickly stirred and then placed in a 90°C constant temperature box for curing to obtain a solid tracer. The results are shown in Table 7.

[0158] The difference between Example 6 and Comparative Example 5 is that Example 6 uses boron trifluoride-monoethylamine as a curing agent, while Comparative Example 4 uses boron trifluoride-benzylamine as a curing agent. The results in Table 7 show that the curing reaction time of Example 6 is only 16 minutes, while the curing reaction time of Comparative Example 5 is as long as 150 minutes, which is not conducive to improving production efficiency. By comparing the tracer content in the obtained solidified material, it is found that the tracer content in the solidified material of Example 6 is equal to the initial concentration (23%) of the tracer raw material in the total slurry, that is, no tracer loss is caused during the curing process, and the tracer content in the solidified material of Comparative Example 5 is 17.3%, which is lower than the initial concentration. This is because the curing time is too long, resulting in the loss of the tracer due to volatilization during the curing reaction; the difference between Comparative Example 4 and Comparative Example 5 is that diethylamine is added as an accelerator in Comparative Example 5, while no accelerator is added in Comparative Example 4. The curing time of Comparative Example 5 is shortened from 210 minutes in Comparative Example 4 to 150 minutes, indicating that the addition of an accelerator is conducive to shortening the curing time. However, under the non-preferred curing agent conditions, even if an accelerator is added to Comparative Example 5, the curing time is 150 minutes, and there is still a problem of too long curing time, which is not conducive to improving production efficiency.

[0159] Table 7

[0160]

[0161] Application Example 1

[0162] The time is: September 2023-March 2024.

[0163] The oil-gas phase slow-release tracer prepared in the present application was used in a certain downhole operation 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 23%. 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 21-22%.

[0164] The above-mentioned embodiments only express the specific implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the protection scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A sustained-release solid tracer, characterized in that: The invention comprises the following raw materials in percentage by mass: 20%-70% of bisphenol A epoxy resin, 5%-40% of tracer, 5%-35% of curing agent, 0%-15% of accelerator and 1%-20% of diluent, wherein the tracer is selected from oil phase tracer or gas phase tracer with a boiling point in the range of 90-150° C., and the curing agent is at least one of N,N-dimethylpiperazine, triethylenediamine, tetramethylamine, 2-methylimidazole, 2-phenylimidazole, boron trifluoride-monoethylamine, boron trifluoride-n-butylamine and boron trifluoride-dimethylaniline; and the sustained-release solid tracer is obtained by curing the above raw materials at a temperature of 50-100° C.

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-54, E-44, E-35, E-20, E-14, 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-20, E-14, E-10, and E-06.

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-44 and E-35 accounts for less than or equal to 40% of the mass percentage of the mixture; the rest are selected from the bisphenol A epoxy resins of the types E-20, E-14, E-10 and E-06.

5. The sustained-release solid tracer according to claim 1, characterized in that: The oil phase tracer with a boiling point in the range of 90-150°C is at least one of methyl perfluoropropionate, methyl perfluoropentanoate, methyl perfluorohexanoate, methyl perfluoroheptanoate, perfluorononyl ethyl acrylate, and perfluorodecyl ethyl acrylate; the gas phase tracer with a boiling point in the range of 90-150°C is at least one of perfluorooctane, perfluorononane, perfluorodimethylcyclohexane, perfluorotoluene, and perfluoronaphthalene.

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

7. The sustained-release solid tracer according to claim 1, characterized in that: The accelerator is one or more of diethylamine, aniline, triethylamine, monoethylamine and n-hexylamine.

8. The sustained-release solid tracer according to any one of claims 1 to 7, characterized in that: The invention comprises the following raw materials in percentage by mass: 30%-60% of bisphenol A epoxy resin, 8%-30% of tracer, 10%-30% of curing agent, 0%-10% of accelerator and 1%-15% of diluent.

9. A method for preparing a sustained-release solid tracer, characterized in that: The following steps are involved: Weigh the raw materials according to any one of claims 1 to 8, Adding a diluent to the bisphenol A epoxy resin, stirring at a speed of 100 rpm to 500 rpm for 1 to 30 min, to obtain slurry A; Adding a tracer to slurry A, stirring at a speed of 100 rpm to 500 rpm for 5 to 30 min, to obtain slurry B; Add an accelerator to slurry B, and then add a curing agent, stir quickly to make the accelerator and curing agent evenly mixed in the slurry, and let it stand at 50-100°C to allow the slurry to undergo a curing reaction. When the slurry is completely hardened, a slow-release solid tracer is obtained.

10. The preparation method according to claim 9, characterized in that: When the bisphenol A epoxy resin is selected from bisphenol A epoxy resins with models of E-20, E-14, E-10 and / or E-6, the bisphenol A epoxy resin needs to be heated and softened first.

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