High-temperature-cured slow-release solid tracer and preparation method thereof

Abstract

The invention discloses a high-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: 15-75% of bisphenol A epoxy resin, 5-50% of a tracer, 5-40% of a curing agent, 0-20% of an accelerant and 1-20% of a diluent, wherein the tracer agent is an oil-phase tracer agent or a gas-phase tracer agent with the boiling point being 100 DEG C or above; the slow-release solid tracer agent is obtained by carrying out a curing reaction on the raw materials at the temperature of 100-200 DEG C. The invention further discloses a preparation method of the slow-release solid tracer agent. According to the technical scheme, the release rate and the release period of the solid tracer agent can be adjusted by adjusting the proportion of all the components of the system and the curing process conditions, so that the application requirements of a production site 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 high-temperature solidified slow-release solid tracer and a preparation method thereof. Background Art

[0002] Tracer technology can not only qualitatively determine the existence of high permeability bands, cracks, large pores, gas channeling channels, etc. in the formation, but also quantitatively determine the formation parameters related to high permeability bands, cracks, pores, gas channeling channels, etc., providing guidance and basis for oil and gas field development. After more than half a century of development, tracer technology has gradually shown a trend of diversified tracer agents, simplified construction, accurate detection, and quantitative interpretation technology. At present, the key to the application of tracer technology is how to achieve a long release period and stable release rate of the tracer's effective components.

[0003] In order to extend the release period of the active ingredients of the tracer in the well, the tracer components are usually mixed into the epoxy resin slurry, and the curing reaction of the epoxy resin and the curing agent is used to make the active components of the tracer be encapsulated in the epoxy resin cured product. The heat resistance, mechanical properties and chemical stability of epoxy cured products depend to a large extent on the curing agent and the curing process conditions. The intensity of the curing reaction determines the performance of the epoxy cured product. Generally speaking, a curing agent with a high curing temperature can prepare an epoxy resin cured product with excellent heat resistance.

[0004] If a high-boiling-point tracer is cured at a higher curing temperature, the resulting epoxy-based solid tracer will have better heat resistance and chemical stability, can maintain a longer service life underground, and extend the release cycle of the tracer. However, if the heat resistance and chemical stability of the epoxy resin cured product are too good, the diffusion process of the tracer's effective components from the inside of the epoxy matrix skeleton structure to the outside will be hindered, resulting in the tracer component concentration in the produced fluid being too low, failing to reach the lower limit of the detection concentration or causing excessive detection errors, which in turn affects the subsequent qualitative and quantitative interpretation of the tracer technology. Therefore, the release rate of the solid tracer should be optimized so that the release cycle and release rate of the tracer meet the use requirements of the oil and gas industry production site, in order to give full play to the application advantages of the tracer technology.

[0005] There are many types of tracers commonly used in oil and gas fields with boiling points above 100°C. There is a wide selection of high-temperature curing agents that are compatible with this type of tracer, and the curing conditions are controllable over a wide range. However, not all curing agent systems and process conditions can produce suitable solid tracers that meet the release rate and release cycle required by the oil and gas industry production site. Generally speaking, the oil and gas industry production site requires that the release rate of the slow-release solid tracer product be moderate, which can ensure that the detection equipment can detect the tracer components from the produced water sample (that is, reach the lower limit of the detection equipment), and ensure a certain use time (that is, the release cycle), and the tracer components can be detected from the produced water sample within the release cycle.

[0006] At present, there are no reports or patents on adjusting the release rate of solid tracers by optimizing the solidification process of high boiling point tracers (boiling point at 100°C and above). 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 high temperature curing (100-200° 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: 15%-75% bisphenol A epoxy resin, 5%-50% tracer, 5%-40% curing agent, 0%-20% accelerator, and 1%-20% diluent; wherein the tracer is an oil phase tracer or a gas phase tracer having a boiling point of 100°C or above; and the sustained-release solid tracer is obtained by a curing reaction of the above raw materials under a temperature condition of 100-200°C.

[0011] In some embodiments, the bisphenol A epoxy resin is at least one of E-51, E-42, E-35, E-14, 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 bisphenol A epoxy resins of E14, E12, E10, and E06.

[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 selected from the types E14, E12, E10, and E06 accounts for greater than or equal to 20% of the mass of the mixture; the rest are selected from the bisphenol A epoxy resins of types E-51, E-42, and E-35.

[0014] In some embodiments, the oil phase tracer with a boiling point of 100° C. and above includes at least one of methyl perfluorodecanoate, methyl perfluoroundecanoate, methyl perfluorododecanoate, methyl perfluorotridecanoate, methyl perfluorotetradecanoate, methyl perfluoropentadecanoate, methyl perfluorohexadecanoate, perfluoromethylethyl acrylate, perfluoroethylethyl acrylate, perfluoropentylethyl acrylate, perfluorohexylethyl acrylate, perfluoroundecylethyl acrylate, and perfluorododecylethyl acrylate.

[0015] In some embodiments, the gas phase tracer with a boiling point of 100° C. or above includes at least one of perfluoroundecane, perfluorododecane, perfluorotridecane, perfluorotetradecane, perfluoropentadecane, perfluorohexadecane, and perfluorobiphenyl.

[0016] In some embodiments, the curing agent is one or more of diaminodiphenylmethane, diaminodiphenyl sulfone, m-phenylenediamine, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, dodecylsuccinic anhydride, chlorendic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, methylcyclohexane tetracarboxylic anhydride, dicyandiamide, and oxalic acid acetohydrazide.

[0017] In some embodiments, the diluent is one or more of acetone, turpentine, xylene, ethanol, toluene, furfuryl alcohol, and ethyl acetate.

[0018] In some embodiments, the accelerator is one or more of linear tertiary amine, triethanolamine, triethylamine, diurea, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methylimidazole.

[0019] In some preferred embodiments, a sustained-release tracer comprises the following raw materials in percentage by weight: 20%-70% bisphenol A epoxy resin, 8%-40% tracer, 10%-35% curing agent, 0%-15% accelerator, and 1%-15% diluent.

[0020] According to the second aspect of the present application, a method for preparing a sustained-release solid tracer is provided, comprising the following steps:

[0021] (1) weighing the raw materials according to any of the above items,

[0022] (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;

[0023] (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;

[0024] (4) Add an accelerator to slurry B, and then add a curing agent. After rapid stirring, heat at 60-90°C for 10-30 minutes for pre-curing, and then stand at 100-200°C to allow the slurry to undergo a curing reaction. When the slurry is completely hardened, a sustained-release solid tracer is prepared.

[0025] Among them, RPM is the abbreviation of revolutions per minute, which represents the number of times the device rotates per minute.

[0026] In some of the embodiments, when the bisphenol A epoxy resin is selected from bisphenol A epoxy resins with models of E14, E12, E10, and E06, the bisphenol A epoxy resin is solid (or paste) at room temperature and needs to be heated and softened before adding a diluent.

[0027] In some preferred embodiments, the heating and softening is heating to 65-110° C. and softening for 8-15 min.

[0028] The beneficial effects of this application are:

[0029] (1) 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 sustained-release solid tracer is prepared under conditions above 100°C (100-200°C) by selecting a high-temperature curing agent and an accelerator.

[0030] (2) The technical solution of the present application is suitable for the solidification of high-boiling-point oil-phase or gas-phase tracers with a boiling point above 100°C, and the obtained solid tracer has excellent heat resistance.

[0031] (3) The technical solution of the present application can adjust the release rate and release period of the solid tracer by adjusting the distribution ratio of each component of the system and the curing process conditions to meet the application requirements of the production site.

[0032] (4) The preparation method provided in the present application can prepare solid tracers in various shapes such as strips, blocks, and rods. The process conditions are simple to operate, the equipment requirements are not high, and large-scale production can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1This is a comparison chart of the tracer release rate (g / month) of Examples 1-8 of the present application within 12 months.

[0034] Figure 2 This is a comparison chart of the cumulative release rate (%) of the tracer in Examples 1-8 of the present application within 12 months. DETAILED DESCRIPTION

[0035] 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.

[0036] 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.

[0037] 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.

[0038] It is well known to those skilled in the art of epoxy resin that epoxy curing 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 sustained-release solid tracer with high temperature curing (100-200°C) and its preparation method and application.

[0039] 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 curing bisphenol A epoxy resin, a diluent, and a curing agent at high temperature (100-200°C) with or without an accelerator.

[0040] The sustained-release solid tracer (composite material) comprises the following raw materials in percentage by mass: 15%-75% of bisphenol-A epoxy resin, 5%-50% of tracer, 5%-40% of curing agent, 0%-20% of accelerator and 1%-20% of diluent.

[0041] In some embodiments, the bisphenol-A epoxy resin is one or more of E-51, E-42, E-35, 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 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.

[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-51 0.48-0.54 E-42 0.38-0.45 E-35 0.30-0.40 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] In some embodiments, when the bisphenol A epoxy resin is a type of bisphenol A epoxy resin, the type is selected from E14, E12, E10, and E06.

[0049] 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 E14, E12, E10, and E06 accounts for greater than or equal to 20% (≥20%) of the (total) mass of the mixture; the rest are selected from the bisphenol A epoxy resins of types E-51, E-42, and E-35 (i.e., ≤80%).

[0050] In some preferred embodiments, one or two bisphenol A epoxy resins are selected.

[0051] In some embodiments, the tracer is an oil phase tracer or a gas phase tracer having a boiling point of 100° C. or above.

[0052] In some embodiments, the oil phase tracer with a boiling point of 100° C. and above includes one or more of methyl perfluorodecanoate, methyl perfluoroundecanoate, methyl perfluorododecanoate, methyl perfluorotridecanoate, methyl perfluorotetradecanoate, methyl perfluoropentadecanoate, methyl perfluorohexadecanoate, perfluoromethylethyl acrylate, perfluoroethylethyl acrylate, perfluoropentylethyl acrylate, perfluorohexylethyl acrylate, perfluoroundecylethyl acrylate, and perfluorododecylethyl acrylate.

[0053] In some embodiments, the gas phase tracer with a boiling point of 100° C. or above includes one or more of perfluoroundecane, perfluorododecane, perfluorotridecane, perfluorotetradecane, perfluoropentadecane, perfluorohexadecane, and perfluorobiphenyl.

[0054] There are many tracers with boiling points of 100°C and above, all of which can be applied to the technical solution of the present application.

[0055] Generally speaking, when tracers are mixed, tracers of the same type are used.

[0056] When multiple tracers are selected, there is no specific requirement for the ratio of the tracers, and preferably one or two tracers are used. One tracer is added each time, stirred evenly, and then another tracer is added and stirred evenly again.

[0057] The boiling points of the tracer compounds listed above are shown in Table 2.

[0058] Table 2

[0059]

[0060]

[0061] In some embodiments, the curing agent is one or more of diaminodiphenylmethane, diaminodiphenyl sulfone, m-phenylenediamine, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, dodecylsuccinic anhydride, chlorendic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, methylcyclohexane tetracarboxylic anhydride, dicyandiamide, and oxalic acid acetohydrazide.

[0062] 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 with very different properties. Generally speaking, when a high-temperature curing agent is selected to perform the epoxy resin curing reaction at a higher temperature, the heat resistance, acid and alkali resistance, etc. of the obtained cured product are better than those cured at a lower temperature. Therefore, from the perspective of improving the stability of the solid tracer, the curing reaction should be completed at a higher temperature. However, if the curing temperature is too high, the structure of the cured product is tight, which will hinder the diffusion rate of the tracer active ingredients from the inside of the cured product to the outside during use, and ultimately cause the tracer active component concentration in the oil and gas field produced fluid to be lower than the lower limit of the detection equipment and fail to detect the results normally, thereby losing the tracer effect that the tracer should have; if the curing temperature is too low, the softening temperature of the cured product will be low, causing it to quickly release the tracer active ingredients at a lower use temperature, shortening the time to exert the tracer effect (i.e. shortening the release cycle of the solid tracer), and failing to fully exert the tracer effect. It can be seen that the curing temperature and the selection of a curing agent that matches the curing conditions will directly affect the performance of the final sustained-release solid tracer product. It is necessary to optimize the curing temperature and the preferred curing agent to ensure that the release rate and release cycle of the solid tracer product meet the use requirements of the oil and gas field production site. The present application can prepare sustained-release solid tracer products with different release rates and release cycles by optimizing the curing agent and the accelerator and controlling the curing conditions (curing temperature, proportion of each component, etc.) to meet the use requirements of different on-site production scenarios, and finally provide a sustained-release solid tracer with adjustable release rate and a preparation method thereof.

[0063] In some embodiments, the diluent is one or more of acetone, turpentine, xylene, ethanol, toluene, furfuryl alcohol, and ethyl acetate.

[0064] The diluent can appropriately reduce the viscosity of the epoxy resin and also disperse the tracer in the slurry well.

[0065] 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.

[0066] In some embodiments, the accelerator is one or more of linear tertiary amine, triethanolamine, triethylamine, diurea, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methylimidazole.

[0067] In some preferred embodiments, a sustained-release tracer comprises the following raw materials in percentage by weight: 20%-70% bisphenol A epoxy resin, 8%-40% tracer, 10%-35% curing agent, 0%-15% accelerator, and 1%-15% diluent.

[0068] The preparation method of the sustained-release solid tracer comprises the following steps:

[0069] (1) Weigh the raw materials according to the above ratio,

[0070] (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;

[0071] (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;

[0072] (4) Add an accelerator to slurry B, and then add a curing agent. After rapid stirring, heat at 60-90°C for 10-30 minutes to complete pre-curing, and then stand at 100-200°C to allow the slurry to undergo a curing reaction. When the slurry is completely hardened, a sustained-release solid tracer is prepared.

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

[0074] In some embodiments, when the bisphenol A epoxy resin is selected from bisphenol A epoxy resins with models of E14, E12, E10, and E06, the bisphenol A epoxy resin is solid at room temperature and needs to be heated and softened before adding a diluent.

[0075] In some preferred embodiments, the heating and softening is heating to 65-110° C. and softening for 8-15 min.

[0076] 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.

[0077] The pre-curing described in step (4) is the initial stage of the curing process, when the epoxy resin and the curing agent begin to react to form a partially cross-linked network structure. At this stage, the viscosity of the resin gradually increases, but a complete three-dimensional network structure has not yet been formed. The purpose of pre-curing is to improve the processing properties of the resin, reduce the molding time, and help control the quality of the final product. Pre-curing can be carried out at room temperature or at other temperatures, but the temperature is significantly lower than the temperature of subsequent high temperature curing under 100-200°C conditions.

[0078] The key to the technical solution of the present application lies in the high temperature curing process at 100-200°C, which determines the quality of the sustained-release solid tracer.

[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] 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, the slurry can be quickly stirred to make the catalyst and the curing agent uniformly mixed in the slurry, and then immediately poured into a mold for pre-curing and high-temperature curing at 100-200°C.

[0082] The criterion for judging the curing reaction molding in the embodiment is that the slurry is completely hardened.

[0083] 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.

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

[0085] Embodiment 1:

[0086] (1) After 60 g of E-51 and 40 g of 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 15 min to obtain slurry A;

[0087] (2) adding 44 g of methyl perfluorodecanoate to slurry A at room temperature, and stirring at 300 rpm for 10 min to obtain slurry B;

[0088] (3) Add 26 g of diaminodiphenylmethane to slurry B at room temperature, stir quickly and evenly, heat at 80° C. for 10 min to complete pre-curing, and then stand at 140° C. to cure and form, thereby obtaining a sustained-release solid tracer.

[0089] Embodiment 2:

[0090] (1) After 50 g of E-42 and 50 g of E-12 were mixed uniformly at room temperature, 3 g of turpentine and 3 g of ethyl acetate were added in sequence, and the mixture was stirred at 300 rpm for 10 min to obtain slurry A;

[0091] (2) adding 24 g of methyl perfluoroundecanoate and 24 g of methyl perfluorotetradecanoate to slurry A in sequence at room temperature, and stirring at 400 rpm for 5 min to obtain slurry B;

[0092] (3) 10 g of a linear tertiary amine and 28 g of hexahydrophthalic anhydride were added to slurry B at room temperature, and the mixture was quickly stirred to be uniform. The mixture was first heated at 80° C. for 10 min to complete pre-curing, and then allowed to stand at 140° C. to cure and form, thereby obtaining a sustained-release solid tracer.

[0093] Embodiment 3:

[0094] (1) After 70 g of E-35 and 30 g of E-14 were mixed uniformly at room temperature, 4 g of xylene and 2 g of furfuryl alcohol were added in sequence, and the mixture was stirred at 400 rpm for 5 min to obtain slurry A;

[0095] (2) adding 47 g of perfluoromethylethyl acrylate to slurry A at room temperature, and stirring at 500 rpm for 15 min to obtain slurry B;

[0096] (3) Add 8 g of 2-ethyl-4-methylimidazole and 27 g of dodecylsuccinic anhydride to slurry B at room temperature, stir quickly and evenly, heat at 80° C. for 10 min to complete pre-curing, and then stand at 140° C. to cure and form, thereby obtaining a sustained-release solid tracer.

[0097] Embodiment 4:

[0098] (1) After 75 g of E-12 and 25 g of E-06 were mixed uniformly at room temperature, 1 g of ethanol and 5 g of furfuryl alcohol were added in sequence, and the mixture was stirred at 500 rpm for 1 min to obtain slurry A;

[0099] (2) adding 47 g of perfluoroundecylethyl acrylate to slurry A at room temperature, and stirring at 200 rpm for 20 min to obtain slurry B;

[0100] (3) After adding 4 g of triethylamine and 3 g of 1-cyanoethyl-2-ethyl-4-methylimidazole to slurry B at room temperature, 16 g of pyromellitic anhydride and 12 g of benzophenone tetracarboxylic dianhydride were added, and the mixture was quickly stirred to be uniform. The mixture was first heated at 80° C. for 10 min to complete pre-curing, and then allowed to stand at 140° C. to cure and form, thereby obtaining a sustained-release solid tracer.

[0101] Embodiment 5:

[0102] (1) After 55 g of E-14 and 45 g of E-10 were mixed uniformly at room temperature, 1 g of furfuryl alcohol and 5 g of ethyl acetate were added in sequence, and the mixture was stirred at 200 rpm for 10 min to obtain slurry A;

[0103] (2) adding 23 g of perfluorododecane and 23 g of perfluoropentadecane to slurry A in sequence at room temperature, and stirring at 400 rpm for 30 min to obtain slurry B;

[0104] (3) 6 g of diurea and 26 g of dicyandiamide were added to slurry B in sequence at room temperature, and the mixture was quickly stirred to be uniform. The mixture was first heated at 80° C. for 10 min to complete pre-curing, and then allowed to stand at 140° C. to cure and form, thereby obtaining a sustained-release solid tracer.

[0105] Embodiment 6:

[0106] (1) After 80 g of E-51 and 20 g of E-12 were mixed uniformly at room temperature, 3 g of acetone and 3 g of ethanol were added in sequence, and the mixture was stirred at 300 rpm for 5 min to obtain slurry A;

[0107] (2) adding 46 g of perfluorobiphenyl to slurry A at room temperature, stirring at 300 rpm for 25 min, to obtain slurry B;

[0108] (3) 6 g of 1-benzyl-2-methylimidazole and 26 g of oxalic acid acetylohydrazide were added to slurry B at room temperature, and the mixture was quickly stirred to be uniform. The mixture was first heated at 80° C. for 10 min to complete pre-curing, and then allowed to stand at 140° C. to cure and form, thereby obtaining a sustained-release solid tracer.

[0109] Embodiment 7:

[0110] (1) After 70 g of E-35 and 30 g of E-14 were mixed uniformly at room temperature, 4 g of xylene and 2 g of furfuryl alcohol were added in sequence, and the mixture was stirred at 400 rpm for 5 min to obtain slurry A;

[0111] (2) adding 47 g of perfluoromethylethyl acrylate to slurry A at room temperature, and stirring at 500 rpm for 15 min to obtain slurry B;

[0112] (3) Add 8 g of 2-ethyl-4-methylimidazole and 27 g of dodecylsuccinic anhydride to slurry B at room temperature, stir quickly and evenly, heat at 80° C. for 10 min to complete pre-curing, and then stand at 100° C. to cure and form, thereby obtaining a sustained-release solid tracer.

[0113] Embodiment 8:

[0114] (1) After 70 g of E-35 and 30 g of E-14 were mixed uniformly at room temperature, 4 g of xylene and 2 g of furfuryl alcohol were added in sequence, and the mixture was stirred at 400 rpm for 5 min to obtain slurry A;

[0115] (2) adding 47 g of perfluoromethylethyl acrylate to slurry A at room temperature, and stirring at 500 rpm for 15 min to obtain slurry B;

[0116] (3) 8 g of 2-ethyl-4-methylimidazole and 27 g of dodecylsuccinic anhydride were added to slurry B at room temperature, and the mixture was quickly stirred to be uniform. The mixture was first heated at 80° C. for 10 min to complete pre-curing, and then allowed to stand at 200° C. to cure and form, thereby obtaining a sustained-release solid tracer.

[0117] This application detects the tracer concentration of the embodiment by sampling the simulated output fluid, calculates the release rate of the sustained-release solid tracer of the embodiment, and obtains the cumulative release rate of the tracer. Experimental method for evaluating the sustained-release rate of sustained-release solid tracers: Weigh a certain amount of sustained-release solid tracer and place it in a high-temperature and high-pressure reactor containing 1000mL of crude oil, seal the reactor, and maintain the pressure in the reactor at 10MPa and the temperature at 120°C. Regularly sample and analyze the concentration of the tracer in the reaction liquid in the reactor, and calculate the release rate and cumulative release rate of the tracer. Continuously monitor for 12 months to obtain the experimental results of the embodiments of this application. After the evaluation experiment, the overall appearance of the sustained-release solid tracer did not change much.

[0118] Figure 1 This is a comparison chart of the tracer release rate (g / month) of Examples 1-8 of the present application within 12 months.

[0119] Figure 2 This is a comparison chart of the cumulative release rate (%) of the tracer in Examples 1-8 of the present application within 12 months.

[0120] from Figure 1 and Figure 2The results show that as the experimental time goes by, the tracer release rate decreases and the cumulative release rate curve gradually slows down. The experimental results show that the entire diffusion process is carried out from the outside of the solid tracer to the inside (slow release). As time goes by, the diffusion path of the tracer active ingredient in the skeleton becomes longer, resulting in a slower tracer release rate. Comparing the results of Examples 1-6, it can be seen that the tracer release rate and cumulative release rate of Examples 2-4 are relatively low, the tracer release rate and cumulative release rate of Example 1 are the fastest, and the tracer release rate and cumulative release rate of Examples 5-6 are in the middle. Examples 2-4 use anhydride curing agents, Example 1 is an aromatic amine curing agent, and Examples 5-6 are cyanamide and hydrazide curing agents. This reflects the effect of different types of curing agents on the stability of the cured product, indicating that anhydride curing agents are more conducive to improving the stability of the cured product; the difference between Examples 7 and 8 and Example 3 is that the curing temperature of Example 7 is 100°C, and the curing temperature of Example 8 is 200°C. From the perspective of tracer release rate and cumulative release rate, the lower the curing temperature, the faster the tracer release rate. This is because at a higher curing temperature, the curing agent reacts more thoroughly with the epoxy resin, and the epoxy cured material structure formed is more compact, making it difficult for the tracer to diffuse out of the cured material framework structure, thereby reducing the tracer release rate and extending the release cycle and service life of the product.

[0121] Figure 1 and Figure 2 The specific data are shown in Table 3.

[0122] Table 3

[0123]

[0124]

[0125] Generally speaking, in order to ensure that the solid tracer can be used normally underground for one year, it is generally required that the cumulative release rate of the tracer within 12 months does not exceed 50%. The solidified tracer release rates of Examples 1-8 of the present patent at a curing temperature of 100-200°C all meet the on-site requirements.

[0126] Based on the technical solution of the present application, those skilled in the art can make adjustments according to on-site needs to prepare sustained-release solidified tracer products with different release rates.

[0127] In order to illustrate the importance of the curing temperature range, curing was carried out at a temperature lower than (90°C) or higher than (250°C) the curing temperature described in the present application, as Comparative Examples 1 and 2; in order to illustrate the influence of the type of curing agent on the release rate of the tracer, trimellitic anhydride and meta-xylylenediamine were used as curing agents, as Comparative Examples 3 and 4, respectively.

[0128] Comparative Example 1:

[0129] (1) After 70 g of E-35 and 30 g of E-14 were mixed uniformly at room temperature, 4 g of xylene and 2 g of furfuryl alcohol were added in sequence, and the mixture was stirred at 400 rpm for 5 min to obtain slurry A;

[0130] (2) adding 47 g of perfluoromethylethyl acrylate to slurry A at room temperature, and stirring at 500 rpm for 15 min to obtain slurry B;

[0131] (3) 8 g of 2-ethyl-4-methylimidazole and 27 g of dodecyl succinic anhydride were added to slurry B at room temperature, and the mixture was quickly stirred and pre-cured at 80°C for 10 min, and then allowed to stand at 90°C for curing to obtain a solid tracer. The results are shown in Table 4.

[0132] Comparative Example 2:

[0133] (1) After 70 g of E-35 and 30 g of E-14 were mixed uniformly at room temperature, 4 g of xylene and 2 g of furfuryl alcohol were added in sequence, and the mixture was stirred at 400 rpm for 5 min to obtain slurry A;

[0134] (2) adding 47 g of perfluoromethylethyl acrylate to slurry A at room temperature, and stirring at 500 rpm for 15 min to obtain slurry B;

[0135] (3) 8 g of 2-ethyl-4-methylimidazole and 27 g of dodecyl succinic anhydride were added to slurry B at room temperature, and after rapid stirring, the slurry was heated at 80°C for 10 min to complete pre-curing, and then allowed to stand at 250°C to cure and form, thereby obtaining a solid tracer. The results are shown in Table 4.

[0136] The difference between Example 3 and Comparative Example 1 is that the curing temperature of Example 3 is 140°C, and the curing temperature of Comparative Example 1 is 90°C. The results in Table 4 show that as the curing temperature increases, the curing time will be shortened. The curing time of Comparative Example 1 is as long as 480 minutes, which is not conducive to improving the efficiency of large-scale production; more importantly, when the curing temperature is 90°C, the cumulative release rate of the tracer in the solidified material for 12 months exceeds 70%, and the one-year service life of the solid tracer cannot be guaranteed, and the use requirements of the oil and gas field production site cannot be met; when the curing temperature is 250°C, the solidified material is very stable, and the cumulative release rate of the tracer in 12 months is 0.5%. The concentration of the tracer in the produced fluid is about 5.2ng / mL, which is lower than the detection limit (20ng / mL) of the detection equipment, so the solid tracer of Comparative Example 2 cannot play a tracing role. It can be seen that a suitable curing temperature is an important factor in ensuring that the solid tracer meets the use requirements of the oil and gas field production site.

[0137] Table 4

[0138]

[0139] Comparative Example 3:

[0140] (1) After 70 g of E-35 and 30 g of E-14 were mixed uniformly at room temperature, 4 g of xylene and 2 g of furfuryl alcohol were added in sequence, and the mixture was stirred at 400 rpm for 5 min to obtain slurry A;

[0141] (2) adding 47 g of perfluoromethylethyl acrylate to slurry A at room temperature, and stirring at 500 rpm for 15 min to obtain slurry B;

[0142] (3) 8 g of 2-ethyl-4-methylimidazole and 27 g of trimellitic anhydride were added to slurry B at room temperature, and after rapid stirring, the slurry was heated at 80°C for 10 min to complete pre-curing, and then allowed to stand at 140°C to cure and form, thereby obtaining a solid tracer. The results are shown in Table 5.

[0143] The difference between Example 3 and Comparative Example 3 is that the curing agent of Example 3 is dodecyl succinic anhydride, and the curing agent of Comparative Example 3 is trimellitic anhydride. The results in Table 5 show that the cumulative release rate of the tracer of Example 3 meets the production and use requirements (1% < release rate < 50%), while the release rate of the tracer of Comparative Example 3 is too fast, and the cumulative release rate exceeds 50%, which does not meet the production and use requirements and cannot ensure the 1-year service life of the solid tracer underground.

[0144] Table 5

[0145]

[0146] Comparative Example 4:

[0147] (1) After 60 g of E-51 and 40 g of 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 15 min to obtain slurry A;

[0148] (2) adding 44 g of methyl perfluorodecanoate to slurry A at room temperature, stirring at 300 rpm for 10 min to obtain slurry B;

[0149] (3) Add 26 g of m-xylylenediamine to slurry B at room temperature, stir quickly and evenly, heat at 80°C for 10 min to complete pre-curing, and then stand at 140°C to cure and form, to obtain a solid tracer. The results are shown in Table 6.

[0150] The difference between Example 1 and Comparative Example 4 is that the curing agent of Example 1 is diaminodiphenylmethane, and the curing agent of Comparative Example 4 is m-xylenediamine. The results in Table 6 show that although both use aromatic amine curing agents, the cumulative release rate of the tracer in Example 1 meets the production and use requirements (1%<release rate<50%), while the release rate of the tracer in Comparative Example 4 is too fast, and the cumulative release rate exceeds 50%, which does not meet the production and use requirements and cannot ensure the 1-year service life of the solid tracer in the well.

[0151] This shows that only with the preferred curing agent and corresponding process conditions of the present application can a sustained-release solid tracer with a service life of 1 year or more be prepared.

[0152] Table 6

[0153]

[0154] Application Example 1

[0155] The time is: July 2023 - July 2024.

[0156] The oil-gas phase slow-release solid tracer prepared in Example 3 of the present application was used for the No. XXX underground operation in the Southwest Oil and Gas Field. The concentration of the active ingredient of the tracer in the produced fluid was greater than 65 ng / mL (within the detection range of the detection equipment). By monitoring the release rate of the tracer, the cumulative release rate of the tracer in 12 months was 9.8%. The solid tracer has been used normally underground for 1 year, meeting the use needs of the production site.

[0157] 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: 15%-75% of bisphenol A epoxy resin, 5%-50% of tracer, 5%-40% of curing agent, 0%-20% of accelerator and 1%-20% of diluent; wherein the tracer is an oil phase tracer or a gas phase tracer with a boiling point of 100° C. or above; and the sustained-release solid tracer is obtained by curing the above raw materials at a temperature of 100-200° C.

2. The sustained-release solid tracer according to claim 1, characterized in that: The bisphenol A type epoxy resin is at least one of E-51, E-42, E-35, 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 bisphenol A epoxy resins of E14, E12, E10, and E06.

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 E14, E12, E10, and E06 accounts for greater than or equal to 20% of the mass of the mixture; the rest are selected from the bisphenol A epoxy resins with types E-51, E-42, and E-35.

5. The sustained-release solid tracer according to claim 1, characterized in that: The oil phase tracer with a boiling point of 100° C. or above includes at least one of methyl perfluorodecanoate, methyl perfluoroundecanoate, methyl perfluorododecanoate, methyl perfluorotridecanoate, methyl perfluorotetradecanoate, methyl perfluoropentadecanoate, methyl perfluorohexadecanoate, perfluoromethylethyl acrylate, perfluoroethylethyl acrylate, perfluoropentylethyl acrylate, perfluorohexylethyl acrylate, perfluoroundecylethyl acrylate, and perfluorododecylethyl acrylate.

6. The sustained-release solid tracer according to claim 1, characterized in that: The gas phase tracer with a boiling point of 100° C. or above includes at least one of perfluoroundecane, perfluorododecane, perfluorotridecane, perfluorotetradecane, perfluoropentadecane, perfluorohexadecane, and perfluorobiphenyl.

7. The sustained-release solid tracer according to claim 1, characterized in that: The curing agent is one or more of diaminodiphenylmethane, diaminodiphenyl sulfone, m-phenylenediamine, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, dodecylsuccinic anhydride, chlorendic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, methylcyclohexane tetracarboxylic anhydride, dicyandiamide, and oxalic acid acetohydrazide.

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

9. The sustained-release solid tracer according to claim 1, characterized in that: The accelerator is one or more of linear tertiary amine, triethanolamine, triethylamine, diurea, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methylimidazole.

10. 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 9, 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, then add a curing agent, quickly stir evenly, heat at 60-90°C for 10-30 minutes for pre-curing, and then stand at 100-200°C to allow the slurry to undergo a curing reaction. When the slurry is completely hardened, a sustained-release solid tracer is prepared.

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