High-temperature clay stabilizer solution as well as preparation method and application thereof

Abstract

The invention provides a high-temperature clay stabilizer solution as well as a preparation method and application thereof, and the high-temperature clay stabilizer solution comprises the following components in percentage by weight: 5-10% of inorganic salt, 45-55% of water, 30-40% of polycondensate of epoxy chloropropane and polyethylene polyamine and the balance of initiator, wherein the epichlorohydrin and polyethylene polyamine polycondensate is obtained by taking epichlorohydrin and polyethylene polyamine as raw materials, and carrying out polymerization reaction for more than 4 hours at the temperature of 60-70 DEG C under the initiation of an initiator. The high-temperature clay stabilizer solution provided by the invention can meet the development requirements of steam injection or hot water injection of a heavy oil thermal production well, and is good in high-temperature resistance and high in stability; clay expansion and migration can be effectively inhibited, the period of validity is long, and the oil production of an oil well and subsequent steam injection or hot water injection development are guaranteed; the material source is wide, the cost performance is high, the preparation method is simple, on-site use is convenient, and the application range is wide.

Description

Technical Field

[0001] The present invention relates to a high-temperature clay stabilizer solution, a preparation method thereof and an application thereof, belonging to the technical field of clay anti-swelling. Background Art

[0002] For oil reservoirs mainly composed of heavy oil and super heavy oil, the main production method is steam huff and puff. In some heavy oil blocks, the formation clay content is high (about 20%). During the steam injection production process, there are generally clay swelling and migration phenomena; when the steam injection cycles are high and the steam injection volume is large, the phenomenon of clay swelling causing the blockage of the flow channel is more serious, ultimately leading to problems such as an increase in steam injection pressure or inability to inject steam, and a decrease in the oil production and liquid production of oil wells or no liquid production.

[0003] At present, the commonly used clay stabilizers in oil fields include inorganic salt type clay stabilizers and polymer type stabilizers such as polyamines and polyquaternary ammonium salts. Among them, inorganic salt type clay stabilizers are easy to obtain, cheap in price and simple to maintain, but their timeliness is poor, the dosage is large, and they are not resistant to water washing. Although polymer type stabilizers such as polyamines and polyquaternary ammonium salts have good anti-swelling effects in hydrochloric acid systems and the dosage is small, their thermal stability is poor, and their temperature resistance decreases with the increase of the relative molecular mass, so they are not suitable for clay anti-swelling under high-temperature conditions. Since these conventional clay stabilizers are prone to failure under high-temperature steam injection conditions, the problem of clay swelling and migration cannot be effectively solved. In view of this problem, developing a high-temperature clay stabilizer suitable for heavy oil thermal recovery, a preparation method thereof and an application thereof has become an urgent technical problem in this field. Summary of the Invention

[0004] In order to solve the above-mentioned disadvantages and deficiencies, an object of the present invention is to provide a high-temperature clay stabilizer solution.

[0005] Another object of the present invention is to provide a preparation method of the above-mentioned high-temperature clay stabilizer solution.

[0006] Another object of the present invention is to provide an application of the above-mentioned high-temperature clay stabilizer solution in the development of heavy oil thermal recovery wells. During the process of steam injection and hot water injection in heavy oil fields, this high-temperature clay stabilizer solution can avoid the problems of formation pore channel blockage and oil well production decline caused by clay swelling in the formation, thereby effectively ensuring the normal production of steam injection and hot water injection in heavy oil blocks.

[0007] In order to achieve the above objects, on the one hand, the present invention provides a high-temperature clay stabilizer solution, wherein, based on the total weight of the high-temperature clay stabilizer solution being 100%, it contains 5%-10% of inorganic salts, 45%-55% of water, 30%-40% of the condensate of epichlorohydrin and polyalkylene polyamine, and the balance of initiator;

[0008] Among them, the epichlorohydrin and polyethylenepolyamine condensate is obtained by using epichlorohydrin and polyethylenepolyamine as raw materials and carrying out a polymerization reaction at 60-70°C for more than 4 h (preferably 4-6 h) under the initiation of an initiator.

[0009] In the present invention, an epichlorohydrin and polyethylenepolyamine condensate is prepared by using a main agent epoxide such as epichlorohydrin and a polyamine compound such as polyethylenepolyamine as raw materials and carrying out a polymerization reaction at 60-70°C for more than 4 h under the initiation of an initiator; among them, the epichlorohydrin molecule contains two active atoms and can react with various substances, and it can undergo homopolymerization or copolymerization with other substances to form a high-molecular compound, while polyethylenepolyamine is a combined product of any several substances among ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine. Its molecular chain simultaneously has structures such as amino groups, polyoxyethylene (or polyoxypropylene), organosiloxane, and multi-arms, so that polyethylenepolyamine combines their excellent properties and has good surface activity and temperature resistance characteristics.

[0010] Among them, a partial reaction formula between epichlorohydrin and polyethylenepolyamine is as follows:

[0011] CH2CHCH2ClO+H2N(CH2CH2NH)2CH2CH2NH2→N(CH2CH2NH)2CH2CH2NCH2C

[0012] H(OH)CH2Cl→epichlorohydrin and polyethylenepolyamine condensate;

[0013]

[0014] As a specific embodiment of the high-temperature clay stabilizer solution described above in the present invention, among them, the initiator includes one or a combination of several of sodium hydroxide, potassium hydroxide, copper chloride, zinc chloride, and organoaluminum compounds, etc.; preferably sodium hydroxide. Among them, sodium hydroxide and potassium hydroxide, as basic compounds, can promote the nucleophilic attack reaction and accelerate the reaction rate in the reaction between epichlorohydrin and polyethylenepolyamine. In addition, copper chloride, zinc chloride, and organoaluminum compounds can also play a certain initiation and catalytic role in the reaction between epichlorohydrin and polyethylenepolyamine and can promote the reaction rate.

[0015] When the initiator is sodium hydroxide and / or potassium hydroxide, it can also be used as a gelation control agent. When carrying out a polycondensation reaction between polyethylenepolyamine and epichlorohydrin, adding a hydroxide can accelerate and promote the ring-opening and ring-closing reactions, making the molecules intertwine with each other to form a macromolecular cross-linked network structure, thereby producing a gel phenomenon.

[0016] As a specific embodiment of the high-temperature clay stabilizer solution described above in the present invention, among them, the molar ratio of epichlorohydrin to polyethylenepolyamine is 1.2-1.0:1.

[0017] As a specific embodiment of the high-temperature clay stabilizer solution described above in the present invention, the mass ratio of the initiator to epichlorohydrin is 0.4 - 0.6:1.

[0018] As a specific embodiment of the high-temperature clay stabilizer solution described above in the present invention, the inorganic salt includes one or a combination of several of potassium chloride, calcium chloride, sodium chloride, magnesium chloride, etc. These inorganic salts can effectively inhibit the hydration swelling of montmorillonite and illite in clay, and the inhibitory performance on the hydration swelling of illite is particularly prominent.

[0019] As a specific embodiment of the high-temperature clay stabilizer solution described above in the present invention, the water includes formation produced water or simulated brine, etc.

[0020] On the other hand, the present invention also provides a preparation method of the high-temperature clay stabilizer solution described above, wherein the preparation method includes:

[0021] Step (1): At normal temperature and pressure, add polyethylenepolyamine and water into a closed reaction kettle, mix evenly and gradually heat up to 50 - 55 °C, and then obtain an aqueous polyethylenepolyamine solution after standing.

[0022] Step (2): Add epichlorohydrin into the closed reaction kettle, mix evenly and gradually heat up to 60 - 70 °C, then add an initiator into the closed reaction kettle. Under the action of the initiator, epichlorohydrin and polyethylenepolyamine carry out a polymerization reaction at 60 - 70 °C for more than 4 h, preferably 4 - 6 h, to obtain a semi-transparent solution of the condensate of epichlorohydrin and polyethylenepolyamine.

[0023] Step (3): Add the inorganic salt into the closed reaction kettle and mix it evenly to obtain the high-temperature clay stabilizer solution.

[0024] As a specific embodiment of the preparation method described above in the present invention, the mixing is achieved by stirring, the stirring time is more than 30 min, preferably 30 - 60 min, more preferably 30 - 45 min, and the standing time is 0.5 - 1 h.

[0025] As a specific embodiment of the preparation method described above in the present invention, in step (2), after the polymerization reaction, it is cooled to normal temperature (25 °C), and then the system is allowed to stand for 1 - 2 h;

[0026] In step (3), after mixing evenly, the system is allowed to stand for 1 - 2 h.

[0027] On another aspect, the present invention also provides the application of the high-temperature clay stabilizer solution described above in the development of heavy oil thermal recovery wells.

[0028] During the application process, the injection volume design of the high-temperature clay stabilizer solution includes:

[0029] Calculated according to the radius of the reservoir underground treated as an ellipsoid, the designed volume of the high-temperature clay stabilizer solution per well is calculated according to the following calculation formula (1):

[0030]

[0031] In formula (1): Q - designed amount of high-temperature clay stabilizer solution (m 3 );

[0032] a, b, c - semi-axis lengths of the ellipsoid (m);

[0033] Φ - formation porosity.

[0034] The injection process of the high-temperature clay stabilizer solution includes:

[0035] Step 1: Before injecting into the formation on site, mix the high-temperature clay stabilizer solution and water evenly according to a mass ratio of 1:2 to obtain a mixed solution;

[0036] Step 2: Inject the mixed solution from the production string using a 700-type cement pump truck;

[0037] Step 3: Observe the pressure change during injection;

[0038] Step 4: After shutting in the well for 24 hours for reaction, open the well for production.

[0039] Compared with the prior art, the beneficial technical effects that the present invention can achieve include:

[0040] The main component of the high-temperature clay stabilizer solution provided by the present invention is the condensate of epichlorohydrin and polyethylenepolyamine. In the molecular chain segments of this synthetic polymer, namely the condensate of epichlorohydrin and polyethylenepolyamine, there are multiple cationic groups, and it has a unique network molecular structure, which can connect with two or more mineral particles and adsorb on the surfaces of clay minerals and other formation particles, thus forming a multi-point adsorption film; the polyhydroxyl groups in the molecular structure of the condensate of epichlorohydrin and polyethylenepolyamine can form a large number of hydrogen bonds with the hydroxyl groups on the hydroxylated formation surface, making the combination of the two more firm, playing a stronger and longer-lasting stabilizing role on clay minerals and other formation particles, effectively reducing the hydration, swelling, and dispersion of clay, and being beneficial to the stability of clay minerals in sensitive sandstones; in addition, the condensate of epichlorohydrin and polyethylenepolyamine also has good inhibition and dispersion ability, long-term effectiveness, and temperature resistance. In the high-temperature environment (250 - 350 °C) of steam injection or hot water injection operations, the high-temperature clay stabilizer solution can still inhibit clay swelling, avoid clay migration, and ensure the steam injection or hot water injection effect and stable production of thermal recovery wells.

[0041] The high-temperature clay stabilizer solution provided by the present invention contains inorganic salts, which can improve the inhibition and anti-swelling effects on clay to a certain extent.

[0042] The high-temperature clay stabilizer solution provided by the present invention can meet the requirements of steam injection or hot water injection development in heavy oil thermal recovery wells, has good high-temperature resistance and strong stability ability; can effectively inhibit clay swelling and migration, has a long validity period, and ensures the oil production of oil wells and subsequent steam injection or hot water injection development; has a wide range of material sources, high cost performance, a simple preparation method, convenient on-site use, and a wide application range. Detailed implementation manners

[0043] It should be noted that the term "including" and any of its variations in the description and claims of the present invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0044] The "ranges" disclosed in the present invention are given in the form of lower and upper limits. There can be one or more lower limits, and one or more upper limits. A given range is defined by selecting a lower limit and an upper limit. The selected lower limit and upper limit define the boundary of a particular range. All ranges defined in this way are combinable, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, ranges of 60-110 and 80-120 are also expected to be understood. In addition, if the minimum range values listed are 1 and 2, and the maximum range values listed are 3, 4 and 5, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.

[0045] In the present invention, unless otherwise specified, the numerical range "a-b" represents an abbreviated representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been fully listed in the present invention, and "0-5" is only an abbreviated representation of these numerical combinations.

[0046] In the present invention, if there is no special description, all the embodiments and preferred embodiments mentioned in the present invention can be combined with each other to form a new technical solution.

[0047] In the present invention, if there is no special description, all the technical features and preferred features mentioned in the present invention can be combined with each other to form a new technical solution.

[0048] In the present invention, unless otherwise specified, all steps mentioned herein can be carried out in sequence or randomly, but preferably in sequence. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) carried out in sequence, or may also include steps (b) and (a) carried out in sequence. For example, it is mentioned that the method may further include step (c), which means that step (c) can be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may also include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0049] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the attached tables and embodiments. The following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the scope of protection of the present invention. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For the reagents or instruments whose manufacturers are not specified, they are all conventional products that can be obtained through commercial purchase.

[0050] Example 1

[0051] This example provides a high-temperature clay stabilizer solution, which is prepared by a preparation method including the following specific steps:

[0052] Step (1): At normal temperature and pressure, 190 g of polyethylenepolyamine (molar ratio of diethylenetriamine: triethylenetetramine: tetraethylenepentamine is 3:4:3) and 540 g of water are added to a closed reaction kettle, stirred evenly for more than 35 minutes, and gradually heated to 50 °C; after stirring ends, stand for 0.5 h to obtain a polyethylenepolyamine aqueous solution.

[0053] Step (2): 150 g of epichlorohydrin is slowly and evenly added into the closed reaction kettle, and stirred evenly for 1 h; gradually raise the temperature and keep the temperature at 65 - 70 °C, add 60 g of sodium hydroxide to the closed reaction kettle and continue to stir slowly. Under the initiation of sodium hydroxide, epichlorohydrin and polyethylenepolyamine carry out a polymerization reaction at 65 - 70 °C for 4.5 h. After the reaction ends, cool down to normal temperature (25 °C) and stand for 1 h to obtain a semi-transparent solution of the condensate of epichlorohydrin and polyethylenepolyamine.

[0054] Step (3): 90 g of potassium chloride is slowly added into the closed reaction kettle, stirred evenly for about 1 h, and then stand for 1.5 h to obtain the high-temperature clay stabilizer solution;

[0055] Based on the total weight of the high-temperature clay stabilizer solution being 100%, it contains 9.9% potassium chloride, 49.5% water, 34.7% epoxy chloropropane and polyethylenepolyamine condensate, and the balance sodium hydroxide.

[0056] Example 2

[0057] This example provides a high-temperature clay stabilizer solution, which is prepared by a preparation method including the following specific steps:

[0058] Step (1): At normal temperature and pressure, add 200 g of polyethylenepolyamine (molar ratio of diethylenetriamine: triethylenetetramine: tetraethylenepentamine is 3:4:3) and 500 g of water to a closed reaction kettle, stir evenly for more than 35 min, and gradually heat to 50 °C; after the stirring ends, let it stand for 0.5 h to obtain an aqueous polyethylenepolyamine solution.

[0059] Step (2): Slowly and evenly add 140 g of epoxy chloropropane into the closed reaction kettle, stir evenly for 1 h, gradually raise the temperature and maintain the temperature at 60 - 65 °C, add 60 g of sodium hydroxide to the closed reaction kettle and continue to stir slowly. Under the initiation of sodium hydroxide, epoxy chloropropane and polyethylenepolyamine polymerize at 60 - 65 °C for 5 h. After the reaction ends, cool down to normal temperature (25 °C) and let it stand for 1 h to obtain a semi-transparent solution of epoxy chloropropane and polyethylenepolyamine condensate.

[0060] Step (3): Slowly add 50 g of potassium chloride into the closed reaction kettle, stir evenly for about 1 h, and then let it stand for 1.5 h to obtain the high-temperature clay stabilizer solution;

[0061] Based on the total weight of the high-temperature clay stabilizer solution being 100%, it contains 5.2% potassium chloride, 51.5% water, 37.1% epoxy chloropropane and polyethylenepolyamine condensate, and the balance sodium hydroxide.

[0062] Example 3

[0063] This example provides a high-temperature clay stabilizer solution, which is prepared by a preparation method including the following specific steps:

[0064] Step (1): At normal temperature and pressure, add 220 g of polyethylenepolyamine (molar ratio of diethylenetriamine: triethylenetetramine: tetraethylenepentamine is 3:4:3) and 450 g of water to a closed reaction kettle, stir evenly for 40 min, and gradually heat to 50 °C; after the stirring ends, let it stand for 0.5 h to obtain an aqueous polyethylenepolyamine solution.

[0065] Step (2): Slowly and evenly add 140 g of epichlorohydrin into a closed reaction kettle, stir evenly for 1 h, gradually raise the temperature and maintain it at 60 - 65°C. Add 60 g of sodium hydroxide into the closed reaction kettle and continue to stir slowly. Under the initiation of sodium hydroxide, epichlorohydrin and polyethylenepolyamine polymerize at 60 - 65°C for 5 h. After the reaction ends, cool down to normal temperature (25°C) and let it stand for 1 h to obtain a translucent solution of the condensate of epichlorohydrin and polyethylenepolyamine.

[0066] Step (3): Slowly add 90 g of potassium chloride into the closed reaction kettle, stir evenly for about 1 h, and then let it stand for 1.5 h to obtain the high-temperature clay stabilizer solution.

[0067] Based on the total weight of the high-temperature clay stabilizer solution being 100%, it contains 9.3% of potassium chloride, 47.0% of water, 37.4% of the condensate of epichlorohydrin and polyethylenepolyamine, and the balance of sodium hydroxide.

[0068] Example 4

[0069] This example provides a high-temperature clay stabilizer solution, which is prepared by a preparation method including the following specific steps:

[0070] Step (1): At normal temperature and pressure, add 220 g of polyethylenepolyamine (molar ratio of diethylenetriamine: triethylenetetramine: tetraethylenepentamine is 3:4:3) and 540 g of water into a closed reaction kettle, stir evenly for more than 40 min, and gradually heat to 50°C. After the stirring ends, let it stand for 0.5 h to obtain an aqueous solution of polyethylenepolyamine.

[0071] Step (2): Slowly and evenly add 140 g of epichlorohydrin into the closed reaction kettle, stir evenly for 1 h, gradually raise the temperature and maintain it at 60 - 65°C. Add 64 g of sodium hydroxide into the closed reaction kettle and continue to stir slowly. Under the initiation of sodium hydroxide, epichlorohydrin and polyethylenepolyamine polymerize at 60 - 65°C for 4.5 h. After the reaction ends, cool down to normal temperature (25°C) and let it stand for 1 h to obtain a translucent solution of the condensate of epichlorohydrin and polyethylenepolyamine.

[0072] Step (3): Slowly add 93 g of potassium chloride into the closed reaction kettle, stir evenly for about 1 h, and then let it stand for 1.5 h to obtain the high-temperature clay stabilizer solution.

[0073] Based on the total weight of the high-temperature clay stabilizer solution being 100%, it contains 8.8% of potassium chloride, 51.2% of water, 33.9% of the condensate of epichlorohydrin and polyethylenepolyamine, and the balance of sodium hydroxide.

[0074] Example 5

[0075] This embodiment provides a high-temperature clay stabilizer solution, which is prepared by a preparation method including the following specific steps:

[0076] Step (1): At normal temperature and pressure, add 220 g of polyalkylene polyamine (the molar ratio of diethylenetriamine: triethylenetetramine: tetraethylenepentamine is 3:4:3) and 630 g of water into a closed reaction kettle, stir evenly for more than 40 min, and gradually heat up to 50 °C; after the stirring ends, let it stand for 0.5 h to obtain an aqueous polyalkylene polyamine solution.

[0077] Step (2): Slowly and evenly add 140 g of epichlorohydrin into the closed reaction kettle, stir evenly for 1 h, gradually heat up and maintain the temperature at 65 - 70 °C, add 68 g of sodium hydroxide into the closed reaction kettle and continue to stir slowly. Under the initiation of sodium hydroxide, epichlorohydrin and polyalkylene polyamine polymerize at 65 - 70 °C for 4 h. After the reaction ends, cool down to normal temperature (25 °C) and let it stand for 1 h to obtain a semi-transparent solution of the condensate of epichlorohydrin and polyalkylene polyamine.

[0078] Step (3): Slowly add 95 g of potassium chloride into the closed reaction kettle, stir evenly for about 1 h, and then let it stand for 1.5 h to obtain the high-temperature clay stabilizer solution;

[0079] Based on the total weight of the high-temperature clay stabilizer solution being 100%, it contains 8.4% of potassium chloride, 54.7% of water, 31.0% of the condensate of epichlorohydrin and polyalkylene polyamine, and the balance of sodium hydroxide.

[0080] Application Example 1

[0081] This application example applies the high-temperature clay stabilizer solution provided in Example 1 to the development of a heavy oil thermal recovery well (Well Huan-3A), including the following steps:

[0082] Well Huan-3A is a heavy oil steam stimulation well. According to a mass ratio of 1:2, 100 m 3 of the high-temperature clay stabilizer solution is mixed with water to prepare 300 m 3 of the injection fluid, and the injection fluid is injected into the production string by a 700-type cement pump truck. During the injection, observe the pressure change, and produce after shutting in the well for 24 hours. The comparison of the production data of Well Huan-3A before and after the measures is shown in Table 1 below.

[0083] Table 1 Comparison of production data of Well Huan-3A before and after the measures

[0084]

[0085] As can be seen from Table 1, the daily oil production and liquid production of Well Huan-3A have increased significantly, and the average oil production increase reaches 0.8 t / d. From the implementation effect, the effective period reaches 134 days.

[0086] Application Example 2

[0087] In this application example, the high-temperature clay stabilizer solution provided in Example 3 was used for the development of a heavy oil thermal recovery well (Well Huan-3B), including the following steps:

[0088] Well Huan-3B is a heavy oil steam stimulation well. 120 m 3 of the high-temperature clay stabilizer solution was mixed with water in a mass ratio of 1:2 to prepare 360 m 3 of injection fluid. The injection fluid was injected into the production string using a 700-type cement pump truck. During the injection, the pressure change was observed, and production was resumed after a 24-hour shut-in reaction. The comparison of production data before and after the measures for Well Huan-3B is shown in Table 2 below.

[0089] Table 2 Comparison of production data before and after the measures for Well Huan-3B

[0090]

[0091] As can be seen from Table 2, the daily oil production and daily liquid production of Well Huan-3B increased significantly, with an average oil increment of 1.2 t / d. From the implementation effect, the effective period reached 121 days.

[0092] As described above, the above are only specific embodiments of the present invention, and the scope of the invention cannot be limited by them. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the scope of protection of the present invention, should still fall within the scope covered by this patent. In addition, the technical features in the present invention can be freely combined and used with each other between technical features, between technical features and technical inventions, and between technical inventions.

Claims

1. A high-temperature clay stabilizer solution, characterized in that, Based on the total weight of the high-temperature clay stabilizer solution being 100%, it contains 5%-10% of inorganic salts, 45%-55% of water, 30%-40% of the condensate of epichlorohydrin and polyethylenepolyamine, and the balance of initiator; Among them, the condensate of epichlorohydrin and polyethylenepolyamine is obtained by using epichlorohydrin and polyethylenepolyamine as raw materials and polymerizing at 60-70°C for more than 4 h under the initiation of an initiator.

2. The high-temperature clay stabilizer solution according to claim 1, wherein, The initiator includes one or a combination of several of sodium hydroxide, potassium hydroxide, copper chloride, zinc chloride, and organoaluminum compounds.

3. The high-temperature clay stabilizer solution according to claim 1 or 2, characterized in that, The molar ratio of epichlorohydrin to polyethylenepolyamine is 1.2-1.0:

1.

4. The high-temperature clay stabilizer solution according to claim 1 or 2, characterized in that, The mass ratio of the initiator to epichlorohydrin is 0.4-0.6:

1.

5. The high-temperature clay stabilizer solution according to claim 1 or 2, characterized in that, The inorganic salts include one or a combination of several of potassium chloride, calcium chloride, sodium chloride, and magnesium chloride.

6. The high-temperature clay stabilizer solution according to claim 1 or 2, characterized in that The water includes formation produced water or simulated brine.

7. The preparation method of the high-temperature clay stabilizer solution according to any one of claims 1-6, characterized in that, The preparation method includes: Step (1): At normal temperature and pressure, add polyethylenepolyamine and water into a closed reaction kettle, mix evenly and gradually heat up to 50-55°C, and then obtain an aqueous solution of polyethylenepolyamine after standing still; Step (2): Add epichlorohydrin into the closed reaction kettle, mix evenly and gradually heat up to 60-70°C, then add an initiator into the closed reaction kettle. Under the action of the initiator, epichlorohydrin and polyethylenepolyamine polymerize at 60-70°C for more than 4 h to obtain a translucent solution of the condensate of epichlorohydrin and polyethylenepolyamine; Step (3): Add inorganic salts into the closed reaction kettle and mix them evenly to obtain the high-temperature clay stabilizer solution.

8. The preparation method according to claim 7, characterized in that, The uniform mixing is achieved by stirring. The stirring time is more than 30 min, and the standing time is 0.5-1 h.

9. The preparation method according to claim 7 or 8, characterized in that In step (2), after the polymerization reaction is completed, it is cooled to normal temperature, and then the system is allowed to stand still for 1-2 h; In step (3), after mixing evenly, the system is allowed to stand still for 1-2 h.

10. Application of the high-temperature clay stabilizer solution according to any one of claims 1-6 in the development of heavy oil thermal recovery wells.

Images