Super absorbent resin, self-adaptive elastomer and application of super absorbent resin and self-adaptive elastomer as oil and gas drilling plugging agent

Abstract

The invention relates to the field of oil and gas drilling, in particular to super absorbent resin, a self-adaptive elastomer and application of the super absorbent resin and the self-adaptive elastomer as an oil and gas drilling plugging agent. The super absorbent resin is a cross-linked copolymer containing a structural unit as shown in a formula (1), a structural unit as shown in a formula (2), a structural unit as shown in a formula (3) and a structural unit as shown in a formula (4), wherein 100 g of the super absorbent resin is placed in 500 g of water at the temperature of 25 DEG C, and the time for achieving the water absorption rate of 500% is 5 min or below. When the self-adaptive elastomer of the super absorbent resin is used for leaking stoppage of a stratum, the self-adaptive elastomer is not limited by multiple scales of the opening size of an underground leakage crack, and a new crack can be quickly plugged in a self-adaptive manner after the size of the crack changes. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the field of oil and gas drilling, and particularly to superabsorbent resins and self-adaptive elastomers and their applications as lost circulation materials for oil and gas drilling. Background Art

[0002] During the process of oil and gas drilling, malignant lost circulation in fractured formations is often encountered. Such lost circulation is characterized by a high lost circulation rate, strong suddenness, and great difficulty in control. It not only causes a large loss of water-based drilling fluid and lost circulation materials, but also reduces the height of the drilling fluid column in the wellbore, induces bottomhole pressure imbalance, and thus leads to downhole complex situations such as wellbore instability. In more serious cases, it may even cause a blowout or even get out of control. Especially when currently moving towards the fields of deep and ultra-deep oil and gas resources, the "Deep Earth Engineering" has become a major national project. The high-temperature, high-pressure environment at the bottom of the well and high-salinity formation water pose severe challenges to the performance reliability of lost circulation materials. Therefore, how to achieve the efficient treatment of malignant lost circulation is of great significance for saving drilling time, reducing drilling costs, and realizing safe, economic, and efficient drilling.

[0003] The main reason why it is difficult to successfully plug malignant lost circulation in fractures is that the prerequisite for successful plugging is the effective matching of the particle size grading of the lost circulation material and the fracture size. However, the actual situation is that it is difficult for the lost circulation material to effectively match the shape and size of the fracture. On the one hand, the fractures in the downhole lost circulation layer have multi-scale complexity, unpredictability, and dynamic size alternation. On the other hand, the sizes of lost circulation materials such as walnut shells and calcium carbonate particles are fixed, without broad-spectrum, size variability, and self-adaptability. This results in the phenomenon of "blind plugging" being widespread in the oilfield, where it may still be impossible to successfully plug the lost circulation layer after repeatedly adjusting the particle size grading and concentration of the lost circulation material for the same lost circulation layer.

[0004] Especially, since the pressure of the drilling fluid column in the wellbore acting on the fractures in the lost circulation layer is affected by factors such as the height of the drilling fluid column, pump pressure, circulation pressure loss, and surge / swabbing pressure, the bottomhole drilling fluid pressure is not stable. This causes the fractures in the lost circulation layer to alternately open and close under the action of the dynamic pressure, that is, the actual downhole fractures are in a process of dynamic size change. This important feature of downhole fractures has been seriously ignored in previous scientific research. It is mainly manifested that the evaluation of lost circulation materials in the laboratory usually uses fractures with a fixed opening size to simulate and evaluate the plugging effect, without considering the plugging ability of the plugging layer after the size change of the same fracture. At this time, due to the change in the size matching relationship between the particles and the fracture, the structure of the initial plugging layer (particle accumulation plugging layer or lost circulation partition wall) becomes loose and is then washed away and fails, triggering re-lost circulation and inducing the phenomenon of "plugging and leaking, leaking and plugging" in the oilfield drilling site. Therefore, achieving efficient one-time plugging of fractured malignant lost circulation formations and effectively reducing the re-lost circulation rate is of great value and huge economic and social benefits for the efficient treatment of fractured lost circulation. Summary of the Invention

[0005] The object of the present invention is to overcome the problem of poor self - adapting plugging ability of plugging materials in the prior art, and to provide a superabsorbent resin and a self - adapting elastomer and their application as oil and gas drilling plugging agents. When the self - adapting elastomer of the superabsorbent resin of the present invention is used for formation plugging, it is not restricted by the multi - scale opening sizes of downhole leakage fractures, can successfully enter the fractures to form a plugging layer, and can quickly and self - adaptively plug new fractures after the fracture sizes change, achieving self - adapting and efficient pressure bearing, thereby improving the success rate of primary plugging and reducing the rate of re - leakage.

[0006] To achieve the above object, on the one hand, the present invention provides a superabsorbent resin, which is a cross - linked copolymer containing the structural units shown in formula (1), the structural units shown in formula (2), the structural units shown in formula (3) and the structural units shown in formula (4); wherein, when 100 g of the superabsorbent resin is placed in 500 g of water at 25 °C, the time taken to reach a water absorption rate of 500% is 5 minutes or less;

[0007] Formula (1) Formula (2)

[0008] Formula (3) Formula (4)

[0009] Among them, R1 - R3, R 10 -R 12 、R 21 -R 23 and R 31 -R 33 each independently selected from H and C1 - C6 alkyl groups; R4 is selected from H or C1 - C6 alkyl groups; R 13 is selected from H, a metal element or C1 - C6 alkyl groups; R 24 -R 28 is selected from H or C1 - C6 alkyl groups; L1 is selected from C0 - C6 alkylene groups; L2 is selected from C1 - C6 alkylene groups; M is selected from H or a metal element.

[0010] On the second aspect, the present invention provides a preparation method of a superabsorbent resin, which includes: in a solvent, using an initiator to initiate the polymerization reaction of copolymerization monomers and a cross - linking agent to obtain a superabsorbent resin; when 100 g of the superabsorbent resin is placed in 500 g of water at 25 °C, the time taken to reach a water absorption rate of 500% is 5 minutes or less;

[0011] Formula (1’) Formula (2’)

[0012] Formula (3’) Formula (4’)

[0013] Among them, R1-R3, R 10 -R 12 , R 21 -R 23 and R 31 -R 33 are each independently selected from H and C1-C6 alkyl groups; R4 is selected from H or C1-C6 alkyl groups; R 13 is selected from H, a metal element or C1-C6 alkyl groups; R 24 -R 28 is selected from H or C1-C6 alkyl groups; L1 is selected from C0-C6 alkylene groups; L2 is selected from C1-C6 alkylene groups; M is selected from H or a metal element.

[0014] The third aspect of the present invention provides a superabsorbent resin prepared by the above method.

[0015] The fourth aspect of the present invention provides an adaptive elastomer, which contains a rubber phase and a water-absorbing resin phase. The water-absorbing resin phase is provided by the above superabsorbent resin, and the surface tackiness of the adaptive elastomer measured by a nanoindentation instrument is 20 mN or more.

[0016] The fifth aspect of the present invention provides a method for preparing an adaptive elastomer. The preparation method includes: kneading and vulcanizing rubber and a water-absorbing resin to obtain an adaptive elastomer, and the water-absorbing resin is the above superabsorbent resin; wherein, the surface tackiness of the adaptive elastomer measured by a nanoindentation instrument is 20 mN or more.

[0017] The sixth aspect of the present invention provides an adaptive elastomer prepared by the above preparation method.

[0018] The seventh aspect of the present invention provides the application of the above adaptive elastomer as a plugging agent in the process of oil and gas drilling.

[0019] The eighth aspect of the present invention provides a plugging agent composition, which contains the above adaptive elastomer.

[0020] The ninth aspect of the present invention provides the application of the above composition as a plugging agent in the process of oil and gas drilling.

[0021] The superabsorbent resin of the present invention has excellent temperature and salt resistance, high self-strength, excellent water retention performance and high surface adhesiveness. The adaptive elastomer formed by using the superabsorbent resin of the present invention has the characteristics of water absorption and expansion and surface tackiness increase, high strength before and after expansion, good tensile properties and large volume expansion ratio. In particular, the water-absorbing resin has good temperature and salt resistance, high strength, good surface adhesiveness and excellent water retention performance. The plugging agent using this adaptive elastomer can adaptively plug multi-scale dynamic cracks, improve the success rate of primary plugging and reduce the rate of re-leakage. Detailed Embodiments

[0022] The endpoints and any values within the ranges disclosed herein are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0023] On the one hand, the present invention provides a superabsorbent resin, which is a crosslinked copolymer containing structural units represented by formula (1), structural units represented by formula (2), structural units represented by formula (3), and structural units represented by formula (4); wherein, when 100 g of the superabsorbent resin is placed in 1000 g of water at 25 °C, the time required to reach a water absorption rate of 500% is 5 minutes or less;

[0024] Formula (1) Formula (2)

[0025] Formula (3) Formula (4)

[0026] Wherein, R1-R3, R 10 -R 12 、R 21 -R 23 and R 31 -R 33 are each independently selected from H and C1-C6 alkyl groups; R4 is selected from H or C1-C6 alkyl groups; R 13 is selected from H, a metal element, or C1-C6 alkyl groups; R 24 -R 28 is selected from H or C1-C6 alkyl groups; L1 is selected from C0-C6 alkylene groups; L2 is selected from C1-C6 alkylene groups; M is selected from H or a metal element.

[0027] In the present invention, the above-mentioned superabsorbent resin forms a resin by means of the crosslinking action of each structural unit and controls its water absorption to obtain a plugging agent component with self-adaptive expansion after being introduced into an elastomer. Among them, the water absorption of the superabsorbent resin needs to meet: when 100 g of the superabsorbent resin is placed in 500 g of water at 25 °C, the time required to reach a water absorption rate of 500% is 5 minutes or less. Preferably, when 100 g of the superabsorbent resin is placed in 100 g of water at 25 °C, the time required to reach a water absorption rate of 500% is 0.5-5 minutes, more preferably 1-3 minutes.

[0028] According to the present invention, preferably, R1-R3, R 10 -R12 , R 21 -R 23 and R 31 -R 33 are each independently selected from H and C1-C4 alkyl; R4 is selected from H or C1-C4 alkyl; R 13 is selected from H, an alkali metal element, or C1-C4 alkyl; R 24 -R 28 is selected from H or C1-C4 alkyl; L1 is selected from C0-C4 alkylene; L2 is selected from C1-C6 alkylene; M is selected from H or an alkali metal element;

[0029] Preferably, R1-R3, R 10 -R 12 , R 21 -R 23 and R 31 -R 33 are each independently selected from H, methyl, ethyl, or n-propyl; R4 is selected from H, methyl, ethyl, or n-propyl; R 13 is selected from H, Li, Na, K, methyl, ethyl, or n-propyl; R 24 -R 28 is selected from H, methyl, ethyl, or n-propyl; L1 is selected from absent, -CH2-, -CH2CH2-, or -CH2CH2CH2-; L2 is selected from -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH(CH3)CH2-, -CH2CH(CH3)-, -CH2CH2CH2CH2-, -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-, -CH2CH2CH(CH3)-, -C(CH3)2CH2-, or -CH2C(CH3)2-; M is selected from H, Li, Na, or K.

[0030] In a preferred embodiment of the present invention, R1-R3, R 10 -R 12 , R 21 -R 23 and R 31 -R 33 are each independently selected from H, methyl, or ethyl, R4 is selected from H, methyl, or ethyl, R 13 is selected from H, Na, K, methyl, or ethyl, R 24 -R 28Each is independently selected from H, methyl or ethyl, L1 is selected from absent, -CH2- or -CH2CH2-, L2 is selected from -CH2CH2-, -CH2CH2CH2-, -CH(CH3)CH2-, -CH2CH(CH3)-, -CH2CH2CH2CH2-, -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-, -CH2CH2CH(CH3)-, -C(CH3)2CH2- or -CH2C(CH3)2-, and M is selected from H, Na or K.

[0031] In the present invention, the absence of an alkylene group in C0 means that the groups connected at both ends are directly bonded.

[0032] According to the present invention, in order to enable the resulting superabsorbent resin to better cooperate with the rubber component to obtain an elastomer that can better adaptively expand in dynamic formation fractures, preferably, the molar ratio of the structural units shown in formula (1), the structural units shown in formula (2), the structural units shown in formula (3), and the structural units shown in formula (4) is 1:1.5 - 8:0.1 - 1.5:0.5 - 5, preferably 1:2 - 6:0.1 - 1:1 - 3, and more preferably 1:3 - 5:0.3 - 0.8:1 - 2.

[0033] According to the present invention, in order to obtain a more suitable water absorption and swelling effect, preferably, the weight average molecular weight of the crosslinked copolymer is 8000 - 80000 g / mol, preferably 10000 - 50000 g / mol, more preferably 10000 - 30000 g / mol, for example 12000 g / mol, 15000 g / mol, 20000 g / mol, 25000 g / mol, and any range within the combination of the above values.

[0034] According to the present invention, the crosslinked structure of the crosslinked copolymer can be selected from a variety of crosslinked structures. However, in order to form a more favorable effect for adaptive expansion with other structural units, preferably, the crosslinked structure in the hypercrosslinked copolymer is provided by the crosslinking agent shown in formula (5):

[0035] Formula (5)

[0036] Wherein, R' and R" are each independently selected from H and C1 - C6 alkyl groups; R 41 -R 46 are each independently selected from H and C1 - C6 alkyl groups; L3 is selected from C1 - C6 alkylene groups.

[0037] It should be understood that the two unsaturated carbon - carbon double bonds provided by the crosslinking agent shown in formula (5) above will initiate the formation of 4 copolymerization active sites (such as forming the crosslinked structure shown in this formula ), thereby forming multiple cross-linked connection structures in the cross-linked copolymer. In combination with the above-mentioned specific content of structural units, a superabsorbent resin with the desired water absorption characteristics of the present invention is formed.

[0038] Preferably, R' and R" are each independently selected from H and C1-C4 alkyl groups; R 41 -R 46 are each independently selected from H and C1-C4 alkyl groups; L3 is selected from C1-C4 alkylene groups.

[0039] More preferably, R' and R" are each independently selected from H, methyl, ethyl or n-propyl; R 41 -R 46 are each independently selected from H, methyl, ethyl or n-propyl; L3 is selected from -CH2-, -CH2CH2- or -CH2CH2CH2-.

[0040] According to the present invention, the content of the above cross-linked structure can be appropriately adjusted according to the water absorption of the desired superabsorbent resin, etc. Preferably, the cross-linked structural units in the cross-linked structure account for 0.5-10 mol% of the total molar amount of the total comonomers, preferably 1-6 mol%.

[0041] The second aspect of the present invention provides a method for preparing a superabsorbent resin, the method comprising: in a solvent, using an initiator to initiate the polymerization reaction of comonomers and a cross-linking agent to obtain a superabsorbent resin; placing 100 g of the superabsorbent resin in 500 g of water at 25°C, and the time taken to reach a water absorption rate of 500% is 5 minutes or less;

[0042] Formula (1') Formula (2')

[0043] Formula (3') Formula (4')

[0044] Among them, R1-R3, R 10 -R 12 , R 21 -R 23 and R 31 -R 33 are each independently selected from H and C1-C6 alkyl groups; R4 is selected from H or C1-C6 alkyl groups; R 13 is selected from H, a metal element or C1-C6 alkyl groups; R 24 -R 28 is selected from H or C1-C6 alkyl groups; L1 is selected from C0-C6 alkylene groups; L2 is selected from C1-C6 alkylene groups; M is selected from H or a metal element.

[0045] In the preparation method of the above superabsorbent resin of the present invention, the comonomers involved can be selected according to the structural units described above, and the present invention will not elaborate here.

[0046] According to the present invention, preferably, the molar ratio of the monomer represented by formula (1'), the monomer represented by formula (2'), the monomer represented by formula (3'), and the monomer represented by formula (4') is 1:1.5 - 8:0.1 - 1.5:0.5 - 5, preferably 1:2 - 6:0.1 - 1:1 - 3, and more preferably 1:3 - 5:0.3 - 0.8:1 - 2.

[0047] According to the present invention, preferably, the weight-average molecular weight of the crosslinked copolymer is 8000 - 80000 g / mol, preferably 10000 - 50000 g / mol, more preferably 10000 - 30000 g / mol, such as 12000 g / mol, 15000 g / mol, 20000 g / mol, 25000 g / mol, and the ranges within any combination of the above numerical values.

[0048] According to the present invention, the crosslinking agent is the crosslinking agent represented by formula (5):

[0049] Formula (5)

[0050] This crosslinking agent is as described above, and the present invention will not elaborate here.

[0051] According to the present invention, preferably, relative to the total molar amount of the comonomers, the amount of the crosslinking agent used is 0.5 - 10 mol%, preferably 1 - 6 mol%.

[0052] According to the present invention, preferably, the conditions of the polymerization reaction include: the temperature is 40 - 100 °C, preferably 50 - 80 °C; the time is 10 - 60 h, preferably 12 - 48 h.

[0053] According to the present invention, the initiator can be selected from various initiators that can introduce the comonomers and crosslinking agent of the present invention, such as selected from azo initiators (such as one or more of azobisisobutyronitrile, azobisisoheptonitrile, azobisisovaleronitrile, dimethyl azobisisobutyrate, azobis(isobutylamidine) hydrochloride, etc.), organic peroxides (such as one or more of benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, etc.), and inorganic peroxides (such as one or more of ammonium persulfate, sodium persulfate, potassium persulfate, etc.). The amount of this initiator can be adjusted accordingly according to the required crosslinked copolymer. Preferably, the amount of the initiator used is 0.1 - 2% by weight of the total weight of the comonomers, preferably 0.1 - 0.5% by weight, and more preferably 0.1 - 0.3% by weight.

[0054] According to the present invention, the solvent used in the polymerization reaction can be selected from various solvents applicable to the polymerization reaction required by the present invention. For example, it can be water or an aqueous solvent containing other solvents. Among them, the amount of the solvent can be adjusted within a wide range. Preferably, the weight ratio of the amount of the solvent to the amount of the comonomer is 100:10 - 50, preferably 100:10 - 30, such as 100:10 - 20.

[0055] According to the present invention, it can be understood that in order to make the initiation process proceed smoothly, the reaction system can be maintained in an anaerobic environment. For example, oxygen can be removed by introducing an inert gas (such as nitrogen, inert gas, etc.). This deoxygenation treatment is preferably carried out before introducing the initiator. The specific process includes: dissolving the comonomer and the crosslinking agent in the solvent, then performing the deoxygenation treatment, and then introducing the initiator to initiate the polymerization reaction.

[0056] According to the present invention, it should be understood that the polymerization reaction system can also be correspondingly treated after the polymerization reaction to prepare the required resin particle product. For example, the resin obtained from the polymerization reaction can be dried after the polymerization reaction (for example, dried at 70 - 120 °C for 10 - 60 h), and then the dried gel is pulverized to obtain the resin particle product. The particle size of the resin particle product can be selected as needed, and usually can be 50 - 500 mesh (for example, 100 - 400 mesh).

[0057] The third aspect of the present invention provides a superabsorbent resin prepared by the above method.

[0058] According to the present invention, although the superabsorbent resin provided in the third aspect of the present invention is directly prepared by the above method, the superabsorbent resin described in the first aspect of the present invention is also applicable to the superabsorbent resin in the third aspect and can be directly applied as the characteristics of the superabsorbent resin in the third aspect.

[0059] The fourth aspect of the present invention provides an adaptive elastomer, which contains a rubber phase and a water-absorbing resin phase. The water-absorbing resin phase is provided by the above superabsorbent resin, and the surface tackiness of the adaptive elastomer measured by a nanoindentation instrument is above 20 mN.

[0060] According to the present invention, by introducing the water-absorbing resin phase of the present invention, the adaptive elastomer can exhibit a certain viscosity on its surface, whereby each component in the plugging composition can be bonded together to achieve the desired effect of dynamically adapting to plugging cracks of different sizes. Preferably, the surface viscosity of the adaptive elastomer measured by a nanoindenter is above 30 mN, preferably 40 - 100 mN, more preferably 50 - 100 mN, such as 60 mN, 65 mN, 70 mN, 75 mN, 80 mN, 85 mN, 90 mN, and ranges within any combination of the above numerical values.

[0061] According to the present invention, preferably, the volume expansion ratio of the adaptive elastomer is 50 - 500%, preferably 100 - 450%, more preferably 200 - 420%, such as 250%, 270%, 300%, 350%, 380%, 400%, and ranges within any combination of the above numerical values; the tensile strength of the adaptive elastomer is, for example, 1 - 5 MPa, preferably 2 - 4.5 MPa, more preferably 3 - 4 MPa.

[0062] According to the present invention, preferably, relative to 100 parts by weight of the rubber phase, the content of the water-absorbing resin phase is 30 - 300 parts by weight (such as 40 parts by weight, 45 parts by weight, 50 parts by weight, 60 parts by weight, 70 parts by weight, 80 parts by weight, 90 parts by weight, 100 parts by weight, 150 parts by weight, 200 parts by weight, 250 parts by weight, etc., and ranges within any combination of the above numerical values), preferably 40 - 200 parts by weight, more preferably 50 - 150 parts by weight.

[0063] According to the present invention, the above-mentioned adaptive elastomer can be understood as a vulcanized rubber, which is formed by introducing a water-absorbing resin into rubber and then vulcanizing, resulting in a vulcanized rubber having a rubber phase and a water-absorbing resin phase. Among them, the rubber phase can be selected from one or more of nitrile rubber, styrene-butadiene rubber, chloroprene rubber, cis-1,4-polybutadiene rubber, natural rubber, ethylene-propylene-diene monomer rubber, etc.

[0064] In a preferred embodiment of the present invention, the adaptive elastomer is basically composed of a rubber phase and a water-absorbing resin phase. It can be considered that the total content of the rubber phase and the water-absorbing resin phase in the adaptive elastomer accounts for more than 90% by weight, preferably more than 95% by weight, more preferably more than 98% by weight, especially more than 99% by weight, such as 99 - 99.9% by weight. Other components can be, for example, sulfur-containing groups introduced by vulcanization.

[0065] The fifth aspect of the present invention provides a method for preparing an adaptive elastomer, which includes: mixing and vulcanizing rubber and a water-absorbing resin to obtain the adaptive elastomer, and the water-absorbing resin is the above-mentioned superabsorbent resin; wherein, the surface tackiness of the adaptive elastomer measured by a nano-indentation instrument is above 20 mN.

[0066] According to the present invention, by mixing and vulcanizing a superabsorbent resin and rubber, an adaptive elastomer with the desired surface tackiness can be obtained. The preferred range of its surface tackiness is as described above, and the present invention will not repeat it here.

[0067] According to the present invention, the rubber and the superabsorbent resin are also as described above, and the present invention will not repeat it here. Preferably, relative to 100 parts by weight of the rubber, the amount of the water-absorbing resin used is 30-300 parts by weight (for example, 40 parts by weight, 45 parts by weight, 50 parts by weight, 60 parts by weight, 70 parts by weight, 80 parts by weight, 90 parts by weight, 100 parts by weight, 150 parts by weight, 200 parts by weight, 250 parts by weight, etc. and ranges within any numerical range selected therefrom), preferably 40-200 parts by weight, and more preferably 50-150 parts by weight.

[0068] According to the present invention, generally, a vulcanizing agent can be introduced during the mixing. Therefore, the mixing in the present invention can include mixing rubber, a water-absorbing resin, and a vulcanizing agent. The amount of the vulcanizing agent can be appropriately selected. For example, relative to 100 parts by weight of the rubber, the amount of the vulcanizing agent used is 0.1-5 parts by weight, preferably 0.2-3 parts by weight, and more preferably 0.3-1.2 parts by weight. The vulcanizing agent can be a vulcanizing agent conventionally used in the preparation of vulcanized rubber in the art. For example, elemental sulfur, triazine-based vulcanizing agents (such as 2,4,6-trimercapto-s-triazine), thiourea-based vulcanizing agents (such as 2-mercaptoimidazoline), quinoxaline-based vulcanizing agents (such as 6-methylquinoxaline-2,3-dithiocarbonate), etc. can be used alone or in combination.

[0069] According to the present invention, the above components can be uniformly dispersed through mixing, and then through vulcanization treatment, the desired adaptive elastomer can be obtained. Preferably, the conditions for the mixing include: temperature is 90-120 °C, and time is 0.5-2 h.

[0070] Preferably, the conditions for the vulcanization include: temperature is 100-220 °C, pressure is 5-20 MPa, and time is 5-20 min. More preferably, the conditions for the vulcanization include: temperature is 120-180 °C, pressure is 5-15 MPa, and time is 5-10 min.

[0071] According to the present invention, the mixing process can be carried out by the mixing methods commonly used in the present invention. For example, the rubber can be plasticized on an open mill first, and then the superabsorbent resin and vulcanizing agent are introduced for mixing, followed by thin passing treatment. After discharging, it is sent to a vulcanizer for vulcanization treatment. After vulcanization treatment, it can be sent for cutting and pulverization treatment to obtain elastomer particles of appropriate size (the size can be, for example, 0.5 - 5 mm) for use as a component of the subsequent plugging agent.

[0072] The sixth aspect of the present invention provides an adaptive elastomer prepared by the above preparation method.

[0073] Although the above adaptive elastomer of the present invention should be directly obtained by the preparation method provided in the fifth aspect above, it should be understood that the adaptive elastomer of the sixth aspect of the present invention may also have the relevant properties and characteristics involved in the adaptive elastomer provided in the fourth aspect above.

[0074] The seventh aspect of the present invention provides the application of the above adaptive elastomer as a plugging agent in the process of oil and gas drilling.

[0075] According to the present invention, the above self - adaptive elastomer can be used as a plugging agent in oil and gas drilling, and can obtain the effect of adaptively plugging dynamic fractures, thereby reducing the re - leakage rate of primary plugging.

[0076] The eighth aspect of the present invention provides a plugging agent composition containing the above adaptive elastomer.

[0077] According to the present invention, the plugging agent composition of the present invention can be used for plugging formation fractures in the process of oil and gas drilling. By introducing the above - mentioned adaptive elastomer component of the present invention into the plugging agent composition of the present invention, the adaptive plugging effect of the obtained plugging agent composition in dynamic fractures can be enhanced. For obtaining a more excellent plugging effect, preferably, the plugging agent composition further contains a plugging component, a filler component, and a viscosity - increasing component. Particularly preferably, the weight ratio of the amounts of the adaptive elastomer, the plugging component, the filler component, and the viscosity - increasing component is 100:100 - 500:10 - 600:20 - 80, preferably 100:200 - 400:20 - 500:30 - 70, more preferably 100:250 - 350:20 - 500:40 - 60, and can be, for example, 100:250 - 300:20 - 60:40 - 60.

[0078] According to the present invention, the plugging component can adopt various types of plugging components and their combinations commonly used in the art. In particular, when the plugging component is one or more of a plugging particle component, a plugging sheet component, and a plugging fiber component, the cooperative effect between the plugging agent compositions of the present invention can be better exerted. Among them, the plugging particle component can be, for example, one or more of hard fruit shells, quartz sand, limestone particles, calcite particles, etc., and its particle size can be, for example, 0.5-5 mm; the hard fruit shell can be one or more of abrasives such as walnut shells, wild jujube shells, or apricot shells, and is a granular filter material processed by processes such as crushing, screening, and polishing of the fruit shell. The plugging sheet component can be, for example, one or more of mica sheets, glass flakes, vermiculite sheets, etc., and its length or width can be, for example, 0.5-5 mm, and its thickness can be, for example, 0.01-0.5 mm. The plugging fiber component can be, for example, one or more of plant fibers, mineral fibers, and polymer fibers. Among them, the length of the plugging fiber can be, for example, more than 0.5 mm, and can be 0.5-10 mm (preferably 1-5 mm), and the aspect ratio of the plugging fiber can be, for example, more than 10, and can be 10-50 (preferably 15-30); among them, the plant fiber can be, for example, one or more of wood fibers, cotton fibers, and cottonseed hull fibers, the mineral fiber can be, for example, one or more of sepiolite fibers, brucite fibers, etc., and the polymer fiber can be, for example, one or more of polypropylene fibers, polyester fibers, polyamide fibers, etc.

[0079] In a preferred embodiment of the present invention, the plugging component is a combination of a plugging particle component, a plugging sheet component, and a plugging fiber component. More preferably, the dosage ratio of the plugging particle component, the plugging sheet component, and the plugging fiber is 100:40-150:20-80, preferably 100:50-100:30-60.

[0080] According to the present invention, the filler component can adopt fillers commonly used in the art, such as clay materials such as bentonite. The thickening component can adopt, for example, one or more of carboxymethyl cellulose, polyanionic cellulose, starch, or biopolymer. Among them, polyanionic cellulose is a water-soluble polymer produced by the chemical reaction of cellulose and carboxymethyl anion groups, and usually includes two technical categories of high viscosity and low viscosity; the biopolymer can be a water-soluble polysaccharide, such as a polysaccharide produced by Xanthomonas through a special fermentation process, and does not contain other polysaccharides such as starch and guar gum.

[0081] The ninth aspect of the present invention provides the application of the above composition as a plugging agent in the process of oil and gas drilling.

[0082] The technical solution proposed by the present invention has the following advantages:

[0083] (1) The plugging layer itself has the ability to adapt to pressure differences through elastic deformation: On the one hand, the plugging material can enter multi-scale leakage cracks through elastic deformation under the leakage pressure difference to form a sealing plugging layer, overcoming the blindness of on-site drilling fluid engineers in selecting the size and gradation of the plugging material when the characteristics of downhole cracks are unknown. On the other hand, when the leakage pressure difference changes, it can resist the change of the pressure difference through its own elastic deformation, thus avoiding the rigid rupture and failure of the plugging layer. In addition, the plugging layer can continuously absorb water and expand, generating contact stress on the crack wall surface, thereby increasing the wall friction and avoiding the slip failure of the plugging layer.

[0084] (2) The plugging layer can adapt to the dynamic change of crack size to achieve plugging: When the crack size decreases, the adaptive plugging layer can withstand a certain extrusion pressure through elastic deformation without generating cracks; when the crack size increases, on the basis of its own elastic recovery for plugging, the plugging layer can further extend and plug through water absorption and expansion, thus comprehensively realizing the double-insurance adaptive plugging of size-dynamically alternating cracks, improving the success rate of one-time plugging and reducing the rate of repeated leakage, saving plugging time and cost.

[0085] (3) Due to the viscosity of the surface of the adaptive elastomer, the particles of the plugging layer and the crack wall surfaces are further bonded into a whole, thereby further enhancing the strength and integrity of the plugging layer.

[0086] The present invention will be described in detail below through embodiments.

[0087] In the following examples and comparative examples:

[0088] The water absorption test method is as follows: Pour 100 g of superabsorbent resin into a beaker, and then add 500 g of deionized water. Shake the beaker appropriately to disperse the resin particles evenly. Start timing when adding deionized water, and stop timing when the liquid mirror surface of the deionized water in the beaker disappears.

[0089] The weight-average molecular weight is tested according to GB / T 30787-2014.

[0090] The tensile properties of the adaptive elastomer are tested according to GB / T528-2009.

[0091] The volume expansion ratio of the adaptive elastomer is tested according to GB / T18173.3-2014.

[0092] The surface viscosity of the adaptive elastomer is obtained through a nanoindentation instrument.

[0093] Resin Preparation Example 1

[0094] This preparation example is used to illustrate the superabsorbent resin of the present invention and its preparation method.

[0095] Four kinds of comonomers: acrylamide, styrene, acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid (molar ratio 1:0.5:4:1), and the crosslinking agent N,N'-methylenebisacrylamide (the dosage of this crosslinking agent is 4 mol% of the total molar dosage of the comonomers) were fully stirred and dissolved in water (the water dosage is in a weight ratio of 100:20 to the total weight of the comonomers). Nitrogen was passed through to remove oxygen for 30 min. Then, an aqueous hydrogen peroxide solution with an initiator concentration of 30 wt% was poured in (such that the hydrogen peroxide dosage is 0.25 wt% relative to the total amount of the comonomers), and a polymerization reaction was initiated at 80 °C for 36 h. After the reaction ended, the superabsorbent resin was taken out and dried in a high-temperature oven at 105 °C for 48 h. The dried gel was crushed and sieved, and the powder particle size was 200 mesh, thus obtaining the superabsorbent resin product SWR-1.

[0096] The weight-average molecular weight of this superabsorbent resin is 20,000 g / mol, and the water absorption test results are shown in Table 1.

[0097] Resin Preparation Example 2

[0098] This preparation example is used to illustrate the superabsorbent resin of the present invention and its preparation method.

[0099] Four kinds of comonomers: methacrylamide, styrene, sodium acrylate and 2-acrylamido-2-methylpropanesulfonic acid (molar ratio 1:0.6:5:1.5), and the crosslinking agent N,N'-methylenebisacrylamide (the dosage of this crosslinking agent is 1 mol% of the total molar dosage of the comonomers) were fully stirred and dissolved in water (the water dosage is in a weight ratio of 100:10 to the total weight of the comonomers). Nitrogen was passed through to remove oxygen for 30 min. Then, the initiator azobisisobutyronitrile was poured in (such that the azobisisobutyronitrile dosage is 0.1 wt% relative to the total amount of the comonomers), and a polymerization reaction was initiated at 40 °C for 12 h. After the reaction ended, the superabsorbent resin was taken out and dried in a high-temperature oven at 75 °C for 36 h. The dried gel was crushed and sieved, and the powder particle size was 50 mesh, thus obtaining the superabsorbent resin product SWR-2.

[0100] The weight-average molecular weight of this superabsorbent resin is 10,000 g / mol, and the water absorption test results are shown in Table 1.

[0101] Resin Preparation Example 3

[0102] This preparation example is used to illustrate the superabsorbent resin of the present invention and its preparation method.

[0103] Four kinds of comonomers: acrylamide, styrene, acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid (molar ratio 1:0.6:4:1.2) were fully stirred and dissolved in water together with the crosslinking agent N,N'-methylenebisacrylamide (the amount of this crosslinking agent was 5 mol% of the total molar amount of the comonomers) (the ratio of the amount of water used to the total weight of the comonomers was 100:30). Nitrogen was passed through to remove oxygen for 30 min. Then, an aqueous hydrogen peroxide solution with an initiator concentration of 30 wt% was poured in (such that the amount of hydrogen peroxide used was 0.15 wt% relative to the total amount of the comonomers), and a polymerization reaction was initiated at 80 °C for 48 h. After the reaction ended, the superabsorbent resin was taken out and dried in a high-temperature oven at 110 °C for 72 h. The dried gel was crushed and sieved, and the powder particle size was 200 mesh, thus obtaining the superabsorbent resin product SWR-3.

[0104] The weight-average molecular weight of this superabsorbent resin was 30000 g / mol, and the water absorption test results are shown in Table 1.

[0105] Resin Preparation Example 4

[0106] This preparation example is used to illustrate the superabsorbent resin of the present invention and its preparation method.

[0107] Using the same method as in Resin Preparation Example 1, the difference being that the molar ratio of the amounts of the comonomers was different. The molar ratio of the amounts of acrylamide, styrene, acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid was 1:1:2:1, thereby obtaining the superabsorbent resin product SWR-4. The weight-average molecular weight of this superabsorbent resin was 22000 g / mol, and its water absorption test results are shown in Table 1.

[0108] Resin Preparation Example 5

[0109] This preparation example is used to illustrate the superabsorbent resin of the present invention and its preparation method.

[0110] Using the same method as in Resin Preparation Example 1, the difference being that the molar ratio of the amounts of the comonomers was different. The molar ratio of the amounts of acrylamide, styrene, acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid was 1:0.1:6:3, thereby obtaining the superabsorbent resin product SWR-5. The weight-average molecular weight of this superabsorbent resin was 21000 g / mol, and its water absorption test results are shown in Table 1.

[0111] Resin Preparation Example 7

[0112] This preparation example is used to illustrate the superabsorbent resin of the present invention and its preparation method.

[0113] Using the same method as in Resin Preparation Example 1, except that the weight ratio of the amount of water to the total weight of the comonomers is 100:40, and the amount of hydrogen peroxide is 1.5% by weight based on the total amount of the comonomers, a superabsorbent resin product SWR-6 is thus prepared. The weight-average molecular weight of this superabsorbent resin is 50,000 g / mol, and the water absorbency test results are shown in Table 1.

[0114] Resin Preparation Comparative Example 1

[0115] Using the same method as in Resin Preparation Example 1, except that the molar ratio of the types and amounts of the comonomers is different, the molar ratio of acrylamide to styrene is 1:1, and the water absorbent resin products DWR-1 are prepared to have the water absorbency shown in Table 1.

[0116] Resin Preparation Comparative Example 2

[0117] Using the same method as in Resin Preparation Example 1, except that the molar ratio of the amounts of the comonomers is different, the molar ratio of acrylamide to 2-acrylamido-2-methylpropanesulfonic acid is 1:0.5, and the water absorbent resin products DWR-2 are prepared to have the water absorbency shown in Table 1.

[0118] Resin Preparation Comparative Example 3

[0119] Using the same method as in Resin Preparation Example 1, except that only acrylic acid is used as the comonomer, a water absorbent resin product DWR-3 is thus prepared, and the water absorbency test results are shown in Table 1.

[0120] Table 1

[0121] Water-absorbing resin number Water absorption test results SWR-1 2.0 min SWR-2 1.0 min SWR-3 3.0 min SWR-4 2.5 min SWR-5 2.1 min SWR-6 5.0 min DWR-1 12 min DWR-2 17.0 min DWR-3 8.0 min

[0122] Self-Adaptive Elastomer Preparation Example 1

[0123] This preparation example is used to illustrate the self-adaptive elastomer of the present invention and its preparation method.

[0124] 100 parts by weight of nitrile rubber (purchased from Lanzhou Petrochemical Company, PetroChina, NBR 33055E grade) is plasticized on an open mill at 40°C and plasticized evenly; 80 parts by weight of superabsorbent resin SWR-1 and 1 part by weight of powdered sulfur are added in sequence and further kneaded at 100°C for 1.5 h until uniform, passed through the mill 5 times thinly, sheeted out, and parked for more than 12 h. Then, the vulcanized test piece is vulcanized using a flat vulcanizer, and the vulcanization conditions are: temperature is 150°C, pressure is 10 MPa, and time is 10 min. Then, the vulcanized test piece is cut, crushed, and granulated, and the particle size is 2 mm to obtain a self-adaptive elastomer SAE-1. The tensile strength, volume expansion ratio, and surface tackiness test results of this elastomer are shown in Table 2.

[0125] Self-Adaptive Elastomer Preparation Example 2

[0126] This preparation example is used to illustrate the self - adaptive elastomer of the present invention and its preparation method.

[0127] 100 parts by weight of neoprene (purchased from Lanzhou Petrochemical Company, PetroChina, grade NBR 33055E) was plasticized on an open mill at 40 °C and mixed evenly; 50 parts by weight of superabsorbent resin SWR - 2 and 0.3 parts by weight of powdered sulfur were added in sequence and further mixed at 90 °C for 2 h until uniform, passed through the mill 5 times thinly, sheeted out, and parked for more than 12 h. Then, the vulcanized test piece was vulcanized using a flat vulcanizer, and the vulcanization conditions were: temperature 120 °C, pressure 5 MPa, and time 5 min. Then, the vulcanized test piece was cut, crushed, and granulated, and the particle size was 12 mm to obtain the self - adaptive elastomer SAE - 2. The test results of the tensile strength, volume expansion ratio, and surface viscosity of this elastomer are shown in Table 2.

[0128] Self - adaptive Elastomer Preparation Example 3

[0129] This preparation example is used to illustrate the self - adaptive elastomer of the present invention and its preparation method.

[0130] 100 parts by weight of nitrile rubber (purchased from Lanzhou Petrochemical Company, PetroChina, grade NBR 33055E) was plasticized on an open mill at 40 °C and mixed evenly; 150 parts by weight of superabsorbent resin SWR - 3 and 1.2 parts by weight of powdered sulfur were added in sequence and further mixed at 120 °C for 0.5 h until uniform, passed through the mill 10 times thinly, sheeted out, and parked for more than 12 h. Then, the vulcanized test piece was vulcanized using a flat vulcanizer, and the vulcanization conditions were: temperature 180 °C, pressure 15 MPa, and time 15 min. Then, the vulcanized test piece was cut, crushed, and granulated, and the particle size was 2 mm to obtain the self - adaptive elastomer SAE - 3. The test results of the tensile strength, volume expansion ratio, and surface viscosity of this elastomer are shown in Table 2.

[0131] Self - adaptive Elastomer Preparation Examples 4 - 7

[0132] Using the same method as in Self - adaptive Elastomer Preparation Example 1, the difference is that superabsorbent resins SWR - 4 to SWR - 6 are used to replace superabsorbent resin SWR - 1 respectively, thereby obtaining self - adaptive elastomers SAE - 4 to SAE - 6. The test results of the tensile strength, volume expansion ratio, and surface viscosity of each elastomer are shown in Table 2.

[0133] Elastomer Comparative Examples 1 - 3

[0134] Using the same method as in Preparation Example 1 of the self-adaptive elastomer, the difference is that superabsorbent resin SWR-1 is replaced by water-absorbing resins DWR-1 to DWR-3 respectively, thereby obtaining elastomers DE-1 to DE-3. The test results of the tensile strength, volume expansion ratio and surface viscosity of each elastomer are shown in Table 2.

[0135] Table 2

[0136]

[0137] Plugging agent Example 1

[0138] This example is used to illustrate the plugging agent composition of the present invention.

[0139] 2 parts by weight of bentonite (drilling-grade bentonite purchased from Anji Tianhong Bentonite Co., Ltd.), 1.5 parts by weight of high-viscosity carboxymethyl cellulose (HV-CMC grade purchased from Renqiu City Kewi Chemical Co., Ltd.), 2 parts by weight of wood fiber (purchased from Shijiazhuang Mengzi Mineral Products Co., Ltd. with a length of 3 mm and an aspect ratio of 25), 3 parts by weight of mica flakes (mica flakes purchased from Shijiazhuang Fanghong Mineral Products Co., Ltd. with a length of 2 mm, a width of 2 mm and a thickness of 0.1 mm), 5 parts by weight of walnut shells (particles with a size of 2 mm purchased from Henan Wansen Environmental Protection Technology Co., Ltd.) and 3 parts by weight of self-adaptive elastomer SAE-1 are successively contacted with 100 parts by weight of water, and after stirring evenly, self-adaptive plugging agent SAP-1 is obtained.

[0140] Plugging agent Example 2

[0141] This example is used to illustrate the plugging agent composition of the present invention.

[0142] 5 parts by weight of bentonite (drilling-grade bentonite purchased from Anji Tianhong Bentonite Co., Ltd.), 0.5 parts by weight of high-viscosity carboxymethyl cellulose (HV-CMC grade purchased from Renqiu City Kewi Chemical Co., Ltd.), 0.5 parts by weight of wood fiber (purchased from Shijiazhuang Mengzi Mineral Products Co., Ltd. with a length of 3 mm and an aspect ratio of 25), 1 part by weight of mica flakes (mica flakes purchased from Shijiazhuang Fanghong Mineral Products Co., Ltd. with a length of 2 mm, a width of 2 mm and a thickness of 0.1 mm), 1 part by weight of walnut shells (particles with a particle size of 2 mm purchased from Henan Wansen Environmental Protection Technology Co., Ltd.) and 1 part by weight of self-adaptive elastomer SAE-2 are successively contacted with 100 parts by weight of water, and after stirring evenly, self-adaptive plugging agent SAP-2 is obtained.

[0143] Plugging agent Example 3

[0144] This example is used to illustrate the plugging agent composition of the present invention.

[0145] 1 part by weight of bentonite (drilling-grade bentonite purchased from Anji Tianhong Bentonite Co., Ltd.), 3 parts by weight of high-viscosity carboxymethyl cellulose (HV-CMC with the trade mark purchased from Renqiu City Kewei Chemical Co., Ltd.), 3 parts by weight of sepiolite fiber (purchased from Shijiazhuang Mengzi Mineral Products Co., Ltd. with a length of 3 mm and an aspect ratio of 25), 6 parts by weight of mica flakes (mica flakes purchased from Shijiazhuang Fanghong Mineral Products Co., Ltd. with a length of 2 mm, a width of 2 mm, and a thickness of 0.1 mm), 10 parts by weight of quartz sand (particles with a particle size of 2 mm purchased from Henan Wansen Environmental Protection Technology Co., Ltd.) and 5 parts by weight of self-adaptive elastomer SAE-3 were successively contacted with 100 parts by weight of water, and after stirring evenly, a self-adaptive plugging agent SAP-3 was obtained.

[0146] Plugging agent Examples 4-7

[0147] This example is used to illustrate the plugging agent composition of the present invention.

[0148] Using the same method as in Plugging agent Example 1, the difference is that self-adaptive elastomers SAE-4 to SAE-6 are respectively used to replace the self-adaptive elastomer SAE-1, thereby obtaining self-adaptive plugging agents SAP-4 to SAP-6.

[0149] Plugging agent Comparative Examples 1-3

[0150] Using the same method as in Plugging agent Example 1, the difference is that elastomers DE-1 to DE-3 are respectively used to replace the self-adaptive elastomer SAE-1, thereby obtaining plugging agents DP-1 to DP-3.

[0151] Plugging agent Comparative Example 4

[0152] Using the same method as in Plugging agent Example 1, the difference is that waste tires of the same size and dosage are used to replace the self-adaptive elastomer SAE-1, thereby obtaining a plugging agent DP-4.

[0153] Plugging agent Comparative Example 5

[0154] Using the same method as in Plugging agent Example 1, the difference is that the self-adaptive elastomer SAE-1 is not added, thereby obtaining a plugging agent DP-5.

[0155] Test Example

[0156] The crack plugging effect of the above plugging agents was evaluated as follows: The plugging effect was evaluated using a crack self-adjusting high-temperature and high-pressure dynamic plugging instrument. The initial width of the crack was 1 mm. After static plugging for 6 h, the crack automatically adjusted to 2 mm. After static plugging for another 6 h, the crack changed back to 1 mm. The maximum plugging pressure of the plugging slurry was respectively investigated, and the experimental temperature was 120 °C.

[0157] Among them, the crack plugging pressure-bearing pressure for the initial plugging is measured after the initial crack width is 1 mm and static plugging for 6 h; the crack plugging pressure-bearing pressure for the secondary plugging is measured after the initial crack width is 1 mm, the crack automatically adjusts to 2 mm after static plugging for 6 h, and then static plugging for another 6 h; the crack plugging pressure-bearing pressure for the tertiary plugging is measured after the crack width returns to 1 mm again after the secondary plugging.

[0158] The test results of the self-adaptive plugging agents SAP-1 to SAP-7 and the plugging agents DP-1 to DP-5 obtained from the above examples and comparative examples are shown in Table 3 below.

[0159] Table 3

[0160]

[0161] It can be seen that the plugging agent formed by the self-adaptive elastomer of the present invention can achieve effective plugging under dynamic changes in crack size.

[0162] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A superabsorbent resin, characterized in that, The superabsorbent resin is a crosslinked copolymer containing structural units represented by formula (1), structural units represented by formula (2), structural units represented by formula (3), and structural units represented by formula (4); wherein, when 100 g of the superabsorbent resin is placed in 500 g of water at 25 °C, the time taken to reach a water absorption rate of 500% is 5 minutes or less; Equation (1) Equation (2) Equation (3) Equation (4) Among them, R1-R3, R 10 -R 12 、R 21 -R 23 and R 31 -R 33 are each independently selected from H and C1-C6 alkyl groups; R4 is selected from H or C1-C6 alkyl groups; R 13 is selected from H, a metal element, or C1-C6 alkyl groups; R 24 -R 28 are each independently selected from H or C1-C6 alkyl groups; L1 is selected from C0-C6 alkylene groups; L2 is selected from C1-C6 alkylene groups; M is selected from H or a metal element.

2. The superabsorbent resin according to claim 1, wherein, R1-R3, R 10 -R 12 , R 21 -R 23 and R 31 -R 33 are each independently selected from H and C1-C4 alkyl; R4 is selected from H or C1-C4 alkyl; R 13 is selected from H, an alkali metal element or C1-C4 alkyl; R 24 -R 28 are each independently selected from H or C1-C4 alkyl; L1 is selected from C0-C4 alkylene; L2 is selected from C1-C6 alkylene; M is selected from H or an alkali metal element; Preferably, R1-R3, R 10 -R 12 、R 21 -R 23 and R 31 -R 33 are each independently selected from H, methyl, ethyl or n-propyl; R4 is selected from H, methyl, ethyl or n-propyl; R 13 is selected from H, Li, Na, K, methyl, ethyl or n-propyl; R 24 -R 28 are each independently selected from H, methyl, ethyl or n-propyl; L1 is selected from absent, -CH2-, -CH2CH2- or -CH2CH2CH2-; L2 is selected from -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH(CH3)CH2-, -CH2CH(CH3)-, -CH2CH2CH2CH2-, -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-, -CH2CH2CH(CH3)-, -C(CH3)2CH2- or -CH2C(CH3)2-; M is selected from H, Li, Na or K.

3. The superabsorbent resin according to claim 1 or 2, wherein, The molar ratio of the content of the structural units represented by formula (1), the structural units represented by formula (2), the structural units represented by formula (3), and the structural units represented by formula (4) is 1:1.5 - 8:0.1 - 1.5:0.5 - 5, preferably 1:2 - 6:0.1 - 1:1 - 3, more preferably 1:3 - 5:0.3 - 0.8:1 - 2; and / or, the weight-average molecular weight of the crosslinked copolymer is 8000 - 80000 g / mol, preferably 10000 - 50000 g / mol, more preferably 10000 - 30000 g / mol.

4. The superabsorbent resin according to any one of claims 1 to 3, wherein The crosslinked structure in the super-crosslinked copolymer is provided by a crosslinking agent represented by formula (5): Equation (5) wherein, R' and R" are each independently selected from H and C1-C6 alkyl; R 41 -R 46 are each independently selected from H and C1-C6 alkyl; L3 is selected from C1-C6 alkylene; Preferably, each of R' and R" is independently selected from H and C1-C4 alkyl; R 41 -R 46 is independently selected from H and C1-C4 alkyl; L3 is selected from C1-C4 alkylene; More preferably, each of R' and R" is independently selected from H, methyl, ethyl or n-propyl; R 41 -R 46 is independently selected from H, methyl, ethyl or n-propyl; L3 is selected from -CH2-, -CH2CH2- or -CH2CH2CH2-; Preferably, the crosslinked structural units in the crosslinked structure account for 0.5 - 10 mol% of the total molar amount of the total comonomers, preferably 1 - 6 mol%.

5. The superabsorbent resin according to any one of claims 1-4, wherein, When 100 g of the superabsorbent resin is placed in 500 g of water at 25 °C, the time taken to reach a water absorption rate of 500% is 0.5 - 5 minutes, preferably 1 - 3 minutes.

6. A method for preparing a superabsorbent resin, characterized in that, The method includes: in a solvent, using an initiator to initiate the polymerization reaction of comonomers and a crosslinking agent to obtain a superabsorbent resin; when 100 g of the superabsorbent resin is placed in 500 g of water at 25 °C, the time taken to reach a water absorption rate of 500% is 5 minutes or less; Formula (1’) Formula (2’) Equation (3') Equation (4') Among them, R1-R3, R 10 -R 12 、R 21 -R 23 and R 31 -R 33 are each independently selected from H and C1-C6 alkyl groups; R4 is selected from H or C1-C6 alkyl groups; R 13 is selected from H, a metal element or C1-C6 alkyl groups; R 24 -R 28 is selected from H or C1-C6 alkyl groups; L1 is selected from C0-C6 alkylene groups; L2 is selected from C1-C6 alkylene groups; M is selected from H or a metal element.

7. The method according to claim 6, wherein R1-R3, R 10 -R 12 , R 21 -R 23 and R 31 -R 33 each independently selected from H and C1-C4 alkyl; R4 is selected from H or C1-C4 alkyl; R 13 is selected from H, an alkali metal element or C1-C4 alkyl; R 24 -R 28 is selected from H or C1-C4 alkyl; L1 is selected from C0-C4 alkylene; L2 is selected from C1-C6 alkylene; M is selected from H or an alkali metal element; Preferably, R1-R3, R 10 -R 12 、R 21 -R 23 and R 31 -R 33 are each independently selected from H, methyl, ethyl or n-propyl; R4 is selected from H, methyl, ethyl or n-propyl; R 13 is selected from H, Li, Na, K, methyl, ethyl or n-propyl; L1 is selected from absent, -CH2-, -CH2CH2- or -CH2CH2CH2-; L2 is selected from -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH(CH3)CH2-, -CH2CH(CH3)-, -CH2CH2CH2CH2-, -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-, -CH2CH2CH(CH3)-, -C(CH3)2CH2- or -CH2C(CH3)2-; M is selected from H, Li, Na or K.

8. The method according to claim 6 or 7, wherein The molar ratio of the amounts of the monomer represented by formula (1'), the monomer represented by formula (2'), the monomer represented by formula (3'), and the monomer represented by formula (4') is 1:1.5 - 8:0.1 - 1.5:0.5 - 5, preferably 1:2 - 6:0.1 - 1:1 - 3, more preferably 1:3 - 5:0.3 - 0.8:1 - 2; and / or, the weight-average molecular weight of the crosslinked copolymer is 8000 - 80000 g / mol, preferably 10000 - 50000 g / mol, more preferably 10000 - 30000 g / mol.

9. The method according to any one of claims 6 - 8, wherein, The crosslinking agent is the crosslinking agent represented by formula (5): Equation (5) wherein R' and R" are each independently selected from H and C1-C6 alkyl; R 41 -R 46 are each independently selected from H and C1-C6 alkyl; L3 is selected from C1-C6 alkylene; Preferably, each of R’ and R” is independently selected from H and C1-C4 alkyl; R 41 -R 46 are each independently selected from H and C1-C4 alkyl; L3 is selected from C1-C4 alkylene; More preferably, each of R' and R" is independently selected from H, methyl, ethyl or n-propyl; R 41 -R 46 are each independently selected from H, methyl, ethyl or n-propyl; L3 is selected from -CH2-, -CH2CH2- or -CH2CH2CH2-; Preferably, the amount of the crosslinking agent used is 0.5 - 10 mol% based on the total molar amount of the comonomers, preferably 1 - 10 mol%.

10. The method according to any one of claims 6-9, wherein, When 100 g of the superabsorbent resin is placed in 500 g of water at 25 °C, the time taken to reach a water absorption rate of 500% is 0.5 - 5 minutes, preferably 1 - 3 minutes.

11. The method according to any one of claims 6 - 10, wherein, The conditions of the polymerization reaction include: the temperature is 40 - 80 °C, preferably 50 - 70 °C; the time is 10 - 60 h, preferably 12 - 48 h; Preferably, the amount of the initiator used is 0.1 - 0.5% by weight of the total weight of the comonomers.

12. A superabsorbent resin prepared by the method according to any one of claims 6 - 11.

13. An adaptive elastomer, the adaptive elastomer containing a rubber phase and a water-absorbing resin phase, the water-absorbing resin phase being provided by the superabsorbent resin according to any one of claims 1-5 or claim 12, and the surface tackiness of the adaptive elastomer measured by a nanoindentation instrument being 20 mN or more, preferably 30 mN or more, more preferably 40-100 mN, and even more preferably 50-100 mN.

14. The adaptive elastomer according to claim 13, wherein, The content of the water-absorbing resin phase is 30-300 parts by weight, preferably 40-200 parts by weight, and more preferably 50-150 parts by weight relative to 100 parts by weight of the rubber phase.

15. The adaptive elastomer according to claim 13 or 14, wherein, The volume expansion ratio of the adaptive elastomer is 50-500%, preferably 100-450%, and more preferably 200-420%; and / or, the tensile strength of the adaptive elastomer is 1-5 MPa, preferably 2-4.5 MPa, and more preferably 3-4 MPa.

16. A preparation method of an adaptive elastomer, the preparation method comprising: Mix and vulcanize rubber and a water-absorbing resin to obtain an adaptive elastomer, the water-absorbing resin being the superabsorbent resin according to any one of claims 1-5 or claim 12; wherein, the surface tackiness of the adaptive elastomer measured by a nanoindentation instrument is 20 mN or more.

17. The preparation method according to claim 16, wherein, The mixing includes mixing rubber, a water-absorbing resin and a vulcanizing agent, wherein the amount of the water-absorbing resin is 30-300 parts by weight, preferably 40-200 parts by weight, and more preferably 50-150 parts by weight relative to 100 parts by weight of the rubber; the amount of the vulcanizing agent is 0.1-5 parts by weight, preferably 0.2-3 parts by weight, and more preferably 0.3-1.2 parts by weight relative to 100 parts by weight of the rubber; Preferably, the vulcanization conditions include: temperature of 100-220 °C, pressure of 5-20 MPa, and time of 5-20 min; more preferably, the vulcanization conditions include: temperature of 120-180 °C, pressure of 5-15 MPa, and time of 5-10 min.

18. An adaptive elastomer prepared by the preparation method according to claim 16 or 17.

19. Use of the adaptive elastomer according to any one of claims 13-15 and 18 as a plugging agent in the process of oil and gas drilling.

20. A plugging agent composition containing the adaptive elastomer according to any one of claims 13-15 and 18.

21. The composition according to claim 20, wherein, The plugging agent composition further contains a plugging component, a filler component and a viscosity-increasing component, and the weight ratio of the amounts of the adaptive elastomer, the plugging component, the filler component and the viscosity-increasing component is 100:100-500:40-100:20-60; Preferably, the plugging component is one or more of a plugging particle component, a plugging sheet component and a plugging fiber component.

22. Use of the composition according to claim 20 or 21 as a plugging agent in the process of oil and gas drilling.

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