Controllable curing leaking stoppage resin system suitable for malignant well leakage stratum as well as preparation method and application of controllable curing leaking stoppage resin system

Abstract

The invention provides a controllable curing plugging resin system suitable for malignant well leakage stratums and a preparation method and application thereof.The system is prepared from, by mass, 35-55 wt% of resin matrix, 1-15 wt% of curing agent, 1-10 wt% of dispersing agent, 1-5 wt% of solubilizer, 1-3 wt% of catalyst, 1-3 wt% of cross-linking agent, 1-5 wt% of flow pattern regulator and 1-8 wt% of weighting material, the sum of the contents of all the components is 100%. The controllable curing plugging resin system suitable for the malignant well leakage stratum has the advantages of being high in high-temperature and high-pressure plugging performance and compression resistance.

Description

TECHNICAL FIELD

[0001] The application provides a controllable solidification plugging resin system suitable for a malignant lost circulation formation, and a preparation method and application thereof, and belongs to the field of oil production engineering. BACKGROUND

[0002] Lost circulation is a phenomenon that a large amount of drilling fluid leaks into a formation during drilling, which not only wastes a large amount of drilling fluid and prolongs the drilling cycle, but also may cause complex situations such as well collapse, blowout and pipe sticking, and even causes major engineering accidents. At present, malignant lost circulation is one of the most common and most difficult drilling engineering complex accidents, and has become one of the key problems in drilling engineering. The lost circulation that cannot be returned (Q DFL ≥ 30 m 3 / h) belongs to malignant lost circulation, and the serious lost circulation occurring in a formation with developed fractures (fracture-cavity) also belongs to the category of malignant lost circulation. At present, the problem of lost circulation, especially the problem of malignant lost circulation in fractured formations, has not been effectively solved at home and abroad, and the drilling time and economic loss are huge, which has become a worldwide problem restricting the progress of oil and gas exploration and development.

[0003] Chinese patent document CN113897186A discloses an oil-based gel consolidation plugging system for oil-based drilling fluids suitable for severely lost circulation formations and its preparation method. In this system, the oil-based gel uses flexible monomer crosslinking combined with rigid units, effectively improving the gel's structural stability. A curable material can be combined with the oil-based gel, using a medium-to-high temperature curing agent to achieve gradient curing, reducing the leakage of the oil-based plugging slurry into the formation and increasing the consolidation strength of the oil-based gel. In the oil-based cement portion, a capsule-type demulsifier is used to adjust the cement's slow-release time, forming a plugging layer with oil-based gel as the main component and curable material and oil-based cement as auxiliary components, thereby achieving effective plugging of severely lost circulation formations. However, the plugging system provided by this invention has poor controllability and insufficient high-temperature stability, making it difficult to achieve long-term plugging in severely lost circulation formations. Chinese patent document CN112980407A discloses a temperature-controllable gel plugging agent, its preparation method, and its application. This plugging agent can adjust the gelation time and gelation strength of the plugging gel system according to different lost circulation formation temperatures, achieving intelligent controllability. However, its high-temperature stability is poor, and its strength cannot be controlled under high-temperature conditions. Chinese patent document CN115160998A discloses a high-temperature resistant, high-strength, curable resin gel plugging agent and its preparation method and application. However, under the high-temperature environment of severely leaking formations, the controllability of this plugging agent is difficult to control, and its long-term stable plugging effect is poor. Chinese patent document CN110003864A provides a drilling fluid internal plugging agent, comprising the following components by weight percentage: main agent 50-95%, curing agent 1-30%, accelerator 0-10%, density regulator 1-60%, viscosity regulator 1-20%, with the total components being 100%. The preparation method of this plugging agent is cumbersome, and its viscosity is high, posing certain difficulties for on-site pumping.

[0004] Therefore, developing a controllable curing resin system with strong high-temperature and high-pressure sealing performance and pressure resistance for formations with severe well leakage is of great significance for effectively solving the problem of drilling fluid loss in formations with severe leakage. Summary of the Invention

[0005] This invention provides a controllable curing plugging resin system suitable for formations with severe well leakage. This system has the characteristics of high-temperature and high-pressure plugging performance and strong pressure resistance.

[0006] This invention also provides a method for preparing a controllable curing plugging resin system suitable for formations with severe well leakage. This method can produce a controllable curing plugging resin system suitable for formations with severe well leakage. The method is characterized by its simple preparation process.

[0007] This invention also provides a method for sealing out malignant well leakage formations of carbonate rock fracture-vuggy type, which has the advantage of good sealing effect.

[0008] This invention provides a controllable curing plugging resin system suitable for formations with severe well leakage, wherein it is prepared from the following raw materials in the indicated mass percentages:

[0009] The composition consists of 35-55 wt% resin matrix, 1-15 wt% curing agent, 1-10 wt% dispersant, 1-5 wt% solubilizer, 1-3 wt% catalyst, 1-3 wt% crosslinking agent, 1-5 wt% flow modifier, 1-8 wt% weighting material, and the balance being water. The total content of all components is 100%.

[0010] The resin matrix is ​​selected from at least one of urea-formaldehyde resin, phenolic resin, unsaturated polyester resin, and polyimide resin;

[0011] The curing agent is selected from at least one of amine curing agents and acid anhydride curing agents;

[0012] The dispersant is selected from at least one of polyethylene glycol, ethanol, and n-butanol;

[0013] The solubilizer includes sodium dodecyl sulfate, fatty acid sorbitan, and betaine-type surfactant;

[0014] The catalyst is selected from at least one of amine catalysts, phenolic catalysts, and substituted urea catalysts;

[0015] The crosslinking agent is selected from at least one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, N-hydroxymethylacrylamide, and ethylene glycol dimethacrylate;

[0016] The flow pattern regulator is selected from at least one of sodium bentonite, lithium bentonite, starch, and sodium carboxymethyl cellulose.

[0017] The weighting material is selected from at least one of barite, calcium carbonate, asbestos, ceramsite, walnut shells, and sand.

[0018] In the resin system described above, the amine curing agent is selected from at least one of ethylenediamine, diethylenetriamine, and dicyandiamide;

[0019] The anhydride curing agent is selected from at least one of phthalic anhydride, tetrahydrophthalic anhydride, and 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride.

[0020] The amine catalyst is selected from at least one of pyridine, N,N-dimethylcyclohexylamine, and triethanolamine; the phenolic catalyst is at least one of phenol, resorcinol, and bisphenol A; and the substituted urea catalyst is at least one of N-p-chlorophenyl-N,N'-dimethylurea, N'-(3,4-dichlorophenyl)-N,N-dimethylurea, and dimethylimidazoleurea.

[0021] The resin system described above, wherein the resin matrix is ​​composed of urea-formaldehyde resin, phenolic resin and unsaturated polyester resin, wherein the mass ratio of urea-formaldehyde resin, phenolic resin and unsaturated polyester resin is (2-5):(2-3):(0.5-1).

[0022] The urea-formaldehyde resin is a water-soluble urea-formaldehyde resin; the phenolic resin is a water-soluble phenolic resin; the unsaturated polyester resin is composed of isophthalic acid unsaturated polyester resin and bisphenol A unsaturated polyester resin, wherein the mass ratio of isophthalic acid unsaturated polyester resin to bisphenol A unsaturated polyester resin is (1-5):1.

[0023] The resin system described above, wherein the curing agent is composed of ethylenediamine, dicyandiamide, and phthalic anhydride, wherein the mass ratio of ethylenediamine, dicyandiamide, and phthalic anhydride is (1-5):(2-3):(1-5); and / or,

[0024] The dispersant is composed of polyethylene glycol and n-butanol, wherein the mass ratio of polyethylene glycol to n-butanol is 1-5:1, and the weight-average molecular weight of the polyethylene glycol is 600-1000; and / or,

[0025] In the solubilizer, the mass ratio of sodium dodecyl sulfate, fatty acid sorbitan, and betaine-type surfactant is (3-5):(2-4):(1-2).

[0026] The resin system described above, wherein the catalyst is composed of triethanolamine, phenol, and N'-(3,4-dichlorophenyl)-N,N-dimethylurea, wherein the mass ratio of triethanolamine, phenol, and N'-(3,4-dichlorophenyl)-N,N-dimethylurea is (1-11):(1-3):(1-4); and / or,

[0027] The flow pattern regulator is composed of sodium bentonite, lithium bentonite and sodium carboxymethyl cellulose, wherein the mass ratio of sodium bentonite, lithium bentonite and sodium carboxymethyl cellulose is (1-5):(1-4):(1-3).

[0028] The weighting material includes barite, asbestos and sand, wherein the mass ratio of barite, asbestos and sand is (3-12):3:(1-4).

[0029] This invention also provides a method for preparing a controllable curing plugging resin system suitable for formations with severe well leakage. This method can be used to prepare any of the above-mentioned resin systems, and includes the following steps:

[0030] 1) The catalyst, dispersant, solubilizer, and curing agent were added to water in sequence and dispersed to obtain curing agent system A;

[0031] 2) Add the resin matrix to the curing agent system A and perform a first heating and stirring treatment to obtain a mixed system B;

[0032] 3) Add the crosslinking agent, flow modifier, and weighting material to the mixture B, and perform a second heating and stirring treatment to obtain the mixture C;

[0033] 4) The mixture C is subjected to a third heating and stirring treatment to obtain the resin system.

[0034] The preparation method described above, wherein the dispersion treatment includes sequential mechanical dispersion treatment and ultrasonic dispersion treatment;

[0035] The mechanical dispersion treatment has a processing speed of 500-1000 rpm, a processing temperature of 20-40℃, and a processing time of 5-20 min;

[0036] The ultrasonic dispersion treatment is performed at a temperature of 20-30℃, a time of 10-20 minutes, and a frequency of 20-40 kHz.

[0037] In the preparation method described above, the first stirring and heating treatment is carried out at a temperature of 20-35°C, a rotation speed of 300-500 rpm, and a treatment time of 30-60 min; and / or,

[0038] The second stirring and heating treatment has a processing temperature of 25-30℃, a processing speed of 500-1000 rpm, and a processing time of 50-80 min.

[0039] In the preparation method described above, the third heating and stirring treatment is carried out in an inert gas atmosphere;

[0040] The third heating and stirring treatment is carried out at a temperature of 40-70℃, a rotation speed of 400-700rpm, and a processing time of 40-100min.

[0041] The present invention also provides a method for sealing a formation with severe well leakage in carbonate rock fracture-vuggy formations, wherein the method includes introducing any of the above-mentioned controllable curing sealing resin systems suitable for formations with severe well leakage into the formation leakage fracture-vuggy formations.

[0042] In the method described above, the controlled curing plugging resin system suitable for formations with severe well leakage is introduced into the formation leakage fractures in any of the following ways:

[0043] The controllable curing plugging resin system suitable for formations with severe well leakage is mixed with drilling fluid and then injected into formation loss fractures; or...

[0044] The controllable curing and plugging resin system suitable for formations with severe well leakage is cured into a solidified body, which is then drilled into the formation leakage fractures.

[0045] The controllable curing plugging resin system for formations with severe well leakage provided by this invention has the characteristics of high-temperature and high-pressure plugging performance and strong compressive strength. Detailed Implementation

[0046] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below. The specific embodiments listed below are merely descriptions of the principles and features of the present invention, and the examples are only for explaining the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] The first aspect of this invention provides a controllable curing plugging resin system suitable for formations with severe well leakage, the system being prepared from the following raw materials by mass percentage:

[0048] The composition consists of 35-55 wt% resin matrix, 1-15 wt% curing agent, 1-10 wt% dispersant, 1-5 wt% solubilizer, 1-3 wt% catalyst, 1-3 wt% crosslinking agent, 1-5 wt% flow modifier, 1-8 wt% weighting material, and the balance being water. The total content of all components is 100%.

[0049] The resin matrix is ​​selected from at least one of urea-formaldehyde resin, phenolic resin, unsaturated polyester resin, and polyimide resin;

[0050] The curing agent is selected from at least one of amine curing agents and acid anhydride curing agents;

[0051] The dispersant is selected from at least one of polyethylene glycol, ethanol, and n-butanol;

[0052] Solubilizers include sodium dodecyl sulfate, fatty acid sorbitan, and betaine-type surfactants;

[0053] The catalyst is selected from at least one of amine catalysts, phenolic catalysts, and substituted urea catalysts;

[0054] The crosslinking agent is selected from at least one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, N-hydroxymethylacrylamide, and ethylene glycol dimethacrylate;

[0055] The flow pattern regulator is selected from at least one of sodium bentonite, lithium bentonite, starch, and sodium carboxymethyl cellulose;

[0056] The weighting material is selected from at least one of barite, calcium carbonate, asbestos, ceramsite, walnut shell, and sand.

[0057] Among them, the amine curing agent is selected from at least one of ethylenediamine, diethylenetriamine, and dicyandiamide; the acid anhydride curing agent is selected from at least one of phthalic anhydride, tetrahydrophthalic anhydride, and 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride; the amine catalyst is selected from at least one of pyridine, N,N-dimethylcyclohexylamine, and triethanolamine; the phenolic catalyst is selected from at least one of phenol, resorcinol, and bisphenol A; and the substituted urea catalyst is selected from at least one of N-p-chlorophenyl-N,N'-dimethylurea, N'-(3,4-dichlorophenyl)-N,N-dimethylurea, and dimethylimidazoleurea.

[0058] The controllable curing sealing resin system for formations with severe well leakage provided by this invention is a sealing material suitable for sealing formations with severe well leakage. The resin matrix is ​​the main material of the controllable curing sealing resin system for formations with severe well leakage provided by this invention. It can be cured to form a high-strength three-dimensional network structure to seal the formation. The selection and addition of appropriate substances, catalysts, dispersants, solubilizers and other additives can make the resin matrix have a more suitable curing time, curing temperature and curing strength for sealing.

[0059] Furthermore, the appropriate selection and addition ratio of weighting materials can enable the controllable curing plugging resin system for severely leaky formations provided by the invention to have a wider range of applicable temperatures, higher adhesion strength, and a more controllable curing process, which can more effectively achieve overall high-strength sealing of severely leaky formations under high-temperature conditions; the appropriate selection and addition ratio of crosslinking agents can improve the degree of crosslinking of the controllable curing plugging resin system for severely leaky formations provided by the invention, thereby having higher curing strength, and can more effectively fill cracks when used for plugging.

[0060] The controllable curing plugging resin system for formations with severe well leakage provided by this invention exhibits synergistic effects among its components, resulting in high cured bond strength, low slurry viscosity, and high quality stability. Its strength rapidly increases under pressure plugging conditions, and it can self-crosslink in fractures, fissures, and cavities to form a three-dimensional network structure. Simultaneously, the controllable curing resin system bonds with sand particles to form a high-strength solidified body, achieving strong retention and filling, improving the strength of the sealing layer, and possessing strong high-temperature and high-pressure plugging performance and compressive strength.

[0061] Meanwhile, the controllable curing plugging resin system for formations with severe well leakage provided by this invention has a temperature resistance of 160℃, a controllable curing time of 3-10 hours, a compressive strength of the solidified body greater than 60MPa, and a sealing strength for fractures greater than 15MPa. This controllable curing plugging resin system for formations with severe well leakage provides strong retention capacity in leakage channels and overall sealing, is applicable to a wide range of fracture sizes, and can achieve long-term stable high-strength sealing under high-temperature conditions. It can effectively mitigate drilling fluid loss in formations with severe well leakage and improve the success rate of first-time plugging.

[0062] The controllable curing plugging resin system for formations with severe well leakage provided by this invention can not only be directly mixed and injected with drilling fluid, but also used in conjunction with bridging plugging materials. It can be injected by pumping while drilling. The preparation method is simple and feasible, low in cost, and convenient for production operations.

[0063] In one embodiment, the amine curing agent is selected from at least one of ethylenediamine, diethylenetriamine, and dicyandiamide; the anhydride curing agent is selected from at least one of phthalic anhydride, tetrahydrophthalic anhydride, and 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride; the amine catalyst is selected from at least one of pyridine, N,N-dimethylcyclohexylamine, and triethanolamine; the phenolic catalyst is at least one of phenol, resorcinol, and bisphenol A; and the substituted urea catalyst is at least one of N-p-chlorophenyl-N,N'-dimethylurea, N'-(3,4-dichlorophenyl)-N,N-dimethylurea (CAS No.: 330-54-1), and dimethylimidazoleurea. Due to the selection of suitable raw materials, the controllable curing plugging resin system suitable for severely leaky formations, possessing the above characteristics, exhibits even more prominent high-temperature and high-pressure plugging performance and pressure resistance.

[0064] In one embodiment, the resin matrix is ​​composed of urea-formaldehyde resin, phenolic resin, and unsaturated polyester resin, wherein the mass ratio of urea-formaldehyde resin, phenolic resin, and unsaturated polyester resin is (2-5):(2-3):(0.5-1). Further, the urea-formaldehyde resin is a water-soluble urea-formaldehyde resin; the phenolic resin is a water-soluble phenolic resin; and the unsaturated polyester resin is composed of isophthalic acid unsaturated polyester resin and bisphenol A unsaturated polyester resin, wherein the mass ratio of isophthalic acid unsaturated polyester resin to bisphenol A unsaturated polyester resin is (1-5):1.

[0065] The controllable curing plugging resin system for formations with severe well leakage provided by the present invention, which possesses the above-mentioned characteristics, can form a three-dimensional network structure with higher strength, thereby making its high-temperature and high-pressure plugging performance and pressure resistance more prominent.

[0066] Further, the urea-formaldehyde resin is a water-soluble urea-formaldehyde resin. The present invention does not specifically limit its molecular weight, but preferably has a weight-average molecular weight of 1000-3000; the phenolic resin is a water-soluble phenolic resin, in granular or powder form, and its molecular weight is not specifically limited, but preferably has a weight-average molecular weight of 1000-2000; the unsaturated polyester resin is a combination of isophthalic acid unsaturated polyester resin and bisphenol A unsaturated polyester resin, wherein the mass ratio of isophthalic acid unsaturated polyester resin to bisphenol A unsaturated polyester resin is 1-5:1; the polyimide resin is a water-soluble polyimide resin.

[0067] In one embodiment, the curing agent is composed of ethylenediamine, dicyandiamide, and phthalic anhydride, wherein the mass ratio of ethylenediamine, dicyandiamide, and phthalic anhydride is (1-5):(2-3):(1-5); further, the dispersant is composed of polyethylene glycol and n-butanol, wherein the mass ratio of polyethylene glycol to n-butanol is 1-5:1, and the weight-average molecular weight of polyethylene glycol is 600-1000; further, in the solubilizer, the mass ratio of sodium dodecyl sulfate, fatty acid sorbitan, and betaine-type surfactant is (3-5):(2-4):(1-2).

[0068] The controllable curing plugging resin system for severely leaky formations provided by the present invention, which possesses the above-mentioned features, allows for easier adjustment of curing time, curing temperature, and curing strength, thus contributing to stronger high-temperature and high-pressure plugging performance and pressure resistance.

[0069] In one embodiment, the catalyst is composed of triethanolamine, phenol, and N'-(3,4-dichlorophenyl)-N,N-dimethylurea, wherein the mass ratio of triethanolamine, phenol, and N'-(3,4-dichlorophenyl)-N,N-dimethylurea is (1-11):(1-3):(1-4); further, the flow pattern regulator is composed of sodium bentonite, lithium bentonite, and sodium carboxymethyl cellulose, wherein the mass ratio of sodium bentonite, lithium bentonite, and sodium carboxymethyl cellulose is (1-5):(1-4):(1-3); further, the weighting material includes barite, asbestos, and sand, wherein the mass ratio of barite, asbestos, and sand is (3-12):3:(1-4).

[0070] The controllable curing plugging resin system for severely leaky formations provided by the present invention, which possesses the above-mentioned characteristics, has even more prominent features in terms of high-temperature and high-pressure plugging performance and compressive strength.

[0071] A second aspect of this invention provides a preparation method for obtaining any of the controllable curing plugging resin systems suitable for severely leaking formations provided in the first aspect of this invention. The preparation method includes the following steps:

[0072] 1) The catalyst, dispersant, solubilizer, and curing agent were added to water in sequence and dispersed to obtain curing agent system A;

[0073] 2) Add the resin matrix to the curing agent system A and perform a first heating and stirring treatment to obtain a mixed system B;

[0074] 3) Add the crosslinking agent, flow modifier, and weighting material to the mixture B, and perform a second heating and stirring treatment to obtain the mixture C;

[0075] 4) The mixture C is subjected to a third heating and stirring treatment to obtain the resin material.

[0076] The meanings of catalyst, dispersant, solubilizer, curing agent, resin matrix crosslinking agent, flow pattern regulator and weighting material are the same as those above, and will not be repeated here.

[0077] Adding the catalyst, dispersant, solubilizer, and curing agent sequentially to water helps to achieve a more uniform dispersion of each component. The dispersion treatment involves dispersing the above components in water. This invention does not limit the specific processing conditions for the dispersion treatment, as long as the requirements for dispersing the above components in water are met.

[0078] The first heating and stirring treatment involves stirring the system obtained after adding the resin matrix to the curing agent system A under heating conditions, which can achieve mixing of the resin matrix and the curing agent system A. This invention does not limit the specific processing conditions of the first heating and stirring treatment, as long as the requirement of achieving mixing of the resin matrix and the curing agent system A is met.

[0079] The second heating and stirring treatment can achieve the mixing of the crosslinking agent, flow modifier, and weighting material with the mixture system B. This invention does not limit the specific processing conditions of the second heating and stirring treatment, as long as the requirement of achieving the mixing of the above components with the mixture system B is met.

[0080] The third heating and stirring treatment can achieve further uniform mixing of the mixture system C. This invention does not limit the specific processing conditions of the third heating and stirring treatment, as long as the requirement of achieving further uniform mixing of the mixture system C is met.

[0081] The method for preparing the controllable curing plugging resin system suitable for formations with severe well leakage provided by the present invention can obtain the controllable curing resin material for formations with severe well leakage provided by the present invention using fewer steps and common processes, and has the characteristics of simple preparation process.

[0082] In one embodiment, the dispersion treatment includes sequential mechanical dispersion treatment and ultrasonic dispersion treatment; the mechanical dispersion treatment has a processing speed of 500-1000 rpm, a processing temperature of 20-40℃, and a processing time of 5-20 min; the ultrasonic dispersion treatment has a processing temperature of 20-30℃, a processing time of 10-20 min, and a processing frequency of 20-40 kHz.

[0083] Mechanical dispersion initially disperses the catalyst, dispersant, solubilizer, and curing agent in water, while ultrasonic dispersion further disperses these components in water through high-frequency vibration. Furthermore, using mechanical dispersion for initial coarse dispersion followed by ultrasonic dispersion for more microscopic dispersion promotes more thorough and uniform dispersion and improves dispersion efficiency. Controlling the mechanical and ultrasonic dispersion processes to meet the above conditions can increase the dispersion rate of the components in water, making the preparation method provided by this invention more efficient.

[0084] In one embodiment, the first stirring and heating treatment is carried out at a temperature of 20-35°C, a rotation speed of 300-500 rpm, and a treatment time of 30-60 min; further, the second stirring and heating treatment is carried out at a temperature of 25-30°C, a rotation speed of 500-1000 rpm, and a treatment time of 50-80 min. The first and second stirring and heating treatments meeting the above conditions can further improve the efficiency of the preparation method provided by the present invention.

[0085] In one embodiment, the third heating and stirring treatment is carried out in an inert gas atmosphere; the treatment temperature for the third heating and stirring treatment is 40-70°C, the treatment speed is 400-700 rpm, and the treatment time is 40-100 min. Carrying the third heating and stirring treatment in an inert gas atmosphere can prevent the material to be treated from oxidizing and failing due to contact with oxygen. This invention does not limit the specific selection of the inert gas; at least one of nitrogen and helium can be selected as the inert gas atmosphere. The third stirring and heating treatment meeting the above conditions can further improve the efficiency of the preparation method provided by this invention.

[0086] The third aspect of the present invention provides a method for sealing carbonate rock fracture-vuggy formations with severe well leakage. The method includes introducing any of the controllable curing sealing resin systems provided in the first aspect of the present invention, suitable for formations with severe well leakage, into the formation leakage fractures and vuggies to seal the carbonate rock fracture-vuggy formations with severe well leakage.

[0087] This invention does not limit the method of introducing resin material into formation leakage fractures and cavities. Common means in the art can be used to introduce resin material into formation leakage fractures and cavities to seal out malignant well leakage formations of carbonate rock fractures and cavities.

[0088] Because the controllable curing plugging resin system for malignant well leakage formations provided by this invention has the characteristics of high-temperature and high-pressure plugging performance and strong compressive strength, when using this material to perform the plugging method for malignant well leakage formations of carbonate rock fracture-vuggy type, the method has the characteristic of good plugging effect.

[0089] Furthermore, in the method for sealing formations with severe well leakage of carbonate rock fracture-vuggy type provided by the present invention, the controlled curing sealing resin system suitable for formations with severe well leakage is introduced into the formation leakage fracture-vuggy cavity specifically in one of the following ways:

[0090] A controlled-curing plugging resin system suitable for formations with severe well leakage can be mixed with drilling fluid and then injected into the formation leakage fractures. Alternatively, the controlled-curing plugging resin system suitable for formations with severe well leakage can be cured into a solidified body, which is then injected into the formation leakage fractures during drilling. Both methods can achieve good sealing results.

[0091] Next, using specific embodiments, the controllable curing and plugging resin system for formations with severe well leakage provided by the present invention will be further described.

[0092] All raw materials used in the embodiments are conventional and commercially available; unless otherwise specified, the methods are existing technologies.

[0093] The urea-formaldehyde resin used in the examples is a water-soluble urea-formaldehyde resin with a weight-average molecular weight of 2000.

[0094] The phenolic resin used is a water-soluble phenolic resin with a weight-average molecular weight of 1200.

[0095] The unsaturated polyester resin used is a combination of isophthalic acid unsaturated polyester resin and bisphenol A unsaturated polyester resin, wherein the mass ratio of isophthalic acid unsaturated polyester resin to bisphenol A unsaturated polyester resin is 2:1, the weight average molecular weight of isophthalic acid unsaturated polyester resin is 800, and the weight average molecular weight of bisphenol A unsaturated polyester resin is 600.

[0096] The weight-average molecular weight of the polyethylene glycol used is 800.

[0097] Example 1

[0098] This embodiment uses the following raw materials to prepare the controllable curing plugging resin system suitable for formations with severe well leakage provided by the present invention:

[0099] The composition consists of 45% resin matrix, 7% curing agent, 5% dispersant, 3% solubilizer, 2% catalyst, 2% crosslinking agent, 3% flow modifier, 5% weighting material, and the balance being water. The total content of all components is 100%.

[0100] The resin matrix is ​​composed of urea-formaldehyde resin, phenolic resin and unsaturated polyester resin, wherein the mass ratio of urea-formaldehyde resin, phenolic resin and unsaturated polyester resin is 4:3:1.

[0101] The curing agent is composed of ethylenediamine, dicyandiamide and phthalic anhydride, wherein the mass ratio of ethylenediamine, dicyandiamide and phthalic anhydride is 3:2:1.

[0102] The dispersant is composed of polyethylene glycol and n-butanol, wherein the mass ratio of polyethylene glycol to n-butanol is 3:1.

[0103] The solubilizer is composed of sodium dodecyl sulfate, fatty acid sorbitan (Span 60), and dodecyl dimethyl betaine, wherein the mass ratio of sodium dodecyl sulfate, fatty acid sorbitan (Span 60), and dodecyl dimethyl betaine is 4:3:1.

[0104] The catalyst is composed of triethanolamine, phenol and N'-(3,4-dichlorophenyl)-N,N-dimethylurea, wherein the mass ratio of triethanolamine, phenol and N'-(3,4-dichlorophenyl)-N,N-dimethylurea is 6:3:1.

[0105] The crosslinking agent is composed of N-hydroxymethylacrylamide, hydroxyethyl methacrylate and ethylene glycol dimethacrylate, wherein the mass ratio of N-hydroxymethylacrylamide, hydroxyethyl methacrylate and ethylene glycol dimethacrylate is 5:2:1.

[0106] The flow pattern regulator is composed of sodium bentonite, lithium bentonite and sodium carboxymethyl cellulose, wherein the mass ratio of sodium bentonite, lithium bentonite and sodium carboxymethyl cellulose is 5:4:2.

[0107] The weighting material is composed of barite, asbestos, and sand, with a mass ratio of 6:3:2.

[0108] The controllable curing plugging resin system suitable for severely leaking formations, as provided in this invention, was prepared using the above-mentioned raw materials according to the following steps:

[0109] 1) Weigh the catalyst, dispersant, solubilizer, and curing agent and add them sequentially to a centrifuge tube containing water. Place the centrifuge tube in a vortex mixer and perform mechanical dispersion at 750 rpm at 25°C for 12 min. Then, perform ultrasonic dispersion on the centrifuge tube at 25°C for 15 min to obtain curing agent system A.

[0110] 2) Add the resin matrix to the curing agent system A obtained in step 1), stir at 400 rpm for 45 minutes at 25°C until it is uniformly mixed to obtain the mixed system B;

[0111] 3) Add the crosslinking agent, flow modifier and weighting material to the mixture system B obtained in step 2), and stir for 75 minutes at a stirring temperature of 27°C and a stirring speed of 750 rpm until uniform, to obtain the mixture system C;

[0112] 4) Pour the obtained mixed system C into a four-necked flask, heat it in a water bath to 50°C, introduce nitrogen gas, and stir it for 60 minutes at 50°C and 500 rpm to make it uniformly dispersed, thus obtaining a controllable curing plugging resin system suitable for formations with severe well leakage, denoted as sample S1.

[0113] Example 2

[0114] This embodiment uses the following raw materials to prepare the controllable curing plugging resin system suitable for formations with severe well leakage provided by the present invention:

[0115] The composition consists of 55% resin matrix, 7% curing agent, 5% dispersant, 3% solubilizer, 2% catalyst, 2% crosslinking agent, 3% flow modifier, 5% weighting material, and the balance being water. The total content of all components is 100%.

[0116] The selection of resin matrix, curing agent, dispersant, solubilizer, catalyst, crosslinking agent, flow modifier, and weighting material is the same as in Example 1.

[0117] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and sample S2 was obtained.

[0118] Example 3

[0119] This embodiment uses the following raw materials to prepare the controllable curing plugging resin system suitable for formations with severe well leakage provided by the present invention:

[0120] The composition consists of 35% resin matrix, 7% curing agent, 5% dispersant, 3% solubilizer, 2% catalyst, 2% crosslinking agent, 3% flow modifier, 5% weighting material, and the balance being water. The total content of all components is 100%.

[0121] The selection of resin matrix, curing agent, dispersant, solubilizer, catalyst, crosslinking agent, flow modifier, and weighting material is the same as in Example 1.

[0122] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and sample S3 was obtained.

[0123] Example 4

[0124] This embodiment is basically the same as Embodiment 1, except that the curing agent is ethylenediamine.

[0125] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and sample S4 was obtained.

[0126] Example 5

[0127] The examples are basically the same as those in Example 1, except that the dispersant is polyethylene glycol.

[0128] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and sample S5 was obtained.

[0129] Example 6

[0130] This embodiment is basically the same as Example 1, except that the solubilizer is sodium dodecyl sulfate.

[0131] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and sample S6 was obtained.

[0132] Example 7

[0133] This embodiment is basically the same as Example 1, except that the catalyst is triethanolamine.

[0134] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and sample S7 was obtained.

[0135] Example 8

[0136] This embodiment is basically the same as Example 1, except that the crosslinking agent is N-hydroxymethylacrylamide.

[0137] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and sample S8 was obtained.

[0138] Example 9

[0139] This embodiment is basically the same as Embodiment 1, except that the flow pattern regulator is sodium carboxymethyl cellulose.

[0140] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and sample S9 was obtained.

[0141] Example 10

[0142] This embodiment is basically the same as Embodiment 1, except that the weighting material is asbestos.

[0143] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and sample S10 was obtained.

[0144] Example 11

[0145] This embodiment is basically the same as Embodiment 1, except that the resin matrix is ​​urea-formaldehyde resin.

[0146] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for severely leaky formations provided by the present invention was prepared according to the steps of Example 1, and sample S11 was obtained.

[0147] Example 12

[0148] This embodiment is basically the same as Embodiment 1, except that the resin matrix is ​​phenolic resin.

[0149] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and sample S12 was obtained.

[0150] Example 13

[0151] This embodiment is basically the same as Embodiment 1, except that the resin matrix is ​​an unsaturated polyester resin.

[0152] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and sample S13 was obtained.

[0153] Comparative Example 1

[0154] This comparative example is basically the same as Example 1, except that no curing agent is added, and the corresponding missing mass is replaced with an equal mass of water.

[0155] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and product D1 was obtained.

[0156] Comparative Example 2

[0157] This comparative example is basically the same as Example 1, except that no dispersant is added and the corresponding missing mass is replaced by an equal mass of water.

[0158] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and product D2 was obtained.

[0159] Comparative Example 3

[0160] This comparative example is basically the same as Example 1, except that no solubilizer is added, and the corresponding missing mass is replaced by an equal mass of water.

[0161] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and product D3 was obtained.

[0162] Comparative Example 4

[0163] This comparative example is basically the same as Example 1, except that no catalyst is added and the corresponding missing mass is replaced by an equal mass of water.

[0164] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and product D4 was obtained.

[0165] Comparative Example 5

[0166] This comparative example is basically the same as Example 1, except that no crosslinking agent is added, and the corresponding missing mass is replaced by an equal mass of water.

[0167] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and product D5 was obtained.

[0168] Comparative Example 6

[0169] This comparative example is basically the same as Example 1, except that no flow modifier is added, and the corresponding missing mass is replaced with an equal mass of water.

[0170] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and product D6 was obtained.

[0171] Comparative Example 7

[0172] This comparative example is basically the same as Example 1, except that no weighting material is added, and the corresponding missing mass is replaced by an equal mass of water.

[0173] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and product D7 was obtained.

[0174] Comparative Example 8

[0175] This comparative example is basically the same as Example 1, except that the resin matrix is ​​epoxy resin.

[0176] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and product D8 was obtained.

[0177] Comparative Example 9

[0178] This comparative example is basically the same as Example 1, except that the resin matrix is ​​bismaleimide resin.

[0179] Using the above-mentioned raw materials, the controllable curing and plugging resin system suitable for formations with severe well leakage provided by the present invention was prepared according to the steps of Example 1, and product D9 was obtained.

[0180] Test case

[0181] The controllable curing plugging resin system (hereinafter referred to as resin material) for severe well leakage formations provided by the present invention, prepared using the above embodiments, and the product prepared in the comparative example were subjected to high-temperature and high-pressure plugging performance tests and compressive strength tests.

[0182] Test Example 1: High Temperature and High Pressure Sealing Performance Test of Resin Materials

[0183] The pressure-bearing sealing performance of resin materials on fractures was studied using a high-temperature and high-pressure fracture physical simulation device. A steel fracture module was used to simulate a fractured and leaky formation. The fracture module was a single wedge-shaped fracture with inlet fracture widths of 1, 3, and 5 mm, and outlet fracture widths of 0.5, 1.5, and 2.5 mm, respectively. The fracture length was 200 mm.

[0184] Determination of curing time: Place 30 mL of resin material in a test tube, put it in an electric vacuum drying oven, and let it stand for curing at 160℃. Take it out at regular intervals to observe the flow of liquid in the heat-resistant test tube. The time when the resin material solidifies and does not flow when inverted is the curing time.

[0185] The high-temperature and high-pressure plugging test steps are as follows: (a) Adjust the temperature of the heating chamber to the simulated formation temperature of 160℃; (b) Place the steel fracture core of the required fracture width into the core holder and apply confining pressure to 15MPa; (c) Inject simulated drilling fluid (the main components of the simulated drilling fluid are bentonite and water, with a content of 3wt%) into the fracture core at an injection rate of 2.5mL / min until saturation; (d) Inject the resin material solution into the fracture core at an injection rate of 2.5mL / min until the solution is completely produced at the fracture outlet; (e) Seal the fracture core model and let it stand until the resin material solution has cured and reacted completely; (f) Inject simulated drilling fluid into the fracture core in reverse at an injection rate of 2.5mL / min, and use data software to record the injection pressure changes in real time. The highest pressure reached when the drilling fluid leaks from the outlet end of the fracture model is the pressure-bearing plugging strength of the resin material on the fracture.

[0186] The sealing strength evaluation criteria for resin materials are defined as follows: when the maximum pressure at the exit end of the wedge crack is greater than 15 MPa, the sealing strength is strong; when the maximum pressure at the exit end of the wedge crack is between 10 and 15 MPa, the sealing strength is medium; when the maximum pressure at the exit end of the wedge crack is between 5 and 10 MPa, the sealing strength is acceptable; and when the maximum pressure at the exit end of the wedge crack is less than 5 MPa, the sealing strength is low.

[0187] The results of the high-temperature and high-pressure sealing performance of the resin material samples prepared in the above embodiments and comparative examples are shown in Table 1.

[0188] Table 1. Results of high-temperature and high-pressure sealing performance of resin materials in wedge-shaped cracks.

[0189]

[0190]

[0191]

[0192] As shown in the data from the examples in Table 1, the high-temperature and high-pressure sealing performance of the resin material is significantly affected by the resin matrix, curing agent, crosslinking agent, and weighting material, and less so by external additives such as catalysts, dispersants, and flow modifiers. The data from the examples in Table 1 also show that the resin material prepared in the examples of this invention exhibits good high-temperature and high-pressure sealing performance, with maximum pressure-bearing sealing capacities of 20.5 MPa, 19.3 MPa, and 18.9 MPa in wedge-shaped cracks with outlet crack widths of 0.5 mm, 1.5 mm, and 2.5 mm, respectively. This indicates that the resin matrix in the resin material can solidify into a high-strength solidified body under the synergistic effect of external additives such as curing agents, crosslinking agents, and weighting materials, achieving efficient crack sealing. In contrast, the comparative examples of this invention show a worse effect compared to the examples, further demonstrating the synergistic effect between the raw materials of this invention.

[0193] Experimental Example 2: Compressive Strength Test of Controlled Curing Resin Leak-Plugging System

[0194] The mold dimensions for preparing the resin material compressive strength sample are 50.8×50.8×50.8mm. 3 The prepared resin material solution was poured into a mold coated with a release agent, placed in an electric vacuum drying oven, and cured at 160℃. After demolding and cooling to room temperature, the sample was tested. The pressure loading rate during the test was 1.2 kN / s. The formula for calculating its compressive strength is as follows:

[0195]

[0196] Where P is the compressive strength of the resin material, in MPa; F is the data obtained during the compressive strength test of the resin material, i.e., the external force load applied by the compression and flexural strength testing machine, in kN; and S is the force-bearing area of ​​the resin material sample, in mm². 2 The sample used in this test was 2580.64 mm. 2 .

[0197] Resin materials with a compressive strength greater than or equal to 50 MPa and a deformation recovery rate greater than or equal to 90% are classified as excellent; those with a compressive strength between 20 MPa and 50 MPa and a deformation recovery rate between 80% and 90% are classified as qualified; and those with a compressive strength less than 20 MPa and a deformation recovery rate less than 80% are classified as unqualified.

[0198] The compressive strength test results of the resin materials prepared in the above embodiments and comparative examples are shown in Table 2.

[0199] Table 2. Test results of compressive strength of resin plugging system samples.

[0200]

[0201]

[0202]

[0203] Table 2 shows the compressive strength test results of the samples formed by the resin material at a curing temperature of 160℃. The data in Table 2 shows that the compressive strength of the resin material samples prepared in the examples is greater than 20 MPa, the deformation recovery rate is greater than 80%, and the compressive strength grade is qualified. Specifically, under the optimal formulation, as shown in Example 1, the compressive strength of the resin material is greater than 60 MPa, the deformation recovery rate is greater than 90%, and the compressive strength grade is excellent. Compared with the examples, the comparative example of the present invention has reduced the addition of some additives, resulting in a worse effect, further demonstrating the synergistic interaction between the raw materials of the present invention. In summary, the resin matrix in the resin material provided by the present invention can only better cure to form a high-strength solid body and achieve excellent compressive strength under the synergistic effect of a certain proportion of curing agent, crosslinking agent, and weighting material, etc.

[0204] After the resin material provided by this invention was mixed with formation water and drilling fluid, and observed after standing, it was found that the two systems were homogeneous and basically unchanged, and no obvious precipitates were found, indicating good system compatibility. This overcomes the shortcomings of existing resin plugging systems that are incompatible with reservoir fluids or working fluids.

[0205] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A controllable solidifying lost circulation resin system suitable for use in a lost circulation zone, characterized in that, Prepared from the following raw materials by mass percentage: Resin matrix 35-55wt%, curing agent 1-15wt%, dispersant 1-10wt%, solubilizing agent 1-5wt%, catalyst 1-3wt%, crosslinking agent 1-3wt%, flow modifier 1-5wt%, weighting material 1-8wt%, the balance is water, the total of each component content is 100%; The resin matrix is selected from at least one of urea-formaldehyde resin, phenol-formaldehyde resin, unsaturated polyester resin, polyimide resin; The curing agent is selected from at least one of amine curing agent, acid anhydride curing agent; The dispersant is selected from at least one of polyethylene glycol, ethanol, n-butanol; The solubilizing agent includes sodium dodecyl sulfate, fatty acid sorbitan and betaine surfactant; The catalyst is selected from at least one of amine catalyst, phenolic catalyst, substituted urea catalyst; The crosslinking agent is selected from at least one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, N-hydroxymethyl acrylamide and ethylene glycol dimethacrylate; The flow modifier is selected from at least one of sodium bentonite, lithium bentonite, starch, sodium carboxymethyl cellulose; The weighting material is selected from at least one of barite, calcium carbonate, asbestos, ceramsite, walnut shell, sand.

2. The resin system of claim 1, wherein, The amine curing agent is selected from at least one of ethylenediamine, diethylenetriamine, dicyandiamide; The acid anhydride curing agent is selected from at least one of phthalic anhydride, tetrahydrophthalic anhydride, 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride; The amine catalyst is selected from at least one of pyridine, N,N-dimethylcyclohexylamine, triethanolamine; the phenolic catalyst is at least one of phenol, resorcinol, bisphenol A; the substituted urea catalyst is at least one of N-p-chlorophenyl-N,N'-dimethylurea, N'-(3,4-dichlorophenyl)-N,N-dimethylurea, dimethylimidazole urea.

3. The resin system according to claim 1 or 2, characterized in that The resin matrix is composed of urea-formaldehyde resin, phenol-formaldehyde resin and unsaturated polyester resin, wherein the mass ratio of urea-formaldehyde resin, phenol-formaldehyde resin and unsaturated polyester resin is (2-5):(2-3):(0.5-1); The urea-formaldehyde resin is water-soluble urea-formaldehyde resin; the phenol-formaldehyde resin is water-soluble phenol-formaldehyde resin; the unsaturated polyester resin is composed of isophthalic acid unsaturated polyester resin and bisphenol A unsaturated polyester resin, wherein the mass ratio of isophthalic acid unsaturated polyester resin and bisphenol A unsaturated polyester resin is (1-5):

1.

4. The resin system according to any one of claims 1 to 3, characterized in that The curing agent is composed of ethylenediamine, dicyandiamide and phthalic anhydride, wherein the mass ratio of ethylenediamine, dicyandiamide and phthalic anhydride is (1-5):(2-3):(1-5); and / or, The dispersant is composed of polyethylene glycol and n-butanol, wherein the mass ratio of polyethylene glycol and n-butanol is 1-5:1, and the weight average molecular weight of the polyethylene glycol is 600-1000; and / or, In the solubilizing agent, the mass ratio of sodium dodecyl sulfate, fatty acid sorbitan and betaine surfactant is (3-5):(2-4):(1-2).

5. The resin system according to any one of claims 1 to 4, characterized in that The catalyst is composed of triethanolamine, phenol and N'-(3,4-dichlorophenyl)-N,N-dimethylurea, wherein the mass ratio of triethanolamine, phenol and N'-(3,4-dichlorophenyl)-N,N-dimethylurea is (1-11):(1-3):(1-4); and / or, The flow type regulator is composed of sodium bentonite, lithium bentonite and sodium carboxymethyl cellulose, wherein the mass ratio of sodium bentonite, lithium bentonite and sodium carboxymethyl cellulose is (1-5):(1-4):(1-3); The weighting material includes barite, asbestos and sand, wherein the mass ratio of barite, asbestos and sand is (3-12):3:(1-4).

6. A process for the preparation of a controlled solidifying lost circulation resin system suitable for use in a lost circulation zone of a well according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: 1) The catalyst, dispersant, solubilizer and curing agent are sequentially added into water for dispersion treatment to obtain a curing agent system A; 2) The resin matrix is added into the curing agent system A for first heating and stirring treatment to obtain a mixed system B; 3) The crosslinking agent, flow type regulator and weighting material are added into the mixed system B for second heating and stirring treatment to obtain a mixed system C; 4) The mixed system C is subjected to third heating and stirring treatment to obtain the resin system.

7. The method of claim 6, wherein, The dispersion treatment comprises sequentially performed mechanical dispersion treatment and ultrasonic dispersion treatment; The mechanical dispersion treatment is performed at a treatment rotation speed of 500-1000 rpm, a treatment temperature of 20-40℃ and a treatment time of 5-20 min; The ultrasonic dispersion treatment is performed at a treatment temperature of 20-30℃, a treatment time of 10-20 min and a treatment frequency of 20-40 kHZ; The first heating and stirring treatment is performed at a treatment temperature of 20-35℃, a treatment rotation speed of 300-500 rpm and a treatment time of 30-60 min; The second heating and stirring treatment is performed at a treatment temperature of 25-30℃, a treatment rotation speed of 500-1000 rpm and a treatment time of 50-80 min.

8. The method according to claim 6 or 7, characterized in that, The third heating and stirring treatment is performed in an inert gas atmosphere; The third heating and stirring treatment is performed at a treatment temperature of 40-70℃, a treatment rotation speed of 400-700 rpm and a treatment time of 40-100 min.

9. A method for plugging a carbonatite fracture-cave type malignant loss circulation zone, characterized in that, The controllable solidification plugging resin system suitable for a malignant lost circulation formation is introduced into a formation leakage fracture.

10. The method of claim 9, wherein, The controllable solidification plugging resin system suitable for a malignant lost circulation formation is introduced into a formation leakage fracture in particular selected from the following any one way: The controllable solidification plugging resin system suitable for a malignant lost circulation formation is mixed with a drilling fluid and then injected into a formation leakage fracture; or, The controllable solidification plugging resin system suitable for a malignant lost circulation formation is solidified into a consolidated body, and then the consolidated body is made to enter a formation leakage fracture while drilling.

Images