Epoxy resin sand consolidation agent and preparation method and sand prevention method thereof

Abstract

The invention discloses an epoxy resin sand consolidation agent, a preparation method thereof and a sand prevention method. The epoxy resin sand consolidation agent comprises a cementing agent system and a curing agent system which are matched for use, the cementing agent system comprises the following components in percentage by mass: 70-80% of epoxy resin, 2-5% of a silane coupling agent, 1-3% of a dispersing agent and 15-25% of a diluent. According to the present invention, the consolidation strength can be improved, the pore blockage can be furthest avoided, the influence on the rock permeability is small, the damage to the stratum is small, the low-temperature curing can be achieved, the curing time can be shortened, and the solvent consumption can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of oil well sand control, and particularly relates to an epoxy resin-based sand consolidating agent, a preparation method thereof, and a sand control method. Background Art

[0002] Resin sand consolidation means pumping liquid and easily flowing resin into the formation, making it evenly distributed in the formation pores, and then gradually curing to form a bond at the contact points between sand grains, thereby preventing sand production from the formation. Since the resin that cements the sand grains is the resin adhering to the contact points of the sand grains, the resin in the sand grain pores is not needed because it will cause blockage of the sand layer after curing, reducing the permeability of the sand layer after cementation. Therefore, a pore-increasing liquid is used to push this part of the excess resin deep into the formation. Resin is a polar cementing agent, and kerosene or diesel can be used as the pore-increasing liquid because they are non-polar liquids and will not dissolve the resin. Moreover, the surface of the sand grains is a hydrophilic surface, and kerosene and diesel will not carry away all the resin. However, in recent years, due to safety and environmental protection requirements, oilfields have prohibited the use of kerosene and diesel as pore-increasing liquids and switched to using clear water for pore increase, resulting in poor resin sand consolidation effect, large permeability loss, insufficient liquid supply in oil wells, and inefficient production.

[0003] Existing sand consolidating agents mainly include several categories such as phenolic resin, urea-formaldehyde resin, furan resin, and epoxy resin. Among them, phenolic resin, urea-formaldehyde resin, and furan resin are applicable to oil layers with formation temperatures higher than 60°C. If the formation temperature is lower than 45°C, curing cannot be achieved. Phenolic resin and furan resin are easily swollen by water, blocking the formation, with a permeability loss of 30 - 40%. Urea-formaldehyde resin has good water solubility and low consolidation strength (2 - 3 MPa), which cannot meet the requirements of sand control and liquid production increase in oil wells. Epoxy resin currently mostly adopts the form of emulsion. In the on-site construction of this type of resin sand consolidating agent, demulsification is difficult to control, the utilization rate of the agent is low, and problems such as "tubing enema" and formation blockage often occur, resulting in major repairs or need for well recompletion of oil wells, increasing the operation cost and construction risk. Summary of the Invention

[0004] The main object of the present invention is to provide an epoxy resin-based sand consolidating agent, a preparation method thereof, and a sand control method to solve the problems of poor curing effect and easy blockage of existing sand consolidating agents.

[0005] According to one aspect of the present invention, an epoxy resin-based sand consolidating agent is proposed, which includes a cementing agent system and a curing agent system used in combination; by mass percentage, the cementing agent system contains: 70 - 80% of epoxy resin, 2 - 5% of silane coupling agent, 1 - 3% of dispersant, and 15 - 25% of diluent.

[0006] According to an embodiment of the present invention, the epoxy resin is E51 epoxy resin.

[0007] According to an embodiment of the present invention, the silane coupling agent is an amino silane coupling agent.

[0008] According to an embodiment of the present invention, the silane coupling agent is KH-550 silane coupling agent; preferably, it is KH-550 silane coupling agent.

[0009] According to an embodiment of the present invention, the dispersant is a water-soluble viscosity reducer for heavy oil; preferably, it is an alkylphenol polyoxyethylene ether carboxylate viscosity reducer for heavy oil.

[0010] According to an embodiment of the present invention, the diluent is an inactive diluent; preferably, it is ethylene glycol monobutyl ether.

[0011] According to an embodiment of the present invention, by mass percentage, the curing agent system comprises: 25-35% of a modified phenolic amine curing agent, 45-55% of an organic solvent, 0.2-0.8% of a pH regulator, and 15-25% of water.

[0012] According to an embodiment of the present invention, the modified phenolic amine curing agent is T31 curing agent.

[0013] According to an embodiment of the present invention, the organic solvent is ethanol.

[0014] According to an embodiment of the present invention, the pH regulator is NaOH.

[0015] According to an embodiment of the present invention, the mass ratio of the cementing agent system to the curing agent system is 1:(7-9).

[0016] According to an embodiment of the present invention, the cementing agent system is a colorless transparent liquid with a bulk density of 0.98-1.08 g / cm 3 , and the viscosity at 25 °C is 200-400 mPa·s; and / or the curing agent system is a light yellow liquid with a bulk density of 0.88-1.02 g / cm 3 , and the viscosity at 25 °C is 10-30 mPa·s.

[0017] According to another aspect of the present invention, there is provided a method for preparing the epoxy resin-based sand consolidating agent as described above, comprising:

[0018] S11, heating the epoxy resin to a flowing state, and mixing and stirring the heated epoxy resin with the silane coupling agent, the dispersant, and the diluent in proportion to obtain a cementing agent system;

[0019] S12, mixing and stirring the modified phenolic amine curing agent, the organic solvent, the pH regulator, and a part of water, and adding another part of water and stirring after being fully dissolved to obtain a curing agent system.

[0020] According to an embodiment of the present invention, in step S11, the epoxy resin is heated to 40 - 50 °C and kept at a constant temperature for 0.5 - 1.5 hours.

[0021] According to an embodiment of the present invention, in steps S11 and S12, stirring is carried out under the condition of 0 - 30 °C.

[0022] According to an embodiment of the present invention, in step S12, the mass of a part of the water added first is 1 / 5 - 1 / 3 of the total mass of the water added.

[0023] According to an embodiment of the present invention, in step S12, first, the pH regulator and a part of the water are mixed and dissolved for 8 - 12 h, then the phenolic amine curing agent and the organic solvent are added and mixed and dissolved continuously. After being fully dissolved, the other part of the water is added.

[0024] According to another aspect of the present invention, a sand control method is provided, which is carried out by using the epoxy resin - based sand consolidating agent as above. The sand control method includes:

[0025] Injecting a pre - flush fluid to clean the formation;

[0026] Injecting the cementing agent system and water simultaneously;

[0027] Injecting clear water for pore enlargement;

[0028] Injecting the curing agent system;

[0029] Closing the well and waiting for setting.

[0030] According to an embodiment of the present invention, the use concentration of the cementing agent system is 12 - 15 wt%, and the average dosage is 50 - 100 Kg / m.

[0031] According to an embodiment of the present invention, the mass dosage of the clear water for pore enlargement is 1 - 1.5 times that of the cementing agent system; and / or the mass dosage of the curing agent system is 7 - 9 times that of the cementing agent system.

[0032] In the technical solution of the present invention, a dispersant is used to reduce the interfacial tension between the epoxy resin and water, control the epoxy resin to be dispersed in the form of micron - sized liquid beads, which is not easy to block the formation and has little influence on the permeability; a silane coupling agent is used to improve the adhesion between the solidified epoxy resin and the surface of sand grains, thereby improving the consolidation strength; using epoxy resin can achieve room - temperature curing and excellent bonding performance; using a diluent can reduce the viscosity of the system and enhance the pumpability of the system. Generally, it can enhance the curing effect, reduce or avoid formation plugging. In addition, it can also achieve low - temperature curing, shorten the curing time, and reduce the solvent dosage. Description of the Drawings

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0034] Figure 1 Shows the electron microscopy detection diagram of the dispersion degree of the binder system in the epoxy resin-based sand consolidant in an aqueous solution according to an embodiment of the present invention. Detailed implementation manners

[0035] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the following further details the embodiments of the present invention in combination with specific embodiments and with reference to the drawings.

[0036] It should be noted that all the expressions using "first" and "second" in the embodiments of the present invention are for distinguishing two entities or parameters with the same name but different, and it can be seen that "first" and "second" are only for the convenience of expression and should not be understood as a limitation on the embodiments of the present invention. This will not be elaborated one by one in the subsequent embodiments.

[0037] The present invention provides an epoxy resin-based sand consolidant, which includes a binder system and a curing agent system used in combination; by mass percentage, the binder system contains: 70 - 80% of epoxy resin, 2 - 5% of silane coupling agent, 1 - 3% of dispersant, and 15 - 25% of diluent. The curing agent system can contain an epoxy resin curing agent and an organic solvent.

[0038] The sand consolidant of the present invention adopts a two-component system (binder system + curing agent system), and the two systems are used in combination separately, which is beneficial to controlling the reaction time, avoiding the premature reaction of the agent in the construction string and blocking the oil pipe, resulting in engineering accidents, and having high construction safety.

[0039] Thermosetting epoxy resin has excellent bonding performance, room temperature curing, no swelling in water, and easy dispersion. Using epoxy resin as the main agent of the sand consolidant can broaden the curing temperature window, improve the consolidation strength of formation sand, extend the sand control effective period, and meet the requirements of sand control and fluid production for thin oil and heavy oil cold production wells. Preferably, the epoxy resin is E51 epoxy resin.

[0040] The silane coupling agent is an excellent adhesion promoter. The Si(OCH2) group in the silane coupling agent can undergo a condensation reaction with the hydroxyl groups on the sand grain surface under certain conditions to form a strong silicon-oxygen bond, and the other end is connected to the active group of the epoxy resin, thereby greatly improving the adhesion between the epoxy resin and the sand grain surface. Preferably, the silane coupling agent is an amino silane coupling agent. Further preferably, the silane coupling agent is KH-550 silane coupling agent.

[0041] The dispersant can reduce the interfacial tension between epoxy resin and water, control the dispersion of epoxy resin in the aqueous solution in the form of micron-sized liquid beads, which is not easy to block the formation, causes little damage, and is beneficial to the recovery of oil well productivity. The dispersant can also reverse the surface of sand grains from oleophilic to hydrophilic, and the polar epoxy resin is easy to wet the hydrophilic surface, improving the cementing effect. Moreover, the present invention is based on the dispersion of the dispersant without emulsification, which can avoid the problems such as difficult demulsification control and low drug utilization rate caused by using the epoxy resin sand consolidant in the form of emulsion in the prior art. Preferably, the dispersant is a water-soluble heavy oil viscosity reducer. Further preferably, the water-soluble heavy oil viscosity reducer is an alkylphenol polyoxyethylene ether carboxylate heavy oil viscosity reducer.

[0042] The diluent can be used as a viscosity modifier to reduce the viscosity of the cementing agent system, thereby enhancing the pumpability of the agent. Preferably, the diluent is a non-active diluent. Further preferably, the diluent is ethylene glycol monobutyl ether, which has good miscibility with epoxy resin. With a dosage of 20-30 wt%, the viscosity of the cementing agent system can be reduced from 10,000-16,000 mPa·s to below 500 mPa·s.

[0043] In some embodiments, by mass percentage, the curing agent system comprises: 25-35% of a modified phenolic amine curing agent, 45-55% of an organic solvent, 0.2-0.8% of a pH regulator, and 15-25% of water.

[0044] The modified phenolic amine curing agent can achieve the curing of epoxy resin at normal temperature and low temperature and has a fast curing speed. Preferably, the modified phenolic amine curing agent is a T31 curing agent, prepared by Mannich reaction, which is an ideal room temperature curing agent for epoxy resin. It can cure various types of epoxy resins in environments such as around 0°C, humidity greater than 80%, and underwater. Due to its low molecular weight, low viscosity, good miscibility with epoxy resin, and strong wettability, it is convenient for construction, has a fast curing speed, and can reduce the well occupation time.

[0045] The organic solvent is used to dissolve the modified phenolic amine curing agent to prevent the curing agent from precipitating when encountering water, which affects the curing effect and blocks the formation. Preferably, the organic solvent is ethanol.

[0046] The pH regulator can improve the water solubility of the modified phenolic amine curing agent, realize the partial replacement of the organic solvent with clear water, reduce the amount of the organic solvent, and lower the cost of the curing agent system. The pH regulator can be an alkaline substance, such as sodium hydroxide, sodium carbonate, sodium bicarbonate, etc. Preferably, the pH regulator is NaOH.

[0047] In some embodiments, the mass ratio of the cementing agent system to the curing agent system is 1:(7-9), preferably 1:8.

[0048] In some embodiments, the binder system is a colorless and transparent liquid with a bulk density of 0.98 - 1.08 g / cm 3 , and the viscosity at 25 °C is 200 - 400 mPa·s. In some embodiments, the curing agent system is a light yellow liquid with a bulk density of 0.88 - 1.02 g / cm 3 , and the viscosity at 25 °C is 10 - 30 mPa·s.

[0049] The present invention also provides a preparation method of the epoxy resin-based sand consolidating agent as described above, including:

[0050] S11, heating the epoxy resin to a flowing state, and mixing and stirring the heated epoxy resin with a silane coupling agent, a dispersant, and a diluent in proportion to obtain a binder system;

[0051] S12, mixing and stirring a modified phenolic amine curing agent, an organic solvent, a pH regulator, and a part of water, and adding another part of water and stirring after complete dissolution. In this step, precipitation of the modified phenolic amine is prevented to avoid affecting the quality of the curing agent system.

[0052] In some embodiments, in step S11, the epoxy resin is heated to 40 - 50 °C and kept at a constant temperature for 0.5 - 1.5 hours; preferably, the epoxy resin is heated to 40 °C in an oven and kept at a constant temperature for 1 hour until it can flow smoothly.

[0053] In some embodiments, in steps S11 and S12, stirring is carried out under the condition of 0 - 30 °C.

[0054] In some embodiments, in step S12, the mass of the part of water added first is 1 / 5 - 1 / 3 of the total added water, preferably 1 / 4. For example, if the curing agent system is designed to contain 20 parts by weight of water, 5 parts by weight of water can be added first, and then 15 parts by weight of water can be added later.

[0055] In some embodiments, in step S12, the pH regulator and a part of water are first mixed and dissolved for 8 - 12 h, then the modified phenolic amine curing agent and the organic solvent are added and mixed for further dissolution, and another part of water is added after complete dissolution.

[0056] The present invention also provides a sand control method using the epoxy resin-based sand consolidating agent as described above, and this sand control method includes:

[0057] S21: Injecting a preflush fluid to clean the formation;

[0058] S22: Simultaneously injecting the binder system as described above and water (carried in by water dilution);

[0059] S23: Injecting clear water for pore enlargement;

[0060] S24: Inject the curing agent system as described above;

[0061] S25: Shut in the well and wait for setting.

[0062] In some embodiments, in step S21, the preflush fluid is: fresh water + 1% α-olefin sulfonate (AOS) + 2% KCl, the construction displacement is not less than 1 m 3 / min, and the preflush fluid volume is 10 m 3 .

[0063] In some embodiments, in step S22, the use concentration of the cementing agent system is 12 - 15 wt%, and the average dosage is 50 - 100 Kg / m.

[0064] In some embodiments, in step S23, the mass dosage of fresh water for pore increasing is 1 - 1.5 times that of the cementing agent system dosage.

[0065] In some embodiments, in step S24, the mass dosage of the curing agent system is 7 - 9 times that of the cementing agent system dosage, preferably 8 times.

[0066] In some embodiments, in step S25, shut in the well and wait for setting for 12 - 24 h to consolidate the loose formation sand in the near-wellbore area of the oil well.

[0067] Compared with the existing chemical sand control technologies, the present invention has the following beneficial effects:

[0068] (1) The sand consolidating agent has low damage. The epoxy resin sand consolidating agent has good water resistance and is easily dispersed into micron-sized small liquid droplets (refer to Figure 1 , the cementing agent is dispersed into micron-sized small liquid droplets in the aqueous solution), and has good mechanical agitation property, is not easy to aggregate, can self-adsorb onto the sand grain surface when encountering formation sand, and forms a very thin curing layer after adsorbing on the formation sand surface. The aqueous solution occupies the rock pores, thus maximizing the avoidance of pore plugging, having little influence on the rock permeability, and the formation damage is within 10%.

[0069] (2) Low-temperature curing reduces the well selection conditions, and can be applied to the existing underground temperatures of oil wells, is not affected by the well temperature, and ensures the curing quality.

[0070] (3) Short curing time, curing can be achieved in 4 - 12 h, and the movable pipe string can be used for the next operation, reducing the well occupation time and shortening the operation cycle.

[0071] (4) High curing strength, the compressive strength of the consolidated core is above 15 MPa, which can meet the requirements of sand control and fluid production for chemical flooding oil wells.

[0072] In some embodiments, by using the epoxy resin sand consolidant as described above, the following can be achieved: the permeability loss of the consolidated core ≤ 10%, the compressive strength of the consolidated core ≥ 15 MPa, and the low-temperature curing ≥ 15 °C.

[0073] The following is an illustration based on specific embodiments.

[0074] Example 1

[0075] The preparation method of the epoxy resin sand consolidant includes the following steps:

[0076] S1: Heat 75 parts by weight of epoxy resin in an oven to 40 °C and keep it at a constant temperature for 1 hour until it reaches a smoothly flowing state;

[0077] S2: Sequentially add the heated 75 parts by weight of E51 epoxy resin, 3 parts by weight of KH-550 silane coupling agent, 2 parts by weight of alkylphenol polyoxyethylene ether carboxylate heavy oil viscosity reducer, and 20 parts by weight of ethylene glycol monobutyl ether into a stirring kettle, and stir evenly under the condition of 0 - 30 °C to obtain the binder system of the epoxy resin sand consolidant;

[0078] S3: Mix 0.5 part by weight of NaOH and 5 parts by weight of clear water and dissolve for 8 - 12 h, then add 30 parts by weight of T31 curing agent and 49.5 parts by weight of ethanol to prevent the precipitation of the T31 curing agent and affect the quality of the curing agent system. After fully dissolving, add water to make up to 20 parts by weight of clear water, and stir evenly under the condition of 0 - 30 °C to obtain the curing agent system of the epoxy resin sand consolidant.

[0079] Conduct experimental evaluation on the epoxy resin sand consolidant:

[0080] (1) Experimental conditions

[0081] a. Φ25 × 50 mm glass tube

[0082] b. Vacuum filtration device

[0083] c. Permeability tester

[0084] d. Material mechanics testing machine

[0085] e. Formation sand with different particle sizes

[0086] f. Binder of the epoxy resin sand consolidant

[0087] g. Curing agent of the epoxy resin sand consolidant

[0088] h. Constant temperature water bath

[0089] i. Analytical balance

[0090] (2) Experimental method

[0091] a. Connect one end of a Φ25×50 mm glass tube to a vacuum filtration device to form a sand consolidation experimental device.

[0092] b. Take 20 g of formation sand and put it into a Φ25×50 mm glass tube. Start the vacuum pump for filtration, pour in clear water to wet the formation sand, and then pour in 1.2 g of the cementing agent system and 9.6 g of the curing agent system in sequence, allowing them to fully soak the formation sand, and then stop the filtration.

[0093] c. Seal both ends of the glass tube and fix it with a clamp to keep the formation sand in a compacted state. Place it in a water bath, set the temperature to 50 °C, cure for 24 h, then take it out, break the glass tube to obtain a consolidated core.

[0094] d. Test the permeability of the consolidated core according to the method of SY / T 5276-2000 "Test Methods for Flexural Strength, Compressive Strength and Permeability of Chemical Sand Control Artificial Cores".

[0095] e. Test the compressive strength of the consolidated core according to the method of SY / T 5276-2000 "Test Methods for Flexural Strength, Compressive Strength and Permeability of Chemical Sand Control Artificial Cores".

[0096] The permeability of the consolidated core in this example was measured to be 11.6 Darcys and the compressive strength was 17.8 MPa.

[0097] Example 2

[0098] The preparation method of the epoxy resin sand consolidant includes the following steps:

[0099] S1: Heat 70 parts by weight of epoxy resin in an oven to 40 °C and keep it at a constant temperature for 1 hour until it reaches a smoothly flowing state;

[0100] S2: Add the heated 70 parts by weight of E51 epoxy resin, 4 parts by weight of KH-550 silane coupling agent, 1 part by weight of alkylphenol polyoxyethylene ether carboxylate heavy oil viscosity reducer, and 25 parts by weight of ethylene glycol monobutyl ether to the stirring kettle in sequence, and stir evenly under the condition of 0-30 °C to obtain the cementing agent system of the epoxy resin sand consolidant;

[0101] S3: Mix 0.8 parts by weight of NaOH and 5 parts by weight of clear water and dissolve for 8-12 h, then add 27 parts by weight of T31 curing agent and 47.2 parts by weight of ethanol to prevent the precipitation of T31 curing agent and affect the quality of the curing agent system. After fully dissolving, add water to make up to 25 parts by weight of clear water, and stir evenly under the condition of 0-30 °C to obtain the curing agent system of the epoxy resin sand consolidant.

[0102] Use an experimental method similar to that in Example 1 to conduct experimental evaluation on the epoxy resin sand consolidant. The permeability of the consolidated core in this example was measured to be 12.2 Darcys and the compressive strength was 17.2 MPa.

[0103] Example 3

[0104] The preparation method of the epoxy resin sand consolidant includes the following steps:

[0105] S1: Heat 80 parts by weight of epoxy resin in an oven to 40 °C and keep it at a constant temperature for 1 hour until it reaches a smoothly flowing state;

[0106] S2: Sequentially add 80 parts by weight of heated E51 epoxy resin, 2 parts by weight of KH-550 silane coupling agent, 3 parts by weight of alkylphenol polyoxyethylene ether carboxylate heavy oil viscosity reducer, and 15 parts by weight of ethylene glycol monobutyl ether into a stirring kettle, and stir evenly under the condition of 0 - 30 °C to obtain the binder system of the epoxy resin sand consolidant;

[0107] S3: Mix 0.3 part by weight of NaOH and 5 parts by weight of clear water and dissolve for 8 - 12 h, then add 32 parts by weight of T31 curing agent and 52.7 parts by weight of ethanol to prevent the precipitation of T31 curing agent and affect the quality of the curing agent system. After fully dissolving, add water to make up to 15 parts by weight of clear water, and stir evenly under the condition of 0 - 30 °C to obtain the curing agent system of the epoxy resin sand consolidant.

[0108] Use a similar experimental method as in Example 1 to conduct experimental evaluation on the epoxy resin sand consolidant. The measured permeability of the consolidated core in this example is 12.0 darcy, and the compressive strength is 17.5 MPa.

[0109] Example 4

[0110] Use the epoxy resin sand consolidant prepared in Example 1 for sand control, and the steps are as follows:

[0111] S1: Inject a pre-treatment fluid into the sand-producing formation. The pre-treatment fluid is clear water + 1% α-olefin sulfonate (AOS) + 2% KCl. The construction displacement is not less than 1 m 3 / min, and the dosage of the pre-treatment fluid is 10 m 3 .

[0112] S2: Inject the binder system of the epoxy resin sand consolidant into the sand-producing formation, carry it in with water for volume increase, and the use concentration is 12 - 15 wt%; the average dosage of the agent is 50 - 100 Kg / m.

[0113] S3: Inject clear water to increase pores; preferably, the dosage is 1 - 1.5 times the dosage of the binder.

[0114] S4: Inject the curing agent system of the epoxy resin sand consolidant, preferably, the dosage is 8 times the dosage of the binder;

[0115] S5: After shutting in the well for curing for 12 - 24 h, wash the well and then lower the pump to put into production.

[0116] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope (including the claims) disclosed by the embodiments of the present invention is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other variations in different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the embodiments of the present invention shall be included within the protection scope of the embodiments of the present invention.

Claims

1. An epoxy resin-based sand consolidant, characterized in that, it includes a binder system and a curing agent system used in combination; by mass percentage, the binder system contains: 70-80% of epoxy resin, 2-5% of silane coupling agent, 1-3% of dispersant, and 15-25% of diluent.

2. The sand consolidant according to claim 1, characterized in that, the epoxy resin is E51 epoxy resin.

3. The sand consolidant according to claim 1, characterized in that, the silane coupling agent is an amino silane coupling agent; preferably KH-550 silane coupling agent.

4. The sand consolidant according to claim 1, characterized in that, the dispersant is a water-soluble heavy oil viscosity reducer; preferably an alkylphenol polyoxyethylene ether carboxylate heavy oil viscosity reducer.

5. The sand consolidant according to claim 1, characterized in that, the diluent is a non-active diluent; preferably ethylene glycol monobutyl ether.

6. The sand consolidant according to claim 1, characterized in that, by mass percentage, the curing agent system contains: 25-35% of modified phenolic amine curing agent, 45-55% of organic solvent, 0.2-0.8% of pH regulator, and 15-25% of water.

7. The sand consolidant according to claim 6, characterized in that, the modified phenolic amine curing agent is T31 curing agent.

8. The sand consolidant according to claim 6, characterized in that, the organic solvent is ethanol.

9. The sand consolidant according to claim 6, characterized in that, the pH regulator is NaOH.

10. The sand consolidant according to claim 1, characterized in that, the mass ratio of the binder system to the curing agent system is 1:(7-9).

11. The sand consolidant according to claim 1, characterized in that, The cementing agent system is a colorless and transparent liquid with a bulk density of 0.98 - 1.08 g / cm 3 , and its viscosity at 25 °C is 200 - 400 mPa·s.

12. The sand consolidant according to claim 6, characterized in that, The curing agent system is a light yellow liquid with a bulk density of 0.88 - 1.02 g / cm 3 , and its viscosity at 25°C is 10 - 30 mPa·s.

13. A preparation method of the epoxy resin-based sand consolidant according to claim 6, including: S11, heating the epoxy resin to a flowing state, and mixing and stirring the heated epoxy resin with the silane coupling agent, dispersant, and diluent in proportion to obtain the binder system; S12, mixing and stirring the modified phenolic amine curing agent, organic solvent, pH regulator, and a part of water, and adding another part of water and stirring after fully dissolving to obtain the curing agent system.

14. The method according to claim 13, characterized in that, in step S11, the epoxy resin is heated to 40-50°C and kept at a constant temperature for 0.5-1.5 hours.

15. The method according to claim 13, characterized in that, in steps S11 and S12, stirring is carried out under the condition of 0-30°C.

16. The method according to claim 13, characterized in that, in step S12, the mass of the part of water added first is 1 / 5-1 / 3 of the total added water volume.

17. The method according to claim 13, characterized in that, In step S12, first mix and dissolve the pH regulator and the part of water for 8 - 12 h, then add the modified phenolic amine curing agent and the organic solvent and continue to mix and dissolve. After complete dissolution, add the other part of water.

18. A sand control method, characterized in that, it is carried out by using the epoxy resin - based sand consolidating agent according to any one of claims 1 - 12, and the sand control method includes: injecting a pre - flush fluid to clean the formation; injecting the cementing agent system and water simultaneously; injecting clear water for pore enlargement; injecting the curing agent system; shutting in the well for waiting for setting.

19. According to the method of claim 18, characterized in that, the use concentration of the cementing agent system is 12 - 15 wt%, and the average dosage is 50 - 100 Kg / m.

20. According to the method of claim 18, characterized in that, the mass dosage of the clear water for pore enlargement is 1 - 1.5 times that of the cementing agent system; and / or the mass dosage of the curing agent system is 7 - 9 times that of the cementing agent system.

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