A high-temperature profile control agent for heavy oil reservoir development, and its preparation method and application

Abstract

The present invention relates to a high-temperature profile control agent for the development of heavy oil reservoirs, a preparation method thereof, and an application thereof. The raw materials for preparing the high-temperature profile control agent include melamines, aldehydes, a reinforcing agent, a coagulant, bentonite, and water. The high-temperature profile control agent provided by the present invention has high resistance to steam scour, strong plugging ability, and high thermal stability. Melamines and aldehydes undergo polycondensation to form melamine resin, and bentonite has strong adhesion, plasticity, and air permeability, and is used in small amounts and has low cost. The role of the coagulant is to adjust the pH value of the high-temperature profile control agent to within the weakly alkaline range of 8-9, thereby accelerating the progress of the melamine polycondensation reaction. The role of the reinforcing agent is to further improve the plugging strength of the profile control agent. The high-temperature profile control agent of the present invention is suitable for profile control of steam drive well groups and profile control and channeling sealing of high-cycle throughput wells, as well as high-pressure steam channeling sealing of low-cycle throughput wells.

Description

Technical Field

[0001] The present invention belongs to the technical field of oilfield development, and relates to a high-temperature profile control agent for heavy oil reservoir development, a preparation method and an application thereof, and specifically relates to a high-temperature profile control agent used to adjust the suction profile and improve the vertical production degree during the development of heavy oil reservoirs, and a preparation method thereof. Background Art

[0002] With the increase in throughput cycles of heavy oil reservoirs, the formation pressure is low, the deficit is serious, the steam channeling problem is becoming increasingly prominent, the oil production rate is low, and the block is in an inefficient production state. Affected by multiple factors such as strong formation heterogeneity, the production process suffers from steam gravity overburden, uneven steam absorption profile, and steam channeling between wells, which seriously reduce the efficiency of heavy oil thermal recovery and affect the improvement of recovery rate.

[0003] At present, there are three major categories of high-temperature profile control agents: the first is solid water plugging agents, which are mainly composed of cement, slag, and plant particles. They have good temperature resistance but poor fluidity and cannot be used for deep plugging. In addition, granular plugging agents have the risk of tubing blockage and cannot be implemented in injection wells; the second is liquid water plugging agents, which are mainly composed of polymer gels. They have good fluidity but insufficient temperature resistance and are easily broken through by steam; the third is foam-based high-temperature profile control agents. This type of profile control agent has good temperature resistance but low strength, a short effective plugging period, and poor plugging effect on large channels.

[0004] Chinese patent CN1415689A discloses a high-temperature profile control agent, its preparation method, and uses. The agent is primarily composed of formaldehyde, phenol, and sodium silicate. While heat-resistant, it is brittle, slow to cure, easily diluted under formation conditions, and still expensive. Chinese patent CN102827595A discloses a steam-injected profile control agent. Melamine is used as the main agent in this high-temperature profile control agent, which is injected into the formation along with the steam. The agent uses the cooling and crystallization of the melamine during its migration to achieve formation plugging. While heat-resistant, the plugging effect is poor and it significantly fluctuates and interferes with the steam injection mainline pressure.

[0005] Therefore, it is necessary to invent a high-temperature profile control agent with good fluidity, temperature resistance, strong sealing ability, adaptability to a wide range of oil reservoir types, not easy to pollute the formation, controllable gelation, ability to penetrate deep into the formation, and low cost. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a high-temperature profile control agent for the development of heavy oil reservoirs, a preparation method and application thereof, and more particularly to a high-temperature profile control agent and a preparation method thereof used to adjust the suction profile and improve the vertical production degree during the development of heavy oil reservoirs.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a high-temperature profile control agent for heavy oil reservoir development. The raw materials for preparing the high-temperature profile control agent include melamine, aldehyde, a reinforcing agent, a coagulant, bentonite and water.

[0009] The high-temperature profile control agent provided by the present invention utilizes a melamine resin generated by the polycondensation reaction of melamine and aldehyde, which has the characteristics of high chemical activity, high bonding strength, high thermal stability, strong low-temperature curing ability, good shear resistance, and fast curing speed. Bentonite has strong adhesion, plasticity, and air permeability, and is used in small amounts and at low cost. The role of the coagulant is to adjust the pH value of the high-temperature profile control agent to a weakly alkaline range of 8-9, thereby accelerating the progress of the melamine polycondensation reaction. The role of the reinforcing agent is to further improve the sealing strength of the profile control agent.

[0010] By using a low-viscosity thermosetting resin as a gelling framework, compounding it with inorganic materials, and bonding at formation temperature to form a composite solid-phase inorganic resin gel system, this profile control agent exhibits long-term resistance to steam temperatures and steam erosion. With sufficient displacement fluid, it can achieve deep profile control and block steam channeling.

[0011] Preferably, the high-temperature profile control agent for heavy oil reservoir development comprises, by mass percentage, 1.2-2% melamine, 0.5-1% aldehyde, 0.4-1.0% enhancer, 0.05-0.2% coagulant, 5-10% bentonite and water.

[0012] When the above-mentioned raw materials are added at a specific mass percentage, the high-temperature profile control agent has the strongest high-temperature resistance, long-term effectiveness and plugging ability.

[0013] The mass percentage of the melamine can be selected from 1.2%, 1.4%, 1.6%, 1.8%, 2%, etc., the mass percentage of the aldehyde can be selected from 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc., the mass percentage of the enhancer can be selected from 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc., the mass percentage of the coagulant can be selected from 0.05%, 0.08%, 0.1%, 0.12%, 0.15%, 0.18%, 0.2%, etc., the mass percentage of the bentonite can be selected from 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, etc. Other specific point values ​​within the above numerical range can be selected, and they will not be repeated here.

[0014] Preferably, the melamines include melamine and / or benzoguanamine.

[0015] Preferably, the aldehyde comprises formaldehyde and / or hexamethylenetetramine.

[0016] Preferably, the reinforcing agent is a combination of graphite and nano-silicon dioxide.

[0017] Graphite has excellent chemical stability at room temperature and excellent high-temperature resistance, with its strength increasing with increasing temperature. During steam flooding or steam huff-and-puff processes, it can further enhance the sealing strength of profile control agents. Nanosilica particles are small (30-50nm), contain numerous micropores, have a large specific surface area, and are high in surface hydroxyl groups. They exhibit excellent dispersibility, stability, reinforcement, thickening, and thixotropy. Adding nanosilica to resins can significantly improve their brittleness, overcoming the drawbacks of elastomer toughening that often reduce material rigidity and strength, thereby achieving enhanced toughness.

[0018] The present invention creatively discovers that graphite and nano-silicon dioxide have a certain synergistic effect in improving the blocking ability.

[0019] Preferably, the mass ratio of graphite and nano-silica in the reinforcing agent is (1-3): (1-4), wherein the specific point values ​​in (1-3) can be selected from 1, 1.5, 2, 2.5, 3, etc., and the specific point values ​​in (1-4) can be selected from 1, 1.5, 2, 2.5, 3, 3.5, 4, etc. Other specific point values ​​within the above numerical range can be selected, and they will not be repeated here.

[0020] When graphite and nano-silica are added in the above-mentioned specific mass ratio, the effect of improving the plugging strength of the profile control agent is optimal.

[0021] Preferably, the coagulant comprises sodium carbonate and / or sodium bicarbonate.

[0022] Preferably, the bentonite includes sodium bentonite and / or lithium bentonite, and more preferably a combination of sodium bentonite and lithium bentonite.

[0023] When the bentonite is a combination of sodium bentonite and lithium bentonite, the adhesion, plasticity and air permeability of the profile control agent are better.

[0024] Preferably, the model of the nano-silica includes any one of SP30, SP30S or SP50, or a combination of at least two of them.

[0025] In a second aspect, the present invention provides a method for preparing the high-temperature profile control agent for heavy oil reservoir development according to the first aspect, the preparation method comprising:

[0026] (1) mixing melamine, a reinforcing agent, bentonite and water, and homogenizing to obtain a mixed solution;

[0027] (2) mixing the mixed solution obtained in step (1) with aldehyde and a coagulant to obtain a high-temperature profile control agent.

[0028] Preferably, the mixing in step (1) is carried out at 45-65°C, for example, 45°C, 48°C, 50°C, 52°C, 55°C, 58°C, 60°C, 62°C, 65°C, etc. Other specific point values ​​within the above numerical range can be selected and will not be repeated here.

[0029] Preferably, the homogenization time is 20-30min, and the rotation speed is 50-200rpm. The homogenization time can be selected as 20min, 21min, 22min, 23min, 24min, 25min, 26min, 27min, 28min, 29min, 30min, etc., and the rotation speed can be selected as 50rpm, 80rpm, 100rpm, 120rpm, 150rpm, 180rpm, 200rpm, etc. Other specific point values ​​within the above numerical range can be selected, and they will not be repeated here.

[0030] Preferably, the water in step (1) comprises clean water and / or oilfield wastewater.

[0031] Preferably, the mixing time in step (2) is 15-30 min, for example, 15 min, 18 min, 20 min, 22 min, 25 min, 28 min, 30 min, etc. Other specific point values ​​within the above numerical range can be selected and will not be repeated here.

[0032] In a third aspect, the present invention provides a use of the high-temperature profile control agent for heavy oil reservoir development according to the first aspect in a heavy oil reservoir development process.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The high-temperature profile control agent provided by the present invention utilizes a melamine resin generated by the polycondensation reaction of melamine and aldehyde, which has the characteristics of high chemical activity, high bonding strength, high thermal stability, strong low-temperature curing ability, good shear resistance, and fast curing speed. Bentonite has strong adhesion, plasticity, and air permeability, and is used in small amounts and at low cost. The role of the coagulant is to adjust the pH value of the high-temperature profile control agent to a weakly alkaline range of 8-9, thereby accelerating the progress of the melamine polycondensation reaction. The role of the reinforcing agent is to further improve the sealing strength of the profile control agent.

[0035] The high-temperature profile control agent provided by the present invention is suitable for profile control in steam drive well groups, profile control and channeling prevention in high-cycle throughput wells, and high-pressure steam channeling prevention in low-cycle throughput wells. This high-temperature profile control agent exhibits excellent fluidity, temperature resistance, long-term effectiveness, simple preparation, and low cost. Furthermore, it features adjustable gelation time, strong sealing capability, adaptability to a wide range of reservoir types, resistance to formation contamination, and the ability to penetrate deep into formations. It effectively addresses production challenges such as uneven steam absorption profiles and interwell steam channeling in conventional heavy oil wells. DETAILED DESCRIPTION

[0036] In order to further illustrate the technical means and effects adopted by the present invention, the technical solutions of the present invention are further described below in conjunction with the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.

[0037] The sources of the active ingredients contained in the products involved in the following embodiments are as follows (only the active ingredients are reflected, and the necessary auxiliary ingredients contained in other commercially available raw materials are not repeated):

[0038] Graphite was purchased from Liaoning Tianyi Industrial Co., Ltd. under the trade name of solid graphite TY-III;

[0039] Sodium bentonite was purchased from the chemical plant of Panjin Liaohe Oilfield Jinyu Group Co., Ltd. under the trade name of grade 1 bentonite powder;

[0040] Lithium-based bentonite was purchased from Kangda Industrial Group Co., Ltd. of Liaohe Oilfield, Liaoning Province under the trade name of bentonite powder grade 1.

[0041] Example 1

[0042] This embodiment provides a high-temperature profile control agent for heavy oil reservoir development. The high-temperature profile control agent comprises, by weight percentage, 1.6% melamine, 0.8% formaldehyde, 0.4% graphite, 0.6% nano-silica SP30, 0.12% sodium carbonate, 4% sodium bentonite, 4% lithium bentonite, and the balance water.

[0043] Its preparation method is:

[0044] (1) Melamine, graphite, sodium bentonite, lithium bentonite and nano-silica SP30 were mixed with clean water at 55°C, stirred and dissolved for 25 minutes at a stirring speed of 100 rpm to obtain a mixed solution;

[0045] (2) The mixed solution obtained in step (1) is mixed with formaldehyde and sodium carbonate, and stirred for 20 minutes to obtain the product.

[0046] Example 2

[0047] This embodiment provides a high-temperature profile control agent for heavy oil reservoir development. The high-temperature profile control agent comprises, by weight percentage, 2% benzoguanamine, 0.5% hexamethylenetetramine, 0.6% graphite, 0.4% nano-silica SP30S, 0.05% sodium bicarbonate, 5% lithium bentonite, 5% sodium bentonite, and the remainder oilfield wastewater.

[0048] Its preparation method is:

[0049] (1) Mixing benzoguanamine, graphite, sodium bentonite, lithium bentonite, and nano-silica SP30S with oilfield wastewater at 45° C., stirring and dissolving for 30 minutes at a stirring speed of 200 rpm to obtain a mixed solution;

[0050] (2) The mixed solution obtained in step (1) was mixed with urotropine and sodium bicarbonate, and stirred for 15 minutes to obtain the product.

[0051] Example 3

[0052] This embodiment provides a high-temperature profile control agent for heavy oil reservoir development. The high-temperature profile control agent comprises, by weight percentage, 1.2% benzoguanamine, 1% hexamethylenetetramine, 0.2% graphite, 0.8% nano-silica SP30S, 0.2% sodium bicarbonate, 2.5% sodium bentonite, 2.5% lithium bentonite, and the remainder oilfield wastewater.

[0053] Its preparation method is:

[0054] (1) Mixing benzoguanamine, graphite, sodium bentonite, lithium bentonite, and nano-silica SP30S with oilfield wastewater at 65° C., stirring and dissolving for 20 minutes at a stirring speed of 50 rpm to obtain a mixed solution;

[0055] (2) The mixed solution obtained in step (1) is mixed with urotropine and sodium bicarbonate, and stirred for 30 minutes to obtain the product.

[0056] Example 4

[0057] This embodiment provides a high-temperature profile control agent for heavy oil reservoir development. The only difference between this embodiment and Example 1 is that it does not contain sodium bentonite, and its reduced mass is distributed to the mass of lithium bentonite, while other components and contents remain unchanged.

[0058] The preparation method is as in Example 1.

[0059] Example 5

[0060] This embodiment provides a high-temperature profile control agent for heavy oil reservoir development. The only difference between this embodiment and Example 1 is that it does not contain lithium bentonite, and its reduced mass is distributed to the mass of sodium bentonite, while other components and contents remain unchanged.

[0061] The preparation method is as in Example 1.

[0062] Example 6

[0063] This embodiment provides a high-temperature profile control agent for heavy oil reservoir development. The only difference between this embodiment and Example 1 is that it does not contain graphite, and its reduced mass is distributed to the mass of nano-silica SP30, while other components and contents remain unchanged.

[0064] The preparation method is as in Example 1.

[0065] Example 7

[0066] This embodiment provides a high-temperature profile control agent for heavy oil reservoir development. The difference between this embodiment and Example 1 is that it does not contain nano-silica SP30, and its reduced mass is distributed to the mass of graphite, while other components and contents remain unchanged.

[0067] The preparation method is as in Example 1.

[0068] Example 8

[0069] This embodiment provides a high-temperature profile control agent for heavy oil reservoir development. The high-temperature profile control agent comprises, by weight percentage, 1.6% melamine, 0.8% formaldehyde, 0.9% graphite, 0.1% nano-silica SP30, 0.12% sodium carbonate, 4% sodium bentonite, 4% lithium bentonite, and the balance water.

[0070] The preparation method is as in Example 1.

[0071] Example 9

[0072] This embodiment provides a high-temperature profile control agent for heavy oil reservoir development. The high-temperature profile control agent comprises, by weight percentage, 1.6% melamine, 0.8% formaldehyde, 0.1% graphite, 0.9% nano-silica SP30, 0.12% sodium carbonate, 4% sodium bentonite, 4% lithium bentonite, and the balance water.

[0073] The preparation method is as in Example 1.

[0074] Example 10

[0075] This embodiment provides a high-temperature profile control agent for heavy oil reservoir development. The high-temperature profile control agent comprises, by weight percentage, 0.1% melamine, 2% formaldehyde, 0.1% graphite, 0.9% nano-silica SP30, 0.5% sodium carbonate, 2% sodium bentonite, 2% lithium bentonite, and the balance water.

[0076] The preparation method is as in Example 1.

[0077] Example 11

[0078] This embodiment provides a high-temperature profile control agent for heavy oil reservoir development. The high-temperature profile control agent comprises, by weight percentage, 3% melamine, 0.1% formaldehyde, 0.9% graphite, 0.1% nano-silica SP30, 0.01% sodium carbonate, 8% sodium bentonite, 8% lithium bentonite, and the balance water.

[0079] The preparation method is as in Example 1.

[0080] Test Example 1

[0081] The high-temperature profile control agent prepared in Examples 1-11 was used in a core single-tube simulation experiment to detect the permeability change of the core before and after treatment with the profile control agent.

[0082] The test method refers to SY_T 6703-2007 General Technical Conditions for Core Flowability Test Instruments.

[0083] The results are shown in Table 1.

[0084] Table 1

[0085] <![CDATA[Pre-blocking permeability (×10 -3 μm 2 )]]> <![CDATA[Permeability after plugging (×10 -3 μm 2 )]]> Blockage rate (%) Example 1 1248 95 92.4 Example 2 1189 97 91.8 Example 3 1245 124 90.0 Example 4 1362 165 87.9 Example 5 1097 152 86.1 Example 6 1245 192 84.6 Example 7 1325 210 84.2 Example 8 1324 135 89.8 Example 9 1201 121 89.9 Example 10 1326 154 88.4 Example 11 1231 148 88.0

[0086] As shown in Table 1, the high-temperature profile control agent for heavy oil reservoir development described herein exhibits strong formation plugging capabilities, with an effective plugging rate exceeding 90%. The present inventors have creatively discovered that graphite and nano-silica exhibit a synergistic effect in enhancing the plugging capability of the high-temperature profile control agent, and the ratio of these two materials is also crucial. Sodium bentonite and lithium bentonite also exhibit a synergistic effect in achieving the aforementioned effects.

[0087] Test Example 2

[0088] The high-temperature profile control agent prepared in Examples 1-11 was subjected to a core single-tube simulation experiment to examine its plugging strength to the formation. The plugging strength of the gel can be described by the breakthrough pressure. The test results are shown in Table 2.

[0089] The determination method refers to SYT5590-2004 performance evaluation method of profile control agent / SY_T 5590-93 performance evaluation method of gel profile control agent.

[0090] Table 2

[0091]

[0092] As shown in Table 2, the high-temperature profile control agent for heavy oil reservoir development described in the present invention has a plugging strength of 30 MPa / m, which can meet the plugging strength requirements of steam flooding and huff-and-puff wells, has a high plugging ability, and can effectively prevent the occurrence of steam channeling. The present invention creatively discovered that graphite and nano-silica have a certain synergistic effect in improving the plugging strength of the high-temperature profile control agent, and the ratio of the two is also very important. Sodium bentonite and lithium bentonite also have a certain synergistic effect on the above-mentioned effects.

[0093] Test Example 3

[0094] The profile control agents prepared in Examples 1-11 were subjected to a temperature resistance test. After the profile control agents were completely solidified, they were placed in a constant temperature box. The temperature of the constant temperature box was adjusted every 24 hours to test their temperature resistance. The experimental results are shown in Table 3.

[0095] Test method:

[0096] Using differential thermal analysis, the material was slowly decomposed in a programmed temperature environment at a heating rate of 10°C / s. Its high temperature resistance can be determined from the differential thermal analysis curve. The analysis curve shows that the colloid has a small decomposition peak at one temperature and a large decomposition peak at another temperature. The former is the water loss temperature of the colloid, and the latter is the decomposition temperature of the entire colloid. The weight loss rate can be obtained by weighing the solid before and after the colloid at the water loss temperature.

[0097] Table 3

[0098]

[0099]

[0100] The data in Table 3 show that the weight loss rate of the profile control agent increases with increasing temperature. When the temperature exceeds 300°C, the agent's structure changes and high-temperature hydration begins. This indicates that the high-temperature profile control agent can withstand temperatures up to 300°C, exhibiting excellent high-temperature resistance and adapting to the applicable conditions of domestic steam stimulation for heavy oil reservoir development.

[0101] Test Example 4

[0102] The high-temperature profile control agents prepared in Examples 1-11 were subjected to a high-temperature long-term stability experiment (experimental temperature was 250° C.) to test the effect of high-temperature environment on the long-term stability of the profile control agents. The dehydration rate of the high-temperature profile control agent solids under high-temperature environment is shown in Table 4.

[0103] Test method refers to QSY LH 0105-2000PR-WSLH-I high temperature water plugging and profile control agent

[0104] Table 4

[0105] One month Two months Three months Four months Five months six months Example 1 0 0 0 1.8 6.9 18.7 Example 2 0 1.2 4.9 8.5 15.4 22.5 Example 3 0 5.2 9.8 16.7 22.4 27.7 Example 4 0 7.5 12.3 19.6 26.7 34.2 Example 5 0 9.4 16.7 24.3 32.8 39.8 Example 6 0 13.6 19.2 29.8 39.4 45.2 Example 7 0 15.9 25.3 31.9 43.2 51.8 Example 8 0 18.7 29.4 38.6 49.1 58.7 Example 9 0 19.2 35.3 46.2 56.7 64.9 Example 10 0 21.3 39.4 57.1 64.2 72.3 Example 11 0 25.1 47.2 64.2 73.9 84.5

[0106] As can be seen from the data in Table 4, the high-temperature profile control agent for heavy oil reservoir development according to the present invention can maintain a low dehydration rate within 6 months at 250°C. This shows that the high-temperature profile control agent according to the present invention can maintain a strong plugging effect for a long time under high temperature conditions for more than 6 months.

[0107] Test Example 5

[0108] The high-temperature profile control agent prepared in Examples 1-11 was subjected to a core single-tube simulation experiment to examine its steam erosion resistance after solidification after injection into the single-tube model.

[0109] Experimental parameters: core length 5.2 cm; core permeability 874×10 -3 μm 2 ; pore volume is 9.8cm 3 The injected steam mass was 9.8 g (1 PV); the injection temperature was 300 °C; the injection flow rate was 0.2 g / min, and the plugging rates were measured after 5 min, 10 min, 20 min, 30 min, 40 min, and 50 min of steam injection, respectively. The results are shown in Table 5.

[0110] Test method refers to QSY LH 0105-2000PR-WSLH-I high temperature water plugging and profile control agent

[0111] Table 5

[0112] 5min 10min 20min 30min 40min 50min Example 1 94.2 93.8 92.7 91.4 90.3 89.8 Example 2 93.9 93.6 92.5 91.5 90.1 89.6 Example 3 93.5 93.2 92.1 90.6 89.7 89.2 Example 4 93.3 92.8 91.8 90.5 89.5 89 Example 5 93.1 92.6 91.6 90.3 89.1 88.6 Example 6 92.7 92.4 91.2 89.9 88.7 88.4 Example 7 92.5 92 90.8 89.5 88.5 88.2 Example 8 93.2 92.9 91.8 90.5 89.5 89 Example 9 92.8 92.7 91.5 90.3 89.3 88.8 Example 10 92.7 92.5 91.3 90 89.2 88.5 Example 11 92.6 92.3 91 89.7 88.8 88.3

[0113] As shown in Table 5, the high-temperature profile control agent for heavy oil reservoir development described in the present invention undergoes a gel-like structure destruction as steam flushing time increases, ultimately forming an aqueous solution that is expelled. When the injected steam volume is 1PV, the core plugging rate of the profile control agent can still be maintained at approximately 90% after 50 minutes, indicating that the profile control agent has very strong resistance to steam flushing. It also demonstrates that the plugging agent can degrade under high temperature, restoring formation permeability. The present invention creatively discovered that graphite and nano-silica have a certain synergistic effect in improving the steam flushing resistance of the high-temperature profile control agent, and the ratio of the two is also very important. Sodium bentonite and lithium bentonite also have a certain synergistic effect in achieving the above-mentioned effects.

[0114] The applicant states that while the above-described embodiments illustrate a high-temperature profile control agent for heavy oil reservoir development, its preparation method, and its application, the present invention is not limited to these embodiments. This does not necessarily mean that the present invention must rely on these embodiments for implementation. Those skilled in the art will appreciate that any improvements to the present invention, equivalent substitutions for raw materials in the present invention, addition of auxiliary components, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

[0115] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0116] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A high-temperature profile control agent for heavy oil reservoir development, characterized in that: The high-temperature profile control agent for heavy oil reservoir development comprises, by weight percentage, 1.2-2% of melamine, 0.5-1% of aldehyde, 0.4-1% of reinforcing agent, 0.05-0.2% of coagulant, 5-10% of bentonite and water; The reinforcing agent is a combination of graphite and nano-silicon dioxide; The mass ratio of graphite to nano-silicon dioxide in the reinforcing agent is (1-3):(1-4).

2. The high-temperature profile control agent for heavy oil reservoir development according to claim 1, characterized in that The melamines include melamine and / or benzoguanamine.

3. The high-temperature profile control agent for heavy oil reservoir development according to claim 1, characterized in that The aldehyde includes formaldehyde and / or hexamine.

4. The high-temperature profile control agent for heavy oil reservoir development according to claim 1, characterized in that The coagulant comprises sodium carbonate and / or sodium bicarbonate.

5. The high-temperature profile control agent for heavy oil reservoir development according to claim 1, characterized in that The bentonite includes sodium bentonite and / or lithium bentonite.

6. The high-temperature profile control agent for heavy oil reservoir development according to claim 5, characterized in that The bentonite is a combination of sodium bentonite and lithium bentonite.

7. The high-temperature profile control agent for heavy oil reservoir development according to claim 1, characterized in that The model of the nano-silicon dioxide includes any one of SP30, SP30S or SP50, or a combination of at least two of them.

8. The method for preparing a high-temperature profile control agent for heavy oil reservoir development according to any one of claims 1 to 7, characterized in that: The preparation method comprises: (1) mixing melamine, a reinforcing agent, bentonite and water, and homogenizing to obtain a mixed solution; (2) mixing the mixed solution obtained in step (1) with aldehyde and a coagulant to obtain a high-temperature profile control agent.

9. The method for preparing a high-temperature profile control agent for heavy oil reservoir development according to claim 8, characterized in that: The mixing in step (1) is carried out at 45-65°C.

10. The method for preparing a high-temperature profile control agent for heavy oil reservoir development according to claim 8, characterized in that: The homogenization time is 20-30 minutes, and the rotation speed is 50-200 rpm.

11. The method for preparing a high-temperature profile control agent for heavy oil reservoir development according to claim 8, characterized in that: The water in step (1) includes clean water and / or oilfield wastewater.

12. The method for preparing a high-temperature profile control agent for heavy oil reservoir development according to claim 8, characterized in that: The mixing time in step (2) is 15-30 minutes.

13. Use of the high-temperature profile control agent for heavy oil reservoir development according to any one of claims 1 to 7 in the heavy oil reservoir development process.

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