CN113201318B - A kind of high temperature and high salt reinforced foam plugging agent and reservoir injection method thereof - Google Patents

Abstract

The invention belongs to the technical field of petroleum exploitation, and particularly relates to a high-temperature and high-salt-resistant reinforced foam plugging agent and a reservoir injection method thereof. The high-temperature and high-salt-resistant reinforced foam plugging agent comprises lignin as the main agent, urotropine as the cross-linking agent, HZ-1 type foaming agent, and methylcellulose with a molecular weight of 80,000 to 200,000 as the strengthening agent. The enhanced foam plugging agent can improve the heterogeneity of the formation, improve the sweep coefficient and the oil washing efficiency, so as to improve the oil displacement effect and the recovery factor.

Description

A kind of high temperature and high salt reinforced foam plugging agent and reservoir injection method thereof

technical field

The invention belongs to the technical field of petroleum exploitation, and particularly relates to a high-temperature and high-salt-resistant reinforced foam plugging agent and a reservoir injection method thereof.

Background technique

With the increase of heavy oil recovery, steam injection thermal oil recovery technology is more and more widely used. However, in the mining process, due to the heterogeneity of the formation, the difference in fluid mobility, and the formation energy deficit in the late huff and puff, problems such as edge and bottom water intrusion and steam channeling are prone to occur during the mining process. The problem of high water cut in oil wells will seriously affect the effect of steam huff and puff, thereby affecting the production effect of oil wells. For some deep high-temperature and high-salt oil layers, the use of plugging agents will be seriously affected by formation temperature and salinity. Most of the current plugging agents cannot be adapted to high temperature environments. Therefore, it is urgent to find a plugging agent that can adjust Formation heterogeneity can effectively prevent water intrusion and steam channeling, and more importantly, it can withstand high temperature and high salt to face complex deep reservoirs.

The existing water plugging technology is mainly polymer jelly water plugging technology. For example, publication number CN111892918A discloses a jelly-type water blocking and profile control agent, which is mainly composed of polyacrylamide, emulsifier, retarder and the like. The jelly formed in the invention has a temperature resistance of 75°C and cannot be applied to a higher oil layer environment.

The main ingredient of the jelly is polyacrylamide, the temperature resistance of the jelly system is 90℃, and the salt resistance can only reach 5×10 ⁴ mg/L .

In summary, although the existing plugging agents can play a good role in profile control for some complex oil layers and improve the efficiency of heavy oil production, they still have the following defects: (1) For deep high-temperature reservoirs, due to the temperature of the oil layer The complex reservoir conditions with high formation water salinity and high formation water lead to problems such as weak temperature and salt resistance, poor stability, low plugging strength and short validity period of common plugging agents when they are applied; (2) common polymerization Physical jelly generally has problems such as poor toughness, easy breakage and short effective time. Due to poor toughness, it will lead to poor stability of the jelly system, poor plugging effect, and low recovery efficiency; (3) For steam flooding and For steam huff and puff wells, due to the heterogeneity of the formation, the problem of steam channeling will be formed in the high-permeability layer, resulting in ineffective production stimulation measures. However, when the conventional plugging agent is applied, although it will have a certain plugging effect on the high-permeability formation, the injection of the plugging agent will also involve the low-permeability layer, thereby affecting the recovery degree of crude oil.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a high-temperature and high-salt-resistant reinforced foam plugging agent and a reservoir injection method for the above-mentioned defects. The reinforced foam plugging agent is resistant to high temperature and salinity; It has strong plugging performance and can only involve high-permeability regions and not low-permeability regions during injection into the formation.

The technical scheme of the invention is as follows: a high-temperature and high-salt-resistant strengthening foam plugging agent, the main agent is lignin, the cross-linking agent is urotropine, the foaming agent is HZ-1 type, and the strengthening agent is a molecular weight of 8-8 200,000 methylcellulose.

The high-temperature and high-salt-resistant reinforced foam plugging agent contains 4.0-6.0% of lignin, 3.5-5.5% of urotropine, 0.3-0.6% of methyl cellulose, and HZ-1 type temperature-resistant The foaming agent is 0.5%, and the balance is water.

The high-temperature and high-salt reinforced foam plugging agent is 4.3% of lignin, 4% of urotropine, 0.35% of methyl cellulose, 0.5% of HZ-1 foaming agent, and the remainder according to the mass percentage. for water.

The reinforced foam plugging agent is suitable for oil reservoirs with a temperature of 175°C and a salinity of 20×10 ⁴ mg/L; the foaming volume of the reinforced foam is 500mL, and the half-life is 14.4min; the reinforced foam plugging agent is heated at 175°C Heating and aging for one month under conditions, the dehydration rate is not higher than 9%.

The gel-forming time of the reinforced foam plugging agent to form jelly in the environment of 80-175°C is 3-22h, of which the gel-forming time is 22h in the environment of 80°C; the gel-forming time is 6.5h in the environment of 100°C; The gel formation time is 5h in the ℃ environment; the gel formation time is 3h in the 160 ℃ environment; the gel formation time is 2.5h in the 175 ℃ environment.

The oil reservoir injection method of the high temperature resistant and high salt reinforced foam plugging agent comprises the following steps:

(1) Well selection: select oil wells with strong formation heterogeneity; large difference in permeability; active edge and bottom water and high water content of produced fluid;

(2) Configure strengthening foam plugging agent: first add the strengthening agent methyl cellulose into the water under stirring conditions, and stir evenly; then add the main agent lignin, cross-linking agent urotropine and HZ-1 type foaming The agent is stirred evenly according to the corresponding proportion, and the solution of strengthening foam plugging agent is prepared;

(3) Liquid injection: inject the reinforced foam plugging agent liquid prepared in step (2) into the oil well with a small displacement of 200-400L/min. The total injected liquid volume is 100-300m ³ , and the reinforced foam plugging agent liquid itself is low The viscosity characteristics and the synergy of the design of the injection parameters make the gel solution spread to the high-permeability area as much as possible, and the initial wellhead injection pressure is recorded during the injection process;

(4) Gas injection: inject nitrogen gas into the oil layer, the injection displacement is 600-2400Nm ³ /h, record the gas injection pressure at the wellhead, and stop the injection when the wellhead gas injection pressure increases by 3-5MPa relative to the initial wellhead injection pressure gas;

(5) Boil the well: Boil the well for 1 to 5 days, so that the strengthened foam plugging agent undergoes a cross-linking reaction to form a stable jelly foam system;

(6) Production: open wells for production, record the changing trends of data such as liquid production, oil production, and gas production.

In the process of injecting the high-temperature and high-salt reinforced foam plugging agent into the formation, it only affects the high-permeability area and does not pollute the low-permeability area.

The beneficial effects of the present invention are as follows: the enhanced foam plugging agent of the present invention can improve the heterogeneity of the formation, improve the sweep coefficient and the oil washing efficiency, so as to improve the oil displacement effect and the recovery factor.

1. The gel-forming time of the reinforced foam plugging agent is controllable, the gel-forming strength is high, and the gel-forming stability is strong, and it can be applied to oil reservoirs with a temperature of 175℃ and a salinity of 20×10 ⁴ mg/L; it can be applied Profile control and water shutoff in thermal recovery heavy oil reservoirs and deep high temperature and high salinity reservoirs.

2. The reinforced foam system formed by the reinforced foam plugging agent has high stability and strong blocking effect, and can effectively block the high-permeability layer, thereby controlling the problems of water intrusion and steam channeling in the mining process.

3. The liquid self-viscosity of the reinforced foam plugging agent of the present invention is low, slightly larger than the viscosity of water. There is essentially no seepage resistance during injection. The viscosity increases only during the gelation process, and the high-permeability layer is blocked with the increase of the gel viscosity.

4. The reservoir injection method for strengthening the foam plugging agent can make the plugging agent injected into the high-permeability layer under certain conditions to protect the low-permeability layer from being polluted, so as to effectively block the high-permeability layer and improve the formation. Heterogeneity prevents complex situations such as steam channeling and water intrusion in the production process of oil wells.

Description of drawings

Fig. 1 is a graph showing the change of gel formation time and gel strength of the reinforced foam system at different temperatures during the whole experiment of Experimental Example 1.

FIG. 2 is a graph showing the variation of dehydration rate and strength of the reinforced foam system with aging time in the whole experimental process of Experimental Example 1. FIG.

3 is a scanning electron microscope image of the reinforced foam system before gelation in the whole experimental process of Experimental Example 1.

FIG. 4 is a scanning electron microscope image of the reinforced foam system after gelation in the whole experimental process of Experimental Example 1. FIG.

Fig. 5 is a graph showing the change of gelation time by changing the dosage of urotropine and lignin in turn according to the orthogonal test method when the strengthening agent is 0.5%, 0.4% and 0.3% respectively in Experimental Example 2.

Figure 6 is a graph showing the change of gel strength in Experimental Example 2 when the reinforcing agent is 0.5%, 0.4% and 0.3% respectively, according to the orthogonal test method, the dosages of urotropine and lignin are changed in turn.

FIG. 7 is a graph showing the effect of lignin concentration on gelation time and gelation strength in Experimental Example 3. FIG.

FIG. 8 is a graph showing the effect of urotropine concentration on gel formation time and gel formation strength in Experimental Example 3. FIG.

FIG. 9 is a graph showing the change of the recovery factor of the high-permeability and low-permeability two core pipes in the whole experiment process of Experimental Example 4. FIG.

FIG. 10 shows the jelly state before and after strengthening the agent at 100° C. during the whole experimental process of Comparative Example 1. FIG.

Detailed ways

The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings.

Example 1

The high-temperature and high-salt reinforced foam plugging agent is based on the mass percentage of the main agent lignin 4.3%, the cross-linking agent urotropine 4%, the strengthening agent 0.35% methyl cellulose with a molecular weight of 80,000 to 200,000, HZ- Type 1 foaming agent 0.5%, the balance is water.

The enhanced foam plugging agent is suitable for reservoirs with a temperature of 175℃ and a salinity of 20×10 ⁴ mg/L.

The gel-forming time of the reinforced foam plugging agent to form jelly in the environment of 80-175°C is 2.5-22h, of which the gel-forming time is 22h in the environment of 80°C; the gel-forming time is 6.5h in the environment of 100°C; The gel-forming time is 5h in ℃ environment; the gel-forming time is 3h in 160 ℃ environment; the gel-forming time is 2.5h in 175 ℃ environment.

The oil reservoir injection method of the high temperature resistant and high salt reinforced foam plugging agent comprises the following steps:

(1) Well selection: select oil wells with strong formation heterogeneity, large difference in permeability, active edge and bottom water, and high water content of produced fluid;

(2) Configure the strengthening foam plugging agent solution: first, under stirring conditions, add 0.35% of the strengthening agent methyl cellulose to the water in proportion by mass, and stir evenly; then add 4.3% of the main agent lignin, 4% of cross-linking Proportion of urotropine and 0.5% HZ-1 foaming agent were mixed uniformly to obtain a solution of strengthening foam plugging agent;

(3) Liquid injection: inject the enhanced foam plugging agent prepared in step (2) into the oil well at a small displacement of 320L/min. The total injected liquid volume is 155m ³ . The characteristics of the enhanced foam plugging agent plus the design of injection parameters When the synergistic effect makes the jelly solution spread to the high permeability area as much as possible, record the initial initial wellhead pressure;

(4) Gas injection: inject nitrogen into the oil layer, the injection displacement is 1200Nm ³ /h, record the gas injection pressure at the wellhead, and stop the gas injection when the gas injection pressure at the wellhead increases by 4.1MPa relative to the initial wellhead injection pressure;

(5) Boil the well: Boil the well for 3 days, so that the strengthened foam plugging agent undergoes a cross-linking reaction to form a stable jelly foam system;

(6) Production: open wells for production, record the changing trends of data such as liquid production, oil production, and gas production.

Experimental example 1

The reinforced foam stability and gel formation state of the reinforced foam plugging agent of the present invention under high temperature conditions are analyzed below through experiments.

1. Experimental steps

To configure a reinforced foam plug, include the following steps:

(1) add 181.7g of ultrapure water to the beaker;

(2) 0.7g of methylcellulose solution was added to the beaker containing ultrapure water under stirring conditions, and stirred well;

(3) add 8.6g lignin, 8g urotropine cross-linking agent, 1g HZ-1 type foaming agent to the beaker, stir with glass rod, and then obtain the strengthening foam system;

(4) Place the obtained reinforced foam solution in ampoules with good airtightness, and then place the ampoules containing the reinforced foam solution in an environment of 90°C, 100°C, 125°C, 150°C, and 175°C, respectively. The gel was heated in the middle to form the gel, and the gel-forming time and the change of the gel-forming strength were recorded.

2. Experimental results and analysis

By recording the gelation time and gel strength changes of the reinforced foam system during gelation, the gelation time and gel strength changes with temperature can be accurately judged, so as to analyze the stability of the reinforced foam and the gelation state under high temperature conditions. .

It can be seen from Figure 1 that with the increase of temperature, the gel formation time is shortened continuously, and the gel formation strength first increases and then decreases. When the temperature is 100 ℃, the gel strength reaches the maximum, the gel strength is H ⁺ level, and the gel time is 6.5h. In the range of 100-140 ℃, the change range of gel strength is relatively small, indicating that the jelly has good temperature resistance and still has good stability under high temperature.

It can be seen from Figure 2 that the reinforced foam is continuously heated at 175 °C for 1 month, the gel strength is only lost by 2 levels, and the dehydration rate is only about 9%, so the reinforced foam system has strong stability. It can be well used in high temperature oil reservoirs.

It can be seen from Figure 3 that before the reinforced foam system gels, the cross-linking points of the entire system have not been connected to form a whole network structure. This is mainly because the reinforced foam system has not been gelatinized at high temperature before crosslinking, and the crosslinking effect of urotropine can only work at high temperature.

It can be seen from Figure 4 that after the reinforced foam system is gelled, the cross-linking points of the entire system are connected together to form a dense network structure. It can also be seen from Figure 5 that there is no vacancy in the entire space, which is also the reason for the strong stability of the reinforced foam system and the relatively high gel strength.

Experimental example 2

1. The purpose of the experiment

When the strengthening agent was 0.5%, 0.4% and 0.3% respectively, the dosage of urotropine and lignin were changed in turn according to the orthogonal test method, and the gel strength and gel time of the foam system were observed.

2. Experimental results and analysis

Table 1 Orthogonal test data

Levels and Factors Lignin (%) Urotropine (%) Methylcellulose(%) 1 3 2 0.3 2 4 3 0.4 3 5 4 0.5 4 6 5 / 5 7 6 /

Combining Figure 5 and Figure 6, it can be seen that when the concentration of urotropine is 3.5-5.5% and the concentration of lignin is 4-6%, the contour lines are relatively dense, indicating that the gelation time and gelation strength are within this concentration range. The change is obvious, the gel formation time is relatively short, and the gel formation strength is relatively large, which can meet the actual oil field production requirements.

Experimental example 3

1. Purpose of the experiment

The effects of main agent lignin concentration, urotropine concentration and strengthening agent concentration on gel formation time and gel strength were studied through single factor experiments respectively.

2. Experimental results and analysis

It can be seen from Fig. 7 that with the increase of lignin concentration, the gel forming time and gel strength increase continuously. When the lignin concentration is 4-6%, the range of gel strength is the most severe.

It can be seen from Figure 8 that with the increase of the concentration of urotropine, the gel formation time is getting smaller and smaller, and the gel formation strength is getting bigger and bigger. When the concentration of urotropine is 3-6%, the change trend of gel strength is more obvious, indicating that the cross-linking reaction of the two is severe.

Table 2 jelly change state when the concentration of fortifier changes

Enhancer Concentration (%) gel state 0 Tofu-like (50%) 0.2 Tofu-like (40%) 0.4 Tofu-like (20%) 0.6 plasticine

It can be seen from Table 2 that the addition or not of the fortifier mainly affects the state of the jelly. The "plasticine-like" jelly itself has a certain elasticity, that is to say, it has a certain self-recovery ability under the condition of appropriate external force. "Tofu-like" jelly refers to the fact that it has no self-recovery ability under the condition of external force, and the jelly will be broken by external force. When the concentration of the fortifier is greater than 0.2%, the tofu-like proportion has been reduced to 40%. Therefore, when the concentration of the strengthening agent is higher than 0.3%, the stability and toughness of the strengthened foam system can meet the requirements of oilfield production.

Experimental example 4

Experiments were carried out on the profile control performance of the enhanced foam plugging agent.

1. Purpose of the experiment

The steam flooding process was simulated in the reservoir, and the effect of oil recovery in high and low permeability areas after injection of enhanced foam was investigated. The experimental temperature was kept at a constant temperature of 100 °C.

2. Experimental steps

(1) First fill two core tubes (φ30cm×2.5cm) with different permeability (9646.41mD and 940.31mD), and vacuum the two core tubes for about 4h;

(2) Weigh the dry weight of the core pipe, saturated water, and weigh the wet weight, and calculate the pore volume of the core pipe;

(3) Carry out water flooding at a speed of 1 mL/min, and calculate the permeability according to Darcy's formula;

(4) Saturate oil with crude oil with a viscosity of 1200 cP, and the speed of saturated oil is 0.1 mL/min;

(5) Place the two core tubes in an environment with a temperature of 100 °C, inject 300 °C steam at a rate of 5 mL/min to 0.3PV in the first two rounds, and record the pressure difference changes at both ends of the core tubes;

(6) Close the core tube valve to soak the well, and the soaking time is 0.5h. Open well for production, record oil production rate, liquid production rate, recovery factor, differential pressure and other parameters;

(7) In the last two rounds, the jelly (the formula is 4.3% lignin + 4% urotropine + 0.35% fortifier), the jelly foam (the formula of the jelly foam system is 4.3% lignin + 4% Urotropine + 0.35% strengthening agent + 0.5% foaming agent, gas-liquid ratio of 1:1) was injected into the core tube at a rate of 1 mL/min, the injection volume was 0.3PV, and the pressure difference at both ends of the core tube was recorded. ; Then stand at 100℃ for 7h to form a gel;

(8) After gelation, inject 0.3PV of steam at 300°C into the core, and record the pressure difference change;

(9) Close the core tube valve to soak the well, and the soaking time is 0.5h. Open well for production, record oil production rate, liquid production rate, recovery factor, differential pressure and other parameters;

3. Experimental results and analysis

By recording the changes of oil production, liquid production and recovery factor in different periods during the whole production process, it is possible to clearly see the increase in oil recovery at each stage, understand the oil production and oil production at each stage, and then summarize the reasons for strengthening foam. yield increase effect.

The whole production stage is divided into four rounds. The first two rounds are the process of injecting steam, and the last two rounds are the process of injecting the enhanced foam system first, and then injecting steam.

As shown in Figure 9, in the first round, the high-permeability pipe produced more oil, and the recovery factor could reach 17%, while the low-permeability pipe had a recovery factor of 5%. With the increase of mining rounds, the high-permeability recovery factor in the second cycle increased by only 5%, and the low-permeability increased by 1%, and in the second production cycle, the high-permeability water cut has increased to 90%. When the enhanced foam system is injected, the recovery factor in the low-permeability pipe increases, the high-permeability recovery factor increases by 3%, the low-permeability recovery factor increases by 13%, and the water content also decreases to a certain extent, from the original 90% down to 60%.

Application example 1

Field application method: When the process is implemented on site, the method of slug injection is adopted, and the injection is carried out according to the ratio of 0.5% foaming agent + 4% urotropine + 0.35% methyl cellulose + 4.3% lignin, and a mixer is equipped on site to stabilize The foaming agent is dispersed and stirred to ensure that the agent is evenly distributed in the solution.

Well case analysis: The well number is CH-13. Since it was put into production in November 2005, 5 rounds of steam injection have been carried out. Affected by the intrusion of edge water, the well has been producing with high water cut since August 2015, with an average water cut of 95.3 %, maintaining a low output of about 1.9 tons of oil per day for a long time. The last round of ordinary nitrogen foam profile control was implemented in December 2017. After the implementation, the peak daily oil production was 2.6 tons, and the cycle average daily oil production was 2.0 tons. In January 2019, the enhanced foam profile control process was implemented, and 120m ³ of jelly foam liquid and 7.3×10 ⁴ Nm ³ of nitrogen were injected into the well. The well saw oil quickly 8 days after it was opened, and the daily peak oil production reached 7.5 tons. The current average daily oil production is 4.8 Compared with the previous round of ordinary nitrogen foam profile control process, the average daily oil increase is 2.8 tons. At present, the cumulative oil increase is 528 tons, which is 176 tons more than the previous round of nitrogen profile control. The process effect is remarkable.

Comparative Example 1

1. Experimental steps

To configure a foam blocker, include the following steps:

(1) add 182.4g of ultrapure water to the beaker;

(2) add 8.6g lignin, 8g urotropine cross-linking agent, 1g HZ-1 type foaming agent to the beaker, stir with glass rod, and then obtain the foam system of Comparative Example 1;

(3) The above-mentioned foam solutions obtained in this comparative example were placed in ampoules with good airtightness, and then the ampoules with foam solutions were placed at 90°C, 100°C, 125°C, 150°C, and 175°C, respectively. Heat aging in the environment, record the gel time and gel strength changes.

2. Experimental results and analysis

Table 3 Comparison between gel time and gel strength before and after strengthening

It can be seen from Figure 10 that when the strengthening agent is added, the overall stability of the jelly is relatively high, the gelling strength is relatively large, and the shape looks like a "plasticine" state with certain elasticity. Under the condition of external force, it can have a certain self-recovery ability. However, the foam system without strengthening agent has poor stability and is easy to break. It mainly presents a "tofu" state, and its elasticity and toughness are very poor. In the state of being subjected to a certain external force, it cannot recover by itself.

It can be seen from Table 3 that when no strengthening agent is added, the strength of the foam system after gelation is lower than that of the strengthened foam system with the strengthening agent added, and it can also be seen from the blocking rate that after adding the strengthening agent, the blocking effect of the gelatin Strengthening, indicating that the compounding effect between the strengthening agent, the main agent and the cross-linking agent is very good, and the addition of the strengthening agent can enhance the toughness and stability of the jelly.

Comparative Example 2

(1) add 181.7g of ultrapure water to the beaker;

(2) 0.7g of methylcellulose solution was added to the beaker containing ultrapure water under stirring conditions, and stirred well;

(3) add 8.6g lignin, 8g phenolic resin, 1g HZ-1 type foaming agent to the beaker, stir evenly with a glass rod, and then obtain a reinforced foam system;

(4) Place the obtained reinforced foam solution in ampoules with good airtightness, and then place the ampoules containing the reinforced foam solution in an environment of 90°C, 100°C, 125°C, 150°C, and 175°C, respectively. Heat to gel.

Table 4. Comparison between gel formation time and gel strength of foam systems with different cross-linking agents

Type of crosslinker gel time (h) gel strength Blocking rate (%) Experimental Example 1 6.5 18 99.45 Comparative Example 2 8 16 98.10

From the comparison in Table 4, it can be seen that when urotropine is used as the cross-linking agent, the gel formation time is relatively fast, indicating that the reaction between the cross-linking agent and the main agent is relatively fast, and the strength of the formed gel is relatively large. , the final blocking effect is greater than that when phenolic resin is used as the crosslinking agent. It can be seen that the compound effect between urotropine and the main agent and the strengthening agent is far greater than the effect of the phenolic resin and the main agent and the strengthening agent.

Comparative Example 3

(1) add 181.7g of ultrapure water to the beaker;

(2) 0.7g of methylcellulose solution was added to the beaker containing ultrapure water under stirring conditions, and stirred well;

(3) add 0.5g main agent HPAM, 1g urotropine, 1g HZ-1 type foaming agent to the beaker, stir evenly with a glass rod, and then obtain a strengthened foam system;

(4) Place the obtained reinforced foam solution in ampoules with good airtightness, and then place the ampoules containing the reinforced foam solution in an environment of 90°C, 100°C, 125°C, 150°C, and 175°C, respectively. Heat to gel.

Table 5. Comparison between gel formation time and gel strength of foam systems with different main agent types

main agent type gel time (h) gel strength Blocking rate (%) Experimental Example 1 6.5 18 99.45 Comparative Example 3 18 13 96.10

It can be seen from Table 5 that after replacing the main agent with HPAM, the jelly strength changes greatly, and the gel formation time is also prolonged. It shows that the polymerization between HPAM and the cross-linking agent is relatively slow, the reaction between the two is not very sufficient, and the final gel strength is relatively small and the blocking rate is relatively poor. Therefore, the compounding effect of lignin, cross-linking agent and strengthening agent is greater than that produced by HPAM.

Claims (6)

1. a high-temperature and high-salt strengthening foam plugging agent is characterized in that, main agent is lignin, and cross-linking agent is urotropine, and foaming agent is HZ-1 type, and strengthening agent is that molecular weight is at 8～20 10,000 methyl cellulose; according to the mass percentage, lignin is 4.0-6.0%, urotropine is 3.5-5.5%, methyl cellulose is 0.3-0.6%, HZ-1 foaming agent is 0.5%, and the rest The amount is water. 2. the high-temperature and high-salt-resistant strengthening foam plugging agent according to claim 1, is characterized in that, according to mass percent lignin is 4.3%, urotropine is 4%, methylcellulose is 0.35%, HZ-1 Type foaming agent is 0.5%, and the balance is water. 3. The high-temperature and high-salt-resistant reinforced foam plugging agent according to claim 1, wherein the reinforced foam plugging agent is suitable for oil reservoirs with a temperature of 175° C. and a salinity of 20×10 ⁴ mg/L; The foaming volume of the foam is 500 mL, and the half-life is 14.4 min; the enhanced foam plugging agent is heated at 175° C. for 30 days, and the dehydration rate is not higher than 9%. 4. The high-temperature and high-salt-resistant reinforced foam plugging agent according to claim 1, characterized in that, the gel-forming time of the reinforced foam plugging agent to form a jelly in an environment of 80 to 175°C is 2.5 to 22h, wherein at 80°C The gel time in the environment is 22h; the gel time in the 100°C environment is 6.5h; the gel time in the 120°C environment is 5h; the gel time in the 160°C environment is 3h; the gel time in the 175°C environment for 2.5h. 5. the oil reservoir injection method of the high temperature resistant and high salt reinforced foam plugging agent of claim 1, is characterized in that, comprises the following steps: (1) Well selection: select oil wells with strong formation heterogeneity; large difference in permeability; active edge and bottom water and high water content of produced fluid; (2) Configure the strengthening foam plugging agent solution: first add the strengthening agent methyl cellulose into the water under stirring conditions, and stir evenly; then add the main agent lignin, the cross-linking agent urotropine and the HZ-1 type The foaming agent is stirred evenly according to the corresponding proportion, and the solution of strengthening foam plugging agent is prepared; (3) Liquid injection: inject the enhanced foam plugging agent solution prepared in step (2) into the oil well at a small displacement of 200-400 L/min, and the total injection liquid volume is 100-300 m ³ . Record the initial wellhead pressure; (4) Gas injection: inject nitrogen gas into the oil layer, the injection displacement is 600-2400Nm ³ /h, record the gas injection pressure at the wellhead, and stop the injection when the wellhead gas injection pressure increases by 3-5MPa relative to the initial wellhead injection pressure. gas; (5) Boil the well: Boil the well for 1 to 5 days, so that the strengthened foam plugging agent undergoes a cross-linking reaction and forms a stable jelly foam system; (6) Production: open wells for production, record the trends of data such as liquid production, oil production and gas production. 6 . The application of the enhanced foam plugging agent in oil reservoir profile control according to claim 1 , wherein, in the process of injecting into the formation, the enhanced foam plugging agent only spreads to the high-permeability area and does not pollute the low-permeability area. 7 .

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