CN108531153B - High-temperature-resistant petroleum resin dispersoid blocking agent and preparation method and application thereof - Google Patents

Abstract

The invention provides a high-temperature resistant petroleum resin dispersoid blocking agent, a preparation method and application thereof, which are prepared from the following raw materials in percentage by weight: 5 to 15 percent of petroleum resin, 0.1 to 0.5 percent of surfactant, 0.05 to 0.4 percent of cationic polyacrylamide, 0.1 to 0.4 percent of triethanolamine, 0.1 to 0.5 percent of sodium bisulfite, 1 to 3 percent of silicon dioxide nano particles, 0.1 to 0.5 percent of pH regulator and the balance of water; the sum of the mass percentages of the raw materials is 100 percent. After the plugging agent is injected into a stratum, cationic polyacrylamide in the plugging agent can perform modification reaction at high temperature of the stratum to obtain sulfonic group modified cationic polyacrylamide, so that the high temperature resistance, salt resistance and stability of the petroleum resin dispersion plugging agent can be effectively improved, and the petroleum resin can smoothly reach the deep part of an oil reservoir and an oil well to realize high-temperature effective water plugging.

Description

A kind of high temperature resistant petroleum resin dispersion blocking agent and its preparation method and application

technical field

The invention relates to a high temperature resistant petroleum resin dispersion plugging agent, a preparation method and application thereof, and belongs to the technical field of oilfield chemistry.

Background technique

Oil well water production is an important phenomenon in the process of oil production. The reasons for oil well water production are generally: (1) injection water and edge water propulsion; (2) bottom water propulsion; (3) upper layer water and lower layer water intrusion; (4) ) interlayer water enters, and interlayer water refers to the interlayer water between the oil layers, that is, the water layer between the upper and lower oil layers. There are many hazards caused by water production in oil wells, such as: (1) sand production in oil wells, which damages the cemented and loose sandstone layers, resulting in sand production, and in severe cases, oil layer collapse or oil well production shutdown; With the continuous increase of the water volume, the weight of the wellbore liquid column increases, resulting in the failure of the self-blowing well; (3) the formation of dead oil areas, the premature water breakthrough of the oil wells will lead to the formation of some dead oil areas underground, which greatly reduces the oil reservoir. (4) Equipment corrosion will corrode oil well equipment and damage well structure, increase the task and difficulty of workover operations, and shorten the life of oil wells; (5) Increase oil production costs, increase ground water injection, and correspondingly increase the surface Water usage, usage of water injection facilities and electricity consumption.

Profile control and water plugging, as a routine measure for water control in oilfields, can increase the reservoir pressure, increase the sweep coefficient of injected water, and thus improve oil recovery. However, with the development of the oil field, the characteristics and environment of the oil reservoir are constantly changing, especially after the oil reservoir enters the high water cut production period, the long-term water flooding makes the development contradiction of the oil reservoir more prominent. technology is always behind the needs of oilfield development. For some high-temperature deep well reservoirs in my country, the reservoir temperature is as high as 130°C. For the above oilfields, polyacrylamide-based high-temperature gel plugging agents and solid particle plugging agents are commonly used in the prior art. The polyacrylamide high-temperature jelly plugging agent takes too long to gel, which is easy to cause blockage in the area near the wellbore, poor jelly stability under high temperature, and the water-based jelly system enters the oil layer during the operation, which is easy to cause damage. The solid particle plugging agent is mainly composed of inorganic solid particles such as cement and fly ash and other organic particles. Phase permeability is used to block the high permeability layer and the water outlet layer to achieve the purpose of adjusting the water absorption profile and plugging water, but this is a non-selective plugging agent, and this granular plugging agent has poor stability and is easy to agglomerate and damage. Reservoir, only suitable for plugging near wellbore. In addition, for high temperature deep well oil reservoirs, Chinese patent document CN101423753A also discloses a special profile control agent for thermal recovery of heavy oil wells. The profile control agent is composed of the following raw materials: anionic polyacrylamide, alkylphenol polyoxyethylene ether, petroleum resin, urotropine, xylene, caustic soda and water. The profile control agent of the invention can be used for a long time at a temperature of 200 ° C and a salinity of more than 20,000 mg/L, but it is unknown whether the profile control agent can be used in a higher salinity condition. The gelling time of amide is fast, the overall stability of the profile control agent emulsion is not good, it is easy to cause blockage in the area near the wellbore, and there are defects of polyacrylamide high-temperature gel blocking agent; and the xylene in the raw material used is a toxic substance, which pollutes the environment. Long-term exposure is also very harmful to the human body, and it is a controlled drug in the oil field.

Therefore, a new type of temperature-resistant and salt-resistant plugging agent was developed, which has strong stability under high temperature and high salinity, can smoothly reach the deep part of the oil well to achieve water plugging, and has oil-water selectivity and excellent plugging effect. It is of great significance to solve the problem of oil well water production in high temperature reservoirs.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the present invention provides a high temperature resistant petroleum resin dispersion blocking agent. After the plugging agent of the present invention is injected into the formation, the cationic polyacrylamide in the cationic polyacrylamide will undergo a modification reaction at the high temperature of the formation, and a sulfonic acid group connected with carbon atoms is introduced to obtain a cationic polyacrylamide modified by the sulfonic acid group. The cationic polyacrylamide has low hydrolysis degree and good thermal stability. It can effectively disperse and stabilize the petroleum resin suspension, and effectively improve the high temperature resistance, salt resistance and stability of the petroleum resin dispersion blocking agent, so that the petroleum resin can be It successfully reached the deep part of the oil well in the reservoir to achieve water plugging. The plugging agent of the invention has excellent temperature resistance and salt resistance, good dispersion stability under high temperature and high salinity, and has oil-water selectivity, and can play an effective plugging role in a high temperature oil reservoir environment of 130°C.

The invention also provides a preparation method and application of a high temperature resistant petroleum resin dispersion blocking agent. The preparation method of the invention is simple, and the modified cationic polyacrylamide is reacted after being injected into the formation, which avoids a series of complex synthesis processes on the ground and reduces costs and dangers (mainly personal safety).

The technical scheme of the present invention is as follows:

A high temperature resistant petroleum resin dispersion plugging agent, comprising the following raw materials by mass percentage: 5% to 15% of petroleum resin, 0.1% to 0.5% of surfactant, 0.05% to 0.4% of cationic polyacrylamide, and 0.1% of triethanolamine %～0.4%, sodium bisulfite 0.1%-0.5%, silica nanoparticles 1%～3%, pH adjuster 0.1%～0.5%, the balance is water; the sum of the mass percentages of each raw material is 100% .

Preferably according to the present invention, the petroleum resin dispersion plugging agent is made from the following percentages of raw materials: 5% to 10% of petroleum resin, 0.1% to 0.3% of surfactant, 0.05% to 0.3% of cationic polyacrylamide, Triethanolamine 0.1%-0.2%, sodium bisulfite 0.15%-0.4%, silica nanoparticles 1%-2%, pH adjuster 0.2%-0.4%, the balance is water; the sum of the mass percentages of each raw material is 100%.

Preferably according to the present invention, the petroleum resin is C5 or C9 petroleum resin, the relative molecular mass is 1000-5000, and the softening point is 100°C-120°C.

Preferably according to the present invention, the surfactant is an amphoteric surfactant; preferably, the surfactant is octadecyl dimethyl ammonium oxide.

Preferably according to the present invention, the weight-average molecular weight of the cationic polyacrylamide is 700×10 ⁴ to 800×10 ⁴ , and the cationic degree is 20-40%.

Preferably according to the present invention, the particle size of the silica nanoparticles is 10-14 nm.

Preferably according to the present invention, the pH adjusting agent is sodium hydroxide.

Preferably according to the present invention, the water is formation water with a salinity of (20-25)×10 ⁴ mg/L, wherein the Na ⁺ content is (7-8)×10 ⁴ mg/L, and the Ca ²⁺ content (0.5-1.5)×10 ⁴ mg/L, Mg ²⁺ content (0.1-0.2)×10 ⁴ mg/L, HCO ₃ ^-content (0.01-0.02)×10 ⁴ mg/L, Cl ^-content is (13-14)×10 ⁴ mg/L; preferably, the water is formation water with a salinity of 22.3×10 ⁴ mg/L, wherein the Na ⁺ content is 7.3×10 ⁴ mg/L, Ca ^{2 The +} content was 1.1×10 ⁴ mg/L, the Mg ²⁺ content was 0.15×10 ⁴ mg/L, the HCO ₃ ^- content was 0.018×10 ⁴ mg/L, and the Cl ^- content was 13.7×10 ⁴ mg/L.

The preparation method of the above-mentioned high temperature resistant petroleum resin dispersion blocking agent, comprising the steps:

Dissolve the surfactant in water, add petroleum resin powder, and fully disperse the petroleum resin dispersion; dissolve the cationic polyacrylamide, triethanolamine, sodium bisulfite and pH adjuster in water, add silica nanoparticles, and fully Disperse to obtain a mixed solution; mix the mixed solution and the petroleum resin dispersion evenly to obtain the petroleum resin dispersion blocking agent.

According to the preferred embodiment of the present invention, the petroleum resin powder adopts a freezing pulverization method, that is, using liquid nitrogen as a cold source, the petroleum resin powder is pulverized into a powder with a particle size of 0.5 micrometers to 10 micrometers.

Preferably according to the present invention, the mass concentration of the petroleum resin in the petroleum resin dispersion liquid is 25-30%.

The above-mentioned high temperature resistant petroleum resin dispersion plugging agent is used for profile control and water plugging of oil wells in high temperature oil reservoirs.

According to the preferred method of the present invention, the application method is as follows: injecting the petroleum resin dispersion plugging agent into the high-temperature oil reservoir oil well, and as the temperature in the oil reservoir oil well gradually increases from top to bottom, the The sulfonic acid group modification reaction of the cationic polyacrylamide with triethanolamine and sodium bisulfite obtains the sulfonic acid group modified cationic polyacrylamide, and the weight average molecular weight of the sulfonic acid group modified cationic polyacrylamide is 710×10 ⁴ ~810×10 ⁴ , it can effectively disperse and stabilize the petroleum resin suspension, effectively improve the high temperature resistance, salt resistance and stability of the petroleum resin dispersion plugging agent, so as to achieve the injection of the petroleum resin dispersion plugging agent into the oil reservoir oil well The purpose of not blocking the near-well zone in the deep part, the petroleum resin after entering the deep part of the oil well begins to soften and become sticky, so as to coalesce and block the water flow channel to achieve the purpose of water blocking.

The technical characteristics and beneficial effects of the present invention are as follows:

1. Polyacrylamide is easily hydrolyzed at high temperature and high salt, and the solubility of polyacrylamide under thermal oxidation and high-salt conditions will deteriorate, resulting in poor stability; in order to improve the above defects, the present invention utilizes cationic polymerization. Carbocations are easy to combine, transfer, and isomerize with alkaline substances under the action of high temperature. Triethanolamine, sodium bisulfite and silica nanoparticles are added to cationic polyacrylamide. After the agent enters the formation, the temperature gradually rises. Under the conditions of high temperature and strong alkali, the cationic polyacrylamide first reacts with triethanolamine, hydroxymethyl replaces one hydrogen on the amide group, and the product reacts with sodium bisulfite, so that Part of the hydroxyl groups on the hydroxymethyl group are replaced by sodium sulfonate groups, which improves the high temperature stability of the product and reduces its degree of hydrolysis under the action of nanoparticles. The final modified cationic polyacrylamide (average molecular weight is 700×10 ⁴ ～800×10 ⁴ ) The temperature resistance is greatly improved and the stability is strong. Under the wetting action of the surfactant, the petroleum resin is dispersed in the surfactant solution. When the modified cationic polyacrylamide is formed, the dispersion stability and the temperature and salt resistance of the petroleum resin dispersion are greatly improved. The defects of other granular plugging agents are improved. After the petroleum resin dispersion prepared by the invention is injected into the formation, due to the existence of the modified cationic polyacrylamide, combined with the surfactant auxiliary, the petroleum resin suspension has excellent temperature resistance and salt resistance, good dispersion stability, and can reach the oil smoothly. It can effectively block the deep oil wells in the high temperature reservoir environment of 130 °C.

2. The petroleum resin dispersion plugging agent of the present invention has good stability under high temperature and high salt, and can be injected into the deep part of the oil well in the oil reservoir without blocking the near-well zone. The petroleum resin after entering the deep part of the oil well in the oil reservoir begins to soften and become sticky to coalesce Block the water flow channel to achieve the purpose of blocking water. Petroleum resin has high viscosity at formation temperature. Using its high viscosity after softening and coalescing to liquid state, it can be adhered and adsorbed on the surface of pore rock to seal the pores of the formation, and the sealing effect is good under high temperature and high salt. The plugging time is long; the petroleum resin in the present invention is insoluble in ethanol and water, but can be dissolved in oil, which can realize selective water plugging but not oil plugging, and can effectively plug high-permeability layers. The water-based gel has no oil-water selectivity, and the polymer forms gel in the pores under the action of the cross-linking agent. Compared with the petroleum resin, the sealing effect on the water layer is poor. The formation can cause contamination, which can plug the oil layer, but it will reduce the recovery rate of water flooding.

3. The raw materials of the present invention are cheap and easy to obtain, and the preparation method is simple; after the petroleum resin dispersion plugging agent of the present invention is injected into the formation, the cationic polyacrylamide in it reacts under the action of the high temperature of the formation to produce modified cationic polyacrylamide, which avoids the occurrence of the cationic polyacrylamide on the ground. A series of complex synthesis processes reduce costs and risks (mainly personal safety).

4. The petroleum resin dispersion prepared by the present invention has good stability after high temperature reaction, and the dispersion stability time can reach 22h at high temperature and high salinity. The blocking agent of the present invention also has a high blocking rate, At high salinity (22×10 ⁴ mg/L) and high temperature (130°C), the blocking rate is as high as 98.3%.

Detailed ways

The present invention will be further described below through specific embodiments, but not limited thereto.

The raw materials used in the examples are all conventional raw materials, which are commercially available; the methods are all prior art unless otherwise specified.

In the embodiment, the petroleum resin used is C9 petroleum resin, available from Guangzhou Liben Co., Ltd., the average relative molecular mass is 3500, and the softening point is 120°C ^; 30%, available from Anhui Jucheng Fine Chemical Co., Ltd.; the silica nanoparticles used have an average particle size of 12 nm, available from Sigma-Aldrich.

The water used is formation water with a salinity of 22.3×10 ⁴ mg/L, of which the Na ⁺ content is 7.3×10 ⁴ mg/L, the Ca ²⁺ content is 1.1×10 ⁴ mg/L, and the Mg ²⁺ content is 0.15 ×10 ⁴ mg/L, HCO ₃ ^-content is 0.018×10 ⁴ mg/L, Cl ^-content is 13.7×10 ⁴ mg/L.

The petroleum resin powder used: adopt the freezing pulverization method, that is, use liquid nitrogen as the cold source to pulverize the petroleum resin into petroleum resin powder with a particle size of 0.5 micrometers to 2 micrometers.

Example 1

A high-temperature resistant petroleum resin dispersion blocking agent, comprising the following percentages of raw materials: C9 petroleum resin 10%, octadecyl dimethyl ammonium oxide 0.2%, cationic polyacrylamide 0.1%, triethanolamine 0.2%, 0.2% of sodium hydrogen sulfate, 1.1% of silica nanoparticles, 0.3% of sodium hydroxide, and the balance of water; the sum of the mass percentages of each raw material is 100%.

The preparation method of the above-mentioned high temperature resistant petroleum resin dispersion blocking agent, comprising the steps:

Add 0.2 g of octadecyl dimethyl ammonium oxide to 25 g of formation water with a salinity of 22.3×10 ⁴ mg/L, fully dissolve and stir evenly, slowly add 10 g of petroleum resin powder (the addition process is controlled within 5-10 minutes), Fully stir and disperse evenly to obtain mixed solution A; add 0.2 g of sodium bisulfite and 0.2 g of triethanolamine to 13 g of formation water with a salinity of 22.3×10 ⁴ mg/L, stir evenly, make it fully dissolved, and add 50 g of mass concentration It is a 0.2% cationic polyacrylamide aqueous solution, and 0.3 g of sodium hydroxide and 1.1 g of silica nanoparticles are added, and the mixture is fully dispersed and stirred to obtain a mixed solution B; the mixed solution A and the mixed solution B are fully mixed to obtain the petroleum resin. Dispersion blocking agent.

Simulate oil well conditions in high temperature oil reservoirs: stir the above obtained petroleum resin dispersion plugging agent at 90°C for 5 hours to obtain a plugging agent after high temperature treatment. In the plugging agent, cationic polyacrylamide undergoes modification reaction to generate sulfonic acid group-modified cationic polyacrylamide, and its weight average molecular weight is 750×10 ⁴ ; It is still stably dispersed and no coalescence occurs, indicating that the sulfonic acid group-modified cationic polyacrylamide formed by the plugging agent of the present invention after use can improve the stability of the petroleum resin under high temperature and high salt conditions.

Example 2

A high temperature resistant petroleum resin dispersion blocking agent, comprising the following percentages of raw materials: C9 petroleum resin 10%, octadecyl dimethyl ammonium oxide 0.25%, cationic polyacrylamide 0.1%, triethanolamine 0.2%, 0.2% of sodium hydrogen sulfate, 1.1% of silica nanoparticles, 0.3% of sodium hydroxide, and the balance of water; the sum of the mass percentages of each raw material is 100%.

The preparation method of the above-mentioned high temperature resistant petroleum resin dispersion blocking agent is consistent with Example 1, the difference is: the consumption of the surfactant octadecyl dimethyl ammonium oxide is 0.25g, and other steps and conditions are the same as those in Example 1. same.

Simulate oil well conditions in high temperature oil reservoirs: stir the above obtained petroleum resin dispersion plugging agent at 90°C for 5 hours to obtain a plugging agent after high temperature treatment. In the plugging agent, the cationic polyacrylamide undergoes a modification reaction to form a sulfonic acid group-modified cationic polyacrylamide, and its weight average molecular weight is 750×10 ⁴ ; the above-mentioned high-temperature-treated plugging agent is placed at 130 ° C for 16 hours, and the petroleum resin It is still stably dispersed and no coalescence occurs, indicating that when the amount of surfactant is within the scope of the present invention, increasing the amount of surfactant can improve the stability of petroleum resin under high temperature and high salt conditions.

Example 3

A high temperature resistant petroleum resin dispersion blocking agent, comprising the following percentages of raw materials: C9 petroleum resin 10%, octadecyl dimethyl ammonium oxide 0.3%, cationic polyacrylamide 0.1%, triethanolamine 0.2%, 0.2% of sodium hydrogen sulfate, 1.1% of silica nanoparticles, 0.3% of sodium hydroxide, and the balance of water; the sum of the mass percentages of each raw material is 100%.

The preparation method of the above-mentioned high temperature resistant petroleum resin dispersion blocking agent is consistent with Example 1, the difference is: the consumption of the surfactant octadecyl dimethyl ammonium oxide is 0.3g, and other steps and conditions are the same as those in Example 1. same.

Simulate oil well conditions in high temperature oil reservoirs: stir the above obtained petroleum resin dispersion plugging agent at 90°C for 5 hours to obtain a plugging agent after high temperature treatment. In the plugging agent, the cationic polyacrylamide undergoes a modification reaction to form a sulfonic acid group-modified cationic polyacrylamide, and its weight average molecular weight is 750×10 ⁴ ; the above-mentioned high-temperature-treated plugging agent is placed at 130 ° C for 17 hours, and the petroleum resin It is still stably dispersed and no coalescence occurs, indicating that when the amount of surfactant is within the scope of the present invention, increasing the amount of surfactant can improve the stability of petroleum resin under high temperature and high salt conditions.

Example 4

A high temperature resistant petroleum resin dispersion plugging agent, comprising the following percentages of raw materials: C9 petroleum resin 10%, octadecyl dimethyl ammonium oxide 0.2%, cationic polyacrylamide 0.15%, triethanolamine 0.2%, 0.2% of sodium hydrogen sulfate, 1.1% of silica nanoparticles, 0.3% of sodium hydroxide, and the balance of water; the sum of the mass percentages of each raw material is 100%.

The preparation method of the above-mentioned high temperature resistant petroleum resin dispersion blocking agent is the same as that in Example 1, the difference is that 50 g of cationic polyacrylamide aqueous solution with a mass concentration of 0.3% is added, and other steps and conditions are the same as those in Example 1.

Simulate oil well conditions in high temperature oil reservoirs: stir the above obtained petroleum resin dispersion plugging agent at 90°C for 5 hours to obtain a plugging agent after high temperature treatment. In the plugging agent, the cationic polyacrylamide undergoes a modification reaction to form a sulfonic acid group-modified cationic polyacrylamide, and its weight average molecular weight is 750×10 ⁴ ; the above-mentioned high-temperature-treated plugging agent is placed at 130 ℃ for 18 hours, and the petroleum resin It is still stably dispersed and no agglomeration occurs, indicating that when the dosage of cationic polyacrylamide is within the scope of the present invention, increasing its dosage can improve the stability of petroleum resin under high temperature and high salt conditions.

Example 5

A high temperature resistant petroleum resin dispersion blocking agent, comprising the following percentages of raw materials: C9 petroleum resin 10%, octadecyl dimethyl ammonium oxide 0.25%, cationic polyacrylamide 0.3%, triethanolamine 0.2%, 0.2% of sodium hydrogen sulfate, 1.1% of silica nanoparticles, 0.3% of sodium hydroxide, and the balance of water; the sum of the mass percentages of each raw material is 100%.

The preparation method of the above-mentioned high temperature resistant petroleum resin dispersion plugging agent is the same as that of Example 2, the difference is that 50g of cationic polyacrylamide aqueous solution with a mass concentration of 0.6% is added, and other steps and conditions are the same as those of Example 2.

Simulate oil well conditions in high temperature oil reservoirs: stir the above obtained petroleum resin dispersion plugging agent at 90°C for 5 hours to obtain a plugging agent after high temperature treatment. In the plugging agent, cationic polyacrylamide undergoes a modification reaction to generate sulfonic acid group-modified cationic polyacrylamide, and its weight average molecular weight is 750×10 ⁴ ; It is still stably dispersed and no agglomeration occurs, indicating that when the dosage of cationic polyacrylamide is within the scope of the present invention, increasing its dosage can improve the stability of petroleum resin under high temperature and high salt conditions.

Example 6

A high temperature resistant petroleum resin dispersion blocking agent, comprising the following percentages of raw materials: C9 petroleum resin 10%, octadecyl dimethyl ammonium oxide 0.3%, cationic polyacrylamide 0.15%, triethanolamine 0.2%, 0.2% of sodium hydrogen sulfate, 1.1% of silica nanoparticles, 0.3% of sodium hydroxide, and the balance of water; the sum of the mass percentages of each raw material is 100%.

The preparation method of the above-mentioned high temperature resistant petroleum resin dispersion blocking agent is the same as that in Example 3, the difference is that 50 g of cationic polyacrylamide aqueous solution with a mass concentration of 0.3% is added, and other steps and conditions are the same as those in Example 3.

Simulate oil well conditions in high temperature oil reservoirs: stir the above obtained petroleum resin dispersion plugging agent at 90°C for 5 hours to obtain a plugging agent after high temperature treatment. In the plugging agent, the cationic polyacrylamide undergoes a modification reaction to form a sulfonic acid group-modified cationic polyacrylamide, and its weight average molecular weight is 750×10 ⁴ ; the above-mentioned high-temperature-treated plugging agent is placed at 130 ℃ for 18 hours, and the petroleum resin It is still stably dispersed and no coalescence occurs, indicating that when the dosage of cationic polyacrylamide is within the scope of the present invention, increasing its dosage can improve the stability of the petroleum resin under high temperature and high salt conditions.

Comparative Example 1

A preparation method of a plugging agent is as described in Example 1, except that sodium hydroxide is not added, and other steps and conditions are consistent with Example 1.

Simulation of high temperature reservoir oil well conditions: the above obtained plugging agent was stirred at 90°C for 5 hours to obtain the plugging agent after high temperature treatment. After the above-mentioned high-temperature-treated plugging agent was placed at 130 °C for 3 hours, the petroleum resin coalesced, indicating that the modified cationic polyacrylamide could effectively improve the stability of the petroleum resin under high temperature and high salt.

The plugging agent prepared in this comparative example has a short stable time and cannot be injected into the deep part of the oil well in the oil reservoir, and premature coalescence occurs, blocking the area near the wellbore.

Comparative Example 2

Add 0.05g of resorcinol and 0.1g of urotropine to 50g of tap water, stir evenly to fully dissolve or disperse, and then add 50g of anionic polypropylene with a mass concentration of 15% and a degree of hydrolysis of 20% prepared with tap water. The amide solution is mixed with the above solution, stirred evenly, and the obtained gel-forming solution is placed in an ampoule bottle and sealed. Then it was placed in an oven at 130°C for 20, 60, and 90 days, respectively, and the dehydration rate of the jelly in the ampoule was calculated.

Table 1 Dehydration rate of water-based jelly

In this comparative example, the dehydration of the jelly is more serious, which will affect its plugging ability in the formation and greatly reduce its plugging ability.

Application example

Blocking ability inspection:

Taking the blocking agent after high temperature treatment obtained in "Example 1-6" as the research object, the blocking ability of the petroleum resin dispersion provided by the present invention was investigated. Taking the glue-forming liquid obtained in "Comparative Example 2" as the research object, the blocking ability of the polyacrylamide-based plugging agent was investigated and used as a comparison. The specific simulation experiment process is as follows: seven sand-packing pipes with an inner diameter of 2.5cm and a length of 20cm are filled with quartz sand grains to obtain simulated cores, which are denoted as 1#, 2#, 3#, 4#, 5#, 6#, 7#, the original permeability k ₁ is obtained after the water is flooded to a stable pressure, and then the plugging agent after high temperature treatment in "Example 1-6" and the gel-forming liquid obtained in "Comparative Example 2" are reversely injected into the above-mentioned In the seven sand-packing pipes, the injection volume is 0.25PV (core pore volume), and then 0.25PV of water is injected for displacement (the purpose of injection is to displace the plugging agent in the middle of the sand-packing pipe, simulating the injection into the deep formation under the formation conditions) , and then put the seven sand-packing pipes in an oven at 130 °C for 30 days and 80 days, respectively, and finally water-flood until the pressure is stable, and measure the permeability k _{2 of} the simulated core after plugging. -k ₂ )/k ₁ *100%, calculate the core plugging rate E, and the experimental results are shown in the following table.

Table 2 Plugging ability test data

The above experimental results show that: the petroleum resin dispersion plugging agent provided by the present invention has excellent plugging performance under the high temperature condition of 130 ° C. Compared with Comparative Example 2, whether it is the plugging effect after 20 days or the plugging effect after 90 days. , are not as good as the plugging effect of the petroleum resin dispersion plugging agent of the present invention, and the petroleum resin dispersion plugging agent has a relatively stable plugging effect for a long time.

Claims (7)

1. A high-temperature resistant petroleum resin dispersoid plugging agent is prepared from the following raw materials in percentage by weight: 5 to 15 percent of petroleum resin, 0.1 to 0.5 percent of surfactant, 0.05 to 0.4 percent of cationic polyacrylamide, 0.1 to 0.4 percent of triethanolamine, 0.1 to 0.5 percent of sodium bisulfite, 1 to 3 percent of silicon dioxide nano particles, 0.1 to 0.5 percent of pH regulator and the balance of water; the sum of the mass percentages of the raw materials is 100 percent;

the petroleum resin is C5 or C9 petroleum resin, the relative molecular mass is 1000-5000, the softening point is 100-120 ℃, the surfactant is octadecyl dimethyl ammonium oxide, and the weight-average molecular weight of the cationic polyacrylamide is 700 × 10⁴～800×10⁴The cation degree is 20-40%, the particle size of the silicon dioxide nano particles is 10-14nm, the pH regulator is sodium hydroxide, and the water has the mineralization degree of (20-25) × 10⁴mg/L of formation water, wherein Na⁺The content is (7-8) × 10⁴mg/L、Ca²⁺The content of the active component is (0.5-1.5) × 10⁴mg/L、Mg²⁺The content of the active component is (0.1-0.2) × 10⁴mg/L、HCO₃ ^-The content of the extract is (0.01-0.02) × 10⁴mg/L、Cl^-The content is (13-14) × 10⁴mg/L。

2. The high-temperature resistant petroleum resin dispersion plugging agent according to claim 1, which is prepared from the following raw materials in percentage by weight: 5 to 10 percent of petroleum resin, 0.1 to 0.3 percent of surfactant, 0.05 to 0.3 percent of cationic polyacrylamide, 0.1 to 0.2 percent of triethanolamine, 0.15 to 0.4 percent of sodium bisulfite, 1 to 2 percent of silicon dioxide nano particles, 0.2 to 0.4 percent of pH regulator and the balance of water; the sum of the mass percentages of the raw materials is 100 percent.

3. The high temperature resistant petroleum resin dispersion plugging agent of claim 1, wherein said water has a degree of mineralization of 22.3 × 10⁴mg/L of formation water, wherein Na⁺The content is 7.3 × 10⁴mg/L、Ca²⁺The content is 1.1 × 10⁴mg/L、Mg²⁺The content is 0.15 × 10⁴mg/L、HCO₃ ^-The content is 0.018 × 10⁴mg/L、Cl^-The content is 13.7 × 10⁴mg/L。

4. The method of preparing a high temperature resistant petroleum resin dispersion block agent of any one of claims 1 to 3, comprising the steps of:

dissolving a surfactant in water, adding petroleum resin powder, and fully dispersing to obtain a petroleum resin dispersion liquid; dissolving cationic polyacrylamide, triethanolamine, sodium bisulfite and a pH regulator in water, adding silicon dioxide nanoparticles, and fully dispersing to obtain a mixed solution; and uniformly mixing the mixed solution and the petroleum resin dispersion solution to obtain the petroleum resin dispersion plugging agent.

5. The method for preparing the high temperature resistant petroleum resin dispersion plugging agent according to claim 4, wherein the petroleum resin powder is obtained by crushing petroleum resin into powder with a particle size of 0.5-10 microns by using a freezing and crushing method, namely using liquid nitrogen as a cold source.

6. The method for preparing the high-temperature resistant petroleum resin dispersion plugging agent according to claim 4, wherein the mass concentration of the petroleum resin in the petroleum resin dispersion liquid is 25-30%.

7. The use of the high temperature resistant petroleum resin dispersion plugging agent of any one of claims 1-3 in high temperature reservoir oil wells for profile control and water plugging;

injecting the petroleum resin dispersion plugging agent into a high-temperature oil reservoir oil well, and gradually increasing the temperature from top to bottom in the oil reservoir oil well to obtain sulfonic modified cationic polyacrylamide through sulfonic modification reaction of cationic polyacrylamide in the petroleum resin dispersion plugging agent, triethanolamine and sodium bisulfite, wherein the weight average molecular weight of the sulfonic modified cationic polyacrylamide is 710 × 10⁴～810×10⁴The petroleum resin dispersion plugging agent can effectively disperse and stabilize petroleum resin suspension, and effectively improve the high temperature resistance, salt resistance and stability of the petroleum resin dispersion plugging agent, thereby achieving the purpose of injecting the petroleum resin dispersion plugging agent into the deep part of an oil reservoir oil well without blocking a near well zone and entering the oilThe petroleum resin at the deep part of the oil-storing well begins to soften and become sticky, so that the water flow channel is coalesced and blocked to achieve the purpose of water blocking.