Three-phase foam system suitable for profile control and flooding of high-temperature and high-salt oil reservoirs and preparation method thereof

Abstract

The application provides a three-phase foam system suitable for profile control and flooding of high-temperature and high-salt oil reservoirs and a preparation method thereof, and belongs to the technical field of foam oil displacement for improving recovery efficiency. The betaine surfactant with a proper carbon chain length is selected to ensure that the system has sufficient foaming rate and good stability, and the sulfonated phenolic aldehyde resin with a proper sulfonation degree is selected to enable it to precipitate and form particles in high-salinity brine to further stabilize the foam, so that the three-phase foam system constructed has excellent temperature resistance and salt resistance, the foaming volume thereof is more than 390 mL in indoor evaluation, the foam half-life is more than 120 min, and the liquid precipitation half-life is more than 7 min. Meanwhile, core displacement experiments show that the preferred foam system of the application has a foam resistance factor greater than 90 when gas and liquid are injected simultaneously, and has a good effect of plugging and controlling gas channeling under the condition of 130 DEG C and a salt content of 220000 mg / L.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of foam flooding for enhanced oil recovery, and particularly relates to a three-phase foam system suitable for profile control and flooding of high-temperature and high-salinity reservoirs and a preparation method thereof. BACKGROUND

[0002] Water flooding is the most commonly used oilfield development technology in the petroleum industry. However, due to the heterogeneity of the formation, the water injection development oilfield will gradually enter the high water cut or even the ultra-high water cut stage, and the water flooding efficiency is extremely low. Therefore, it is necessary to combine the enhanced oil recovery technology to control water and stabilize oil and to improve the reservoir producing degree as much as possible. The foam has the characteristics of high apparent viscosity, strong selective plugging of "blocking large but not small, blocking water but not oil", and reducing oil-water interfacial tension, which can effectively improve the formation oil-water mobility ratio, block high permeability areas, expand swept volume, and effectively improve the recovery. However, the foam system is a thermodynamically unstable system. The conventional two-phase foam is composed of a surfactant solution and a gas (nitrogen, air or carbon dioxide), which is generally only suitable for medium-low temperature and medium-low salinity reservoirs. The development of a foam system suitable for high-temperature and high-salinity reservoirs is a great challenge. Therefore, people construct a temperature-resistant and salt-resistant foam system by optimizing the surfactant, and introduce polymers, nanoparticles or clay, fly ash and other solid particles to construct a three-phase foam to further improve its adaptability in high-temperature and high-salinity reservoirs.

[0003] Chinese patent CN 107841302 A discloses a modified nano-smithkline three-phase foam profile control and flooding system and a preparation method thereof. The foam system is composed of a liquid phase composed of 0.15%-0.35% of a foaming agent (a combination of one or both of alkyl sulfopropyl betaine and alkyl amide propyl betaine), 0.04%-0.1% of a foam stabilizer (modified nano-graphite particles) and the balance of water, and a gas phase in a ratio of 1:(1-3). The system can effectively reduce the oil-water interfacial tension at 80℃, has good foaming efficiency and stability, and has good mobility control ability, but the applicable reservoir salinity conditions are not known.

[0004] Chinese patent CN 105038756 B discloses a carbon dioxide foam system with hydrophilic nanoparticles for oil displacement and a preparation method thereof. The system is composed of 0.1-0.3 parts of a nonionic surfactant, 1-2 parts of hydrophilic nanoparticles, 0.01-0.2 parts of an inorganic salt, 0.2-0.8 parts of carbon dioxide and 100 parts of water. The system has good temperature resistance and salt tolerance, can resist 80℃ and 4000mg / L of salt, and has lower cost and better dispersion stability than the foaming agent with hydrophobic particles.

[0005] Chinese patent CN 103980873 B discloses a kind of three-phase foam composite oil displacement system and its application, the system is by one or combination of tetradecyl hydroxysulfobetaine, cocamide propyl betaine surfactant as foaming agent, the composite system of high molecular polymer and gel dispersion as foam stabilizer with water composition liquid phase and nitrogen, carbon dioxide or natural gas gas phase with 1-1.5 gas-liquid ratio composition, with higher liquid film strength and viscoelasticity, can have good enhanced recovery effect under the condition of 90 DEG C, 9600 mg / L.

[0006] Chinese patent CN 109971443 B discloses a kind of three-phase foam channeling sealing agent and its preparation method, heavy oil exploitation method for plugging, the channeling sealing agent is by 0.3% sodium dodecyl sulfate as foaming agent, 3%-4% alpha-starch, 3%-4% acrylamide, 0.01%-0.02% initiator, 0.1%-0.15% crosslinking agent, 0.1%-0.2% control agent, 0.5%-30% solid particles and water composition, good temperature resistance, high plugging efficiency, can be used for plugging gas channeling channel.

[0007] Chinese patent CN 112226227 B discloses an aerogel particle-carbon dioxide-water-based three-phase foam system, which is composed of carbon dioxide, liquid phase and aerogel particles, can form a selective plugging effect of "water plugging but not oil plugging" in the dominant channel of the reservoir, and enhances the oil displacement efficiency and sweep efficiency of the water-based carbon dioxide foam.

[0008] Chinese patent CN 109517592 B discloses an ultra-high characteristic value three-phase flue gas foam for oil and gas fields and a preparation method thereof, the foam system is composed of flue gas as gas phase, liquid phase composed of surfactant, pH value regulator and inorganic salt aqueous solution, and solid phase composed of fly ash and nano silicon dioxide, which can adapt to high temperature of 230 DEG C, has good temperature resistance and pressure resistance, and can be used for development operation of high temperature and high pressure oil and gas layers.

[0009] It can be seen that the performance and plugging effect of three-phase foam are significantly improved compared with ordinary foam, and the temperature resistance and salt tolerance are also enhanced, but there are still few foam systems that can resist temperature of 130 DEG C and salinity of 220000 mg / L. High temperature can cause the decomposition of polymer-based strengthening agent for enhancing the viscoelasticity and strength of foam liquid film, and the agent shrinks into a cluster, which destroys the stability of foam. In high-salinity reservoir environment, nano particles, clay and other solid-phase materials for strengthening foam can aggregate or flocculate, which significantly affects the stability of foam, and even destroys the stability of foam. Therefore, it is necessary to develop solid-phase particles that can be stably and uniformly dispersed under high temperature and high salinity conditions, and to construct three-phase foam that is stable under high temperature and high salinity. SUMMARY

[0010] This invention addresses the problems existing in the prior art by providing a three-phase foam system suitable for regulating and driving high-temperature, high-salinity oil reservoirs, and its preparation method. The three-phase foam system of this invention can withstand temperatures up to 130℃ and salinity up to 220,000 mg / L, exhibiting good foaming rate and stability. It can be used in the Tarim Basin's high-temperature, high-salinity oil reservoirs to regulate and plug gas channeling, thereby improving gas injection recovery.

[0011] To achieve the above objectives, in a first aspect, this application provides a three-phase foam system suitable for high-temperature, high-salinity reservoir regulation and flooding, comprising a liquid phase and a gas phase consisting of 0.05%-0.6% by mass of a foaming agent, 0.05%-0.3% by mass of a particulate foam stabilizer, and the balance being brine; wherein the foaming agent is hydroxysulfonated betaine; and the particulate foam stabilizer is nano-micron-sized solid-phase foam-stabilizing particles formed by the precipitation of sulfonated phenolic resin in high-salinity brine; wherein the degree of sulfonation of the sulfonated phenolic resin is 40%-65%.

[0012] Preferably, the foaming agent is selected from one or more betaine surfactants such as lauramidopropyl hydroxysulfonate betaine, oleamide propyl hydroxysulfonate betaine, and erucamide propyl hydroxysulfonate betaine, and more preferably lauramidopropyl hydroxysulfonate betaine.

[0013] Preferably, the sulfonated phenolic resin has an average molecular weight of 100,000-120,000.

[0014] Preferably, the degree of sulfonation of the sulfonated phenolic resin is 40%-50%, and most preferably 50%.

[0015] Preferably, the brine is highly saline formation water or simulated formation water, and the total salinity of the brine is ≥

[0016] 220,000 mg / L, with calcium and magnesium ion content greater than 12,000 mg / L.

[0017] Preferably, the gas phase is one of air, nitrogen or carbon dioxide, and the volume ratio of the gas phase to the liquid phase is (7-10):1, more preferably 9:1.

[0018] Secondly, this application provides a method for preparing a three-phase foam system suitable for high-temperature, high-salinity reservoir conditioning and flooding, comprising the following steps:

[0019] 1) Disperse the foaming agent in the salt water and stir until the solution is evenly dispersed;

[0020] 2) Add a certain amount of foam stabilizer and stir evenly to obtain the liquid phase of the foam system;

[0021] 3) the prepared liquid phase is poured into a high-temperature high-pressure foam evaluation instrument, then the gas phase is filled into the evaluation instrument, the evaluation instrument is heated to the experimental temperature by using an electric heating jacket, and finally the three-phase foam system is obtained by stirring at a speed of 2500-3000 r / min for 1 min.

[0022] Preferably, in step 1), the solution is stirred at a speed of 50-200 r / min for 0.5-3 hours until the solution is uniformly dispersed.

[0023] Preferably, in step 3), 100 mL of the prepared liquid phase is taken by a measuring cylinder and added into the high-temperature high-pressure foam evaluation instrument, then a certain pressure of gas is filled into the evaluation instrument by using a steel cylinder gas source, the evaluation instrument is heated to the experimental temperature by using an electric heating jacket, and finally the three-phase foam system is obtained by stirring at a speed of 2500-3000 r / min for 1 min.

[0024] In a third aspect, the application provides application of the above-mentioned three-phase foam system suitable for high-temperature high-salt reservoir profile control and flooding in an oil reservoir gas drive oil recovery process.

[0025] In the application, the functions of the components and the stability principle of the three-phase foam are as follows:

[0026] In the application, the preferred betaine surfactant has good temperature resistance and salt resistance, and the short carbon chain hydroxyl sulfobetaine can be quickly adsorbed at the gas-liquid interface and easily foamed (with a large foaming volume). Generally, the shorter the carbon chain length of the betaine surfactant, the larger the foaming volume, but because the hydrophobic chain is short, the interaction is weak, the flow is easy, and it is difficult to maintain the stability of the gas-liquid interface for a long time, so the foam stability time is limited, and therefore a suitable carbon chain length of the surfactant needs to be selected. The carbon chain length of the industrial hydroxyl sulfobetaine is generally 10-24, and the lauryl amide propyl hydroxyl sulfobetaine with a carbon chain length of 12 is preferred in the application, which has a retention rate of more than 90% after aging at 130℃ for 7 days, has good foaming rate, liquid separation half-life and defoaming half-life under high temperature (130℃) and high salt (220000 mg / L) conditions, has low adsorption in the formation, and has good foam propagation effect.

[0027] The solid-phase stable bubble particle in the application is formed by precipitation of sulfonated phenolic resin in high-salinity brine, and the phenolic resin has certain temperature resistance and salt resistance after sulfonation treatment, and is a commonly used material in high-temperature and high-salinity drilling fluid. The stability of two-phase foam is limited under high-temperature and high-salinity conditions, so the sulfonated phenolic resin particles are introduced to stabilize the foam. First, the solubility of the sulfonated phenolic resin in the brine is controlled by optimizing the sulfonation degree of the sulfonated phenolic resin. The required sulfonated phenolic resin can be dissolved in low-salt water, but can be precipitated in 220,000 mg / L brine to form uniform solid-phase particles and adsorbed on the foam liquid film to improve the foam stability. The sulfonated phenolic resin has both hydrophilic groups and hydrophobic groups in the resin structure, which can be uniformly distributed on the liquid film of the foam, effectively slow down the liquid drainage speed, increase the mechanical strength of the liquid film, and improve the plugging capacity and stability of the foam system under high-temperature and high-salinity conditions.

[0028] The brine in the application is high-salinity formation water or simulated formation water. Since the sulfonated phenolic resin has certain temperature resistance and salt resistance, it will completely dissolve in low-salinity brine and cannot precipitate to form stable solid-phase particles. Therefore, the salinity of the brine for preparing the three-phase foam is required to be greater than or equal to 220,000 mg / L.

[0029] The gas phase in the application can be any one of air, nitrogen or carbon dioxide, which is flexible to choose and convenient for construction and application.

[0030] The application has the following beneficial effects:

[0031] 1. The three-phase foam system of the application has good temperature resistance and salt resistance, and has good foaming performance under high-temperature (130℃) and high-salt (220,000 mg / L, wherein the calcium and magnesium ion content is greater than 12,000 mg / L) conditions, with a foaming rate greater than 390%, a liquid precipitation half-life greater than 7 min, and a defoaming half-life greater than 120 min.

[0032] 2. The three-phase foam of the application can achieve good plugging effect, and the resistance factor generated in the core experiment is greater than 90.

[0033] 3. The three-phase foam of the application has simple components, is convenient to prepare and use, and has low cost, and is suitable for plugging and controlling gas channeling and foam oil displacement operation in high-temperature and high-salinity reservoirs. DETAILED DESCRIPTION

[0034] It is worth noting that the raw materials used in the application are ordinary commercially available products, and their sources are not specifically limited. The technical solutions of the application are described below through specific examples.

[0035] The bulk foam properties and plugging properties of the foam system are evaluated in the following examples and comparative examples. The bulk foam property evaluation is performed in a HCPM-III type high temperature and high pressure foam evaluation instrument, the experimental conditions are 130℃, the pressure is 2MPa, and during the experiment, 100mL of different concentrations of different foaming agent system solutions prepared by accurately measuring the corresponding simulated formation water are injected into the foam evaluation instrument, then stirred at a speed of 3000r / min for 1min, the initial foam volume after stirring is complete is the foaming volume V f , then the foam volume and the volume of the foaming liquid precipitated over time are recorded, when the volume of the foaming liquid precipitated reaches 50mL, the time is the half-life of the liquid precipitation T l , when the foam volume decreases to half of the initial foam volume, the time is the half-life of the foam T f . The foam plugging property represents the ability of foam gas channeling control, the resistance factor measured by core displacement experiment is used as a measure of the ability of foam gas channeling control, the experimental conditions are 130℃, the back pressure is set to 2MPa, and during the experiment, the gas-liquid ratio is 9:1, wherein the total injection speed is 6m / d when the gas and liquid are injected together, and the resistance factor RF is the ratio of the pressure difference between the two ends of the core when the foam moves to equilibrium to the pressure difference between the two ends of the core when the gas and water are injected together.

[0036] Example 1

[0037] A sulfonated phenolic resin stable foam system suitable for high temperature and high salt reservoirs, 0.4% by mass of lauryl amide propyl hydroxyl sulfobetaine is used as a foaming agent, 0.05% by mass of sulfonated phenolic resin powder with a sulfonation degree of 50% is used as a foam stabilizer, and the foam system liquid phase is obtained after the above foaming agent, foam stabilizer and the remaining water are uniformly mixed and stirred. The preparation method of the foaming agent is as follows: according to the proportion in this embodiment, 1.371g of lauryl amide propyl hydroxyl sulfobetaine with a mass fraction of 35% is added to 118.569g of 220000mg / L simulated formation water, and stirred with a glass rod at room temperature for a few minutes to fully mix and uniform, then 0.06g of sulfonated phenolic resin is added to the solution, and then stirred with a magnetic stirrer at 200r / min for 20min to obtain the liquid phase of the foam system.

[0038] Accurately measure 100mL of foaming agent solution and add it to the foam evaluation instrument, the foaming volume of the system is 400mL, the half-life of the liquid precipitation is 410s, and the half-life of the foam is 100min at 132.4℃, nitrogen pressure 2.55MPa measured by the high temperature and high pressure foam evaluation instrument. The core permeability selected in the core displacement experiment is 80mD, and the resistance factor is 55.3.

[0039] Example 2

[0040] A sulfonated phenolic resin particle stable foam system suitable for high temperature and high salt reservoirs, 0.4% lauryl amide propyl hydroxyl sulfobetaine by mass percentage is used as a foaming agent, 0.1% sulfonated phenolic resin powder with a sulfonation degree of 50% by mass percentage is used as a foam stabilizer, and the foam system liquid phase can be obtained after the foaming agent, the foam stabilizer and the remaining water are uniformly mixed and stirred. The preparation method of the foaming agent is as follows: 1.371 g of lauryl amide propyl hydroxyl sulfobetaine with a mass fraction of 35% is added to 118.509 g of 220,000 mg / L simulated formation water according to the proportion in the embodiment, and a glass rod is used to stir for several minutes at room temperature to fully mix and uniform, then 0.12 g of sulfonated phenolic resin is added to the solution, and then a magnetic stirrer is used to stir at 200 r / min for 20 min to obtain the foam system liquid phase.

[0041] Accurately take 100 mL of the foaming agent solution and add it to the foam evaluator, and the foaming volume of the system is 395 mL, the liquid separation half-life is 420 s, and the foam half-life is 125 min when the system is measured by the high temperature and high pressure foam evaluator at 133.5°C and nitrogen pressure of 2.43 MPa. The core displacement experiment selects a core with a permeability of 80 mD, and the resistance factor is 93.8.

[0042] Example 3

[0043] A sulfonated phenolic resin particle stable foam system suitable for high temperature and high salt reservoirs, 0.4% lauryl amide propyl hydroxyl sulfobetaine by mass percentage is used as a foaming agent, 0.1% sulfonated phenolic resin powder with a sulfonation degree of 50% by mass percentage is used as a foam stabilizer, and the foam system liquid phase can be obtained after the foaming agent, the foam stabilizer and the remaining water are uniformly mixed and stirred. The preparation method of the foaming agent is as follows: 1.371 g of lauryl amide propyl hydroxyl sulfobetaine with a mass fraction of 35% is added to 118.509 g of 220,000 mg / L simulated formation water according to the proportion in the embodiment, and a glass rod is used to stir for several minutes at room temperature to fully mix and uniform, then 0.12 g of sulfonated phenolic resin is added to the solution, and then a magnetic stirrer is used to stir at 200 r / min for 20 min to obtain the foam system liquid phase.

[0044] Accurately take 100 mL of the foaming agent solution and add it to the foam evaluator, and the foaming volume of the system is 395 mL, the liquid separation half-life is 420 s, and the foam half-life is 125 min when the system is measured by the high temperature and high pressure foam evaluator at 133.5°C and nitrogen pressure of 2.43 MPa. The core displacement experiment selects a core with a permeability of 80 mD, and the resistance factor is 93.8.

[0045] Example 4

[0046] A sulfonated phenolic resin particle stable foam system suitable for high temperature and high salt reservoirs, 0.4% lauryl amide propyl hydroxyl sulfobetaine by mass percentage is used as a foaming agent, 0.3% sulfonated phenolic resin powder with a sulfonation degree of 50% by mass percentage is used as a foam stabilizer, and the foam system liquid phase can be obtained after the foaming agent, the foam stabilizer and the remaining water are uniformly mixed and stirred. The preparation method of the foaming agent is as follows: 1.371g of lauryl amide propyl hydroxyl sulfobetaine with a mass fraction of 35% is added to 118.269g of 220000mg / L simulated formation water according to the proportion in the embodiment, and a glass rod is used to stir for several minutes at room temperature to fully mix and uniform, then 0.36g of sulfonated phenolic resin is added to the solution, and then a magnetic stirrer is used to stir at 200r / min for 20min to obtain the foam system liquid phase.

[0047] Accurately take 100mL of the foaming agent solution into the foam evaluator, and the foaming volume of the system is 385mL, the liquid separation half-life is 430s, and the foam half-life is 148min when the system is at 134.3℃ and the nitrogen pressure is 2.43MPa, which is measured by a high temperature and high pressure foam evaluator. The resistance factor is 95.7 in the core displacement experiment, and the selected core permeability is 80mD.

[0048] Example 5

[0049] A sulfonated phenolic resin particle stable foam system suitable for high temperature and high salt reservoirs, 0.4% lauryl amide propyl hydroxyl sulfobetaine by mass percentage is used as a foaming agent, 0.3% sulfonated phenolic resin powder with a sulfonation degree of 50% by mass percentage is used as a foam stabilizer, and the foam system liquid phase can be obtained after the foaming agent, the foam stabilizer and the remaining water are uniformly mixed and stirred. The preparation method of the foaming agent is as follows: 1.371g of lauryl amide propyl hydroxyl sulfobetaine with a mass fraction of 35% is added to 118.269g of 220000mg / L simulated formation water according to the proportion in the embodiment, and a glass rod is used to stir for several minutes at room temperature to fully mix and uniform, then 0.36g of sulfonated phenolic resin is added to the solution, and then a magnetic stirrer is used to stir at 200r / min for 20min to obtain the foam system liquid phase.

[0050] Accurately take 100mL of the foaming agent solution into the foam evaluator, and the foaming volume of the system is 385mL, the liquid separation half-life is 430s, and the foam half-life is 148min when the system is at 134.3℃ and the nitrogen pressure is 2.43MPa, which is measured by a high temperature and high pressure foam evaluator. The resistance factor is 95.7 in the core displacement experiment, and the selected core permeability is 80mD.

[0051] Example 6

[0052] A sulfonated phenolic resin particle stable foam system suitable for high temperature and high salt reservoirs, 0.28% lauryl amide propyl hydroxyl sulfobetaine by mass percentage is used as a foaming agent, 0.1% sulfonated phenolic resin powder with a sulfonation degree of 50% by mass percentage is used as a foam stabilizer, and the foam system liquid phase can be obtained after the foaming agent, the foam stabilizer and the remaining water are uniformly mixed and stirred. The preparation method of the foaming agent is as follows: 0.96g of lauryl amide propyl hydroxyl sulfobetaine with a mass fraction of 35% is added to 118.92g of 220000mg / L simulated formation water according to the proportion in the embodiment, and a glass rod is used to stir for several minutes at room temperature to fully mix and uniform, then 0.12g of sulfonated phenolic resin is added to the solution, and then a magnetic stirrer is used to stir at 200r / min for 20min to obtain the foam system liquid phase.

[0053] Accurately take 100mL of the foaming agent solution into the foam evaluator, and the foaming volume of the system is 390mL, the liquid separation half-life is 436s, and the foam half-life is 156min when the system is measured by the high temperature and high pressure foam evaluator at 132.6℃ and nitrogen pressure of 2.77MPa. The core displacement experiment selects a core with a permeability of 80mD, and the resistance factor is 101.5.

[0054] Example 7

[0055] A sulfonated phenolic resin particle stable foam system suitable for high temperature and high salt reservoirs, 0.1% lauryl amide propyl hydroxyl sulfobetaine by mass percentage is used as a foaming agent, 0.1% sulfonated phenolic resin powder with a sulfonation degree of 50% by mass percentage is used as a foam stabilizer, and the foam system liquid phase can be obtained after the foaming agent, the foam stabilizer and the remaining water are uniformly mixed and stirred. The preparation method of the foaming agent is as follows: 0.96g of lauryl amide propyl hydroxyl sulfobetaine with a mass fraction of 35% is added to 118.92g of 220000mg / L simulated formation water according to the proportion in the embodiment, and a glass rod is used to stir for several minutes at room temperature to fully mix and uniform, then 0.12g of sulfonated phenolic resin is added to the solution, and then a magnetic stirrer is used to stir at 200r / min for 20min to obtain the foam system liquid phase.

[0056] Accurately take 100mL of the foaming agent solution into the foam evaluator, and the foaming volume of the system is 390mL, the liquid separation half-life is 436s, and the foam half-life is 156min when the system is measured by the high temperature and high pressure foam evaluator at 132.6℃ and nitrogen pressure of 2.77MPa. The core displacement experiment selects a core with a permeability of 80mD, and the resistance factor is 101.5.

[0057] Example 8

[0058] A sulfonated phenolic resin particle stable foam system suitable for high-temperature and high-salt reservoirs is prepared by mixing 0.6% of lauryl amidopropyl hydroxyl sultaine by mass percentage as a foaming agent, 0.1% of sulfonated phenolic resin powder with a sulfonation degree of 50% as a foam stabilizer, and the rest of water. The liquid phase of the foam system is obtained after uniform mixing and stirring. The foaming agent is prepared by adding 2.057g of lauryl amidopropyl hydroxyl sultaine with a mass fraction of 35% to 117.823g of 220000mg / L simulated formation water according to the proportion in the embodiment, stirring for several minutes at room temperature to fully mix and uniform, then adding 0.12g of sulfonated phenolic resin to the solution, and stirring for 20 minutes at 200r / min by a magnetic stirrer to obtain the liquid phase of the foam system.

[0059] 100mL of the foaming agent solution is accurately measured and added to the foam evaluator. The foaming volume of the system is 395mL, the liquid separation half-life is 430s, and the foam half-life is 147min at 134.1℃ and nitrogen pressure of 2.57MPa measured by a high-temperature and high-pressure foam evaluator. The core displacement experiment is selected for a core with a permeability of 80mD, and the resistance factor is 100.3.

[0060] Example 9

[0061] A sulfonated phenolic resin particle stable foam system suitable for high-temperature and high-salt reservoirs is prepared by mixing 0.6% of lauryl amidopropyl hydroxyl sultaine by mass percentage as a foaming agent, 0.1% of sulfonated phenolic resin powder with a sulfonation degree of 50% as a foam stabilizer, and the rest of water. The liquid phase of the foam system is obtained after uniform mixing and stirring. The foaming agent is prepared by adding 2.057g of lauryl amidopropyl hydroxyl sultaine with a mass fraction of 35% to 117.823g of 220000mg / L simulated formation water according to the proportion in the embodiment, stirring for several minutes at room temperature to fully mix and uniform, then adding 0.12g of sulfonated phenolic resin to the solution, and stirring for 20 minutes at 200r / min by a magnetic stirrer to obtain the liquid phase of the foam system.

[0062] 100mL of the foaming agent solution is accurately measured and added to the foam evaluator. The foaming volume of the system is 395mL, the liquid separation half-life is 430s, and the foam half-life is 147min at 134.1℃ and nitrogen pressure of 2.57MPa measured by a high-temperature and high-pressure foam evaluator. The core displacement experiment is selected for a core with a permeability of 80mD, and the resistance factor is 100.3.

[0063] Comparative Example 1

[0064] The difference from the embodiment 2 is that the foaming agent is oleic acid amidopropyl hydroxysultaine. The performance parameters of the embodiment 2 and the comparative example 1 are compared in Table 2. The experimental results show that the foaming capacity and the foam stability of the comparative example 1 sample are equivalent to those of the embodiment 2, and the measured resistance factor is slightly lower than that of the embodiment 2, that is, the channeling blocking capacity is slightly lower than that of the embodiment 2, but the solubility of the foaming agent of the comparative example 1 at room temperature is slightly poor, and the foaming agent needs to be fully heated in a 90℃ water bath to completely dissolve, and the effective component of the foaming agent is precipitated again when the temperature is restored to room temperature.

[0065] Comparative example 2

[0066] The difference from the embodiment 2 is that the foaming agent is erucic acid amidopropyl hydroxysultaine. The performance parameters of the embodiment 2 and the comparative example 2 are compared in Table 2. The experimental results show that the foaming capacity and the foam stability of the comparative example 2 sample are very poor, and the measured resistance factor is far lower than that of the embodiment 2, that is, the channeling blocking capacity is far lower than that of the embodiment 2, and the main reason is that the carbon chain of the foaming agent used in the comparative example 2 is relatively long, and the solubility of the foaming agent in the high salinity brine at room temperature is very poor, that is, even if the solution is heated in a 90℃ water bath, the solution as a whole is not clear and transparent, but is uniformly turbid white.

[0067] Comparative example 3

[0068] The difference from the embodiment 2 is that the mass fraction of the foam stabilizer is zero, that is, no foam stabilizer is added. The performance parameters of the embodiment 2 and the comparative example 3 are compared in Table 2. The experimental results show that the foaming capacity of the comparative example 3 sample is equivalent to that of the embodiment 2, but the foam stability is poor, and the measured resistance factor is obviously lower than that of the embodiment 2, that is, the channeling blocking capacity is not as good as that of the embodiment 2.

[0069] Comparative example 4

[0070] The difference from the embodiment 2 is that the sulfonation degree of the sulfonated phenolic resin is 70%. The performance parameters of the embodiment 2 and the comparative example 4 are compared in Table 2. The sulfonated phenolic resin with high sulfonation degree has high solubility in high salinity brine, and cannot precipitate to form particle stable foam. The experimental results show that the foaming capacity of the comparative example 4 sample is equivalent to that of the embodiment 2, but the foam stability is poor, and the measured resistance factor is obviously lower than that of the embodiment 2, that is, the channeling blocking capacity is not as good as that of the embodiment 2.

[0071] Comparative example 5

[0072] The difference from the embodiment 2 is that the water used is 110000mg / L brine. The performance parameters of the embodiment 2 and the comparative example 5 are compared in Table 2. The sulfonated phenolic resin has high solubility in low salinity brine, and cannot precipitate to form particle stable foam. The experimental results show that the foaming capacity of the comparative example 5 sample is equivalent to that of the embodiment 2, but the foam stability is poor, and the measured resistance factor is obviously lower than that of the embodiment 2, that is, the channeling blocking capacity is not as good as that of the embodiment 2.

[0073] Table 1: Summary of the composition and performance parameters of the foam system in Examples 1-9

[0074] Example 1 2 3 4 5 6 7 8 9 Foaming agent mass fraction 0.4％ 0.4％ 0.4％ 0.4％ 0.4％ 0.28％ 0.1％ 0.6％ 0.4％ Stabilizing agent mass fraction 0.05％ 0.1％ 0.2％ 0.3％ 0.1％ 0.1％ 0.1％ 0.1％ 0.1％ Foaming volume / mL 400 395 390 385 390 390 350 395 400 Foam half-life / min 100 125 135 148 120 156 83.5 147 120 Liquid drainage half-life / s 410 420 435 430 420 436 420 430 425 Experimental temperature / °C 132.4 133.5 134.9 134.3 133.3 132.6 135.1 134.1 134.6 Experimental pressure / MPa 2.55 2.43 2.66 2.43 2.52 2.77 2.67 2.57 2.55 Resistance factor 55.3 93.8 98.6 95.7 91.3 101.5 54.5 100.3 90.8

[0075] Note: In the experiment for determining the foam resistance factor, the experimental conditions were the same: temperature 130℃, back pressure 2MPa, gas-liquid ratio 9:1, and gas-liquid injection speed 6m / d. The components in Table 1 were all measured by weight.

[0076] Table 2: Comparison of the performance parameters of Example 2 and Comparative Examples 1-5

[0077] Item Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Foaming agent mass fraction 0.4％ 0.4％ 0.4％ 0.4％ 0.4％ 0.4％ Stabilizing agent mass fraction 0.1％ 0.1％ 0.1％ 0 0.1％ 0.1％ Foaming volume / mL 395 400 220 400 405 425 Foam half-life / min 125 75 35 86 40 50 Liquid drainage half-life / s 420 500 50 430 400 130 Experimental temperature / °C 133.5 128.9 132.6 131.3 130.2 129.5 Experimental pressure / MPa 2.43 2.60 2.30 2.52 2.49 2.53 Resistance factor 93.8 71.8 15.2 21.1 25.7 31.8

[0078] The results of the examples of the present application show that the foam system of the present application has excellent foam performance under the conditions of 130℃ and salt content 220000mg / L, with a foaming volume of more than 390mL, a foam half-life of more than 120min, and a liquid separation half-life of more than 7min. In addition, the core displacement results show that the foam resistance factor is greater than 90, indicating that the present application has good plugging and gas channeling control effect under the conditions of 130℃ and salt content 220000mg / L, and can effectively improve the gas drive recovery, thus solving the problem of lack of foam system for gas channeling control in high-temperature and high-salt reservoirs.

[0079] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A three-phase foam system suitable for profile control and flooding of high-temperature and high-salinity oil reservoirs, characterized in that, The three-phase foam system is composed of a liquid phase with a mass fraction of 0.05%-0.6% of a foaming agent, 0.05%-0.3% of a particle foam stabilizer and the rest of brine and a gas phase; the foaming agent is lauryl amidopropyl hydroxyl sulfonate; the particle foam stabilizer is a nanometer or micrometer solid phase foam stabilizing particle formed by precipitation of sulfonated phenolic aldehyde resin in high salinity brine; the sulfonated degree of the sulfonated phenolic aldehyde resin is 40%-65%. The total salinity of the brine is ≥220000 mg / L.

2. The three-phase foam system of claim 1, wherein, The average molecular weight of the sulfonated phenolic aldehyde resin is 100000-120000; the sulfonated degree of the sulfonated phenolic aldehyde resin is 40%-50%.

3. The three-phase foam system of claim 2, wherein, The sulfonated degree of the sulfonated phenolic aldehyde resin is 50%.

4. The three-phase foam system of claim 1, wherein, The brine is high salinity formation water or simulated formation water, and the content of calcium and magnesium ions in the brine is greater than 12000 mg / L.

5. The three-phase foam system of claim 1, wherein, The gas phase is one of air, nitrogen or carbon dioxide, and the volume ratio of the gas phase to the liquid phase is (7-10):

1.

6. The three-phase foam system of claim 5, wherein, The volume ratio of the gas phase to the liquid phase is 9:

1.

7. A process for the preparation of a three-phase foam system according to any one of claims 1 to 6, characterised in that, The method comprises the following steps: 1) dispersing the foaming agent in the brine and stirring until the solution is uniformly dispersed; 2) adding a certain amount of foam stabilizer and stirring until uniform to obtain the liquid phase of the foam system; 3) pouring the prepared liquid phase into a high temperature and high pressure foam evaluation instrument, then pressurizing with the gas phase and stirring at a speed of 1000-5000 r / min to generate foam, thereby obtaining the three-phase foam system; or alternatively, the gas phase and the liquid phase of the three-phase foam are alternately injected into the formation or core to generate the three-phase foam system.

8. The preparation method according to claim 7, characterized in that, In step 1), the solution is stirred at a speed of 50-200 r / min for 0.5-3 hours until the solution is uniformly dispersed.

9. Application of the three-phase foam system of any one of claims 1-6 or the three-phase foam system prepared by the preparation method of any one of claims 7-8 in the process of oil reservoir gas flooding.