High-temperature-resistant bubble-producing dispersion liquid, preparation method and application thereof

Abstract

The application provides a high-temperature-resistant bubble-producing dispersion liquid and a preparation method and application thereof. Raw materials of the bubble-producing dispersion liquid include a betaine surfactant, weathered coal, polyacrylamide, phenolic resin and water.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas field development engineering, and particularly relates to a foam-generating dispersion liquid, a preparation method and application thereof. BACKGROUND

[0002] Due to structural deformation or deposition, a fracture-cave type reservoir forms a porous medium with a high specific surface area, and the pores and fractures have high connectivity, but the permeability of the oil layer is relatively low. In the process of oil and gas exploitation, in order to improve the recovery efficiency and maintain the reservoir pressure, water injection, steam injection and foam injection technologies are widely used. Due to the complex pore structure of the formation, the injected water usually only flows along the dominant channel, resulting in that other pores cannot be utilized, and the water cut rises rapidly in the late stage of oilfield development, and the water drive is inefficient or ineffective, resulting in that a large amount of remaining oil in the upper part of the formation cannot be utilized. In order to improve the problem of water drive development in the late stage of the reservoir, some scholars propose that the low density of gas can form an artificial gas cap to drive attic oil. However, in actual field tests, there are problems such as injection gas channeling along the dominant channel, strong gravity differentiation effect, and large gas-liquid mobility ratio, resulting in that the number of inefficient and ineffective gas channeling well groups increases, and the oil displacement efficiency of gas injection decreases.

[0003] In view of the harsh high-temperature and high-salinity formation conditions of the fracture-cave type reservoir, two types of foam systems have been developed: one is a compound foam system, and the other is a gel foam system. However, due to the harsh formation conditions, the compound foam system has a poor stability, with a half-life period of 7 min and a defoaming half-life period of 20 min; the foaming performance of the gel foam system is only 65%, and the toughness is poor and the shear is fragile, so it is urgent to develop a high-stability foam system to further improve the foam flooding efficiency. SUMMARY

[0004] One of the present application provides a foam-generating dispersion liquid, which comprises a betaine surfactant, weathered coal, polyacrylamide, phenolic resin and water.

[0005] In one specific embodiment, the betaine surfactant is at least one of hydroxylsulfonyl betaine, cocamide propyl betaine and lauryl propyl betaine.

[0006] In one specific embodiment, the carbon content of the weathered coal is 60wt% to 66wt%, and the ash content is 15wt% to 23wt%. For example, the weathering time of the weathered coal is 3 months to 4 months. The weathering factor can be atmospheric and sunlight erosion.

[0007] In one specific embodiment, the particle size of the weathered coal is 200 mesh to 400 mesh.

[0008] In one specific embodiment, the polyacrylamide is a non-ionic polyacrylamide.

[0009] In one embodiment, the non-ionic polyacrylamide has a relative molecular weight of 4 million to 6 million.

[0010] In one embodiment, the betaine surfactant is used in an amount of 0.3% to 0.7%, the weathered coal is used in an amount of 13% to 15%, the polyacrylamide is used in an amount of 0.4% to 0.8%, and the phenolic resin is used in an amount of 0.6% to 0.9%, with the mass of water being taken as 100%.

[0011] In one embodiment, the phenolic resin is a liquid phenolic resin.

[0012] The second aspect of the present application provides a method for preparing the foam-generating dispersion liquid as described in any one of the first aspect of the present application, comprising the following steps:

[0013] 1) mixing polyacrylamide with water to obtain a polyacrylamide aqueous solution;

[0014] 2) mixing phenolic resin with the polyacrylamide aqueous solution to obtain a polyacrylamide-phenolic resin aqueous solution;

[0015] 3) mixing betaine surfactant with the polyacrylamide-phenolic resin aqueous solution to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0016] 4) mixing weathered coal with the polyacrylamide-phenolic resin-betaine aqueous solution to obtain the foam-generating dispersion liquid.

[0017] In one embodiment, in step 1), the mixing is uniform at 600 to 800 rpm for 30 to 45 min.

[0018] In one embodiment, in step 2), the mixing is uniform at 600 to 800 rpm for 45 to 75 min.

[0019] In one embodiment, in step 3), the mixing is uniform at 400 to 600 rpm for 5 to 10 min.

[0020] In one embodiment, in step 4), the dispersion mixing is performed by ultrasonic for 5 to 10 min.

[0021] The third aspect of the present application provides the use of the foam-generating dispersion liquid according to any one of the first aspect of the present application or prepared by the method of any one of the second aspect of the present application in displacing oil stored in cracks and / or fractures and pores in high-temperature and high-salinity fractured-porous reservoirs.

[0022] In one embodiment, the application is for use in displacing oil stored in fractures and / or vugs of a high-temperature and high-salinity vugular reservoir caused by deposition.

[0023] In one embodiment, the application is for use in displacing oil stored in fractures and / or vugs of a high-temperature and high-salinity vugular reservoir caused by marine deposition.

[0024] In one embodiment, the upper limit of the high temperature is 150℃, and the upper limit of the salinity is 21×10 4 mg / L.

[0025] Advantages of the present application:

[0026] (1) The foam-generating dispersion liquid of the present application can be applied to high-temperature and high-salinity reservoirs, and can withstand a temperature of 150℃, a total salinity of 21×10 4 mg / L, and calcium ions of up to 1.4×10 4 mg / L, and magnesium ions of up to 1×10 4 mg / L.

[0027] (2) The foam-generating dispersion liquid of the present application greatly provides stability of the foam through synergistic effects between components, and prolongs the half-life of the foam.

[0028] (3) The raw materials used in the present application, weathered coal particles, polyacrylamide, and phenolic resin, are low in price and widely used in the field of petroleum and chemical industry, and the system greatly reduces production cost while improving stability of the foam. DETAILED DESCRIPTION

[0029] The present application will be further described below in conjunction with examples, but the examples of the present application are only exemplary descriptions, and the embodiments do not constitute a limitation on the present application in any case.

[0030] Example 1

[0031] The temperature- and salinity-resistant foam-generating dispersion liquid includes the following raw materials by weight: 0.3g of hydroxylsulfonyl betaine, 13g of 200-mesh weathered coal particles (carbon content of 66wt%, ash content of 15wt%, formed by atmospheric and sunlight erosion for 3 months), 0.4g of non-ionic polyacrylamide with a relative molecular weight of 5 million, 0.6g of thermosetting phenolic resin, and 100g of mineralized water.

[0032] The specific steps of the method for preparing the temperature- and salinity-resistant foam-generating dispersion liquid are as follows:

[0033] (1) Prepare simulated formation water with a salinity of 21×10 4 mg / L, wherein the calcium ions are 1.4×10 4mg / L, magnesium ion 1.0 x 10 4 mg / L;

[0034] (2) 0.4 g of non-ionic polyacrylamide was added to 100 g of simulated formation water and stirred at 600 rpm for 45 min to mix evenly, to obtain a polyacrylamide aqueous solution;

[0035] (3) 0.6 g of thermosetting phenolic resin was added to the polyacrylamide aqueous solution, and stirring was continued at 600 rpm for 45 min to form a uniform polyacrylamide-phenolic resin aqueous solution;

[0036] (4) 0.3 g of hydroxyl sulfobetaine was added to the polyacrylamide-phenolic resin aqueous solution, and low-speed stirring was performed at 400 rpm for 5 min to prevent foaming in advance, to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0037] (5) 13 g of weathered coal particles were added to the polyacrylamide-phenolic resin-betaine aqueous solution, and ultrasonic cavitation dispersion was performed at 20 kHz for 5 min to obtain a stable foam-producing dispersion.

[0038] Foaming volume and liquid drainage half-life determination: the high-temperature and high-pressure foam evaluator was heated to 150°C, the foam-producing dispersion was poured into the evaluator, nitrogen was added to the foam-producing dispersion at the same time as the foam-producing dispersion was poured into the evaluator, and the amount of nitrogen added was sufficient to saturate the foam-producing dispersion at 150°C to prevent gasification of the foam-producing dispersion, and high-speed rotation was performed at 6500 rpm for 15 min after 55 min, to obtain a foam system, at this time, the high-temperature and high-pressure foam evaluator was inverted, and at the same time, a stopwatch was started, and the foaming volume and liquid drainage half-life of the foam were recorded on the visual window, and the results are shown in Table 1.

[0039] Foam viscoelastic modulus determination: the foam-producing dispersion was added to a syringe, and then the syringe was fixed to the high-temperature and high-pressure interfacial tension instrument Tracker-H, 3 MPa of N2 was injected into the cavity of the high-temperature and high-pressure interfacial tension instrument to ensure that the cavity pressure was higher than the saturation vapor pressure at the corresponding temperature, the position of the needle of the syringe and the camera was adjusted by rotating the rotation button on the sliding groove to ensure that the driving motor formed a pear-shaped bubble at the syringe, and the interfacial viscoelastic modulus was obtained by Fourier transform, and the results are shown in Table 1.

[0040] Example 2

[0041] A temperature and salt resistant foamable dispersion liquid was prepared by mixing the following ingredients by weight: 0.5 g of hydroxyl sulfobetaine, 15 g of 200 mesh weathered coal particles (carbon content of 66 wt%, ash content of 15 wt%, formed by weathering for 3 months under the atmosphere and sunlight), 0.6 g of non-ionic polyacrylamide with a relative molecular weight of 5 million, 0.9 g of thermosetting phenolic resin, and 100 g of mineralized water.

[0042] The specific steps of the method for preparing the temperature and salt resistant foamable dispersion liquid are as follows:

[0043] (1) Prepare simulated formation water with a salinity of 21 x 10 4 mg / L, wherein the calcium ion is 1.4 x 10 4 mg / L, and the magnesium ion is 1.0 x 10 4 mg / L;

[0044] (2) Add 0.6 g of non-ionic polyacrylamide to 100 g of the simulated formation water and stir at 600 rpm for 45 min to uniformly mix, to obtain a polyacrylamide aqueous solution;

[0045] (3) Add 0.9 g of thermosetting phenolic resin to the polyacrylamide aqueous solution and continue to stir at 600 rpm for 45 min to form a uniform polyacrylamide-phenolic resin aqueous solution;

[0046] (4) Add 0.5 g of hydroxyl sulfobetaine to the polyacrylamide-phenolic resin aqueous solution, and stir at 400 rpm for 5 min to prevent premature foaming during high-speed stirring, to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0047] (5) Add 15 g of weathered coal particles to the polyacrylamide-phenolic resin-betaine aqueous solution, and cavitate and disperse at 20 kHz for 5 min using ultrasonic waves, to obtain a stable foamable dispersion liquid.

[0048] Foaming volume and liquid drainage half-life determination: heat the high-temperature and high-pressure foam evaluation instrument to 150°C, pour the foamable dispersion liquid into the evaluation instrument, and add nitrogen to the foamable dispersion liquid at the same time as pouring the foamable dispersion liquid into the evaluation instrument, until the foamable dispersion liquid reaches the saturated vapor pressure at 150°C, to prevent the foamable dispersion liquid from vaporizing, and then rotate at 6500 rpm for 15 min after 55 min, to obtain a foam system, at this time, invert the high-temperature and high-pressure foam evaluation instrument, and at the same time, start a stopwatch, and record the foaming volume and liquid drainage half-life of the foam on the visual window, and the results are shown in Table 1.

[0049] Viscoelastic modulus determination of the foam: The foam-generating dispersion liquid was added into a syringe, and then the syringe was fixed to a Tracker-H high-temperature high-pressure interfacial tension instrument. N2 at 3 MPa was injected into the cavity of the high-temperature high-pressure interfacial tension instrument to ensure that the cavity pressure was higher than the saturation vapor pressure at the corresponding temperature. The position of the needle of the syringe and the camera was adjusted by rotating the rotary button on the sliding groove to ensure that the driving motor formed a pear-shaped bubble at the syringe. The instrument automatically identified the interfacial viscoelastic modulus obtained by Fourier transform. The results are shown in Table 1.

[0050] Example 3

[0051] The temperature-resistant and salt-resistant foam-generating dispersion liquid comprises the following raw materials by weight: 0.7 g of hydroxyl sulfobetaine, 15 g of 200-mesh weathered coal particles (carbon content of 66 wt%, ash content of 15 wt%, formed by atmospheric and sunlight erosion for 3 months), 0.8 g of non-ionic polyacrylamide with a relative molecular weight of 5 million, 0.9 g of thermosetting phenolic resin, and 100 g of mineralized water.

[0052] The specific steps of the method for preparing the temperature-resistant and salt-resistant foam-generating dispersion liquid are as follows:

[0053] (1) Prepare simulated formation water with a salinity of 21 × 10 4 mg / L, wherein the calcium ion is 1.4 × 10 4 mg / L, and the magnesium ion is 1.0 × 10 4 mg / L;

[0054] (2) Add 0.8 g of non-ionic polyacrylamide to 100 g of simulated formation water and stir at 600 rpm for 45 min to obtain a polyacrylamide aqueous solution;

[0055] (3) Add 0.9 g of thermosetting phenolic resin to the polyacrylamide aqueous solution and continue to stir at 600 rpm for 45 min to form a uniform polyacrylamide-phenolic resin aqueous solution;

[0056] (4) Add 0.7 g of hydroxyl sulfobetaine to the polyacrylamide-phenolic resin aqueous solution, and stir at 400 rpm for 5 min to prevent premature foaming during high-speed stirring, to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0057] (5) Add 15 g of weathered coal particles to the polyacrylamide-phenolic resin-betaine aqueous solution, and cavitate and disperse for 5 min at 20 kHz by ultrasonic waves to obtain a stable foam-generating dispersion liquid.

[0058] Foaming volume and drainage half-life determination: The high-temperature and high-pressure foam evaluator was heated to 150℃, and the foam-forming dispersion was poured into it. Nitrogen was added to the foam-forming dispersion at the same time as the foam-forming dispersion was poured into the evaluator, and the amount of nitrogen was adjusted to reach the saturated vapor pressure of the foam-forming dispersion at 150℃ to prevent the foam-forming dispersion from vaporizing. After 55 min, the foam system was obtained by high-speed rotation at 6500 rpm for 15 min. At this time, the high-temperature and high-pressure foam evaluator was inverted, and at the same time, a stopwatch was started, and the foaming volume and drainage half-life of the foam were recorded on the visual window. The results are shown in Table 1.

[0059] Foam viscoelastic modulus determination: The foam-forming dispersion was added to a syringe, which was then fixed to the high-temperature and high-pressure interfacial tension instrument Tracker-H. N2 at 3 MPa was injected into the cavity of the high-temperature and high-pressure interfacial tension instrument to ensure that the cavity pressure was higher than the saturated vapor pressure at the corresponding temperature. The position of the needle of the syringe and the camera was adjusted by rotating the rotary button on the sliding groove to ensure that the driving motor formed a pear-shaped bubble at the syringe. The instrument automatically identified the interfacial viscoelastic modulus obtained by Fourier transform. The results are shown in Table 1.

[0060] Example 4

[0061] The difference from Example 2 is that the hydroxyl sulfobetaine is replaced by cocamidopropyl betaine.

[0062] The temperature-resistant and salt-tolerant foam-forming dispersion includes the following raw materials by weight: cocamidopropyl betaine 0.5 g, 200-mesh weathered coal particles (carbon content 66 wt%, ash content 15 wt%, formed by atmospheric and sunlight erosion for 3 months) 15 g, non-ionic polyacrylamide with a relative molecular weight of 5 million 0.6 g, thermosetting phenolic resin 0.9 g, and mineralized water 100 g.

[0063] The specific steps of the method for preparing the temperature-resistant and salt-tolerant foam-forming dispersion are as follows:

[0064] (1) Prepare simulated formation water with a salinity of 21 x 10 4 mg / L, wherein the calcium ion is 1.4 x 10 4 mg / L, and the magnesium ion is 1.0 x 10 4 mg / L;

[0065] (2) Add 0.6 g of non-ionic polyacrylamide to 100 g of simulated formation water and stir at 600 rpm for 45 min to obtain a uniform polyacrylamide aqueous solution;

[0066] (3) Add 0.9 g of thermosetting phenolic resin to the polyacrylamide aqueous solution and continue stirring at 600 rpm for 45 min to form a uniform polyacrylamide-phenolic resin aqueous solution;

[0067] (4) Add 0.5 g of cocamide propyl betaine to the polyacrylamide-phenolic resin aqueous solution, and stir at a low speed of 400 rpm for 5 min to prevent premature foaming during high-speed stirring, to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0068] (5) Add 15 g of weathered coal particles to the polyacrylamide-phenolic resin-betaine aqueous solution, and cavitate and disperse at 20 kHz for 5 min to obtain a stable foam-generating dispersion.

[0069] Foaming volume and liquid drainage half-life determination: heat the high-temperature and high-pressure foam evaluator to 150°C, pour the foam-generating dispersion into the evaluator, and add nitrogen to the foam-generating dispersion at the same time as pouring the foam-generating dispersion into the evaluator, until the foam-generating dispersion reaches the saturated vapor pressure at 150°C, to prevent the foam-generating dispersion from vaporizing, and then rotate at a high speed of 6500 rpm for 15 min after 55 min, to obtain a foam system, at this time, invert the high-temperature and high-pressure foam evaluator, and at the same time, start a stopwatch, and record the foaming volume and liquid drainage half-life of the foam on the visual window, the results are shown in Table 1.

[0070] Foam viscoelastic modulus determination: add the foam-generating dispersion to a syringe, then fix the syringe to the high-temperature and high-pressure interfacial tension instrument Tracker-H, inject 3 MPa of N2 into the cavity of the high-temperature and high-pressure interfacial tension instrument to ensure that the cavity pressure is higher than the saturated vapor pressure at the corresponding temperature, adjust the position of the needle of the syringe and the camera on the rotating button on the sliding groove to ensure that the driving motor forms a pear-shaped bubble at the syringe, and the instrument automatically identifies the interfacial viscoelastic modulus obtained by Fourier transform, the results are shown in Table 1.

[0071] Example 5

[0072] The difference from Example 2 is that the hydroxyl sulfobetaine is replaced by lauryl propyl betaine.

[0073] The temperature-resistant and salt-tolerant foam-generating dispersion includes the following raw materials by weight: lauryl propyl betaine 0.5 g, 200-mesh weathered coal particles (carbon content of 66 wt%, ash content of 15 wt%, formed by atmospheric and sunlight erosion for 3 months) 15 g, non-ionic polyacrylamide with a relative molecular weight of 5 million 0.6 g, thermosetting phenolic resin 0.9 g, and mineralized water 100 g.

[0074] The specific steps of the temperature-resistant and salt-tolerant foam-generating dispersion preparation method are as follows:

[0075] (1) Prepare simulated formation water with a salinity of 21 × 10 4 mg / L, wherein the calcium ion is 1.4 × 10 4mg / L, magnesium ion 1.0 x 10 4 mg / L;

[0076] (2) 0.6 g of non-ionic polyacrylamide was added to 100 g of simulated formation water and stirred at 600 rpm for 45 min to mix evenly, to obtain a polyacrylamide aqueous solution;

[0077] (3) 0.9 g of thermosetting phenolic resin was added to the polyacrylamide aqueous solution and stirred at 600 rpm for 45 min to form a uniform polyacrylamide-phenolic resin aqueous solution;

[0078] (4) 0.5 g of lauryl propyl betaine was added to the polyacrylamide-phenolic resin aqueous solution, and low-speed stirring was performed at 400 rpm for 5 min to prevent foaming in advance, to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0079] (5) 15 g of weathered coal particles were added to the polyacrylamide-phenolic resin-betaine aqueous solution, and ultrasonic cavitation dispersion was performed at 20 kHz for 5 min to obtain a stable foam-generating dispersion.

[0080] Foaming volume and liquid drainage half-life determination: the high-temperature and high-pressure foam evaluator was heated to 150°C, the foam-generating dispersion was poured into the evaluator, nitrogen was added to the foam-generating dispersion at the same time, and the amount of nitrogen added was until the foam-generating dispersion reached the saturated vapor pressure at 150°C, to prevent the foam-generating dispersion from vaporizing, and high-speed rotation was performed at 6500 rpm for 15 min after 55 min, to obtain a foam system, at this time, the high-temperature and high-pressure foam evaluator was inverted, and at the same time, a stopwatch was started, and the foaming volume and liquid drainage half-life of the foam were recorded on the visual window, and the results are shown in Table 1.

[0081] Foam viscoelastic modulus determination: the foam-generating dispersion was added to a syringe, and then the syringe was fixed to the high-temperature and high-pressure interfacial tension instrument Tracker-H, 3 MPa of N2 was injected into the cavity of the high-temperature and high-pressure interfacial tension instrument to ensure that the cavity pressure was higher than the saturated vapor pressure at the corresponding temperature, the position of the needle of the syringe and the camera was adjusted by rotating the rotation button on the sliding groove to ensure that the driving motor formed a pear-shaped bubble at the syringe, and the interfacial viscoelastic modulus was obtained by Fourier transform, and the results are shown in Table 1.

[0082] Example 6

[0083] The difference from Example 2 is only that the relative molecular weight of the non-ionic polyacrylamide is 4 million.

[0084] A temperature and salt resistant foamable dispersion liquid was prepared by mixing the following ingredients by weight: 0.5 g of hydroxyl sulfobetaine, 15 g of 200 mesh weathered coal particles (carbon content of 66 wt%, ash content of 15 wt%, formed by weathering for 3 months under the atmosphere and sunlight), 0.6 g of non-ionic polyacrylamide with a relative molecular weight of 4 million, 0.9 g of thermosetting phenolic resin, and 100 g of mineralized water.

[0085] The specific steps of the method for preparing the temperature and salt resistant foamable dispersion liquid are as follows:

[0086] (1) Prepare simulated formation water with a salinity of 21 x 10 4 mg / L, wherein the calcium ion is 1.4 x 10 4 mg / L, and the magnesium ion is 1.0 x 10 4 mg / L;

[0087] (2) Add 0.6 g of non-ionic polyacrylamide to 100 g of the simulated formation water and stir at 600 rpm for 45 min to uniformly mix, to obtain a polyacrylamide aqueous solution;

[0088] (3) Add 0.9 g of thermosetting phenolic resin to the polyacrylamide aqueous solution and continue to stir at 600 rpm for 45 min to form a uniform polyacrylamide-phenolic resin aqueous solution;

[0089] (4) Add 0.5 g of hydroxyl sulfobetaine to the polyacrylamide-phenolic resin aqueous solution, and stir at 400 rpm for 5 min to prevent premature foaming during high-speed stirring, to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0090] (5) Add 15 g of weathered coal particles to the polyacrylamide-phenolic resin-betaine aqueous solution, and cavitate and disperse for 5 min under ultrasonic waves at 20 kHz to obtain a stable foamable dispersion liquid.

[0091] Foaming volume and liquid drainage half-life determination: heat the high-temperature and high-pressure foam evaluation instrument to 150°C, pour the foamable dispersion liquid into the evaluation instrument, and add nitrogen to the foamable dispersion liquid at the same time as pouring the foamable dispersion liquid into the evaluation instrument, until the foamable dispersion liquid reaches the saturated vapor pressure at 150°C, to prevent the foamable dispersion liquid from vaporizing, and rotate at 6500 rpm for 15 min after 55 min, to obtain a foam system, at this time, invert the high-temperature and high-pressure foam evaluation instrument, and at the same time, start a stopwatch, and record the foaming volume and liquid drainage half-life of the foam on the visual window, and the results are shown in Table 1.

[0092] Viscoelastic modulus determination of the foam: The foam-generating dispersion liquid was added into a syringe, which was then fixed to a Tracker-H high-temperature and high-pressure interfacial tension instrument. N2 at 3 MPa was injected into the cavity of the high-temperature and high-pressure interfacial tension instrument to ensure that the cavity pressure was higher than the saturated vapor pressure at the corresponding temperature. The position of the needle of the syringe and the camera was adjusted by rotating the rotary button on the sliding groove to ensure that the driving motor formed a pear-shaped bubble at the syringe. The instrument automatically identified the interfacial viscoelastic modulus obtained by Fourier transform. The results are shown in Table 1.

[0093] Example 7

[0094] The only difference from Example 2 is that the relative molecular weight of the non-ionic polyacrylamide is 6 million.

[0095] The temperature-resistant and salt-resistant foam-generating dispersion liquid comprises the following raw materials by weight: 0.5 g of hydroxyl sulfobetaine, 15 g of 200-mesh weathered coal particles (carbon content of 66 wt%, ash content of 15 wt%, formed by atmospheric and sunlight erosion for 3 months), 0.6 g of non-ionic polyacrylamide with a relative molecular weight of 6 million, 0.9 g of thermosetting phenolic resin, and 100 g of mineralized water.

[0096] The specific steps of the method for preparing the temperature-resistant and salt-resistant foam-generating dispersion liquid are as follows:

[0097] (1) Prepare simulated formation water with a salinity of 21 × 10 4 mg / L, wherein the calcium ion is 1.4 × 10 4 mg / L, and the magnesium ion is 1.0 × 10 4 mg / L;

[0098] (2) Add 0.6 g of non-ionic polyacrylamide to 100 g of simulated formation water and stir at 600 rpm for 45 min to obtain a uniform polyacrylamide aqueous solution;

[0099] (3) Add 0.9 g of thermosetting phenolic resin to the polyacrylamide aqueous solution and continue to stir at 600 rpm for 45 min to form a uniform polyacrylamide-phenolic resin aqueous solution;

[0100] (4) Add 0.5 g of hydroxyl sulfobetaine to the polyacrylamide-phenolic resin aqueous solution. To prevent premature foaming during high-speed stirring, stir at 400 rpm for 5 min to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0101] (5) Add 15 g of weathered coal particles to the polyacrylamide-phenolic resin-betaine aqueous solution and cavitate and disperse for 5 min at 20 kHz using ultrasonic waves to obtain a stable foam-generating dispersion liquid.

[0102] Foaming volume and drainage half-life determination: the high temperature and high pressure foam evaluator was heated to 150℃, the foam generating dispersion was poured into it, nitrogen was added to the foam generating dispersion at the same time as the foam generating dispersion was poured into the evaluator, the amount of nitrogen was added until the foam generating dispersion reached the saturated vapor pressure at 150℃ to prevent the foam generating dispersion from vaporizing, after 55 min, high speed rotation was performed at 6500 rpm for 15 min to obtain the foam system, at this time, the high temperature and high pressure foam evaluator was inverted, at the same time, a stopwatch was started, the foaming volume and drainage half-life of the foam were recorded on the visual window, the results are shown in Table 1.

[0103] Foam viscoelastic modulus determination: the foam generating dispersion was added to a syringe, then the syringe was fixed to the high temperature and high pressure interfacial tension instrument Tracker-H, 3 MPa of N2 was injected into the cavity of the high temperature and high pressure interfacial tension instrument to ensure that the cavity pressure was higher than the saturated vapor pressure at the corresponding temperature, the position of the needle of the syringe and the camera was adjusted by rotating the rotation button on the sliding groove to ensure that the driving motor formed a pear-shaped bubble at the syringe, the instrument automatically recognized the interfacial viscoelastic modulus obtained by Fourier transform, the results are shown in Table 1.

[0104] Example 8

[0105] The difference from Example 2 is that the mesh number of the weathered coal particles is 400 mesh, and the weathering time is 4 months.

[0106] The temperature and salt resistant foam generating dispersion includes the following raw materials by weight: hydroxyl sulfobetaine 0.5 g, 400 mesh weathered coal particles (carbon content of 60 wt%, ash content of 23 wt%, formed by atmospheric and sunlight erosion for 4 months) 15 g, non-ionic polyacrylamide with a relative molecular weight of 5 million 0.6 g, thermosetting phenolic resin 0.9 g, mineralized water 100 g.

[0107] The specific steps of the temperature and salt resistant foam generating dispersion preparation method are as follows:

[0108] (1) prepare simulated formation water with a salinity of 21 x 10 4 mg / L, wherein the calcium ion is 1.4 x 10 4 mg / L, and the magnesium ion is 1.0 x 10 4 mg / L;

[0109] (2) 0.6 g of non-ionic polyacrylamide is added to 100 g of simulated formation water and stirred at 600 rpm for 45 min to make it uniformly mixed to obtain a polyacrylamide aqueous solution;

[0110] (3) 0.9 g of thermosetting phenolic resin is added to the polyacrylamide aqueous solution and continues to be stirred at 600 rpm for 45 min to form a uniform polyacrylamide-phenolic resin aqueous solution;

[0111] (4) Add 0.5 g of hydroxyl sulfobetaine to the polyacrylamide-phenolic resin aqueous solution, and stir at a low speed of 400 rpm for 5 min to prevent premature foaming, to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0112] (5) Add 15 g of 400-mesh weathered coal particles to the polyacrylamide-phenolic resin-betaine aqueous solution, and cavitate and disperse at 20 kHz for 5 min to obtain a stable foam-generating dispersion.

[0113] Foaming volume and liquid drainage half-life determination: heat the high-temperature and high-pressure foam evaluator to 150°C, pour the foam-generating dispersion into the evaluator, and add nitrogen to the foam-generating dispersion at the same time as the pouring, until the foam-generating dispersion reaches the saturated vapor pressure at 150°C, to prevent the foam-generating dispersion from vaporizing, and then rotate at a high speed of 6500 rpm for 15 min after 55 min, to obtain a foam system, at this time, invert the high-temperature and high-pressure foam evaluator, and at the same time, start a stopwatch, and record the foaming volume and liquid drainage half-life of the foam on the visual window, and the results are shown in Table 1.

[0114] Foam viscoelastic modulus determination: add the foam-generating dispersion to a syringe, and then fix the syringe to the high-temperature and high-pressure interfacial tension instrument Tracker-H, inject 3 MPa of N2 into the cavity of the high-temperature and high-pressure interfacial tension instrument to ensure that the cavity pressure is higher than the saturated vapor pressure at the corresponding temperature, adjust the position of the needle of the syringe and the camera on the rotating button on the sliding groove, to ensure that the driving motor forms a pear-shaped bubble at the syringe, and the instrument automatically identifies the interfacial viscoelastic modulus obtained by Fourier transform, and the results are shown in Table 1.

[0115] Example 9

[0116] The difference from Example 2 is that the mixing conditions of steps (2) to (5) are different.

[0117] The temperature-resistant and salt-resistant foam-generating dispersion includes the following raw materials by weight: 0.5 g of hydroxyl sulfobetaine, 15 g of 200-mesh weathered coal particles (carbon content of 66 wt%, ash content of 15 wt%, formed by atmospheric and sunlight erosion for 3 months), 0.6 g of non-ionic polyacrylamide with a relative molecular mass of 5 million, 0.9 g of thermosetting phenolic resin, and 100 g of mineralized water.

[0118] The specific steps of the temperature-resistant and salt-resistant foam-generating dispersion preparation method are as follows:

[0119] (1) Prepare simulated formation water with a salinity of 21 × 10 4 mg / L, wherein the calcium ion is 1.4 × 10 4mg / L, magnesium ion 1.0 x 10 4 mg / L;

[0120] (2) 0.6 g of non-ionic polyacrylamide was added to 100 g of simulated formation water and stirred at 800 rpm for 30 min to mix evenly, to obtain a polyacrylamide aqueous solution;

[0121] (3) 0.9 g of thermosetting phenolic resin was added to the polyacrylamide aqueous solution and stirred at 800 rpm for 75 min to form a uniform polyacrylamide-phenolic resin aqueous solution;

[0122] (4) 0.5 g of hydroxyl sulfobetaine was added to the polyacrylamide-phenolic resin aqueous solution, and low-speed stirring was performed at 600 rpm for 5 min to prevent foaming in advance, to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0123] (5) 15 g of 200-mesh weathered coal particles were added to the polyacrylamide-phenolic resin-betaine aqueous solution, and ultrasonic cavitation dispersion was performed at 20 kHz for 10 min to obtain a stable foam-generating dispersion.

[0124] Foaming volume and liquid drainage half-life determination: the high-temperature and high-pressure foam evaluator was heated to 150°C, the foam-generating dispersion was poured into the evaluator, nitrogen was added to the foam-generating dispersion at the same time, and the amount of nitrogen was adjusted until the foam-generating dispersion reached the saturated vapor pressure at 150°C, to prevent the foam-generating dispersion from vaporizing, and high-speed rotation was performed at 6500 rpm for 15 min after 55 min, to obtain a foam system, at this time, the high-temperature and high-pressure foam evaluator was inverted, and a stopwatch was opened at the same time, and the foaming volume and liquid drainage half-life of the foam were recorded on the visual window, and the results are shown in Table 1.

[0125] Foam viscoelastic modulus determination: the foam-generating dispersion was added to a syringe, and then the syringe was fixed to the high-temperature and high-pressure interfacial tension instrument Tracker-H, 3 MPa of N2 was injected into the cavity of the high-temperature and high-pressure interfacial tension instrument to ensure that the cavity pressure was higher than the saturated vapor pressure at the corresponding temperature, the position of the needle of the syringe and the camera was adjusted by rotating the rotation button on the sliding groove to ensure that the driving motor formed a pear-shaped bubble at the syringe, and the interfacial viscoelastic modulus was obtained by Fourier transform, and the results are shown in Table 1.

[0126] Comparative Example 1

[0127] The difference from Example 2 is only that the non-ionic polyacrylamide is replaced by xanthan gum.

[0128] The foam-generating dispersion liquid comprises the following raw materials by weight: 0.5 g of hydroxysultaine, 15 g of 200-mesh weathered coal particles, 0.6 g of xanthan gum, 0.9 g of thermosetting phenolic resin, and 100 g of mineralized water.

[0129] The specific steps of the method for preparing the foam-generating dispersion liquid are as follows:

[0130] (1) A simulated formation water with a salinity of 21 x 10 4 mg / L is prepared, wherein the calcium ion concentration is 1.4 x 10 4 mg / L, and the magnesium ion concentration is 1.0 x 10 4 mg / L.

[0131] (2) 0.6 g of xanthan gum is added to 100 g of the simulated formation water, and the mixture is stirred at a high speed of 600 rpm for 45 min to obtain a xanthan gum aqueous solution;

[0132] (3) 0.9 g of thermosetting phenolic resin is added to the xanthan gum aqueous solution, and the mixture is stirred at a high speed of 600 rpm for 50 min to form a uniform xanthan gum-phenolic resin aqueous solution;

[0133] (4) 0.5 g of hydroxysultaine is added to the xanthan gum-phenolic resin aqueous solution, and the mixture is stirred at a low speed of 600 rpm for 10 min to prevent premature foaming during high-speed stirring, to obtain a xanthan gum-phenolic resin-sweet potato base aqueous solution;

[0134] (5) 15 g of weathered coal particles is added to the xanthan gum-phenolic resin-sweet potato base aqueous solution, and the mixture is cavitated and dispersed by ultrasonic waves at 20 kHz for 5 min to obtain a stable foam-generating dispersion liquid.

[0135] Foaming volume and liquid drainage half-life determination: the high-temperature and high-pressure foam evaluator is heated to 150°C, the foam-generating dispersion liquid is poured into the evaluator, nitrogen is added to the foam-generating dispersion liquid at the same time, and the amount of nitrogen is adjusted to the amount required to reach the saturated vapor pressure of the foam-generating dispersion liquid at 150°C, to prevent the foam-generating dispersion liquid from vaporizing, and the foam-generating dispersion liquid is rotated at a high speed of 6500 rpm for 15 min after 55 min, to obtain a foam system. At this time, the high-temperature and high-pressure foam evaluator is inverted, and a stopwatch is started at the same time. The foaming volume and liquid drainage half-life of the foam are recorded on the visual window. The results are shown in Table 1.

[0136] Viscoelastic modulus determination of the foam: The foam-generating dispersion liquid was added into a syringe, and then the syringe was fixed to a Tracker-H high-temperature high-pressure interfacial tension instrument. N2 at 3 MPa was injected into the cavity of the high-temperature high-pressure interfacial tension instrument to ensure that the cavity pressure was higher than the saturation vapor pressure at the corresponding temperature. The position of the needle of the syringe and the camera was adjusted by rotating the rotary button on the sliding groove to ensure that the driving motor formed a pear-shaped bubble at the syringe. The instrument automatically identified the interfacial viscoelastic modulus obtained by Fourier transform. The results are shown in Table 1.

[0137] Comparative Example 2

[0138] The difference from Example 2 is that the thermosetting phenolic resin is replaced by dimethyl stearate.

[0139] The foam-generating dispersion liquid comprises the following raw materials by weight: 0.5 g of hydroxyl sulfobetaine, 15 g of 200-mesh weathered coal particles, 0.6 g of non-ionic polyacrylamide with a relative molecular mass of 5 million, 0.9 g of dimethyl stearate, and 100 g of mineralized water.

[0140] The specific steps of the foam-generating dispersion liquid preparation method are as follows:

[0141] (1) Prepare simulated formation water with a salinity of 21 × 10 4 mg / L, wherein the calcium ion is 1.4 × 10 4 mg / L, and the magnesium ion is 1.0 × 10 4 mg / L;

[0142] (2) Add 0.4 g of non-ionic polyacrylamide to 100 g of simulated formation water and stir at 600 rpm for 45 min to obtain a uniform polyacrylamide aqueous solution;

[0143] (3) Add 0.6 g of dimethyl stearate to the polyacrylamide aqueous solution and continue to stir at 600 rpm for 50 min to form a uniform polyacrylamide-dimethyl stearate aqueous solution;

[0144] (4) Add 0.3 g of hydroxyl sulfobetaine to the polyacrylamide-dimethyl stearate aqueous solution. To prevent foaming during high-speed stirring, stir at 600 rpm for 10 min to obtain a polyacrylamide-dimethyl stearate-betaine aqueous solution;

[0145] (5) Add 15 g of weathered coal particles to the polyacrylamide-dimethyl stearate-betaine aqueous solution and cavitate and disperse for 5 min under ultrasonic waves at 20 kHz to obtain a stable foam-generating dispersion liquid.

[0146] Foaming volume and drainage half-life determination: the high temperature and high pressure foam evaluator was heated to 150℃, the foam generating dispersion was poured into it, nitrogen was added to the foam generating dispersion at the same time as the foam generating dispersion was poured into the evaluator, the amount of nitrogen was added until the foam generating dispersion reached the saturated vapor pressure at 150℃, to prevent the foam generating dispersion from vaporizing, after 55 min, high speed stirring was performed at 6500 rpm for 15 min, to obtain the foam system, at this time, the high temperature and high pressure foam evaluator was inverted, at the same time, a stopwatch was started, the foaming volume and drainage half-life of the foam were recorded on the visual window, the results are shown in Table 1.

[0147] Foam viscoelastic modulus determination: the foam generating dispersion was added to a syringe, then the syringe was fixed to the high temperature and high pressure interfacial tension instrument Tracker-H, 3 MPa of N2 was injected into the cavity of the high temperature and high pressure interfacial tension instrument to ensure that the cavity pressure was higher than the saturated vapor pressure at the corresponding temperature, the position of the needle of the syringe and the camera was adjusted by rotating the rotation button on the sliding groove, to ensure that the driving motor formed a pear-shaped bubble at the syringe, the instrument automatically identified the interfacial viscoelastic modulus obtained by Fourier transform, the results are shown in Table 1.

[0148] Comparative Example 3

[0149] The difference from Example 2 is that the weathered coal is replaced by fly ash.

[0150] The foam generating dispersion includes the following raw materials by weight: 0.5 g of hydroxyl sulfobetaine, 15 g of 200 mesh fly ash particles, 0.6 g of non-ionic polyacrylamide with a relative molecular weight of 5 million, 0.9 g of thermosetting phenolic resin, and 100 g of mineralized water.

[0151] The specific steps of the foam generating dispersion preparation method are as follows:

[0152] (1) prepare simulated formation water with a salinity of 21 x 10 4 mg / L, wherein the calcium ion is 1.4 x 10 4 mg / L, and the magnesium ion is 1.0 x 10 4 mg / L;

[0153] (2) 0.8 g of non-ionic polyacrylamide is added to 100 g of simulated formation water, and stirred at 600 rpm for 45 min to obtain a uniform polyacrylamide aqueous solution;

[0154] (3) 0.9 g of thermosetting phenolic resin is added to the polyacrylamide aqueous solution and stirred at 600 rpm for 50 min to form a uniform polyacrylamide-phenolic resin aqueous solution;

[0155] (4) 0.7 g of hydroxysulfobetaine was added into the polyacrylamide-phenolic resin aqueous solution, and low-speed stirring was performed at 600 rpm for 10 min to prevent premature foaming, to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0156] (5) 15 g of fly ash particles were added into the polyacrylamide-phenolic resin-betaine aqueous solution, and ultrasonic cavitation dispersion was performed at 20 kHz for 5 min to obtain a stable foam-generating dispersion.

[0157] Foaming volume and liquid drainage half-life determination: the high-temperature and high-pressure foam evaluator was heated to 150°C, the foam-generating dispersion was poured into the evaluator, nitrogen was added into the foam-generating dispersion at the same time, and the amount of nitrogen was adjusted to the amount required to reach the saturated vapor pressure of the foam-generating dispersion at 150°C, to prevent the foam-generating dispersion from being gasified, and high-speed rotation was performed at 6500 rpm for 15 min after 55 min, to obtain a foam system, at this time, the high-temperature and high-pressure foam evaluator was inverted, and a stopwatch was started at the same time, and the foaming volume and liquid drainage half-life of the foam were recorded on the visual window, and the results are shown in Table 1.

[0158] Foam viscoelastic modulus determination: the foam-generating dispersion was added into a syringe, and then the syringe was fixed to the high-temperature and high-pressure interfacial tension instrument Tracker-H, 3 MPa of N2 was injected into the cavity of the high-temperature and high-pressure interfacial tension instrument to ensure that the cavity pressure was higher than the saturated vapor pressure at the corresponding temperature, the position of the needle of the syringe and the camera was adjusted by rotating the rotation button on the sliding groove, to ensure that the driving motor formed a pear-shaped bubble at the syringe, and the instrument automatically recognized the interfacial viscoelastic modulus obtained by Fourier transform, and the results are shown in Table 1.

[0159] Comparative Example 4

[0160] The difference from Example 2 is only that the weathering time of the weathered coal is different, so that the carbon content and the ash content are different, and the carbon content is 52 wt%, and the ash content is 31 wt%, and the weathering is formed by atmospheric and sunlight erosion for 5 months.

[0161] The foam-generating dispersion includes the following raw materials by weight: 0.5 g of hydroxysulfobetaine, 15 g of 200-mesh weathered coal particles, 0.6 g of non-ionic polyacrylamide with a relative molecular weight of 5 million, 0.9 g of thermosetting phenolic resin, and 100 g of mineralized water.

[0162] The specific steps of the foam-generating dispersion preparation method are as follows:

[0163] (1) 21 × 10 4 mg / L of simulated formation water was prepared, wherein the calcium ion was 1.4 × 10 4 mg / L, and the magnesium ion was 1.0 × 10 4mg / L;

[0164] (2) 0.8 g of non-ionic polyacrylamide was added to 100 g of simulated formation water and stirred at 600 rpm for 45 min to mix evenly, to obtain a polyacrylamide aqueous solution;

[0165] (3) 0.9 g of thermosetting phenolic resin was added to the polyacrylamide aqueous solution and stirred at 600 rpm for 50 min to form a uniform polyacrylamide-phenolic resin aqueous solution;

[0166] (4) 0.7 g of hydroxyl sulfobetaine was added to the polyacrylamide-phenolic resin aqueous solution, and low-speed stirring was performed at 600 rpm for 10 min to prevent premature foaming during high-speed stirring, to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0167] (5) 15 g of weathered coal particles were added to the polyacrylamide-phenolic resin-betaine aqueous solution, and cavitation dispersion was performed under ultrasonic waves at 20 kHz for 5 min to obtain a stable foam-generating dispersion.

[0168] Foaming volume and liquid drainage half-life determination: the high-temperature and high-pressure foam evaluator was heated to 150°C, the foam-generating dispersion was poured into the evaluator, nitrogen was added to the foam-generating dispersion at the same time, and the amount of nitrogen added was sufficient to saturate the foam-generating dispersion at 150°C to prevent gasification of the foam-generating dispersion, and high-speed rotation was performed at 6500 rpm for 15 min after 55 min, to obtain a foam system, at this time, the high-temperature and high-pressure foam evaluator was inverted, and at the same time, a stopwatch was started, and the foaming volume and liquid drainage half-life of the foam were recorded on the visual window, and the results are shown in Table 1.

[0169] Foam viscoelastic modulus determination: the foam-generating dispersion was added to a syringe, and then the syringe was fixed to the high-temperature and high-pressure interfacial tension instrument Tracker-H, 3 MPa of N2 was injected into the cavity of the high-temperature and high-pressure interfacial tension instrument to ensure that the cavity pressure was higher than the saturation vapor pressure at the corresponding temperature, the position of the needle of the syringe and the camera was adjusted by rotating the rotation button on the sliding groove to ensure that the driving motor formed a pear-shaped bubble at the syringe, and the interfacial viscoelastic modulus was obtained by Fourier transform, and the results are shown in Table 1.

[0170] Comparative Example 5

[0171] The difference from Example 2 is only that the weathering time of the weathered coal is different, so that the carbon content and ash content are different, specifically, the carbon content is 70 wt%, and the ash content is 9 wt%, and the weathering is formed by atmospheric and sunlight erosion for 2 months.

[0172] The foam-generating dispersion liquid comprises the following raw materials by weight: 0.5 g of hydroxyl sulfobetaine, 15 g of 200-mesh weathered coal particles, 0.6 g of non-ionic polyacrylamide with a relative molecular weight of 5 million, 0.9 g of thermosetting phenolic resin, and 100 g of mineralized water.

[0173] The specific steps of the method for preparing the foam-generating dispersion liquid are as follows:

[0174] (1) Prepare simulated formation water with a salinity of 21 x 10 4 mg / L, wherein the calcium ion concentration is 1.4 x 10 4 mg / L, and the magnesium ion concentration is 1.0 x 10 4 mg / L;

[0175] (2) Add 0.8 g of non-ionic polyacrylamide to 100 g of the simulated formation water and stir at 600 rpm for 45 min to obtain a polyacrylamide aqueous solution;

[0176] (3) Add 0.9 g of thermosetting phenolic resin to the polyacrylamide aqueous solution and continue to stir at 600 rpm for 50 min to form a uniform polyacrylamide-phenolic resin aqueous solution;

[0177] (4) Add 0.7 g of hydroxyl sulfobetaine to the polyacrylamide-phenolic resin aqueous solution, and stir at 600 rpm for 10 min to prevent premature foaming during high-speed stirring, to obtain a polyacrylamide-phenolic resin-betaine aqueous solution;

[0178] (5) Add 15 g of weathered coal particles to the polyacrylamide-phenolic resin-betaine aqueous solution, and cavitate and disperse for 5 min under ultrasonic waves at 20 kHz to obtain a stable foam-generating dispersion liquid.

[0179] Foaming volume and liquid drainage half-life determination: heat the high-temperature and high-pressure foam evaluator to 150°C, pour the foam-generating dispersion liquid into it, and add nitrogen to the foam-generating dispersion liquid at the same time as pouring it into the evaluator, until the foam-generating dispersion liquid reaches the saturated vapor pressure at 150°C, to prevent the foam-generating dispersion liquid from vaporizing, and then rotate at 6500 rpm for 15 min after 55 min, to obtain a foam system. At this time, invert the high-temperature and high-pressure foam evaluator, and at the same time, start a stopwatch and record the foaming volume and liquid drainage half-life of the foam on the visual window. The results are shown in Table 1.

[0180] Viscoelastic modulus determination of foam: The foam generating dispersion liquid was added into a syringe, and then the syringe was fixed to a Tracker-H high temperature and high pressure interfacial tensiometer. N2 was injected into the cavity of the high temperature and high pressure interfacial tensiometer at a pressure of 3 MPa to ensure that the cavity pressure was higher than the saturated vapor pressure at the corresponding temperature. The position of the needle of the syringe and the camera was adjusted by rotating the rotary button on the sliding groove to ensure that the driving motor formed a pear-shaped bubble at the syringe. The interfacial viscoelastic modulus was obtained by Fourier transform, and the results are shown in Table 1.

[0181] Comparative Example 6

[0182] The difference from Example 3 is only that polyacrylamide is not added.

[0183] The foam generating dispersion liquid comprises the following raw materials by weight: 0.7 g of hydroxyl sulfobetaine, 15 g of 200-mesh weathered coal particles (carbon content of 66 wt%, ash content of 15 wt%, formed by atmospheric and sunlight erosion for 3 months), and 100 g of mineralized water.

[0184] The specific steps of the foam generating dispersion liquid preparation method are as follows:

[0185] (1) Prepare simulated formation water with a salinity of 21 x 10 4 mg / L, wherein the calcium ion is 1.4 x 10 4 mg / L, and the magnesium ion is 1.0 x 10 4 mg / L;

[0186] (2) Add 0.7 g of hydroxyl sulfobetaine to 100 g of simulated formation water, and stir at a low speed of 400 rpm for 5 min to prevent foaming during high-speed stirring, to obtain a betaine aqueous solution;

[0187] (3) Add 15 g of weathered coal particles to the betaine aqueous solution, and cavitate and disperse for 5 min at 20 kHz by ultrasonic waves to obtain a stable foam generating dispersion liquid.

[0188] Foaming volume and liquid drainage half-life determination: The high temperature and high pressure foam evaluation instrument was heated to 150°C, and the foam generating dispersion liquid was poured into it. Nitrogen was added to the foam generating dispersion liquid at the same time as the foam generating dispersion liquid was poured into the evaluation instrument, and the amount of nitrogen was adjusted until the foam generating dispersion liquid reached the saturated vapor pressure at 150°C to prevent the foam generating dispersion liquid from vaporizing. After 55 min, high-speed rotation was performed at 6500 rpm for 15 min to obtain a foam system. At this time, the high temperature and high pressure foam evaluation instrument was inverted, and at the same time a stopwatch was started. The foaming volume and liquid drainage half-life of the foam were recorded on the visual window, and the results are shown in Table 1.

[0189] Determination of the viscoelastic modulus of foam: The foam-generating dispersion was added to a syringe, and then the syringe was fixed to the Tracker-H high-temperature and high-pressure interfacial tensiometer. 3 MPa of N2 was injected into the chamber of the high-temperature and high-pressure interfacial tensiometer to ensure that the chamber pressure was higher than the saturated vapor pressure at the corresponding temperature. The position of the syringe needle and the camera was adjusted by rotating the rotary button on the slide to ensure that the drive motor formed a pear-shaped bubble at the syringe. The instrument automatically identified and obtained the interfacial viscoelastic modulus through Fourier transform. The results are shown in Table 1.

[0190] Comparative Example 7

[0191] The only difference from Example 3 is that no weathered coal was added.

[0192] The foaming dispersion comprises the following raw materials by weight: 0.7g of hydroxysulfobetaine, 0.8g of nonionic polyacrylamide with a relative molecular weight of 5 million, 0.9g of thermosetting phenolic resin, and 100g of mineralized water.

[0193] The specific steps for preparing the foam-generating dispersion are as follows:

[0194] (1) Prepare a solution with a mineralization degree of 21×10 4 Simulated formation water at a concentration of mg / L, containing 1.4 × 10 mg / L calcium ions. 4 mg / L, magnesium ions 1.0×10 4 mg / L;

[0195] (2) Add 0.8g of nonionic polyacrylamide to 100g of simulated formation water and stir at 600rpm for 45min to mix it evenly to obtain a polyacrylamide aqueous solution.

[0196] (3) Add 0.9g of thermosetting phenolic resin to the polyacrylamide aqueous solution and continue stirring at 600rpm for 45min to form a uniform polyacrylamide-phenolic resin aqueous solution.

[0197] (4) Add 0.7g of hydroxysulfonate betaine to the polyacrylamide-phenol resin aqueous solution. To prevent premature foaming during high-speed stirring, stir at low speed of 400rpm for 5min to obtain foam-producing dispersion.

[0198] Foaming volume and drainage half-life measurement: The high temperature and high pressure foam evaluator was heated to 150°C, the foam generating dispersion was poured into it, nitrogen was added to the foam generating dispersion at the same time as the foam generating dispersion was poured into the evaluator, the amount of nitrogen was added until the foam generating dispersion reached the saturated vapor pressure at 150°C to prevent the foam generating dispersion from vaporizing, after 55 min, high speed rotation was performed at 6500 rpm for 15 min to obtain the foam system. At this time, the high temperature and high pressure foam evaluator was inverted, at the same time, a stopwatch was started, the foaming volume and drainage half-life of the foam were recorded on the visual window, the results are shown in Table 1.

[0199] Foam viscoelastic modulus measurement: The foam generating dispersion was added to a syringe, then the syringe was fixed to the high temperature and high pressure interfacial tension instrument Tracker-H, 3 MPa of N2 was injected into the cavity of the high temperature and high pressure interfacial tension instrument to ensure that the cavity pressure was higher than the saturated vapor pressure at the corresponding temperature, the position of the needle of the syringe and the camera was adjusted by rotating the rotation button on the sliding groove to ensure that the driving motor formed a pear-shaped bubble at the syringe, the instrument automatically identified the interfacial viscoelastic modulus obtained by Fourier transform, the results are shown in Table 1.

[0200] Table 1

[0201]

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Claims

1. A foaming dispersion, the raw materials of which include betaine-type surfactant, weathered coal, polyacrylamide, phenolic resin and water; The weathered coal has a carbon content of 60 wt% to 66 wt% and an ash content of 15 wt% to 23 wt%. The particle size of the weathered coal is 200 mesh to 400 mesh; The polyacrylamide is a nonionic polyacrylamide; The nonionic polyacrylamide has a relative molecular weight of 4 million to 6 million. Using water as 100%, the amount of the betaine-type surfactant is 0.3% to 0.7%, the amount of the weathered coal is 13% to 15%, the amount of the polyacrylamide is 0.4% to 0.8%, and the amount of the phenolic resin is 0.6% to 0.9%. The phenolic resin is a thermosetting phenolic resin.

2. The foam-generating dispersion according to claim 1, characterized in that, The betaine-type surfactant is at least one of hydroxysulfobetaine, cocamidopropyl betaine, and lauroylpropyl betaine.

3. A method for preparing the foam-generating dispersion as described in claim 1 or 2, comprising the following steps: 1) Mix polyacrylamide with water to obtain an aqueous solution of polyacrylamide; 2) Mix the phenolic resin with the polyacrylamide aqueous solution to obtain a polyacrylamide-phenolic resin aqueous solution; 3) Mix the betaine-type surfactant with the polyacrylamide-phenolic resin aqueous solution to obtain a polyacrylamide-phenolic resin-betaine aqueous solution; 4) The weathered coal is mixed with the polyacrylamide-phenolic resin-betaine aqueous solution to obtain the foam-producing dispersion.

4. The method according to claim 3, characterized in that, In step 1), mix thoroughly at 600 to 800 rpm for 30 to 45 minutes; and / or In step 2), mix thoroughly at 600 to 800 rpm for 45 to 75 minutes; and / or In step 3), mix thoroughly at 400 to 600 rpm for 5 to 10 minutes.

5. The method according to claim 3, characterized in that, In step 4), the mixture is dispersed and mixed by ultrasound for 5 to 10 minutes.

6. The application of the foam-producing dispersion according to claim 1 or 2, or the foam-producing dispersion prepared by the method according to any one of claims 3 to 5, in displacing fractured and / or fractured reservoir oil in high-temperature, high-salinity fractured-vuggy oil reservoirs; The application is for displacing oil stored in fractures and / or within fractures of high-temperature, high-salinity fractured-vuggy reservoirs caused by sedimentation. The upper limit for the high temperature is 150°C, and the upper limit for the mineralization is 21 × 10⁻⁶. 4 mg / L.

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