Nanobubble oil displacement and storage integrated experimental device and method

Abstract

The present invention belongs to the technical field of oil and gas field development engineering and discloses an integrated nanobubble flooding and storage experimental device and method. The method generates nanobubble water with different gas sources, different dissolved gas contents, and different sizes; injects fluid into a microfluidic chip; simulates the temperature and pressure conditions of a real oil reservoir; compares different flooding effects; and calculates the storage volume. Based on experimental requirements, the present invention can adjust the gas source of the nanobubble generation system to generate nanobubble water with different gas sources and analyze the impact of the gas source type on nanobubble flooding. The nanobubble generation system's operating time can be adjusted to generate nanobubble water with different dissolved gas contents and analyze the impact of dissolved gas content on nanobubble flooding. The nanobubble generation system's gas injection volume can be adjusted to generate nanobubble water with different diameters and analyze the impact of nanobubble diameter on nanobubble flooding, as well as analyze the storage effect of nanobubbles as a storage medium.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field development engineering, and in particular relates to a nano-bubble oil displacement and burial storage integrated experimental device and method. Background Art

[0002] In oilfield development, the main displacement methods include polymer flooding, surfactant flooding, gas flooding, and miscible flooding. These methods primarily increase crude oil recovery by increasing the viscosity of the displacing phase or decreasing the viscosity of the oil phase, improving the mobility ratio, increasing the sweep coefficient, or improving interfacial properties to enhance oil washing efficiency. However, traditional displacement methods suffer from limited sweep range, high levels of residual oil in remaining pores, and environmental pollution. To further improve crude oil recovery, new displacement methods are needed. Traditional carbon storage methods primarily involve injecting high-purity carbon dioxide into formations, which is subject to problems such as gas crossflow and leakage. To further improve carbon storage quality, new methods are also needed.

[0003] Nanobubbles are bubbles with a diameter of less than 100 nm. They possess the following properties: their surface charge makes them less likely to aggregate in a dispersed phase, resulting in a stable system. Their internal pressure is higher than that of conventional bubbles, allowing them to dissolve more gas per unit volume. Their rupture triggers cavitation, releasing a large number of free radicals and the gases trapped within. Their large surface area provides strong adsorption capacity, and their high mass transfer efficiency accelerates chemical reactions. The excellent physical and chemical properties of nanobubbles make them a highly effective oil displacement agent and a highly efficient storage medium for gases such as carbon dioxide. Therefore, nanobubbles are being considered as a new oil displacement agent for oilfield development or as a storage medium for carbon sequestration. Currently, there is limited research on nanobubble oil displacement and storage, and the displacement and storage mechanisms are still unclear.

[0004] Therefore, in order to analyze the oil displacement mechanism and storage mechanism of nanobubbles, it is necessary to manufacture an integrated nanobubble oil displacement and storage experimental device, conduct nanobubble oil displacement and storage microscopic visualization experiments to analyze the displacement effects of nanobubbles with different gas sources, different dissolved gas amounts and different diameters, as well as the storage effects of different gas sources, and then determine the displacement mechanism of nanobubbles for crude oil and the storage mechanism of nanobubbles as a storage medium. Summary of the Invention

[0005] In order to overcome the problems existing in the related art, the embodiments disclosed in the present invention provide an integrated experimental device and method for nanobubble oil displacement and storage.

[0006] The technical solution is as follows: a nanobubble oil displacement and storage integrated experimental method, comprising:

[0007] S1, by adjusting the gas source of the gas cylinder, the operation time of the nanobubble generator and the air intake, nanobubble water with different gas sources, different dissolved gas amounts and different sizes is generated;

[0008] S2, adjust the fluid injection system to inject fluid into the microfluidic chip;

[0009] S3, adjust the injection pressure of the confining pressure pump and the temperature of the water bath circulation pump to simulate the temperature and pressure conditions of the real oil reservoir;

[0010] S4, using a high-resolution microscope and high-speed camera to capture and record the oil displacement process of nanobubble water, and compare the oil displacement effects of nanobubbles with different gas sources, different dissolved gas amounts, and different bubble diameters;

[0011] S5, obtain the retention state of gas in the microfluidic chip through a high-resolution microscope and a high-speed camera, and calculate the storage amount based on the data obtained by carbon dioxide content detection sensor A and carbon dioxide content detection sensor B.

[0012] In step S4, the oil displacement process of nanobubble water is captured and recorded by a high-resolution microscope and a high-speed camera, and the oil displacement effects of different gas sources are compared, including:

[0013] When the pores in the microfluidic chip are completely saturated with water, the oil phase is injected into the microfluidic chip at a flow rate of 0.01 ml / min. When the oil phase is completely saturated, nanobubble water is injected into the microfluidic chip at a flow rate of 0.01 ml / min. A high-speed camera is used to record images of the nanobubble water flooding at 0.5 PV, 1 PV, 1.5 PV, 2 PV and no injection. The area A1 of the nanobubble water flooding in the microfluidic chip and the total area A0 of the etched area of the microfluidic chip are identified by image recognition software, and the sweep coefficient E of the nanobubble water flooding is calculated. v , the expression is:

[0014]

[0015] Where: E v represents the sweep coefficient in %; A1 represents the swept area of nanobubble water in cm 2 ; A0 represents the total area of the etched area, in cm 2 ;

[0016] Identify the area A of the remaining oil phase in the affected area using image recognition software r And the area A of the oil phase when no nanobubble water is injected into the same area o , calculate the oil washing efficiency E of nanobubble water flooding D , the expression is:

[0017]

[0018] Where: E D Indicates oil washing efficiency, unit is %; A r Indicates the area of the remaining oil phase in the affected area, in cm 2 ; A o Represents the area of the oil phase in the same area when no nanobubble water is injected, in cm 2 ;

[0019] The final calculated recovery factor E R :

[0020] E R =E v ×E D (3)

[0021] Where: E R It represents the recovery rate in %.

[0022] The gas source was changed and the above steps were repeated to compare the sweep coefficient, oil washing efficiency and final recovery rate of nanobubble water flooding with different gas sources, and to analyze the influence of the type of gas contained in the nanobubbles on the flooding effect.

[0023] In step S4, the oil displacement process of nanobubble water is captured and recorded by a high-resolution microscope and a high-speed camera, and the oil displacement effects of different dissolved gas amounts are compared, including:

[0024] The gas source in the gas cylinder is CO2. The operation time of the nanobubble generator is set to 5 minutes, 10 minutes, 15 minutes, and 20 minutes respectively. Nanobubble water samples with different dissolved gas amounts are obtained. The solubility of CO2 in the nanobubble water generated at the four operation times is determined using the carbon dioxide content detection sensor A. Nanobubble water flooding experiments were carried out, experimental images were obtained, the sweep coefficient, oil washing efficiency and recovery factor when injecting 2PV were calculated and compared, and the influence of the dissolved gas content of nanobubble water on the flooding effect was analyzed.

[0025] In step S4, the oil displacement process of nanobubble water is captured and recorded by a high-resolution microscope and a high-speed camera, and the oil displacement effects of nanobubbles with different bubble diameters are compared.

[0026] The gas source in the gas cylinder was CO2. The cylinder valve was adjusted so that the pressure gauge A read 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, and 0.5 MPa, respectively. This set five different gas injection volumes. The nanobubble generator was operated for 5 minutes each time to produce nanobubble water with five different diameter distributions. The size distributions of the five groups of nanobubble water were determined using a nanoparticle tracking analyzer (NTA). Nanobubble water flooding experiments were conducted, and experimental images were obtained. The sweep coefficient, oil washing efficiency, and recovery factor when injected at 2PV were calculated and compared. The influence of the diameter of the nanobubble water on the flooding effect was analyzed.

[0027] In step S5, the retention state of gas in the microfluidic chip is obtained by a high-resolution microscope and a high-speed camera, and the storage amount is calculated based on the data obtained by the carbon dioxide content detection sensor A and the carbon dioxide content detection sensor B. The method includes: when the pores in the microfluidic chip are completely saturated with water, the high-resolution microscope is used to obtain the pores, and then 1PV of nanobubble water is injected at a flow rate of 0.01ml / min. When the injection is completed, the carbon dioxide content detection sensor B is used to measure the solubility of CO2 in the sample. Calculate the buried storage volume Q0:

[0028]

[0029] Where: Q0 represents the buried amount, the unit is mol; Indicates the solubility of CO2 in the nanobubble water sample, in mol / L; Indicates the solubility of CO2 in the tail liquid collector, in mol / L; V 孔 Represents the total volume of the etched pores in the microfluidic chip, in L; V 尾 Indicates the volume of the liquid in the tail liquid collector, in L;

[0030] Adjust the temperature of the water bath circulation pump, repeat the above steps, and analyze the effect of temperature on CO2 storage capacity.

[0031] Another object of the present invention is to provide a nanobubble flooding and storage integrated experimental device, which implements the nanobubble flooding and storage integrated experimental method described above, and comprises: a nanobubble generation system, a fluid injection system, a microchannel liquid migration system, a microchannel constant temperature and pressure system, and an information collection and transmission system;

[0032] The nanobubble generating system is used to generate nanobubble water with different gas sources, different dissolved gas amounts and different sizes by adjusting the gas source of the gas cylinder, the operating time of the nanobubble generator and the air intake volume;

[0033] The fluid injection system is used to inject fluid into the microfluidic chip;

[0034] The liquid migration system in the microchannel is used to simulate the migration of fluid in the pores of the formation;

[0035] The microchannel constant temperature and pressure system is used to simulate the temperature and pressure conditions of a real oil reservoir by adjusting the injection pressure of the confining pressure pump and the temperature of the water bath circulation pump;

[0036] The information acquisition and transmission system shown is used to obtain and record the oil displacement process of nanobubble water through a high-resolution microscope and a high-speed camera, and compare the oil displacement effects of nanobubbles with different gas sources, different dissolved gas amounts, and different bubble diameters; and is also used to obtain the retention state of gas in the microfluidic chip through a high-resolution microscope and a high-speed camera, and calculate the storage volume based on the data obtained by carbon dioxide content detection sensor A and carbon dioxide content detection sensor B.

[0037] Furthermore, the nanobubble generating system includes a gas cylinder, a gas cylinder valve, an adapter, a pressure gauge A, a connecting line A, a nanobubble generator, a connecting line B, a nanobubble water container, and a sample outflow port, wherein the adapter inlet end is connected to the gas outlet of the gas cylinder, the adapter outlet end is connected to the gas inlet of the nanobubble generator via the connecting line A, the water inlet of the nanobubble generator is connected to the connecting port A, and the nanobubble generator outlet is connected to the connecting port via the connecting line B. The sample can be obtained from the sample outflow port;

[0038] The fluid injection system includes a micro-flow syringe pump, valve A, valve B, valve C, piston container A, piston container B, piston container C, valve D, valve E, valve F, valve G, and pressure gauge B. The piston container A, piston container B, and piston container C are injected by the micro-flow syringe pump, the sample outlet is connected to the top of the piston container A through a pipeline, and the top outlets of the three piston containers are connected to the injection port through pipelines.

[0039] The liquid transport system in the microchannel includes a clamping and injection device, a microfluidic chip, a clamping and outflow device, a pressure gauge C, and a tail liquid collector, wherein the interior of the clamping and injection device is connected to the interior of the injection port and is connected to the injection port of the microfluidic chip, the interior of the clamping and outflow device is connected to the outflow port and is connected to the outflow port of the microfluidic chip, and the outflow port is connected to the tail liquid collector through a connecting pipeline;

[0040] The microchannel constant temperature and constant pressure system includes a high-temperature sealing clamp, a water bath circulation pump, and a confining pressure pump, wherein the water bath circulation pump is connected to the water bath circulation inlet and the water bath circulation outlet of the high-temperature sealing clamp through a connecting pipeline, and the confining pressure pump is connected to the confining pressure application interface through a connecting pipeline;

[0041] The information collection and transmission system includes a carbon dioxide content detection sensor A, a pressure sensor, a temperature sensor, a carbon dioxide content detection sensor B, a high-speed camera, a high-resolution microscope, and a computer, wherein the carbon dioxide content detection sensor A, the pressure sensor, the temperature sensor, and the carbon dioxide content detection sensor B communicate with the computer, the high-resolution microscope is arranged directly above the laser-etched channel area of the microfluidic chip, and a high-speed camera is provided on one side of the high-resolution microscope, and the high-speed camera communicates with the computer.

[0042] Furthermore, the gas source in the gas cylinder is one of air, CO2, H2, N2, and O2;

[0043] The adapter inlet end and the adapter outlet end, wherein the adapter inlet end is connected to the G5 / 8 internal thread outlet port of the gas cylinder, and the adapter outlet end is connected to a PU tube with an outer diameter of 6mm and an inner diameter of 4mm;

[0044] The nano bubble generator includes an air inlet, a water inlet, and a nano bubble generator outlet, wherein the air inlet is connected to the connecting pipeline A, the water inlet is connected to the connecting port A, and the generated nano bubbles flow out from the nano bubble generator outlet.

[0045] Furthermore, the nanobubble water container includes a sample outflow port, a connection port A, and a connection port B, wherein the connection port A is connected to the water inlet, and the connection port B is connected to the nanobubble generator outlet via a connecting line B, and the generated nanobubble sample can be obtained from the sample outflow port;

[0046] The microfluidic chip includes an injection port, a laser-etched channel area and a fluid outflow port, wherein the fluid injection port, the laser-etched channel area and the fluid outflow port are connected end to end in sequence, and the fluid passes through the injection port, the laser-etched channel area and the fluid outflow port in sequence.

[0047] Furthermore, the high-temperature sealing clamp includes a clamping device, a water bath circulation inlet, a confining pressure application interface, a water bath circulation outlet, a pressure sensor interface, an injection port, an outflow port, and a temperature sensor interface; wherein, a microfluidic chip is placed above the clamping device, the water bath circulation inlet and the water bath circulation outlet are connected to the water bath circulation pump, and the confining pressure application interface is connected to the confining pressure pump.

[0048] Combining all of the above technical solutions, the present invention has the following beneficial effects: the experimental device provided by the present invention includes a nanobubble generation system, a nanobubble injection system, a microchannel liquid transport system, and an information acquisition and transmission system. By varying the gas source, injection volume, and operating time of the nanobubble generation system, nanobubbles with different gas sources, different diameters, and different concentrations can be generated. The oil displacement effects of nanobubbles with different gas sources, different diameters, and different dissolved gas contents can then be compared, their displacement mechanisms analyzed, and the sealing effect of the nanobubbles analyzed. Furthermore, the sealing effect of the nanobubbles as a storage medium can be analyzed.

[0049] Compared with the prior art, the advantages of the present invention further include:

[0050] (1) According to the experimental requirements, the gas source of the nanobubble generation system was adjusted to generate nanobubble water with different gas sources, and the effect of the gas source type on nanobubble flooding was analyzed.

[0051] (2) According to the experimental requirements, the operation time of the nanobubble generation system was adjusted to generate nanobubble water with different dissolved gas amounts, and the effect of dissolved gas amount on nanobubble oil displacement was analyzed.

[0052] (3) According to the experimental requirements, the gas injection volume of the nanobubble generation system was adjusted to generate nanobubble water with different diameters, and the effect of nanobubble diameter on nanobubble oil displacement was analyzed.

[0053] (4) According to the experimental requirements, the gas source of the nanobubble generation system was adjusted to generate nanobubble water with different gas sources, and the storage effect of nanobubbles as a storage medium for different gases was analyzed.

[0054] (5) According to experimental requirements, the temperature of the water bath circulation pump and the injection pressure of the confining pressure pump can be adjusted to simulate the temperature and pressure conditions of a real oil reservoir.

[0055] (6) Visualization can be achieved using high-resolution microscopes and high-speed cameras. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure;

[0057] Figure 1 Schematic diagram of a nanobubble oil displacement and storage integrated experimental device provided by an embodiment of the present invention;

[0058] Figure 2 is a schematic diagram of an adapter provided by an embodiment of the present invention;

[0059] Figure 3 Schematic diagram of a nanobubble generator provided by an embodiment of the present invention;

[0060] Figure 4 This is a schematic diagram of a nano bubble water container provided by an embodiment of the present invention;

[0061] Figure 5 Schematic diagram of a microfluidic chip provided by an embodiment of the present invention;

[0062] Figure 6 is a schematic diagram of a high-temperature sealing clamp provided by an embodiment of the present invention;

[0063] Figure 7 This is a flow chart of the nanobubble oil displacement and storage integrated experimental method provided by an embodiment of the present invention;

[0064] Figure 8 This is a diagram showing the displacement effect of the air nanobubble water provided by an embodiment of the present invention when injected at 2PV;

[0065] In the figure: 1-gas cylinder, 2-gas cylinder valve, 3-adapter, 4-pressure gauge A, 5-connecting pipeline A, 6-nanobubble generator, 7-connecting pipeline B, 8-nanobubble water container, 9-sample outflow port, 10-carbon dioxide content detection sensor A, 11-microflow syringe pump, 12-valve A, 13-valve B, 14-valve C, 15-piston container A, 16-piston container B, 17-piston container C, 18-valve D, 19-valve E, 20-valve F, 21-valve G, 22-pressure gauge B, 23-pressure sensor, 24-clamping and injection device, 25-microfluidic chip, 26-clamping and outflow device, 27-high temperature sealing clamp, 28-water bath circulation pump, 29-confining pressure pump, 30-temperature sensor, 31-pressure gauge C, 32-tail liquid collector, 33-carbon dioxide content detection sensor B, 34-high-speed camera, 35-high-resolution microscope, 36-computer, 37-adapter inlet, 38-adapter outlet, 39-air inlet, 40-water inlet, 41-nanobubble generator outlet, 42-connector A, 43-connector B, 44-injection port, 45-laser-etched channel area, 46-outflow port, 47-clamping device, 48-water bath circulation inlet, 49-confining pressure application interface, 50-water bath circulation outlet, 51-pressure sensor interface, 52-injection port, 53-outflow port, 54-temperature sensor interface. DETAILED DESCRIPTION

[0066] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0067] The innovative features of the nanobubble flooding and storage integrated experimental device and method provided in the embodiments of the present invention are: adjusting the gas source of the nanobubble generation system according to experimental requirements to generate nanobubble water with different gas sources, and analyzing the effect of the gas source type on nanobubble flooding; adjusting the operating time of the nanobubble generation system to generate nanobubble water with different dissolved gas amounts, and analyzing the effect of the dissolved gas amount on nanobubble flooding; adjusting the gas injection volume of the nanobubble generation system to generate nanobubble water with different diameters, and analyzing the effect of the nanobubble diameter on nanobubble flooding; and analyzing the storage effect of nanobubbles as a storage medium.

[0068] Example 1, as Figures 1-6 As shown, the nanobubble flooding and storage integrated experimental device provided by the embodiment of the present invention includes: a nanobubble generation system, a fluid injection system, a liquid migration system in a microchannel, a microchannel constant temperature and pressure system, and an information acquisition and transmission system;

[0069] The nanobubble generating system is used to generate nanobubbles. The nanobubble generating system includes a gas cylinder 1, a valve A12, an adapter 3, a pressure gauge A4, a connecting line A5, a nanobubble generator 6, a connecting line B7, a nanobubble water container 8, and a sample outflow port 9. The adapter inlet end 37 is connected to the gas outlet of the gas cylinder 1, the adapter outlet end 38 is connected to the gas inlet 39 of the nanobubble generator 6 via the connecting line A5, the water inlet 40 of the nanobubble generator 6 is connected to the connecting port A42, and the nanobubble generator outlet 41 is connected to the connecting port 43 via the connecting line B7. The sample can be obtained from the sample outflow port 9.

[0070] It should be further pointed out that by replacing the gas in the gas cylinder 1, nanobubble water with different gas sources can be generated. By setting different operating times of the nanobubble generator 6, nanobubble water with different dissolved gas amounts can be generated. The concentration of carbon dioxide in the nanobubble water can be adjusted. The carbon dioxide content can be obtained by detecting the sensor A10. By adjusting the gas cylinder valve 2 to change the air intake volume of the air inlet 39, nanobubble water containing bubbles of different diameters can be generated. The size distribution of the nanobubbles can be determined using a nanoparticle tracking analyzer (NTA).

[0071] The fluid injection system includes a micro-flow injection pump 11, a valve A12, a valve B13, a valve C14, a piston container A15, a piston container B16, a piston container C17, a valve D18, a valve E19, a valve F20, a valve G21, a pressure gauge B22, wherein:

[0072] The piston container A15, piston container B16 and piston container C17 are injected by a micro-flow syringe pump 11. The sample outlet 9 is connected to the top of the piston container A15 through a pipeline. The top outlets 53 of the three piston containers are connected to the injection port 52 through pipelines.

[0073] The liquid migration system in the microchannel is used to simulate the migration of fluid in the pores of the formation;

[0074] The liquid transport system in the microchannel includes a clamping and injection device 24, a microfluidic chip 25, a clamping and outflow device 26, a pressure gauge C31, and a tail liquid collector 32; wherein the interior of the clamping and injection device 24 is connected to the interior of the injection port 52 and is connected to the injection port 44 of the microfluidic chip 25, the interior of the clamping and outflow device 26 is connected to the outflow port 53 and is connected to the outflow port 46 of the microfluidic chip 25, and the outflow port 53 is connected to the tail liquid collector 32 through a connecting pipeline;

[0075] The microchannel constant temperature and constant pressure system includes a high-temperature sealing holder 27, a water bath circulation pump 28, and a confining pressure pump 29; wherein the water bath circulation pump 28 is connected to the water bath circulation water inlet 48 and the water bath circulation water outlet 50 of the high-temperature sealing holder 27 via a connecting pipeline, and the confining pressure pump 29 is connected to the confining pressure application interface 49 via a connecting pipeline;

[0076] The information collection and transmission system includes a carbon dioxide content detection sensor A10, a pressure sensor 23, a temperature sensor 30, a carbon dioxide content detection sensor B33, a high-speed camera 34, a high-resolution microscope 35, and a computer 36; wherein, the carbon dioxide content detection sensor A10, the pressure sensor 23, the temperature sensor 30, and the carbon dioxide content detection sensor B33 communicate with the computer 36, the high-resolution microscope 35 is arranged directly above the laser-etched channel area 45 of the microfluidic chip 25, and a high-speed camera 34 is provided on one side of the high-resolution microscope 35, and the high-speed camera 34 communicates with the computer 36.

[0077] In the embodiment of the present invention, the gas source in the gas cylinder 1 can be replaced with air, CO2, H2, N2, O2, etc.

[0078] In an embodiment of the present invention, the adapter inlet end 37 and the adapter outlet end 38, wherein the adapter inlet end 37 is connected to the G5 / 8 internal thread gas outlet port of the gas cylinder 1, and the adapter outlet end 38 is connected to a PU tube with an outer diameter of 6 mm and an inner diameter of 4 mm.

[0079] In this embodiment of the present invention, the nanobubble generator 6 includes an air inlet 39, a water inlet 40, and a nanobubble generator outlet 41, wherein the air inlet 39 is connected to the connecting pipeline A5, the water inlet 40 is connected to the connecting port B42, and the generated nanobubbles flow out from the nanobubble generator outlet 41.

[0080] In this embodiment of the present invention, the nanobubble water container 8 includes a sample outflow port 9, a connection port A42, and a connection port B43. The connection port A42 is connected to the water inlet 40, and the connection port B43 is connected to the nanobubble generator outlet 41 via a connecting line B7. The generated nanobubble sample can be obtained from the sample outflow port 9.

[0081] In an embodiment of the present invention, the microfluidic chip 25 includes an injection port 44, a laser-etched channel area 45 and a fluid outflow port 46; wherein the fluid injection port 44, the laser-etched channel area 45 and the fluid outflow port 46 are connected end to end in sequence, and the fluid passes through the injection port 44, the laser-etched channel area 45 and the fluid outflow port 46 in sequence.

[0082] It should be further pointed out that the laser-etched channel area 45 of the selected microfluidic chip 25 contains pores with three coordination numbers, namely 3, 4, and 6, with a pore radius of 150um, a throat radius of 100um, and a pore-throat ratio of 1.5. Compared with the microfluidic chip 25 with only one coordination number, this chip can simultaneously observe the swept areas of pores with three different coordination numbers and analyze the influence of the coordination number on the swept area; it can observe the changes in the fluid seepage characteristics when a fluid flows from a pore with one coordination number to a pore with another coordination number; the S-shaped design can extend the migration distance of the fluid in the pore on a chip of a certain size, reduce the influence of the injection end on the seepage, and better restore the seepage characteristics of the real formation pores.

[0083] In an embodiment of the present invention, the high-temperature sealing clamp 27 includes a clamping device 47, a water bath circulation inlet 48, a confining pressure application interface 49, a water bath circulation outlet 50, a pressure sensor interface 51, an injection port 52, an outflow port 53, and a temperature sensor interface 54; wherein, the microfluidic chip 25 is placed above the clamping device 47, the water bath circulation inlet 48 and the water bath circulation outlet 50 are connected to the water bath circulation pump 28, and the confining pressure application interface 49 is connected to the confining pressure pump 29.

[0084] Example 2, as Figure 7As shown, the nanobubble oil displacement and storage integrated experimental method provided by the embodiment of the present invention includes:

[0085] S1, generating nanobubble water with different gas sources, different dissolved gas amounts and different sizes by adjusting the gas source of the gas cylinder 1, the operating time of the nanobubble generator 6 and the air intake;

[0086] S2, injecting appropriate fluids (deionized water, silicone oil, nanobubble water, etc.) into the microfluidic chip 25 by adjusting the fluid injection system; deionized water is injected when saturated with water; silicone oil is injected when saturated with oil; deionized water and nanobubble water are injected when displacing;

[0087] S3, by adjusting the injection pressure of the confining pressure pump 29 and the temperature of the water bath circulation pump 28, the temperature and pressure conditions of the real oil reservoir are simulated;

[0088] S4, using a high-resolution microscope 35 and a high-speed camera 34 to capture and record the oil displacement process of nanobubble water, and compare the oil displacement effects of nanobubbles with different gas sources, different dissolved gas amounts, and different bubble diameters;

[0089] S5, obtain the retention state of gas in the microfluidic chip 25 through a high-resolution microscope 35 and a high-speed camera 34, and calculate the storage amount based on the data obtained by the carbon dioxide content detection sensor A10 and the carbon dioxide content detection sensor B33.

[0090] Specifically, in step S4, during operation, if it is desired to analyze the effects of different gas sources in the nanobubbles, i.e., the types of gases contained therein, on the displacement effect, before the experiment, an appropriate amount of deionized water is first added to the nanobubble water container 8, the gas cylinder 1 is opened, and the deionized water and gas are collected in the nanobubble generator 6. The operation time of the nanobubble generator 6 is set to 5 minutes, and the generated nanobubble water is stored in the nanobubble water container 8. The nanobubble water flows from the sample outlet 9 through the connecting pipeline to the piston container A15, the oil phase is added to the piston container B16, and deionized water is added to the piston container C17. The injection pressure of the confining pressure pump 29 and the temperature of the water bath circulation pump 28 are adjusted to simulate the temperature and pressure conditions of a real oil reservoir, and the micro-flow injection pump 11 is adjusted. Deionized water is injected into the microfluidic chip 25 at a flow rate of 0.01 ml / min. When the pores in the microfluidic chip 25 are observed to be completely saturated with water through a high-resolution microscope 35, oil phase is injected into the microfluidic chip 25 at a flow rate of 0.01 ml / min. When the oil phase is completely saturated, nanobubble water is injected into the microfluidic chip 25 at a flow rate of 0.01 ml / min. A high-speed camera 34 is used to record images of the nanobubble water flooding at injection times of 0.5 PV, 1 PV, 1.5 PV, 2 PV, and no injection. The area A1 of the nanobubble water-swept region in the microfluidic chip 25 and the total area A0 of the etched region of the microfluidic chip 25 are identified by image recognition software, and the sweep coefficient E of the nanobubble water flooding is calculated. v , the expression is:

[0091]

[0092] Where: E v represents the sweep coefficient in %; A1 represents the swept area of nanobubble water in cm 2 ; A0 represents the total area of the etched area, in cm 2 ;

[0093] Identify the area A of the remaining oil phase in the affected area using image recognition software r And the area A of the oil phase when no nanobubble water is injected into the same area o , calculate the oil washing efficiency E of nanobubble water flooding D , the expression is:

[0094]

[0095] Where: E D Indicates oil washing efficiency, unit is %; A r Indicates the area of the remaining oil phase in the affected area, in cm 2 ; A o Represents the area of the oil phase in the same area when no nanobubble water is injected, in cm 2;

[0096] The final calculated recovery factor E R :

[0097] E R =E v ×E D (3)

[0098] Where: E R It represents the recovery rate in %.

[0099] The gas source was changed and the above steps were repeated to compare the sweep coefficient, oil washing efficiency and final recovery rate of nanobubble water flooding with different gas sources, and to analyze the influence of the type of gas contained in the nanobubbles on the flooding effect.

[0100] In step S4, if the effect of nanobubble dissolved gas volume on the displacement effect is to be analyzed, the gas source in the gas cylinder 1 is CO2, the operation time of the nanobubble generator 6 is set to 5 minutes, 10 minutes, 15 minutes and 20 minutes respectively, and the nanobubble water samples with these four different dissolved gas volumes are obtained. The carbon dioxide content detection sensor A10 is used to determine the solubility of CO2 in the nanobubble water generated at the four operation times. Nanobubble water flooding experiments were carried out, experimental images were obtained, the sweep coefficient, oil washing efficiency and recovery factor when injecting 2PV were calculated and compared, and the influence of the dissolved gas content of nanobubble water on the flooding effect was analyzed.

[0101] In step S4, if the effect of nanobubble diameter on the displacement effect is to be analyzed, the gas source in the gas cylinder 1 is CO2, and the gas cylinder valve 2 is adjusted so that the pressure gauge A4 reads 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, and 0.5 MPa, respectively, thereby setting five different gas injection volumes. The nanobubble generator 6 is operated for 5 minutes each to generate nanobubble water with five different diameter distributions. The size distributions of the five groups of nanobubble water are determined using a nanoparticle tracking analyzer (NTA). A nanobubble water flooding experiment is conducted, experimental images are obtained, and the sweep coefficient, oil washing efficiency, and recovery factor when injected at 2 PV are calculated and compared to analyze the effect of the nanobubble water diameter on the displacement effect.

[0102] In step S5, when calculating the storage capacity, if the purpose is to analyze the effect of nanobubbles as a storage medium for CO2, the gas source in gas cylinder 1 is CO2, the gas cylinder valve 2 is adjusted so that the pressure gauge A4 reads 0.5 MPa, the nanobubble generator 6 is operated for 30 minutes, a nanobubble water sample is obtained, and the solubility of CO2 in the sample is measured using the carbon dioxide content detection sensor A10. Adjust the injection pressure of the confining pressure pump 29 and the temperature of the water bath circulation pump 28 to simulate the temperature and pressure conditions of a real oil reservoir. Adjust the micro-flow injection pump 11 to inject deionized water into the microfluidic chip 25 at a flow rate of 0.01 ml / min. When the pores in the microfluidic chip 25 are completely saturated with water, observe through a high-resolution microscope 35. Then, inject 1 PV of nanobubble water at a flow rate of 0.01 ml / min. When the injection is complete, use the carbon dioxide content detection sensor B33 to measure the solubility of CO2 in the sample. Calculate the buried storage volume Q0:

[0103]

[0104] Where: Q0 represents the buried amount, the unit is mol; Indicates the solubility of CO2 in the nanobubble water sample, in mol / L; Indicates the solubility of CO2 in the tail liquid collector 32, in mol / L; V 孔 Represents the total volume of the etched pores in the microfluidic chip, in L; V 尾 represents the volume of the liquid in the tail liquid collector 32, in L;

[0105] Adjust the temperature of the water bath circulation pump 28 and repeat the above steps to analyze the effect of temperature on the CO2 storage capacity.

[0106] Example 3, exemplary, uses this experimental device to analyze the effect of the type of gas contained in the nanobubbles on the displacement effect.

[0107] Using air as the gas source, the nanobubble generator 6 was operated for 30 minutes to obtain an air nanobubble water sample. A microfluidic chip 25 containing three coordination numbers was selected. The confining pressure pump 29 had an injection pressure of 0.1 MPa, and the water bath circulation pump 28 had a temperature of 25° C. Deionized water was injected into the microfluidic chip 25 at a flow rate of 0.01 ml / min. When the pores in the microfluidic chip 25 were observed to be completely saturated with water using a high-resolution microscope 35 , an oil phase was injected into the microfluidic chip 25 at a flow rate of 0.01 ml / min. When the oil phase was completely saturated, nanobubble water was injected into the microfluidic chip 25 at a flow rate of 0.01 ml / min. A high-speed camera 34 was used to record images of the nanobubble water flooding at injection times of 0.5 PV, 1 PV, 1.5 PV, 2 PV, and no injection. Image recognition software was used to identify the area A1 of the nanobubble water-swept region in the microfluidic chip 25 and the total area A0 of the etched region of the microfluidic chip 25, and the sweep coefficient E of the nanobubble water flooding was calculated. v :

[0108]

[0109] Identify the area A of the remaining oil phase in the affected area using image recognition software r And the area A of the oil phase when no nanobubble water is injected into the same area o , calculate the oil washing efficiency E of nanobubble water flooding D , the expression is:

[0110]

[0111] The final calculated recovery factor E R :

[0112] E R =E v ×E D

[0113] The gas source was changed and the above steps were repeated to compare the sweep coefficient, oil washing efficiency and final recovery rate of nanobubble water flooding with different gas sources, and to analyze the effect of the type of gas contained in the nanobubbles on the flooding effect. Figure 8 This is the displacement effect diagram of air nanobubble water when injected at 2PV.

[0114] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0115] The above description is only a preferred specific implementation method of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A nanobubble oil displacement and storage integrated experimental method, characterized in that: The method includes: S1, by adjusting the gas source of the gas cylinder (1), the operating time of the nanobubble generator (6) and the air intake, nanobubble water with different gas sources, different dissolved gas amounts and different sizes is generated; S2, adjusting the fluid injection system to inject fluid into the microfluidic chip (25); S3, adjusting the injection pressure of the confining pressure pump (29) and the temperature of the water bath circulation pump (28) to simulate the temperature and pressure conditions of a real oil reservoir; S4, using a high-resolution microscope (35) and a high-speed camera (34) to capture and record the oil displacement process of nanobubble water, and compare the oil displacement effects of nanobubbles with different gas sources, different dissolved gas amounts, and different bubble diameters; Comparison of oil displacement effects with different dissolved gas volumes includes: The gas source in the gas cylinder (1) is CO2. The operation time of the nanobubble generator (6) is set to 5 minutes, 10 minutes, 15 minutes and 20 minutes respectively. The nanobubble water samples with different dissolved gas amounts are obtained. The solubility of CO2 in the nanobubble water generated at the four operation times is determined using the carbon dioxide content detection sensor A (10). Nanobubble water flooding experiments were conducted, experimental images were obtained, and the sweep coefficient, oil washing efficiency, and recovery factor when injecting 2PV were calculated and compared. The effect of the dissolved gas content of nanobubble water on the flooding effect was analyzed. Comparison of nanobubble flooding effects with different bubble diameters includes: The gas source in the gas cylinder (1) is CO2, and the gas cylinder valve (2) is adjusted so that the pressure gauge A (4) reads 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, and 0.5 MPa, respectively, thereby setting five different gas injection volumes. The nanobubble generator (6) is operated for 5 minutes to generate five nanobubble waters with different diameter distributions. The size distributions of the five groups of nanobubble waters are determined using a nanoparticle tracking analyzer (NTA). A nanobubble water flooding experiment is conducted, experimental images are obtained, and the sweep coefficient, oil washing efficiency, and recovery factor when 2PV is injected are calculated and compared. The influence of the diameter of the nanobubble water on the flooding effect is analyzed. S5, obtaining the retention state of gas in the microfluidic chip (25) through a high-resolution microscope (35) and a high-speed camera (34), and calculating the storage amount based on the data obtained by the carbon dioxide content detection sensor A (10) and the carbon dioxide content detection sensor B (33), including: obtaining the pores in the microfluidic chip (25) completely saturated with water through the high-resolution microscope (35), and then injecting 1PV of nanobubble water at a flow rate of 0.01ml / min. When the injection is completed, using the carbon dioxide content detection sensor B (33) to measure the solubility of CO2 in the sample Calculate the buried storage volume Q0: Where: Q0 represents the buried amount, the unit is mol; Indicates the solubility of CO2 in the nanobubble water sample, in mol / L; Indicates the solubility of CO2 in the tail liquid collector (32), in mol / L; V 孔 Represents the total volume of the etched pores in the microfluidic chip, in L; V 尾 represents the volume of the liquid in the tail liquid collector (32), in L; Adjust the temperature of the water bath circulation pump (28), repeat the above steps, and analyze the effect of temperature on the CO2 storage capacity.

2. The nanobubble flooding and storage integrated experimental method according to claim 1, wherein In step S4, the oil displacement process of nanobubble water is acquired and recorded by a high-resolution microscope (35) and a high-speed camera (34), and the oil displacement effects of different gas sources are compared, including: When the pores in the microfluidic chip (25) are completely saturated with water, the oil phase is injected into the microfluidic chip (25) at a flow rate of 0.01 ml / min. When the oil phase is completely saturated, nanobubble water is injected into the microfluidic chip (25) at a flow rate of 0.01 ml / min. A high-speed camera (34) is used to record images of the nanobubble water flooding at injection of 0.5 PV, 1 PV, 1.5 PV, 2 PV and no injection. The area A1 of the nanobubble water flooding in the microfluidic chip (25) and the total area A0 of the etched area of the microfluidic chip (25) are identified by image recognition software, and the sweep coefficient E of the nanobubble water flooding is calculated. v , the expression is: Where: E v represents the sweep coefficient in %; A1 represents the swept area of nanobubble water in cm 2 ; A0 represents the total area of the etched area, in cm 2 ; Identify the area A of the remaining oil phase in the affected area using image recognition software r And the area A of the oil phase when no nanobubble water is injected into the same area o , calculate the oil washing efficiency E of nanobubble water flooding D , the expression is: Where: E D Indicates oil washing efficiency, unit is %; A r Indicates the area of the remaining oil phase in the affected area, in cm 2 ; A o Represents the area of the oil phase in the same area when no nanobubble water is injected, in cm 2 ; The final calculated recovery factor E R : AND R =And v ×E D (3) Where: E R It represents the recovery rate in %. The gas source was changed and the above steps were repeated to compare the sweep coefficient, oil washing efficiency and final recovery rate of nanobubble water flooding with different gas sources, and to analyze the influence of the type of gas contained in the nanobubbles on the flooding effect.

3. A nanobubble oil displacement and storage integrated experimental device, characterized in that: The device implements the nanobubble oil displacement and storage integrated experimental method according to any one of claims 1 to 2, and comprises: a nanobubble generation system, a fluid injection system, a liquid migration system in a microchannel, a microchannel constant temperature and pressure system, and an information collection and transmission system; The nanobubble generating system is used to generate nanobubble water with different gas sources, different dissolved gas amounts and different sizes by adjusting the gas source of the gas cylinder (1), the operating time of the nanobubble generator (6) and the air intake volume; The fluid injection system is used to inject fluid into the microfluidic chip (25); The liquid migration system in the microchannel is used to simulate the migration of fluid in the pores of the formation; The microchannel constant temperature and pressure system is used to simulate the temperature and pressure conditions of a real oil reservoir by adjusting the injection pressure of the confining pressure pump (29) and the temperature of the water bath circulation pump (28); The information acquisition and transmission system is used to obtain and record the oil displacement process of nanobubble water through a high-resolution microscope (35) and a high-speed camera (34), and compare the oil displacement effects of nanobubbles with different gas sources, different dissolved gas amounts, and different bubble diameters; and is also used to obtain the retention state of gas in a microfluidic chip (25) through a high-resolution microscope (35) and a high-speed camera (34), and calculate the storage amount based on data obtained by a carbon dioxide content detection sensor A (10) and a carbon dioxide content detection sensor B (33).

4. The nanobubble flooding and storage integrated experimental device according to claim 3, wherein: The nanobubble generating system comprises a gas cylinder (1), a gas cylinder valve (2), an adapter (3), a pressure gauge A (4), a connecting line A (5), a nanobubble generator (6), a connecting line B (7), a nanobubble water container (8), and a sample outflow port (9), wherein the adapter inlet end (37) is connected to the gas outlet of the gas cylinder (1), the adapter outlet end (38) is connected to the gas inlet (39) of the nanobubble generator (6) via the connecting line A (5), the water inlet (40) of the nanobubble generator (6) is connected to the connecting port A (42), and the nanobubble generator outlet (41) is connected to the connecting port (43) via the connecting line B (7), and the sample can be obtained from the sample outflow port (9); The fluid injection system includes a micro-flow injection pump (11), a valve A (12), a valve B (13), a valve C (14), a piston container A (15), a piston container B (16), a piston container C (17), a valve D (18), a valve E (19), a valve F (20), a valve G (21), and a pressure gauge B (22), wherein the piston container A (15), the piston container B (16), and the piston container C (17) are controlled to be injected by the micro-flow injection pump (11), the sample outflow port (9) is connected to the top of the piston container A (15) through a pipeline, and the outflow ports (53) on the top of the three piston containers are connected to the injection port (52) through pipelines; The liquid transport system in the microchannel includes a clamping and injection device (24), a microfluidic chip (25), a clamping and outflow device (26), a pressure gauge C (31), a tail liquid collector (32), wherein: The interior of the clamping and injection device (24) is connected to the interior of the injection port (52), and is connected to the injection port (44) of the microfluidic chip (25); the interior of the clamping and outflow device (26) is connected to the outflow port (53), and is connected to the outflow port (46) of the microfluidic chip (25); the outflow port (53) is connected to the tail liquid collector (32) through a connecting pipeline; The microchannel constant temperature and constant pressure system comprises a high-temperature sealing holder (27), a water bath circulation pump (28), and a confining pressure pump (29), wherein the water bath circulation pump (28) is connected to a water bath circulation water inlet (48) and a water bath circulation water outlet (50) of the high-temperature sealing holder (27) via a connecting pipeline, and the confining pressure pump (29) is connected to a confining pressure application interface (49) via a connecting pipeline; The information acquisition and transmission system includes a carbon dioxide content detection sensor A (10), a pressure sensor (23), a temperature sensor (30), a carbon dioxide content detection sensor B (33), a high-speed camera (34), a high-resolution microscope (35), and a computer (36), wherein the carbon dioxide content detection sensor A (10), the pressure sensor (23), the temperature sensor (30), and the carbon dioxide content detection sensor B (33) communicate with the computer (36), the high-resolution microscope (35) is arranged directly above the laser-etched channel area (45) of the microfluidic chip (25), and a high-speed camera (34) is provided on one side of the high-resolution microscope (35), and the high-speed camera (34) communicates with the computer (36).

5. The nanobubble flooding and storage integrated experimental device according to claim 4, characterized in that: The gas source in the gas cylinder (1) is one of air, CO2, H2, N2, and O2; The adapter inlet end (37) and the adapter outlet end (38), wherein the adapter inlet end (37) is connected to the G5 / 8 internal thread gas outlet port of the gas cylinder (1), and the adapter outlet end (38) is connected to a PU tube with an outer diameter of 6 mm and an inner diameter of 4 mm; The nano bubble generator (6) comprises an air inlet (39), a water inlet (40), and a nano bubble generator outlet (41), wherein the air inlet (39) is connected to a connecting pipeline A (5), the water inlet (40) is connected to a connecting port A (42), and the generated nano bubbles flow out from the nano bubble generator outlet (41).

6. The nanobubble oil displacement and storage integrated experimental device according to claim 4, characterized in that: The nanobubble water container (8) comprises a sample outflow port (9), a connection port A (42), and a connection port B (43), wherein the connection port A (42) is connected to the water inlet (40), and the connection port B (43) is connected to the nanobubble generator outlet (41) via a connecting line B (7), and the generated nanobubble sample can be obtained from the sample outflow port (9); The microfluidic chip (25) includes a fluid injection port (44), a laser-etched channel region (45) and a fluid outflow port (46), wherein the fluid injection port (44), the laser-etched channel region (45) and the fluid outflow port (46) are connected end to end in sequence, and the fluid passes through the fluid injection port (44), the laser-etched channel region (45) and the fluid outflow port (46) in sequence.

7. The nanobubble oil displacement and storage integrated experimental device according to claim 4, characterized in that: The high-temperature sealing clamp (27) includes a clamping device (47), a water bath circulation water inlet (48), a confining pressure application interface (49), a water bath circulation water outlet (50), a pressure sensor interface (51), an injection port (52), an outflow port (53), and a temperature sensor interface (54), wherein: A microfluidic chip (25) is placed above the clamping device (47), a water bath circulation inlet (48) and a water bath circulation outlet (50) are connected to a water bath circulation pump (28), and a confining pressure application interface (49) is connected to a confining pressure pump (29).

Images