A Visualization Fluid Migration Experimental Device and Method

Abstract

The present invention provides a visualization fluid migration experimental device and method. The device includes: a housing, a heating part, a fluid migration part and an observation window; wherein, the fluid migration part is composed of at least two nested transparent capillaries; the heating part is arranged inside the housing, the fluid migration part passes through the housing and the heating part and is detachably connected to the housing and the heating part, and the heating part can heat the fluid migration part; the fluid migration part penetrating into the heating part can be observed through the observation window. The device can perform microscopic visualization observation of fluid migration under high temperature and pressure conditions.

Description

Technical Field

[0001] The present invention relates to the technical fields of oil and gas geology, ore deposit geology, fluid inclusions and microscopic analysis, and particularly relates to a visualization fluid migration experimental device and method. Background Art

[0002] Under underground deep conditions, fluid properties such as the density, solubility, viscosity, and interfacial tension of oil, gas, and water fluids will undergo significant changes, affecting the migration modes of oil, gas, and water multiphase fluids. Therefore, realizing the observation of the laws of fluid migration under high temperature and high pressure is an important requirement in the geological field and the petroleum field, which helps us further understand the activities of deep fluids, the mineralization, and the hydrocarbon accumulation processes.

[0003] Currently, fluid migration experiments under high temperature and high pressure are mainly carried out using high temperature and high pressure holders. Usually, a core is placed in the holder, and then a fluid is injected from the inlet of the holder at a certain pressure or flow rate to conduct an indoor fluid migration experiment. In order to withstand a large fluid pressure, the wall thickness of the autoclave body is usually made of thick pressure-resistant steel plates, which are mainly used to measure parameters such as fluid flow rate through experiments, and the saturation of fluids in rocks. The autoclave body of the holder is not visible, and it is impossible to directly understand the real fluid state under high temperature and high pressure, and the migration process of fluids inside the pores cannot be observed.

[0004] Currently, in order to achieve visual observation of fluid migration, quartz glass tubes are usually used; however, the diameter of quartz glass tubes is relatively large (usually greater than 1 mm). On the one hand, it is difficult to simulate real rock pores; on the other hand, it is difficult to withstand high pressure, and it is also difficult to perform high-temperature heating; in addition, due to the large diameter of quartz glass tubes, it is difficult to cooperate with online observation instruments such as laser Raman and microscopic infrared.

[0005] For example, a pore-scale simulation experimental device for microbial and air alternating oil displacement in a porous medium (CN106703764A) uses a microscopic visualization transparent quartz sand model, which is made of transparent organic glass by processing. It includes alternately welding capillary tubes into variable-diameter transparent capillary tubes using a special melting tool. The capillary tubes have diameters of 0.3 cm and 0.5 cm and a length of 27 cm, and have the above-mentioned disadvantages. Moreover, in the welding method, it is difficult to ensure the change of pore diameter at the interface. If the inner diameter of the capillary tube is at the nanometer level, it may be blocked by the molten quartz at the welded part; in addition, the welded part is a stress concentration point, and it is difficult to ensure that it does not crack under high temperature and high pressure. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a visualization fluid migration experimental device that can perform microscopic visualization observation of fluid migration under relatively high temperature and pressure conditions.

[0007] To achieve the above object, the present invention provides a visualization fluid migration experimental device, wherein the device comprises:

[0008] a housing, a heating part, a fluid migration part and an observation window; wherein,

[0009] the fluid migration part is composed of at least two transparent capillary tubes nested together;

[0010] the heating part is arranged inside the housing, and the fluid migration part passes through the housing and the heating part and the housing, and the heating part can heat the fluid migration part;

[0011] the fluid migration part penetrating into the heating part can be observed through the observation window.

[0012] In the above visualization fluid migration experimental device, the fluid migration part can be moved along the penetrating direction to adjust the part of the fluid migration part penetrating into the housing and the heating part, so as to observe each section of the fluid migration part through the observation window.

[0013] In the above visualization fluid migration experimental device, the fluid migration part passes through the housing and the heating part and the housing, so that the fluid migration part can be detachably connected to the housing and the heating part.

[0014] In the above visualization fluid migration experimental device, preferably, the heating part is a heating plate; in a specific embodiment, the heating plate includes a metal plate and at least two heating rods arranged on the metal plate.

[0015] In the above visualization fluid migration experimental device, preferably, the heating part is provided with a temperature acquisition component for acquiring the temperature at the position where the heating part contacts the fluid migration part. More preferably, the temperature acquisition component is used to acquire the temperature at the position where the heating part contacts the fluid migration part and is near the observation port.

[0016] In the above visualization fluid migration experimental device, preferably, the heating part is further provided with a temperature controller with a PID self-tuning function, so as to realize local precise temperature control of the penetrated fluid migration part.

[0017] In the above visualization fluid migration experimental device, preferably, a heat insulation part is arranged between the heating part and the housing. In a specific embodiment, the heat insulation part includes heat insulation cotton.

[0018] In the above visualization fluid migration experimental device, preferably, in the fluid migration part, the length of the transparent capillary tube nested inside is less than the length of the transparent capillary tube nested outside.

[0019] In the above visualization fluid migration experimental device, preferably, the transparent capillary tube is a quartz capillary tube.

[0020] In the above visualization fluid migration experimental device, preferably, the fluid migration part is composed of two nested transparent capillary tubes. The inner diameter of the transparent capillary tube nested inside is 50 nm - 500 nm, and the inner diameter of the transparent capillary tube nested outside is 50 nm - 500 μm. More preferably, the outer diameter of the transparent capillary tube nested outside is 100 nm - 500 μm.

[0021] In the above visualization fluid migration experimental device, preferably, the inner diameter of the transparent capillary tube does not exceed 10 μm.

[0022] In a specific embodiment, the fluid migration part is composed of two nested quartz capillary tubes. The inner diameter of the capillary tube nested outside is 330 μm and the outer diameter is 660 μm, and the outer diameter of the capillary tube nested inside is 200 - 330 μm.

[0023] In the above visualization fluid migration experimental device, preferably, an interface part is provided at the inlet of the fluid migration part, and the interface part at the inlet of the fluid migration part can realize the connection between the fluid migration part and the fluid injection device.

[0024] In the above visualization fluid migration experimental device, preferably, an interface part is provided at the outlet of the fluid migration part, and the interface part at the outlet of the fluid migration part can realize the connection between the fluid migration part and the back pressure control component.

[0025] In the above visualization fluid migration experimental device, preferably, the length of the outer shell does not exceed 100 mm, the width does not exceed 100 mm, and the height does not exceed 100 mm. In this preferred scheme, the visualization fluid migration experimental device is small in size and can be placed inside instruments such as micro Raman and infrared for on-line observation of physical and chemical properties, such as determination of parameters such as density, solubility, and interfacial tension. At the same time, in this preferred scheme, due to its small thickness, it can be placed on the microscope stage, and the phase state change and migration of substances inside the capillary tube can be observed through the observation window using a microscope, ensuring that a clear image can be seen within the working distance of the objective lens and spectroscopic tests can be carried out.

[0026] In the above visualization fluid migration experimental device, preferably, the quartz capillary tubes are not welded during nesting. In a specific embodiment, the smaller diameter capillary tube is directly placed into the larger diameter capillary tube when nesting. If the small capillary tube needs to be fixed, its outer surface can be bonded to each other with glue.

[0027] The present invention also provides a visualization fluid migration experimental method, wherein this method is carried out using the above visualization fluid migration experimental device.

[0028] In the above visualization method for fluid migration experiment, preferably, the method includes: closing the outlet of the fluid migration section, heating the fluid migration section using the heating section, injecting water into the fluid migration section at a predetermined injection pressure at a predetermined temperature, and observing the migration process of water in the fluid migration section.

[0029] In the above visualization method for fluid migration experiment, preferably, the method includes: closing the outlet of the fluid migration section, heating the fluid migration section using the heating section, injecting oil into the fluid migration section at a predetermined injection pressure at a predetermined temperature, and observing the migration process of oil in the fluid migration section.

[0030] In the above visualization method for fluid migration experiment, preferably, the method includes: after saturating the fluid migration section with water, heating the fluid migration section using the heating section, setting a certain back pressure at the outlet of the fluid migration section, injecting oil and / or gas into the fluid migration section at a predetermined injection pressure at a predetermined temperature, and observing the migration process of the fluid in the fluid migration section. More preferably, observing the migration process of the fluid in the fluid migration section includes: the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid migration section (i.e., observing the migration law of the fluid from large pores to small pores), the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid migration section (i.e., observing the migration law of the fluid from small pores to large pores), the process of the fluid entering more than two capillaries from one capillary in the fluid migration section (i.e., the migration law of the fluid from one pore to more than two pores), the process of the fluid entering one capillary from more than two capillaries in the fluid migration section (i.e., the migration law of the fluid converging from more than two pores to one pore), at least one of the migration state of the fluid and the contact characteristics between oil and / or gas and water. During this process, the temperature, injection pressure, and back pressure can be determined according to the needs of the simulation; for example, they can be determined by conventional methods based on the conditions of the simulated formation and production conditions, etc.

[0031] In the above visualization method for fluid migration experiment, preferably, the method includes: after saturating the fluid migration part with water, heating the fluid migration part using the heating part, setting a certain back pressure at the outlet of the fluid migration part, injecting oil and / or gas into the fluid migration part at different injection pressures at a predetermined temperature, and observing the migration process of the fluid in the fluid migration part, wherein the different injection pressures include injection pressures lower than the back pressure and injection pressures that break through the back pressure. More preferably, observing the migration process of the fluid in the fluid migration part includes: the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid migration part (i.e., observing the migration law of the fluid from large pores to small pores), the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid migration part (i.e., observing the migration law of the fluid from small pores to large pores), the process of the fluid entering more than two capillaries from one capillary in the fluid migration part (i.e., the migration law of the fluid from one pore to more than two pores), the process of the fluid entering one capillary from more than two capillaries in the fluid migration part (i.e., the migration law of the fluid converging from more than two pores to one pore), at least one of the migration state of the fluid and the contact characteristics between the oil and / or gas and water. During this process, the temperature, injection pressure, and back pressure can be determined according to the needs of the simulation; for example, they can be determined by conventional methods based on the conditions of the simulated formation and production conditions, etc.

[0032] In the above visualization method for fluid migration experiment, preferably, the method includes: after saturating the fluid migration part with oil, heating the fluid migration part using the heating part, setting a certain back pressure at the outlet of the fluid migration part, injecting water and / or gas into the fluid migration part at a predetermined injection pressure at a predetermined temperature, and observing the migration process of the fluid in the fluid migration part. More preferably, observing the migration process of the fluid in the fluid migration part includes: the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid migration part (i.e., observing the migration law of the fluid from large pores to small pores), the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid migration part (i.e., observing the migration law of the fluid from small pores to large pores), the process of the fluid entering more than two capillaries from one capillary in the fluid migration part (i.e., the migration law of the fluid from one pore to more than two pores), the process of the fluid entering one capillary from more than two capillaries in the fluid migration part (i.e., the migration law of the fluid converging from more than two pores to one pore), at least one of the migration state of the fluid and the contact characteristics between the water and / or gas and oil. During this process, the temperature, injection pressure, and back pressure can be determined according to the needs of the simulation; for example, they can be determined by conventional methods based on the conditions of the simulated formation and production conditions, etc.

[0033] In the above visualization fluid migration experimental method, preferably, the method includes: after saturating the fluid migration section with oil, heating the fluid migration section using the heating section, setting a certain backpressure at the outlet of the fluid migration section, injecting water and / or gas into the fluid migration section at different injection pressures at a predetermined temperature, and observing the migration process of the fluid in the fluid migration section, where the different injection pressures include injection pressures lower than the backpressure and injection pressures that break through the backpressure. More preferably, observing the migration process of the fluid in the fluid migration section includes: the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid migration section (i.e., observing the migration law of the fluid from large pores to small pores), the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid migration section (i.e., observing the migration law of the fluid from small pores to large pores), the process of the fluid entering two or more capillaries from one capillary in the fluid migration section (i.e., the migration law of the fluid from one pore to two or more pores), the process of the fluid entering one capillary from two or more capillaries in the fluid migration section (i.e., the migration law of the fluid converging from two or more pores to one pore), at least one of the migration state of the fluid and the contact characteristics between water and / or gas and oil. During this process, the temperature, injection pressure, and backpressure can be determined according to the needs of the simulation; for example, they can be determined by conventional methods based on the situation of the simulated formation and the production situation, etc.

[0034] In the above visualization fluid migration experimental method, the process of the fluid entering two or more capillaries from one capillary in the fluid migration section can refer to the process of the fluid in the capillary nested outside in the fluid migration section simultaneously entering the capillary nested inside and the channels between the capillaries nested outside; it can refer to the process of the fluid in the capillary nested outside in the fluid migration section simultaneously entering two or more capillaries nested inside. In the above visualization fluid migration experimental method, the process of the fluid entering one capillary from two or more capillaries in the fluid migration section can refer to the process of the fluid in the capillary nested inside in the fluid migration section and the fluid in the channels between the capillaries nested outside simultaneously entering the capillary nested outside; it can refer to the process of the fluid in two or more capillaries nested inside simultaneously entering the capillary nested outside.

[0035] In the above visualization fluid migration experimental method, preferably, during the process of observing the migration process of the fluid in the fluid migration section, specifically observe the shape of bubbles or oil droplets when the fluid enters a single (or multiple) large pore(s) with different diameters from small pores, and determine the maximum diameter that can be generated and the conditions such as temperature, pressure, and flow rate for forming a single bubble or oil droplet.

[0036] In the above visualization fluid migration experiment method, preferably, during the process of observing the migration process of the fluid in the fluid migration part, specifically observe the shape of the bubbles or oil droplets when the fluid enters from larger pores into single (or multiple) small pores with different diameters, and determine the maximum diameter that can be generated and the conditions such as temperature, pressure, and flow rate for forming a single bubble or oil droplet.

[0037] In the above visualization fluid migration experiment method, preferably, the method includes: after saturating the fluid migration part with water, heating the fluid migration part using the heating part, setting a certain back pressure at the outlet of the fluid migration part, injecting gas into the fluid migration part at a predetermined injection pressure at a predetermined temperature, and observing the interfacial contact relationship between the gas, water, and the capillary of the fluid migration part to determine the contact angle. During this process, the temperature, injection pressure, and back pressure can be determined according to the needs of the simulation; for example, they can be determined by conventional methods based on the simulated formation conditions and production conditions, etc.

[0038] In the above visualization fluid migration experiment method, preferably, the method includes: after saturating the fluid migration part with water, heating the fluid migration part using the heating part, setting a certain back pressure at the outlet of the fluid migration part, injecting gas into the fluid migration part at different injection pressures at a predetermined temperature, and observing the interfacial contact relationship between the gas, water, and the capillary of the fluid migration part to determine the contact angle. During this process, the temperature, injection pressure, and back pressure can be determined according to the needs of the simulation; for example, they can be determined by conventional methods based on the simulated formation conditions and production conditions, etc.

[0039] In the above visualization fluid migration experiment method, the fluid refers to the general term of oil, gas, and water, and the fluid during the process of observing the migration process of the fluid in the fluid migration part can include oil, gas, and water.

[0040] In the above visualization fluid migration experiment method, the water can be simulated formation water or actual formation water, such as brine, but is not limited to this; the oil can be simulated oil or actual crude oil, but is not limited to this.

[0041] In the above visualization fluid migration experiment method, preferably, the method includes observing the migration process of the fluid in the fluid migration part through an observation window using a microscope.

[0042] In the above visualization fluid migration experiment method, preferably, the method includes placing the above visualization fluid migration experiment device inside a micro-Raman and / or infrared instrument for on-line observation of fluid physical and chemical properties, such as parameters like density, solubility, and interfacial tension.

[0043] In the above visualization fluid migration experiment method, preferably, the method further includes performing the above process at different temperatures.

[0044] In the above visualization fluid migration experimental method, preferably, the method further includes performing the above process under different back pressures.

[0045] In the above visualization fluid migration experimental method, the diameter of the transparent capillary in the fluid migration part is determined according to the simulation requirements.

[0046] Due to its small inner diameter (50 nm - 500 μm), the capillary can withstand a relatively high fluid pressure (the inventor found that the quartz capillary can withstand a fluid pressure of up to 300 Mpa at most), and the transparent capillary (such as a quartz capillary) is completely visible, and can be observed under a microscope and online spectroscopy tests can be carried out. The visualization fluid migration experimental device provided by the present invention uses nested combinations of transparent capillaries with different diameters to simulate rock pores with different diameters. When using this visualization fluid migration experimental device to conduct a visualization fluid migration experiment, fluids such as oil, gas, and water can be injected into the capillary, and conditions such as the fluid pressure and flow rate at the inlet and outlet can be controlled to realize the fluid migration law inside and at the joints of pores with different diameters, and the capillary can be heated and pressurized to simulate the high temperature and high pressure conditions underground; and by connecting test instruments such as microscopic spectroscopy, the fluid flow and migration at the micro- and nano-scales can be observed in real time, and the changes in the fluid composition can also be measured online by connecting a laser Raman spectrometer, an infrared spectrometer, etc.

[0047] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0048] 1. Nested combinations of transparent capillaries with different inner and outer diameters are used to simulate rock pores with different diameters, and the fluid migration law inside and at the joints of pores with different diameters is observed; among them, the observation of the fluid migration law at the joints includes the observation of the migration law of the fluid entering from a large pore into a small pore and from a small pore into a large pore, quantitatively controlling and comparing the influence of the sizes of different pore diameters on fluid migration, and the migration law of the fluid entering from one pore into two (or more) pores or the fluid converging from two (or more) pores into one pore. In a specific embodiment, nested combinations of transparent capillaries with different inner and outer diameters are used to simulate rock pores with different diameters, and the shape observation of bubbles or oil droplets, the maximum diameter that can be generated, and the conditions such as temperature, pressure, and flow rate for forming a single bubble or oil droplet are determined when the fluid enters from a small pore into a single (or multiple) large pores with different diameters; the shape observation of bubbles or oil droplets, the maximum diameter that can be generated, and the conditions such as temperature, pressure, and flow rate for forming a single bubble or oil droplet are observed when the fluid enters from a larger pore into a single (or multiple) small pores with different diameters.

[0049] 2. The capillary can withstand high temperature and high pressure. The capillary can be heated by the heating part, and by controlling the fluid pressure and flow rate at the inlet and outlet of the capillary, the high temperature and high pressure conditions underground can be simulated. Brief Description of the Drawings

[0050] Figure 1 Structural Schematic of the Visual Fluid Migration Experimental Device Provided by an Embodiment of the Present Invention Figure 1 。

[0051] Figure 2 Structural Schematic of the Visual Fluid Migration Experimental Device Provided by an Embodiment of the Present Invention Figure 2 。

[0052] Figure 3 Schematic Diagram of the Structure of the Fluid Migration Part of the Visual Fluid Migration Experimental Device Provided by an Embodiment of the Present Invention.

[0053] Figure 4 Contact Angle Test Diagram in an Embodiment of the Present Invention Detailed Description of the Invention

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0055] Next, with reference to several representative embodiments of the present invention, the principles and spirits of the present invention will be elaborated in detail.

[0056] An embodiment of the present invention provides a visual fluid migration experimental device, wherein the device includes:

[0057] A housing, a heating part, a fluid migration part, and an observation window; wherein, the fluid migration part is composed of at least two transparent capillary tubes nested; the heating part is arranged inside the housing, the fluid migration part passes through the housing and the heating part and is detachably connected to the housing and the heating part, and the heating part can heat the fluid migration part; the fluid migration part penetrating into the heating part can be observed through the observation window.

[0058] Further, the heating part is selected as a heating plate; furthermore, the heating plate includes a metal plate and at least two heating rods arranged on the metal plate.

[0059] Further, the heating part is provided with a temperature acquisition component for acquiring the temperature at the position where the heating part contacts the fluid migration part; furthermore, the temperature acquisition component is used to acquire the temperature at the position where the heating part contacts the fluid migration part and is near the observation port. The temperature acquisition component can be selected as a thermocouple.

[0060] Further, the heating part is provided with a temperature controller with a PID self-tuning function.

[0061] Further, a heat insulation part is provided between the heating part and the outer shell. For example, heat insulation cotton can be filled between the heating part and the outer shell as the heat insulation part.

[0062] Further, in the fluid transport part, the length of the capillary nested inside is less than the length of the capillary nested outside.

[0063] Further, the transparent capillary is a quartz capillary.

[0064] For example, the fluid transport part is composed of two nested quartz capillaries. The outer diameter of the capillary nested outside is 330 μm for the inner diameter and 660 μm for the outer diameter, and the outer diameter of the capillary nested inside is 200 - 330 μm.

[0065] Further, the fluid transport part is composed of two nested transparent capillaries. The inner diameter of the transparent capillary nested inside is 50 nm - 500 nm, and the inner diameter of the transparent capillary nested outside is 50 nm - 500 μm; furthermore, the outer diameter of the transparent capillary nested outside is 100 nm - 1000 μm.

[0066] Further, an interface part is provided at the inlet of the fluid transport part, and the interface part at the inlet of the fluid transport part can connect the fluid transport part with the fluid injection device.

[0067] Further, an interface part is provided at the outlet of the fluid transport part, and the interface part at the outlet of the fluid transport part can connect the fluid transport part with the back pressure control component.

[0068] Further, the length of the outer shell does not exceed 100 mm, the width does not exceed 100 mm, and the height does not exceed 100 mm.

[0069] Further, the heating part can achieve heating not exceeding 500 °C.

[0070] See Figures 1 - 3 , Another embodiment of the present invention provides a visualization fluid transport experimental device, wherein the device includes: an outer shell 201, a heating part 202, a heat insulation part 204, a fluid transport part 203, and an observation window 205; wherein,

[0071] The fluid transport part 203 is composed of at least two nested transparent quartz capillaries; the outer diameter of the capillary nested in the outermost part of the fluid transport part 203 is less than 2 mm;

[0072] The heating part 202 is composed of an aluminum plate 2021 and four heating rods 2022 arranged on the aluminum plate 2021;

[0073] The heating part 202 is arranged inside the outer shell 201. An insulating part is arranged between the heating part 202 and the outer shell 201, and the insulating part is composed of insulating cotton; holes with a diameter of 2 mm are drilled in the outer shell 201 and the heating part 202 for the fluid transport part 203 to pass through, so as to realize the detachable connection of the fluid transport part 203 with the outer shell 201 and the heating part 202;

[0074] The heating part 202 can heat the fluid transport part 203; through the observation window 205, the fluid transport part 203 penetrating into the heating part 202 can be observed;

[0075] The heating part 202 is provided with a thermocouple 2023 for collecting the temperature at a position in the heating part that is in contact with the fluid transport part 203 and near the observation port 205; and the heating part 202 is provided with a temperature controller with a PID self-tuning function;

[0076] An interface part is arranged at the inlet of the fluid transport part 203, and the interface part at the inlet of the fluid transport part 203 can connect the fluid transport part 203 with the fluid injection device; an interface part is arranged at the outlet of the fluid transport part 203, and the interface part at the outlet of the fluid transport part 203 can connect the fluid transport part 203 with the back pressure control component.

[0077] Wherein, the fluid transport part 203 is composed of two nested transparent capillary tubes. The inner diameter of the transparent capillary tube nested inside is 50 nm - 500 nm, the inner diameter of the transparent capillary tube nested outside is 50 nm - 500 μm, and the outer diameter of the transparent capillary tube nested outside is 100 nm - 1000 μm.

[0078] An embodiment of the present invention provides a visualization fluid transport experiment method. Among them, this method uses Figures 1 - 3 the shown visualization fluid transport experiment device. The fluid transport part 203 is composed of two nested transparent quartz capillary tubes. The inner diameter of the capillary tube nested inside is 50 - 500 nm, the inner diameter of the capillary tube nested outside is 50 nm - 500 μm, the outer diameter of the capillary tube nested outside is 100 nm - 1000 μm, and the length of the capillary tube nested inside is less than the length of the capillary tube nested outside; this method includes:

[0079] Step 1: Install the visualization fluid transport experiment device on the microscope observation table; adjust the microscope to enable the microscope to observe the fluid transport process in the fluid transport part 203 through the observation window 205; connect the inlet of the fluid transport part 203 with the injection pump, and connect the outlet of the fluid transport part 203 with the pressure limiting valve;

[0080] Step 2: Use the heating part 202 to heat the fluid transport part 203;

[0081] Step 3: Under the heating state, close the outlet of the fluid migration part 203, inject brine into the fluid migration part 203 at a predetermined injection pressure, and use a microscope to observe the migration process of the brine in the fluid migration part 203;

[0082] Step 4: After saturating the fluid migration part 203 with brine, continue to heat the fluid migration part 203 using the heating part 202, and set a certain back pressure at the outlet of the fluid migration part 203. Inject oil and / or gas into the fluid migration part 203 at a predetermined injection pressure (the injection pressure is less than the back pressure), and use a microscope to observe the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid migration part 203, the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid migration part 203, the process of the fluid entering two capillaries from one capillary in the fluid migration part 203 (i.e., the process of the fluid entering the capillary nested inside and the channel between the capillaries nested outside simultaneously from the capillary nested outside in the fluid migration part 203), the process of the fluid entering one capillary from two capillaries in the fluid migration part 203 (the process of the fluid in the capillary nested inside and the fluid in the channel between the capillaries nested outside entering the capillary nested outside simultaneously in the fluid migration part 203), the migration state of the fluid, and the contact characteristics between the oil and / or gas and water;

[0083] Step 5: Continue to heat the fluid migration part 203 using the heating part 202, increase the injection pressure to break through the back pressure, and use a microscope to observe the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid migration part 203, the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid migration part 203, the process of the fluid entering two capillaries from one capillary in the fluid migration part 203 (i.e., the process of the fluid entering the capillary nested inside and the channel between the capillaries nested outside simultaneously from the capillary nested outside in the fluid migration part 203), the process of the fluid entering one capillary from two capillaries in the fluid migration part 203 (the process of the fluid in the capillary nested inside and the fluid in the channel between the capillaries nested outside entering the capillary nested outside simultaneously in the fluid migration part 203), the migration state of the fluid, and the contact characteristics between the oil and / or gas and water;

[0084] Wherein, when the gas is injected into the fluid migration part 203 at a predetermined injection pressure (the injection pressure is less than the back pressure) in Step 4, the contact angle can be determined by observing the interfacial contact relationship between the gas, water, and the capillary of the fluid migration part when the gas passes through the tube wall in Step 4 and Step 5;

[0085] Step 6: After saturating the fluid migration part 203 with oil, continue to heat the fluid migration part 203 using the heating part 202, and set a certain backpressure at the outlet of the fluid migration part 203. Inject water and / or gas into the fluid migration part 203 at a predetermined injection pressure (the injection pressure is less than the backpressure), and use a microscope to observe at least one of the following processes: the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid migration part 203, the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid migration part 203, the process of the fluid entering two capillaries from one capillary in the fluid migration part 203 (i.e., the process of the fluid entering the capillary nested inside and the channel between the capillaries nested outside simultaneously from the capillary nested outside in the fluid migration part 203), the process of the fluid entering one capillary from two capillaries in the fluid migration part 203 (the process of the fluid in the capillary nested inside and the fluid in the channel between the capillaries nested outside entering the capillary nested outside simultaneously in the fluid migration part 203), the migration state of the fluid, and the contact characteristics between water and / or gas and oil;

[0086] Step 7: Continue to heat the fluid migration part 203 using the heating part 202, increase the injection pressure to break through the backpressure, and use a microscope to observe at least one of the following processes: the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid migration part 203, the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid migration part 203, the process of the fluid entering two capillaries from one capillary in the fluid migration part 203 (i.e., the process of the fluid entering the capillary nested inside and the channel between the capillaries nested outside simultaneously from the capillary nested outside in the fluid migration part 203), the process of the fluid entering one capillary from two capillaries in the fluid migration part 203 (the process of the fluid in the capillary nested inside and the fluid in the channel between the capillaries nested outside entering the capillary nested outside simultaneously in the fluid migration part 203), the migration state of the fluid, and the contact characteristics between water and / or gas and oil;

[0087] Step 8: Change the pressure and temperature, and repeat the above Steps 2 - 7.

[0088] In the above method, the schematic diagram of the contact angle test is as Figure 4 shown; the results of the contact angles measured at different pressures at 25°C are as Figure 4 shown.

[0089] In the above method, instruments such as micro-Raman and infrared can be combined for on-line observation of the physical and chemical properties of the fluid, such as parameters like density, solubility, contact angle, and interfacial tension.

[0090] In the above method, during the observation of fluid migration using a microscope, the shape of bubbles or oil droplets can be observed when the fluid enters a single (or multiple) large pore(s) with different diameters from small pores, and the maximum diameter that can be generated, as well as the conditions such as temperature, pressure, and flow rate for forming a single bubble or oil droplet, can be determined.

[0091] In the above method, during the observation of fluid migration using a microscope, during the process of observing the migration process of the fluid in the fluid migration part, specifically, the shape of bubbles or oil droplets can be observed when the fluid enters a single (or multiple) small pore(s) with different diameters from larger pores, and the maximum diameter that can be generated, as well as the conditions such as temperature, pressure, and flow rate for forming a single bubble or oil droplet, can be determined.

[0092] In the above method, transparent capillary tubes with different inner and outer diameters can be nested and combined to simulate rock pores with different diameters and perform the processes of the above steps 1 - 8, so as to determine the influence of the sizes of different pore diameters on fluid migration.

[0093] In the present invention, specific embodiments are applied to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those of ordinary skill in the art, based on the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A visualization fluid migration experimental device, wherein, The device includes: a housing, a heating part, a fluid transport part, and an observation window; wherein, the fluid transport part is composed of at least two transparent capillaries nested together; the length of the transparent capillary nested inside is less than the length of the transparent capillary nested outside; the heating part is arranged inside the housing, the fluid transport part passes through the housing and the heating part, and the heating part can heat the fluid transport part; through the observation window, the fluid transport part penetrating into the heating part can be observed, and the fluid transport process in the fluid transport part that can be observed includes: the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid transport part, the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid transport part, the transport state of the fluid, and at least one of the contact characteristics between oil and / or gas and water.

2. The experimental apparatus according to claim 1, wherein, The heating part is a heating plate; the heating plate includes a metal plate and at least two heating rods arranged on the metal plate.

3. The experimental device according to claim 1, wherein, The heating part is provided with a temperature acquisition component for acquiring the temperature at the position where the heating part contacts the fluid transport part.

4. The experimental apparatus according to claim 3, wherein, The temperature acquisition component is used to acquire the temperature at the position where the heating part contacts the fluid transport part and is near the observation port.

5. The experimental device according to any one of claims 1-4, wherein, The heating part is further provided with a temperature controller with a PID self-tuning function.

6. The experimental apparatus according to claim 1, wherein, A heat insulation part is arranged between the heating part and the housing.

7. The experimental apparatus according to claim 1, wherein, The transparent capillary is a quartz capillary.

8. The experimental apparatus according to claim 1 or 7, wherein, The inner diameter of the transparent capillary is 50 nm - 500 μm.

9. The experimental apparatus according to claim 8, wherein, The fluid transport part is composed of two transparent capillaries nested together. The inner diameter of the transparent capillary nested inside is 50 nm - 500 nm, and the inner diameter of the transparent capillary nested outside is 50 nm - 500 μm.

10. According to the experimental device described in claim 1, wherein, an interface part is arranged at the inlet of the fluid transport part, and this interface part is used to connect the fluid transport part with a fluid injection device; an interface part is arranged at the outlet of the fluid transport part, and this interface part is used to connect the fluid transport part with a back pressure control component.

11. The experimental apparatus according to claim 1, wherein The length of the housing does not exceed 100 mm, the width does not exceed 100 mm, and the height does not exceed 100 mm.

12. A method for visualizing fluid migration experiments, wherein, This method is carried out using the visualization fluid transport experimental device described in any one of claims 1 - 11.

13. The method according to claim 12, wherein, This method includes: closing the outlet of the fluid transport part, heating the fluid transport part using the heating part, injecting water or oil into the fluid transport part at a predetermined injection pressure at a predetermined temperature, and observing the transport process of water or oil in the fluid transport part.

14. The method according to claim 12, wherein, The method includes: after saturating the fluid migration section with water, heating the fluid migration section using a heating section, setting a certain back pressure at the outlet of the fluid migration section, injecting oil and / or gas into the fluid migration section at a predetermined injection pressure at a predetermined temperature, and observing the migration process of the fluid in the fluid migration section; wherein, the observing the migration process of the fluid in the fluid migration section includes at least one of the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid migration section, the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid migration section, the migration state of the fluid, and the contact characteristics between the oil and / or gas and water.

15. The method according to claim 12, wherein The method includes: after saturating the fluid migration section with water, heating the fluid migration section using a heating section, setting a certain back pressure at the outlet of the fluid migration section, injecting oil and / or gas into the fluid migration section at different injection pressures at a predetermined temperature, and observing the migration process of the fluid in the fluid migration section, wherein the different injection pressures include an injection pressure lower than the back pressure and an injection pressure breaking through the back pressure; wherein, the observing the migration process of the fluid in the fluid migration section includes at least one of the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid migration section, the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid migration section, the process of the fluid entering more than two capillaries from one capillary in the fluid migration section, the process of the fluid entering one capillary from more than two capillaries in the fluid migration section, the migration state of the fluid, and the contact characteristics between the oil and / or gas and water.

16. The method according to claim 12, wherein, The method includes: after saturating the fluid migration section with oil, heating the fluid migration section using a heating section, setting a certain back pressure at the outlet of the fluid migration section, injecting water and / or gas into the fluid migration section at a predetermined injection pressure at a predetermined temperature, and observing the migration process of the fluid in the fluid migration section; wherein, the observing the migration process of the fluid in the fluid migration section includes at least one of the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid migration section, the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid migration section, the process of the fluid entering more than two capillaries from one capillary in the fluid migration section, the process of the fluid entering one capillary from more than two capillaries in the fluid migration section, the migration state of the fluid, and the contact characteristics between the water and / or gas and oil.

17. The method according to claim 12, wherein, The method includes: after saturating the fluid migration section with oil, heating the fluid migration section using a heating section, setting a certain back pressure at the outlet of the fluid migration section, injecting water and / or gas into the fluid migration section at different injection pressures at a predetermined temperature, and observing the migration process of the fluid in the fluid migration section, where the different injection pressures include injection pressures lower than the back pressure and injection pressures that break through the back pressure; wherein, observing the migration process of the fluid in the fluid migration section includes: at least one of the process of the fluid entering the capillary nested inside from the capillary nested outside in the fluid migration section, the process of the fluid entering the capillary nested outside from the capillary nested inside in the fluid migration section, the process of the fluid entering more than two capillaries from one capillary in the fluid migration section, the process of the fluid entering one capillary from more than two capillaries in the fluid migration section, the migration state of the fluid, and the contact characteristics between water and / or gas and oil.

18. The method according to claim 12, wherein, The method includes: after saturating the fluid migration section with water, heating the fluid migration section using a heating section, setting a certain back pressure at the outlet of the fluid migration section, injecting gas into the fluid migration section at a predetermined injection pressure at a predetermined temperature, and observing the interfacial contact relationship between the gas, water, and the capillary of the fluid migration section to determine the contact angle; The method includes: after saturating the fluid migration section with water, heating the fluid migration section using a heating section, setting a certain back pressure at the outlet of the fluid migration section, injecting gas into the fluid migration section at different injection pressures at a predetermined temperature, and observing the interfacial contact relationship between the gas, water, and the capillary of the fluid migration section to determine the contact angle.

19. The method according to any one of claims 12 - 18, wherein, The method includes observing the migration process of the fluid in the fluid migration section using a microscope through an observation window.

20. The method according to any one of claims 12 - 18, wherein, The method includes placing the visualized fluid migration experimental device inside a micro-Raman and / or infrared instrument for on-line observation of the physical and chemical properties of the fluid.

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