High-temperature and high-pressure gas-water two-phase matrix crack scaling physical simulation device and method

Abstract

The invention provides a high-temperature and high-pressure gas-water two-phase matrix crack scaling physical simulation device and method. The double-medium scaling and blocking conditions caused by formation pressure reduction under the high-temperature and high-pressure gas-water two-phase condition can be effectively simulated. Through the visual gas-liquid-solid three-phase separator, whether small solid particles can migrate to the visual gas-liquid-solid three-phase separator from the rock core or not can be observed in real time, and meanwhile, the collected solution can be discharged for ion content measurement. The scaling amount in the rock core can be calculated according to the ion content change before and after scaling, the volume of blocked pores is calculated according to the scaling amount, then the porosity corresponding to different blocking degrees is calculated, and the flow of gas and water is controlled through the two high-pressure displacement pumps respectively. The two check valves connected to the liquid outlet pipeline and the gas outlet pipeline are combined to ensure constant-flow displacement of gas and water without mutual channeling, and the formation high-gas-water-ratio flow mixing condition of a high-pressure gas well can be truly simulated.

Description

Technical Field

[0001] The present invention belongs to the technical field of petroleum instruments, and particularly relates to a physical simulation device and method for scale formation in high-temperature and high-pressure gas-water two-phase matrix fractures. Background Art

[0002] During the production process of high-pressure gas wells, formation scaling can block formation pores and lead to a decline in permeability, seriously affecting the gas well production, and even shutting down the well for production suspension. High-pressure gas wells are characterized by high temperature and pressure, high gas production, low water production, and well-developed natural fractures. How to simulate the on-site production characteristics in actual production through indoor physical experiments is a major problem. At the same time, simulating scale formation in high-temperature and high-pressure gas-water two-phase matrix fractures is of great significance for clarifying the formation scaling mechanism of high-pressure gas wells, efficient exploitation of gas wells, and design of plugging removal construction.

[0003] At present, the physical simulation devices for scale formation at home and abroad can be divided into two categories: static scale formation devices and dynamic scale formation devices, mainly aiming at the scale blockage caused by the incompatibility between injected water and formation water. The static scale formation device transfers formation water to a PVT cell and conducts scale formation experiments under formation temperature and pressure. The whole experimental process is carried out under static conditions and cannot simulate the formation flow situation. The dynamic scale formation devices include dynamic scale formation in pipelines and dynamic scale formation in porous media, both of which use the on-site sampled water as the experimental flowing medium and use a high-pressure displacement pump to provide displacement pressure, which is not very convenient. Summary of the Invention

[0004] The present invention provides a physical simulation device and method for scale formation in high-temperature and high-pressure gas-water two-phase matrix fractures, which solves the problems that the static scale formation device cannot simulate the formation flow and the dynamic scale formation device is not very convenient to use.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A physical simulation device for scale formation in high-temperature and high-pressure gas-water two-phase matrix fractures includes a core holder, a liquid collection bottle is connected to the core holder, a visual gas-liquid-solid three-phase separator is arranged between the core holder and the liquid collection bottle, a second high-pressure displacement pump, a third high-pressure displacement pump, a first intermediate container, and a second intermediate container are also connected to the core holder, a first high-pressure displacement pump is connected to the first intermediate container, a fourth high-pressure displacement pump is connected to the second intermediate container, and an electric heating constant temperature box is arranged outside the core holder, the first intermediate container, the second intermediate container, and the visual gas-liquid three-phase separator.

[0007] Preferably, a visual sapphire observation window is arranged on the side wall of the visual gas-liquid-solid three-phase separator, and a filter is arranged at the bottom of the visual gas-liquid-solid three-phase separator.

[0008] Preferably, a camera acquisition device is arranged outside the visual gas-liquid-solid three-phase separator, and the camera acquisition device and the visual sapphire observation window are at the same horizontal position.

[0009] Preferably, a back pressure valve is connected between the core holder and the second high-pressure displacement pump, and a gas flowmeter is connected to the back pressure valve.

[0010] Preferably, a first check valve is connected between the first intermediate container and the core holder.

[0011] Preferably, a second check valve is connected between the second intermediate container and the core holder.

[0012] Preferably, a second pressure gauge is arranged between the core holder and the first check valve, and a seventh pressure gauge is arranged between the core holder and the second check valve.

[0013] A physical simulation method for high-temperature and high-pressure gas-water two-phase matrix fracture scaling, based on a physical simulation device for high-temperature and high-pressure gas-water two-phase matrix fracture scaling, includes:

[0014] Load a core into the core holder;

[0015] Load formation water and natural gas into the first intermediate container and the second intermediate container respectively:

[0016] According to the on-site formation temperature and pressure conditions, set the temperature of the electric heating constant temperature box, and set the pressures of the first high-pressure displacement pump, the second high-pressure displacement pump, the third high-pressure displacement pump and the fourth high-pressure displacement pump;

[0017] Inject natural gas and formation water into the core holder at a constant flow rate and ratio;

[0018] Simulate the scaling occurring during the decline of formation pressure in the exploitation of high-pressure gas wells;

[0019] Realtime observe and record whether solid small particles can migrate from the core to the visual gas-liquid-solid three-phase separator;

[0020] By observing whether there are solid particles in the visual gas-liquid-solid three-phase separator, judge whether solid small particles can migrate in different core combinations;

[0021] Drain the solution in the visual gas-liquid-solid three-phase separator at regular intervals, test the ion types and contents of the solution, and calculate the porosity corresponding to different plugging degrees through the measurement of the ion types and contents of the solution.

[0022] Preferably, calculating the porosity corresponding to different plugging degrees through the measurement of the ion types and contents of the solution is specifically:

[0023] The ion content of the solution at the front end of the core scaling is the known C0, and the ion content of the solution in the visualized gas-liquid-solid three-phase separator after the core scaling is Ci. The scaling amount mi in the core can be calculated through C0 and Ci. Given that the molecular weight of the scale is M and the density is ρ, the blocked pore volume Vi can be calculated through the scaling amount, and then the porosity φi corresponding to different blockage degrees can be calculated.

[0024] Preferably, the blocked pore volume Vi after the core scaling can be expressed as

[0025] Vi = (C0 - Ci)M / ρ

[0026] In the formula: Vi is the blocked pore volume caused by the scaling amount, cm 3 ; C0 and Ci are the ion contents of the solution before and after scaling, respectively, mol; M is the molecular weight of the scale, g / mol; ρ is the density, g / cm 3 .

[0027] The porosity after the core scaling can be expressed as

[0028] φi = (Vp - Vi) / Vb

[0029] In the formula: φi is the porosity corresponding to different blockage degrees after the core scaling, dimensionless; Vp is the pore volume of the core before scaling, cm 3 ; Vb is the total volume of the core, cm 3 .

[0030] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a physical simulation device for high-temperature and high-pressure gas-water two-phase matrix fracture scaling, which can effectively simulate the double-medium scaling blockage caused by the decrease of formation pressure under high-temperature and high-pressure gas-water two-phase conditions. Through the visualized gas-liquid-solid three-phase separator, it can be observed in real time whether solid small particles can migrate from the core to the visualized gas-liquid-solid three-phase separator, and at the same time, the collected solution can be discharged for ion content measurement. Through the change of ion content before and after scaling, the scaling amount in the core can be calculated, the blocked pore volume can be calculated through the scaling amount, and then the porosity corresponding to different blockage degrees can be calculated.

[0031] Furthermore, by controlling the flow rates of gas and water respectively through two high-pressure displacement pumps, and combining two check valves connected to the liquid outlet pipeline and the gas outlet pipeline to ensure constant-flow displacement of gas and water without mutual crossflow, it can truly simulate the high gas-water ratio flow mixing situation of the formation in a high-pressure gas well.

[0032] Furthermore, by opening two holes in the left end cover of the core holder, it is ensured that the liquid inlet pipeline at the front end of the core does not scale, the gas and water are mixed in the core, and the scaling position is inside the core instead of in the pipeline for transporting formation water.

[0033] Furthermore, through the variable core combination in the core holder, the scaling environment of the formation dual media can be realistically simulated to determine whether solid small particles can migrate in the pore spaces of the core matrix or fracture pores. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a sectional view of the present invention;

[0035] Figure 2 is a schematic structural diagram of a visual gas-liquid-solid three-phase separator;

[0036] Figure 3 is a flowchart of a physical simulation method for high-temperature and high-pressure gas-water two-phase matrix fracture scaling of the present invention;

[0037] In the figure: 1 first high-pressure displacement pump, 2 first pressure gauge, 3 first valve, 4 first intermediate container, 5 second valve, 6 first check valve, 7 second pressure gauge, 8 core holder, 9 electric heating constant temperature box, 10 back pressure valve, 11 gas flowmeter, 12 third pressure gauge, 13 visual sapphire observation window, 14 visual gas-liquid-solid three-phase separator, 15 filter, 16 third valve, 17 fourth pressure gauge, 18 second high-pressure displacement pump, 19 fourth valve, 20 liquid collection bottle, 21 fourth valve, 22 fifth pressure gauge, 23 third high-pressure displacement pump, 24 fourth high-pressure displacement pump, 25 sixth pressure gauge, 26 fifth valve, 27 second intermediate container, 28 sixth valve, 29 second check valve, 30 seventh pressure gauge, 31 camera acquisition device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] 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. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected 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 fall within the scope of protection of the present invention.

[0040] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0041] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0042] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0043] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "connected" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0044] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the drawings.

[0045] As Figure 1 shown, the present invention provides a physical simulation device for high-temperature and high-pressure gas-water two-phase matrix fracture scaling, including a core holder 8. A liquid collection bottle 20 is connected to the core holder 8. A visual gas-liquid-solid three-phase separator 14 is arranged between the core holder 8 and the liquid collection bottle 20. A second high-pressure displacement pump 18, a third high-pressure displacement pump 23, a first intermediate container 4 and a second intermediate container 27 are also connected to the core holder 8. A first high-pressure displacement pump 1 is connected to the first intermediate container, and a fourth high-pressure displacement pump 24 is connected to the second intermediate container 27. An electric heating constant temperature box 9 is arranged outside the core holder 8, the first intermediate container 4, the second intermediate container 27 and the visual gas-liquid three-phase separator 14.

[0046] Another embodiment of the present invention provides a physical simulation device for high-temperature and high-pressure gas-water two-phase matrix fracture scaling, including a core holder 8, a liquid collection bottle 20 is connected to the core holder 8, a visual gas-liquid-solid three-phase separator 14 is arranged between the core holder 8 and the liquid collection bottle 20, a second high-pressure displacement pump 18, a third high-pressure displacement pump 23, a first intermediate container 4 and a second intermediate container 27 are also connected to the core holder 8, a first high-pressure displacement pump 1 is connected to the first intermediate container, a fourth high-pressure displacement pump 24 is connected to the second intermediate container 27, and an electric heating type constant temperature box 9 is arranged outside the core holder 8, the first intermediate container 4, the second intermediate container 27 and the visual gas-liquid three-phase separator 14.

[0047] A visual sapphire observation window 13 is arranged on the side wall of the visual gas-liquid-solid three-phase separator 14, and a filter 15 is arranged at the bottom of the visual gas-liquid-solid three-phase separator 14.

[0048] Another embodiment of the present invention provides a physical simulation device for high-temperature and high-pressure gas-water two-phase matrix fracture scaling, including a core holder 8, a liquid collection bottle 20 is connected to the core holder 8, a visual gas-liquid-solid three-phase separator 14 is arranged between the core holder 8 and the liquid collection bottle 20, a second high-pressure displacement pump 18, a third high-pressure displacement pump 23, a first intermediate container 4 and a second intermediate container 27 are also connected to the core holder 8, a first high-pressure displacement pump 1 is connected to the first intermediate container, a fourth high-pressure displacement pump 24 is connected to the second intermediate container 27, and an electric heating type constant temperature box 9 is arranged outside the core holder 8, the first intermediate container 4, the second intermediate container 27 and the visual gas-liquid three-phase separator 14.

[0049] A visual sapphire observation window 13 is arranged on the side wall of the visual gas-liquid-solid three-phase separator 14, and a filter 15 is arranged at the bottom of the visual gas-liquid-solid three-phase separator 14.

[0050] A camera acquisition device 31 is arranged outside the visual gas-liquid-solid three-phase separator 14, and the camera acquisition device 31 is at the same horizontal position as the visual sapphire observation window 13.

[0051] Another embodiment of the present invention provides a physical simulation device for scale formation in high-temperature and high-pressure gas-water two-phase matrix fractures, including a core holder 8, a liquid collection bottle 20 is connected to the core holder 8, a visual gas-liquid-solid three-phase separator 14 is arranged between the core holder 8 and the liquid collection bottle 20, a second high-pressure displacement pump 18, a third high-pressure displacement pump 23, a first intermediate container 4 and a second intermediate container 27 are also connected to the core holder 8, a first high-pressure displacement pump 1 is connected to the first intermediate container, a fourth high-pressure displacement pump 24 is connected to the second intermediate container 27, and an electrothermal constant-temperature box 9 is arranged outside the core holder 8, the first intermediate container 4, the second intermediate container 27 and the visual gas-liquid three-phase separator 14.

[0052] A back-pressure valve 10 is connected between the core holder 8 and the second high-pressure displacement pump 18, and a gas flowmeter 11 is connected to the back-pressure valve 10.

[0053] Another embodiment of the present invention provides a physical simulation device for scale formation in high-temperature and high-pressure gas-water two-phase matrix fractures, including a core holder 8, a liquid collection bottle 20 is connected to the core holder 8, a visual gas-liquid-solid three-phase separator 14 is arranged between the core holder 8 and the liquid collection bottle 20, a second high-pressure displacement pump 18, a third high-pressure displacement pump 23, a first intermediate container 4 and a second intermediate container 27 are also connected to the core holder 8, a first high-pressure displacement pump 1 is connected to the first intermediate container, a fourth high-pressure displacement pump 24 is connected to the second intermediate container 27, and an electrothermal constant-temperature box 9 is arranged outside the core holder 8, the first intermediate container 4, the second intermediate container 27 and the visual gas-liquid three-phase separator 14.

[0054] A first check valve 6 is connected between the first intermediate container 4 and the core holder 8.

[0055] Another embodiment of the present invention provides a physical simulation device for scale formation in high-temperature and high-pressure gas-water two-phase matrix fractures, including a core holder 8, a liquid collection bottle 20 is connected to the core holder 8, a visual gas-liquid-solid three-phase separator 14 is arranged between the core holder 8 and the liquid collection bottle 20, a second high-pressure displacement pump 18, a third high-pressure displacement pump 23, a first intermediate container 4 and a second intermediate container 27 are also connected to the core holder 8, a first high-pressure displacement pump 1 is connected to the first intermediate container, a fourth high-pressure displacement pump 24 is connected to the second intermediate container 27, and an electrothermal constant-temperature box 9 is arranged outside the core holder 8, the first intermediate container 4, the second intermediate container 27 and the visual gas-liquid three-phase separator 14.

[0056] A first check valve 6 is connected between the first intermediate container 4 and the core holder 8.

[0057] A second one-way valve 29 is connected between the second intermediate container 27 and the core holder 8.

[0058] Another embodiment of the present invention provides a physical simulation device for high-temperature and high-pressure gas-water two-phase matrix fracture scaling, which includes a core holder 8. A liquid collection bottle 20 is connected to the core holder 8. A visual gas-liquid-solid three-phase separator 14 is arranged between the core holder 8 and the liquid collection bottle 20. A second high-pressure displacement pump 18, a third high-pressure displacement pump 23, a first intermediate container 4, and a second intermediate container 27 are also connected to the core holder 8. A first high-pressure displacement pump 1 is connected to the first intermediate container. A fourth high-pressure displacement pump 24 is connected to the second intermediate container 27. An electric heating constant-temperature box 9 is arranged outside the core holder 8, the first intermediate container 4, the second intermediate container 27, and the visual gas-liquid three-phase separator 14.

[0059] A first one-way valve 6 is connected between the first intermediate container 4 and the core holder 8.

[0060] A second one-way valve 29 is connected between the second intermediate container 27 and the core holder 8.

[0061] A second pressure gauge is arranged between the core holder 8 and the first one-way valve 6, and a seventh pressure gauge 30 is arranged between the core holder 8 and the second one-way valve 29.

[0062] Another embodiment of the present invention provides a physical simulation device for high-temperature and high-pressure gas-water two-phase matrix fracture scaling. The entire device includes a high-pressure displacement pump, an intermediate container, a pressure gauge, a valve, a one-way valve, a core holder 8, an electric heating constant-temperature box 9, a back-pressure valve 10, a gas flowmeter 11, a visual sapphire observation window 13, a visual gas-liquid-solid three-phase separator 14, a filter 15, a liquid collection bottle 20, and a camera acquisition device 31.

[0063] The high-pressure displacement pump includes a first high-pressure displacement pump 1, a second high-pressure displacement pump 18, a third high-pressure displacement pump 23, and a fourth high-pressure displacement pump 24. The first high-pressure displacement pump 1 is connected to the first intermediate container 4 through a liquid inlet pipeline, and a first valve 3 and a first pressure gauge 2 are installed on the liquid inlet pipeline. The second high-pressure displacement pump 18 is connected to the back-pressure valve 10 through a liquid inlet pipeline, and a third valve 16 and a fourth pressure gauge 17 are sequentially installed on the liquid inlet pipeline. The third high-pressure displacement pump 23 is connected to the core holder 8 through a liquid inlet pipeline, and a fourth valve 19 and a fifth pressure gauge 22 are sequentially installed on the liquid inlet pipeline. The fourth high-pressure displacement pump 24 is connected to the second intermediate container 27 through a gas inlet pipeline, and a fifth valve 26 and a sixth pressure gauge 25 are installed on the gas inlet pipeline.

[0064] The first intermediate container 4 and the core holder 8 are connected through a liquid outlet pipeline, and a second valve 5, a first check valve 6, and a second pressure gauge 7 are successively installed on the liquid outlet pipeline. The second intermediate container 27 and the core holder 8 are connected through a gas outlet pipeline, and a sixth valve 28, a second check valve 29, and a seventh pressure gauge 30 are successively installed on the gas outlet pipeline.

[0065] The right end of the core holder 8 is connected to the visual gas-liquid-solid three-phase separator 14. The upper end of the visual gas-liquid three-phase separator 14 is connected to the gas outlet pipeline, and a third pressure gauge 12, a back pressure valve 10, and a gas flow meter 11 are successively connected to the gas outlet pipeline. The lower end of the visual gas-liquid three-phase separator 14 is connected to the liquid outlet pipeline, and a filter 15, a fourth valve 19, and a liquid collection bottle 20 are successively installed on the liquid outlet pipeline. Visual sapphire observation windows 13 are installed on both sides of the visual gas-liquid-solid three-phase separator 14, and a camera acquisition device 31 is installed outside the visual sapphire observation windows.

[0066] The present invention also provides a physical simulation method for high-temperature and high-pressure gas-water two-phase matrix fracture scaling, including:

[0067] A physical simulation method for high-temperature and high-pressure gas-water two-phase matrix fracture scaling includes the following steps:

[0068] S101 Load a core into the core holder 8;

[0069] S102 Respectively load formation water and natural gas into the first intermediate container 4 and the second intermediate container 27:

[0070] S103 According to the on-site formation temperature and pressure conditions, set the temperature of the electrothermal constant temperature box 9, and set the pressures of the first high-pressure displacement pump 1, the second high-pressure displacement pump 18, the third high-pressure displacement pump 23, and the fourth high-pressure displacement pump 24;

[0071] S104 Inject natural gas and formation water into the core holder 8 at a constant flow rate and ratio;

[0072] S105 Simulate the scaling occurring during the decline of formation pressure in the exploitation of a high-pressure gas well;

[0073] S106 Observe and record in real time whether solid small particles can migrate from the core to the visual gas-liquid-solid three-phase separator;

[0074] S107 Judge whether solid small particles can migrate in different core combinations by observing whether there are solid particles in the visual gas-liquid-solid three-phase separator;

[0075] S108 Release the solution in the visual gas-liquid-solid three-phase separator at regular intervals, test the ion types and contents of the solution, and calculate the porosity corresponding to different degrees of blockage through the measurement of the ion types and contents of the solution.

[0076] Specifically as follows:

[0077] S1: Loading the core into the core holder 8: The core in the core holder 8 is a variable core combination, and the core combination method can be selected according to the actual formation conditions. The combination method can be two matrix cores in series, or a matrix-fracture core in series, where the fracture is a horizontal or vertical fracture. If it is an artificial fracture, sand can also be added to the fracture to observe whether there is a combined blockage of scale and sand, simulating the scaling environment of dual media in the formation.

[0078] S2: Loading formation water and natural gas into the two intermediate containers respectively: Filter the formation water sampled on site to remove suspended solids or impurities to avoid blocking the pipeline. After testing the ion content of the filtered formation water, load it into the first intermediate container 4, and load natural gas into the second intermediate container 27.

[0079] S3: Heating and pressurizing: According to the formation temperature and pressure conditions on site, set the temperature of the electrothermal constant temperature box to the formation temperature, with a constant temperature time of more than 12 hours, and set the pressures of the first high-pressure displacement pump 1 and the fourth high-pressure displacement pump 24 to the formation pressure; the second high-pressure displacement pump 18 provides back pressure so that the pressure in the core holder can be maintained under high-pressure conditions; the third high-pressure displacement pump 23 provides confining pressure to simulate the overlying formation pressure in the actual reservoir.

[0080] S4: Injecting fluids into the core holder 8: Open the connection valve, and inject natural gas and formation water into the core at a constant flow rate and ratio. The two high-pressure displacement pumps control the gas and water flow rates respectively. At the same time, to avoid gas-water cross-flow in the pipeline, two check valves are added to ensure constant-flow displacement of gas and water without cross-flow. The gas in the intermediate container filled with gas is natural gas saturated with water, and the water in the intermediate container filled with formation water is formation water saturated with natural gas. To ensure that the liquid inlet pipeline at the front end of the core does not scale, two holes are opened in the left end cover of the core holder, one for gas inlet and the other for water inlet, to ensure that gas and water are mixed in the core, and the scaling position is inside the core rather than in the pipeline for transporting formation water.

[0081] S5: Scaling due to high-temperature pressure drop in the core: Control the outlet pressure of the core holder through the back pressure valve 10 to simulate the scaling that occurs during the decline of formation pressure in the exploitation of high-pressure gas wells, rather than the scaling caused by the incompatibility of injected water and formation water simulated by most current scaling devices.

[0082] S6: Visual gas-liquid-solid three-phase separator: The solid small particles can be observed and recorded in real time through the camera acquisition device 31 to determine whether they can migrate from the core to the visual gas-liquid-solid three-phase separator 14. There is a large hole at the left end of the visual gas-liquid-solid three-phase separator 14 to facilitate the migration of gas-liquid-solid three phases to the visual separator 14. The upper end of the visual gas-liquid-solid three-phase separator 14 has an opening for gas outlet, and the upper end is connected to a pipeline to the backpressure valve 10. There is a filter 15 and a liquid collection bottle 20 at the lower end, and the collected solution can be discharged for ion content measurement.

[0083] S7: Migration of solid small particles in the core: By observing whether there are solid particles in the visual gas-liquid-solid three-phase separator, it can be determined whether the solid small particles can migrate in different core combinations. If solid small particles are observed in the visual gas-liquid-solid three-phase separator of the matrix core series combination, it indicates that the solid small particles can migrate in the pores of the matrix core; if solid small particles are observed in the visual gas-liquid-solid three-phase separator of the matrix-fracture core series combination, it indicates that the solid small particles can migrate in the fractures.

[0084] S8: The change of core porosity during the scaling process can be obtained: The solution in the visual gas-liquid-solid three-phase separator is discharged at regular intervals, and the ion types and contents of the solution are tested. The ion content of the solution at the front end of the core scaling is known as C0, and the ion content of the solution in the visual gas-liquid-solid three-phase separator after the core scaling is Ci. The scaling amount mi in the core can be calculated through C0 and Ci. Given that the molecular weight of the scale is M and the density is ρ, the blocked pore volume Vi can be calculated through the scaling amount, and then the porosity φi corresponding to different blockage degrees can be calculated.

[0085] The blocked pore volume Vi after core scaling can be expressed as

[0086] Vi = (C0 - Ci)M / ρ1

[0087] In the formula: Vi is the blocked pore volume caused by the scaling amount, cm 3 ; C0 and Ci are the ion contents of the solution before and after scaling, mol; M is the molecular weight of the scale, g / mol; ρ is the density, g / cm 3 .

[0088] The porosity after core scaling can be expressed as

[0089] φi = (Vp - Vi) / Vb 2

[0090] In the formula: φi is the porosity corresponding to different blockage degrees after core scaling, dimensionless; Vp is the pore volume of the core before scaling, cm 3 ; Vb is the total volume of the core, cm 3 .

[0091] Although the embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments and application fields. The above specific embodiments are merely illustrative and guiding, rather than restrictive. Under the inspiration of the specification, those of ordinary skill in the art can also make many forms without departing from the scope protected by the claims of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A physical simulation device for scale formation in matrix fractures of high-temperature and high-pressure gas-water two-phase flow, characterized in that, it includes a core holder (8), a liquid collection bottle (20) is connected to the core holder (8), a visual gas-liquid-solid three-phase separator (14) is arranged between the core holder (8) and the liquid collection bottle (20), and a second high-pressure displacement pump (18), a third high-pressure displacement pump (23), a first intermediate container (4) and a second intermediate container (27) are also connected to the core holder (8). A first high-pressure displacement pump (1) is connected to the first intermediate container, and a fourth high-pressure displacement pump (24) is connected to the second intermediate container (27). An electric heating type constant temperature box (9) is arranged outside the core holder (8), the first intermediate container (4), the second intermediate container (27) and the visual gas-liquid three-phase separator (14).

2. The physical simulation device for scale formation in matrix fractures of high-temperature and high-pressure gas-water two-phase flow according to claim 1, characterized in that, a visual sapphire observation window (13) is arranged on the side wall of the visual gas-liquid-solid three-phase separator (14), and a filter (15) is arranged at the bottom of the visual gas-liquid-solid three-phase separator (14).

3. The physical simulation device for scale formation in matrix fractures of high-temperature and high-pressure gas-water two-phase flow according to claim 2, characterized in that, a camera acquisition device (31) is arranged outside the visual gas-liquid-solid three-phase separator (14), and the camera acquisition device (31) is at the same horizontal position as the visual sapphire observation window (13).

4. The physical simulation device for scale formation in matrix fractures of high-temperature and high-pressure gas-water two-phase flow according to claim 1, characterized in that, a back pressure valve (10) is connected between the core holder (8) and the second high-pressure displacement pump (18), and a gas flow meter (11) is connected to the back pressure valve (10).

5. The physical simulation device for scale formation in matrix fractures of high-temperature and high-pressure gas-water two-phase flow according to claim 1, characterized in that, a first check valve (6) is connected between the first intermediate container (4) and the core holder (8).

6. The physical simulation device for scale formation in matrix fractures of high-temperature and high-pressure gas-water two-phase flow according to claim 5, characterized in that, a second check valve (29) is connected between the second intermediate container (27) and the core holder (8).

7. The physical simulation device for scale formation in matrix fractures of high-temperature and high-pressure gas-water two-phase flow according to claim 6, characterized in that, a second pressure gauge is arranged between the core holder (8) and the first check valve (6), and a seventh pressure gauge (30) is arranged between the core holder (8) and the second check valve (29).

8. A physical simulation method for scale formation in matrix fractures of high-temperature and high-pressure gas-water two-phase flow, based on the physical simulation device for scale formation in matrix fractures of high-temperature and high-pressure gas-water two-phase flow according to any one of claims 1-7, characterized in that, it includes: loading a core into the core holder (8); loading formation water and natural gas into the first intermediate container (4) and the second intermediate container (27) respectively: Set the temperature of the electrothermal constant temperature box (9) and the pressures of the first high-pressure displacement pump (1), the second high-pressure displacement pump (18), the third high-pressure displacement pump (23) and the fourth high-pressure displacement pump (24) according to the on-site formation temperature and pressure conditions; Inject natural gas and formation water into the core holder (8) at a constant flow rate and ratio; Simulate the scaling occurring during the decline of formation pressure in the exploitation of a high-pressure gas well; Observe and record in real time whether solid small particles can migrate from the core to the visual gas-liquid-solid three-phase separator; Judge whether solid small particles can migrate in different core combinations by observing whether there are solid particles in the visual gas-liquid-solid three-phase separator; Discharge the solution in the visual gas-liquid-solid three-phase separator at regular intervals, test the types and contents of solution ions, and calculate the porosity corresponding to different degrees of blockage through the measurement of the types and contents of solution ions.

9. A physical simulation method for high-temperature and high-pressure gas-water two-phase matrix fracture scaling according to claim 8, characterized in that, Calculating the porosity corresponding to different degrees of blockage through the measurement of the types and contents of solution ions specifically is: The content of solution ions at the front end of core scaling is known as C0, and the content of solution ions in the visual gas-liquid-solid three-phase separator after core scaling is Ci. The scaling amount mi in the core can be calculated through C0 and Ci. Given that the molecular weight of the scale is M and the density is ρ, the blocked pore volume Vi can be calculated through the scaling amount, and then the porosity φi corresponding to different degrees of blockage can be calculated.

10. A physical simulation method for high-temperature and high-pressure gas-water two-phase matrix fracture scaling according to claim 9, characterized in that, The blocked pore volume Vi after core scaling can be expressed as Vi = (C0 - Ci)M / ρ (1) Where: Vi is the blocked pore volume caused by the scale deposition amount, cm 3 ; C0 and Ci are the solution ion contents before and after scale deposition, mol; M is the molecular weight of the scale, g / mol; ρ is the density, g / cm 3 ; The porosity after core scaling can be expressed as φi = (Vp - Vi) / Vb (2) Where: φi is the porosity corresponding to different degrees of blockage after core fouling, dimensionless; Vp is the pore volume of the core before fouling, cm 3 ; Vb is the total volume of the core, cm 3 .

Images