A high-temperature and high-pressure core testing device, method and application

Abstract

The present invention discloses a high-temperature and high-pressure core testing device, method, and application. The device includes a pressure control mechanism, a drainage mechanism, a heating device, an observation device, and a core holding chamber; the core holding chamber is suitable for holding cores; the drainage mechanism is suitable for inputting liquid into the core holding chamber; the pressure control mechanism includes an oil cylinder, a hydraulic pump, a hydraulic source, an accumulator, and a gas cylinder; a piston is provided in the oil cylinder, and the hydraulic pump can pump hydraulic oil into the oil cylinder to push the piston to pressurize the core holding chamber; an air bag is provided in the accumulator, the air bag is connected to the gas cylinder, and the accumulator is connected to the oil cylinder, and the gas in the gas cylinder can pass into the air bag to discharge the hydraulic oil in the accumulator into the oil cylinder, and the gas in the air bag can be released to suck the hydraulic oil in the oil cylinder into the accumulator. The device comprehensively utilizes the advantages of fast oil pressure pressurization and high air pressure regulation accuracy to achieve the target pressure quickly and accurately, and efficiently simulate the high-temperature and high-pressure environment of the core.

Description

Technical Field

[0001] The present invention relates to the field of rock testing experiments, and in particular to a high-temperature and high-pressure core testing device, method and application. Background Art

[0002] As we all know, with the continuous excavation and exploitation of surface oil and gas fields, shallow oil and gas resources are becoming increasingly scarce. Researchers are turning their attention to deep oil and gas fields. Researching these deep oil and gas fields requires simulating the high-temperature and high-pressure environments found deep underground. By examining the changes in the physical properties of oil-bearing rocks under varying pressures and temperatures, we can study the formation, evolution, and migration of reservoirs. This data provides valuable insights into the development of oil and gas fields.

[0003] Oil and gas buried deep within the earth's strata are exposed to high temperatures and high pressures. Therefore, testing the properties of core rock requires placing it in this environment. While many existing experimental instruments at home and abroad can simulate these environments and observe the properties of core rock under these conditions, they still have certain limitations. Summary of the Invention

[0004] In order to enrich the product types of core testing devices under high temperature and high pressure conditions and increase the selection space of core testing methods under high temperature and high pressure conditions, the embodiments of the present invention provide a high temperature and high pressure core testing device, method and application.

[0005] In a first aspect, an embodiment of the present invention provides a high-temperature and high-pressure core testing device, comprising a pressure control mechanism, a drainage mechanism, a heating device, an observation device, and a core holding chamber;

[0006] The core holding chamber is suitable for holding cores;

[0007] The drainage mechanism is connected to the core holding chamber and is suitable for inputting liquid into the core holding chamber;

[0008] The pressure control mechanism includes an oil cylinder, a hydraulic pump, a hydraulic source, an accumulator and a gas cylinder;

[0009] The hydraulic source is connected to the hydraulic pump, a piston is provided in the oil cylinder, the upper end of the oil cylinder is connected to the hydraulic pump, and the lower end of the oil cylinder is connected to the core holding chamber. The hydraulic pump can pump hydraulic oil into the oil cylinder to push the piston to pressurize the core holding chamber;

[0010] An air bag is provided in the accumulator, the air bag is connected to the gas cylinder, and the accumulator is connected to the oil cylinder. The gas in the gas cylinder can flow into the air bag to discharge the hydraulic oil in the accumulator into the oil cylinder, and the gas in the air bag can be discharged to suck the hydraulic oil in the oil cylinder into the accumulator.

[0011] The heating device is arranged below the core holding chamber and is suitable for heating the core holding chamber;

[0012] The observation device is arranged on the side of the core containing chamber and is suitable for observing the core containing chamber.

[0013] In one or some optional embodiments, the high-temperature and high-pressure core testing device further includes an exhaust mechanism;

[0014] The exhaust mechanism includes a stop valve and an exhaust valve connected by pipelines;

[0015] The stop valve pipeline is connected to the upper part of the core holding chamber. When the stop valve and the exhaust valve are in an open state, the gas in the core holding chamber can be discharged.

[0016] In one or some optional embodiments, the core holding chamber includes an upper shell, a transparent window and a lower shell;

[0017] The transparent window is arranged between the upper shell and the lower shell.

[0018] In one or some optional embodiments, the observation device includes a light emitter and a macro camera;

[0019] The light emitter and the macro camera face the transparent window.

[0020] In one or some optional embodiments, a control valve is provided between the oil cylinder and the hydraulic pump;

[0021] The control valve is used to control the on / off of the fluid path between the oil cylinder and the hydraulic pump.

[0022] In one or some optional embodiments, a first pressure gauge is provided between the hydraulic pump and the control valve.

[0023] In one or some optional embodiments, the drainage mechanism includes a water tank, a filter, an electric pump, a high-pressure valve and an overflow valve;

[0024] The water tank, the filter screen, the electric pump, the high-pressure valve and the core holding chamber are sequentially connected by pipelines;

[0025] The overflow valve is connected to the outlet of the electric pump and the water tank respectively.

[0026] In one or some optional embodiments, the heating device includes an adjustable heating wire, an AC power supply, a switch, a temperature sensor and a fuse that are electrically connected in sequence.

[0027] In one or some optional embodiments, the high-temperature and high-pressure core testing device further includes a temperature and pressure sensor and a second pressure gauge in communication with the core holding chamber.

[0028] In one or some optional embodiments, a charging valve is provided between the gas cylinder and the accumulator.

[0029] In a second aspect, an embodiment of the present invention provides a high-temperature and high-pressure core testing method, using the high-temperature and high-pressure core testing device described in the first aspect, comprising:

[0030] Place the core into the core holding chamber and turn on the observation device;

[0031] Inflating the air bag with gas from the gas cylinder so that the air bag reaches a first preset pressure;

[0032] injecting liquid into the core holding chamber through the drainage mechanism until the gas in the core holding chamber is completely discharged;

[0033] Pumping hydraulic oil into the oil cylinder through a hydraulic pump to push the piston down to the bottom of the oil cylinder;

[0034] heating the core holding chamber by a heating device so that the temperature inside the core holding chamber reaches a preset temperature, and pumping hydraulic oil into the oil cylinder by a hydraulic pump until the pressure inside the core holding chamber reaches a second preset pressure;

[0035] The gas in the airbag is slowly released to suck the hydraulic oil in the oil cylinder into the accumulator. The pressure in the oil cylinder changes accordingly, the piston moves upward, and the pressure in the core holding chamber slowly decreases. The core oil discharge is observed and recorded by the observation device to determine the pressure at the time of core oil discharge.

[0036] In a third aspect, an embodiment of the present invention provides an application of the high-temperature and high-pressure core testing device described in the first aspect in high-temperature and high-pressure core testing.

[0037] The beneficial effects of the above technical solutions provided in the embodiments of the present invention include at least:

[0038] The high-temperature and high-pressure core testing device provided in the embodiment of the present invention heats the core holding chamber through a heating device so that the core holding chamber reaches a preset temperature, thereby simulating the high-temperature conditions of the core. By pumping hydraulic oil into the cylinder, the core holding chamber can be pressurized. By inflating and deflating the airbag, the hydraulic oil flows between the accumulator and the cylinder, so that the piston action accurately adjusts the pressure in the core holding chamber. The advantages of fast oil pressure change and fast pressurization as well as slow air pressure change and high pressure regulation accuracy are comprehensively utilized to achieve the target pressure quickly and accurately, efficiently simulate the high-temperature and high-pressure environment of the core, and obtain the pressure difference at the oil outlet point of the core by discharging the gas in the accumulator after reaching the preset temperature and preset pressure. It has great practical significance for the research and testing of core characteristics.

[0039] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0040] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0042] Figure 1 A schematic diagram of the structural principle of a high-temperature and high-pressure core testing device provided in an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of the external structure of a high-temperature and high-pressure core testing device provided in an embodiment of the present invention;

[0044] Figure 3 The figure is a flow chart of the high-temperature and high-pressure core testing method provided in an embodiment of the present invention.

[0045] In the picture:

[0046] 1 is a pressure control mechanism, 11 is a cylinder, 111 is a piston, 12 is a hydraulic pump, 13 is a hydraulic source, 14 is an accumulator, 141 is an air bag, 15 is a gas cylinder, 16 is a control valve, and 17 is an inflation valve;

[0047] 2 is the drainage mechanism, 21 is the water tank, 22 is the filter screen, 23 is the electric pump, 24 is the high-pressure valve, and 25 is the overflow valve;

[0048] 3 is a heating device, 31 is an adjustable heating wire, 32 is an AC power supply, 33 is a switch, 34 is a temperature sensor, and 35 is a fuse;

[0049] 4 is an observation device, 41 is a light emitter, and 42 is a macro camera;

[0050] 5 is a core storage chamber, 51 is an upper shell, 52 is a transparent window, and 53 is a lower shell;

[0051] 6 is an exhaust mechanism, 61 is a stop valve, and 62 is an exhaust valve;

[0052] 7 is the first pressure gauge, 8 is the temperature and pressure sensor, and 9 is the second pressure gauge;

[0053] 100 is the core. DETAILED DESCRIPTION

[0054] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0055] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "far," "near," "front," and "back" and the like, indicating positions or relationships, are based on the positions or relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0056] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0057] The inventors have found that in existing high-temperature and high-pressure core experimental equipment, due to the complex internal pressure characteristics of the liquid, it is difficult to control the pressure adjustment in the high-temperature and high-pressure closed chamber, and the pressure adjustment accuracy is not high.

[0058] Based on this, an embodiment of the present invention provides a high-temperature and high-pressure core testing device, method and application, which are described in detail below through specific embodiments.

[0059] Example 1

[0060] The embodiment of the present invention provides a high temperature and high pressure core testing device, referring to Figure 1 and Figure 2 As shown, it includes a pressure control mechanism 1, a drainage mechanism 2, a heating device 3, an observation device 4 and a core holding chamber 5;

[0061] The core holding chamber 5 is suitable for holding the core 100;

[0062] The drainage mechanism 2 is connected to the core holding chamber 5 and is suitable for inputting liquid into the core holding chamber 5;

[0063] The pressure control mechanism 1 includes an oil cylinder 11, a hydraulic pump 12, a hydraulic source 13, an accumulator 14 and a gas cylinder 15;

[0064] The hydraulic source 13 is connected to the hydraulic pump 12. A piston 111 is provided in the oil cylinder 11. The upper end of the oil cylinder 11 is connected to the hydraulic pump 12, and the lower end of the oil cylinder 11 is connected to the core storage chamber 5. The hydraulic pump 12 can pump hydraulic oil into the oil cylinder 11 to push the piston 111 to pressurize the core storage chamber 5.

[0065] An airbag 141 is provided in the accumulator 14. The airbag 141 is connected to the gas cylinder 15. The accumulator 14 is connected to the oil cylinder 11. The gas in the gas cylinder 15 can flow into the airbag 141 to discharge the hydraulic oil in the accumulator 14 into the oil cylinder 11. In addition, the gas in the airbag 141 can be discharged to suck the hydraulic oil in the oil cylinder 11 into the accumulator 14.

[0066] The heating device 3 is arranged below the core holding chamber 5 and is suitable for heating the core holding chamber 5;

[0067] The observation device 4 is arranged on the side of the core containing chamber 5 and is suitable for observing the core containing chamber 5 .

[0068] In the embodiment of the present invention, since the accumulator 14 and the oil cylinder 11 are connected up and down, the space between the accumulator 14 and the airbag 141 and the upper part of the piston 111 are filled with hydraulic oil. When gas is introduced into the airbag 141 to expand the airbag 141, the hydraulic oil is discharged from the accumulator 14 into the oil cylinder 11, thereby pushing the piston 111 downward, thereby indirectly pressurizing the core holding chamber 5; when gas is discharged from the airbag 141 to shrink the airbag, the hydraulic oil in the oil cylinder 11 is sucked into the accumulator 14, and the pressure in the oil cylinder 11 is reduced, thereby causing the piston 111 to move upward, thereby indirectly releasing the pressure on the core holding chamber 5. The pressure control principle of the pressure control mechanism 1 provided in the embodiment of the present invention is that: due to the rapid change of hydraulic pressure, the hydraulic pump 12 can push the piston 111 to move downward quickly when pumping the hydraulic oil in the hydraulic source 13 into the cylinder 11, thereby quickly pressurizing the core holding chamber 5, so that the pressure in the core holding chamber 5 quickly reaches the target pressure value, while the air pressure changes slowly. In the process of inflating the airbag 141 or releasing the gas in the airbag 141, the hydraulic oil flows between the cylinder 11 and the accumulator 14, so that the piston 111 moves slowly, thereby realizing precise pressure regulation of the core holding chamber 5.

[0069] In the embodiment of the present invention, the gas used for pressure regulation stored in gas cylinder 15 is nitrogen. Because nitrogen has a large compression space, precise pressure regulation can be achieved through the filling and release of nitrogen. Through experiments, the inventors have found that, under conditions of high temperature and high pressure in the core holding chamber 5, the pressure within the core holding chamber 5 can be precisely fine-tuned by filling or releasing nitrogen, with an adjustment accuracy of up to 0.01 MPa. Obviously, the gas used for pressure regulation is not limited to nitrogen; other gases can also be used, as long as they can achieve fine pressure regulation. This is not a limitation here.

[0070] In the embodiment of the present invention, referring to Figure 1 As shown, a control valve 16 is provided between the oil cylinder 11 and the hydraulic pump 12 , and the control valve 16 can control the on-off of the fluid path between the hydraulic pump 12 and the oil cylinder 11 .

[0071] In a specific embodiment, an inflation valve 17 is provided between the gas cylinder 15 and the airbag 141 . The inflation valve 17 can control the on-off of the pipeline between the gas cylinder 15 and the airbag 141 . When the inflation valve 17 is opened, the gas in the gas cylinder 15 can flow into the airbag 141 .

[0072] In one embodiment, referring to Figure 1 and Figure 2As shown, the core storage chamber 5 may include an upper shell 51, a transparent window 52, ​​and a lower shell 53, which are arranged in sequence. The transparent window 52 is disposed between the upper shell 51 and the lower shell 53. When the core 100 is contained in the core storage chamber 5, the shape of the core 100 can be observed through the transparent window 52. The upper shell 51, the transparent window 52, ​​and the lower shell 53 all have good thermal conductivity. The heating device 3 can heat the core storage chamber 5 to simulate the high temperature conditions surrounding the core 100.

[0073] In one embodiment, referring to Figure 1 and Figure 2 As shown, the high-temperature and high-pressure core testing device may further include an exhaust mechanism 6, which is in communication with the upper portion of the core storage chamber 5. The gas in the core storage chamber 5 can be discharged through the exhaust mechanism 6. The exhaust mechanism 6 includes a stop valve 61 and an exhaust valve 62 connected by pipelines. The stop valve 61 is connected by a pipeline to the upper shell 51 of the core storage chamber 5. When the stop valve 61 and the exhaust valve 62 are simultaneously opened, the gas in the core storage chamber 5 can be discharged.

[0074] In one embodiment, referring to Figure 1 and Figure 2 As shown, the drainage mechanism 2 may include a water tank 21, a filter 22, an electric pump 23, a high-pressure valve 24, and a relief valve 25. The water tank 21, filter 22, electric pump 23, high-pressure valve 24, and core holding chamber 5 are sequentially connected by pipelines. The electric pump 23 can pump water from the water tank 21 into the core holding chamber 5. When the core holding chamber 5 contains a core 100, the liquid discharged into the core holding chamber 5 by the drainage mechanism 2 displaces the gas in the core holding chamber 5. Furthermore, the liquid enters the lower portion of the piston 111 in the oil cylinder 11, causing a significant change in the pressure in the core holding chamber 5 when the piston 111 is actuated. In this embodiment, the purpose of injecting liquid into the core holding chamber 5 to displace the gas is to better increase the pressure to simulate the high temperature and high pressure conditions surrounding the core 100.

[0075] In one embodiment, referring to Figure 1 and Figure 2 As shown, a filter screen 22 is provided at the outlet of the water tank 21 to filter the liquid flowing out of the water tank 21 to prevent impurities in the liquid from entering the pipeline and causing blockage or damage to the equipment and pipeline. A high-pressure valve 24 is used to control the flow of the pipeline between the electric pump 23 and the core storage chamber 5. When the high-pressure valve 24 is opened, the electric pump 23 can pump liquid into the core storage chamber 5. The relief valve 25 is connected to the outlet of the electric pump 23 and the water tank 21 respectively. When the high-pressure valve 24 reaches a preset pressure threshold, the relief valve 25 opens to release the liquid, thereby ensuring that the pipeline pressure is within the preset pressure range and ensuring the safe and stable operation of the pipeline and equipment.

[0076] In one embodiment, referring to Figure 1and Figure 2 As shown, the heating device 3 can utilize a PWM-controlled heater, comprising an adjustable heating wire 31, an AC power supply 32, a switch 33, a temperature sensor 34, and a fuse 35 electrically connected in sequence. The switch 33 can adjust the AC power level to achieve temperature regulation. The PWM-controlled heater heats the lower shell 53 of the core storage chamber 5, raising the temperature within the chamber to a target value, thereby simulating the high-temperature environment of the core 100. Clearly, the heating device 3 is not limited to the aforementioned PWM-controlled heater; other heating and temperature-raising devices may also be employed. For details, please refer to the prior art and will not be elaborated upon here.

[0077] In one embodiment, referring to Figure 1 As shown, the observation device 4 includes a light emitter 41 and a macro camera 42 facing the transparent window 52. The light emitter 41 emits light to illuminate the core 100 in the transparent window 52, ​​and the macro camera 42 captures and stores the images within the transparent window 52. The images captured by the macro camera 42 can be used to observe the changes in the core 100 in the core holding chamber 5. The observation device 4 can capture and record the process of the core 100 undergoing morphological changes, and the temperature and temperature in the core holding chamber 5 can be continuously monitored by the temperature and pressure sensor 8. The light emitter 41 can output ultraviolet light to accurately observe the oil production of the core 100.

[0078] The high-temperature and high-pressure core testing device provided in an embodiment of the present invention pressurizes and heats the core holding chamber through the cooperation of the pressure control mechanism 1 and the heating device 3, so that the core holding chamber 5 can simulate the high-temperature and high-pressure environment of the core 100, and then test the core 100 under high-temperature and high-pressure conditions.

[0079] In one embodiment, referring to Figure 1 As shown, a first pressure gauge 7 is provided between the hydraulic pump 12 and the control valve 16 , through which the pressure above the first piston 111 in the oil cylinder 11 can be monitored. When the pressure is too high, the oil pumping is stopped to ensure safe operation.

[0080] In one embodiment, referring to Figure 1 As shown, the high-temperature, high-pressure core testing apparatus also includes a temperature and pressure sensor 8 and a second pressure gauge 9 in communication with the core holding chamber 5. The temperature and pressure sensor 8 monitors the temperature and pressure within the core holding chamber 5 in real time to determine whether the pressure within the core holding chamber 5 has reached the target temperature and pressure, and to perform heating and pressurization operations accordingly. The second pressure gauge 9 is a mechanical pressure gauge that also monitors the pressure within the core holding chamber 5 in real time. Working in conjunction with the temperature and pressure sensor 8, it serves as a calibration and safety feature, enabling timely detection of abnormalities.

[0081] In the embodiment of the present invention, the process of using the high temperature and high pressure core testing device to test the core 100 under high temperature and high pressure conditions may specifically include:

[0082] The gas in the gas cylinder 15 is introduced into the airbag 141 in advance to expand the airbag 141. The pressure above the second piston 141 in the accumulator 14 is roughly the same as the pressure in the space where the core is located during the experiment. The purpose of pre-inflation is to generate a sufficient pressure difference between the core holding chamber 5 and the outside world when the gas in the accumulator 14 is released.

[0083] Fix the core 100 in the core storage chamber 5 and use screws to tighten the upper and lower shells 53 and the transparent window 52 to ensure the tightness of the core storage chamber 5;

[0084] The liquid is discharged from the water tank 21 into the core holding chamber 5 by the electric pump 23 until the exhaust mechanism 6 stops discharging gas. Then, the stop valve 61 and the high-pressure valve 24 are closed successively. If there are bubbles stuck in the core holding chamber 5, the core holding chamber 5 can be shaken to ensure that the gas is completely discharged.

[0085] The hydraulic oil is pumped into the upper part of the oil cylinder 11 by the hydraulic pump 12 until the piston 111 in the oil cylinder 11 is pressed down to the bottom of the oil cylinder 11;

[0086] The heating device 3 is started to heat the interior of the shell to a preset temperature. After the liquid expands due to the heat and pushes up the piston 111, the hydraulic pump 12 continues to pump hydraulic oil into the upper part of the cylinder 11, causing the piston 111 to move downward under the action of the oil pressure, pressurizing the interior of the shell to a preset pressure, thereby simulating the high temperature and high pressure environment in the core holding chamber 5;

[0087] The nitrogen in the airbag 141 is slowly released. At this time, the pressure in the airbag 141 drops and it begins to contract. The hydraulic oil in the oil cylinder 11 is sucked into the accumulator 14. The oil pressure in the oil cylinder 11 changes accordingly, and the piston 111 moves upward, indirectly reducing the pressure in the core storage chamber 5. During the nitrogen release process, the core 100 is continuously observed through the observation device 4 until oil and gas are precipitated from the core 100 under the condition of the internal and external pressure difference. The pressure during the oil and gas precipitation is recorded to obtain the pressure at the oil outlet point.

[0088] The high-temperature and high-pressure core testing device provided in the embodiment of the present invention heats the core holding chamber 5 through the heating device 3 so that the core holding chamber 5 reaches a preset temperature, thereby simulating the high-temperature conditions of the core. By pumping hydraulic oil into the oil cylinder 11, the core holding chamber 5 can be pressurized. By inflating and deflating the air bag 141, the pressure in the core holding chamber 5 can be accurately adjusted. The advantages of fast oil pressure change and fast pressurization as well as slow air pressure change and high pressure regulation accuracy are comprehensively utilized to achieve the target pressure quickly and accurately, and efficiently simulate the high-temperature and high-pressure environment of the core 100. After reaching the preset temperature and preset pressure, the pressure of the oil outlet of the core 100 can be obtained by discharging the gas in the air bag 141, which has great practical significance for the research and testing of the characteristics of the core 100.

[0089] Example 2

[0090] Based on the same inventive concept, an embodiment of the present invention further provides a high-temperature and high-pressure core testing method, using the high-temperature and high-pressure core testing device described in Example 1, comprising:

[0091] S101: Place the core 100 into the core holding chamber 5 and turn on the observation device 4;

[0092] S102: Filling the gas in the gas cylinder 15 into the air bag 141 so that the air bag 141 reaches a first preset pressure;

[0093] S103: Liquid is introduced into the core holding chamber 5 through the drainage mechanism 2 until the gas in the core holding chamber 5 is completely discharged;

[0094] S104: Pumping hydraulic oil into the oil cylinder 11 through the hydraulic pump 12 to push the piston 111 downward to the bottom of the oil cylinder 11;

[0095] S105: The core holding chamber 5 is heated by the heating device 3 so that the temperature inside the core holding chamber 5 reaches a preset temperature, and the hydraulic oil is pumped into the oil cylinder 11 by the hydraulic pump 12 until the pressure inside the core holding chamber 5 reaches a second preset pressure;

[0096] S106: The gas in the air bag 141 is slowly released to suck the hydraulic oil in the oil cylinder 11 into the accumulator 14. The pressure in the oil cylinder 11 changes accordingly, the piston moves upward, and the pressure in the core holding chamber 5 slowly decreases. The oil discharge from the core 100 is observed and recorded by the observation device 4 to determine the pressure at the time of oil discharge from the core 100.

[0097] In the embodiment of the present invention, the high-temperature and high-pressure core testing method corresponds to the high-temperature and high-pressure core testing device described in Example 1. Its specific implementation process can refer to the process of implementing high-temperature and high-pressure core testing using the high-temperature and high-pressure core testing device in Example 1. The repeated parts will not be repeated here.

[0098] Example 3

[0099] Based on the same inventive concept, an embodiment of the present invention further provides an application of the high-temperature and high-pressure core testing device described in Example 1 in high-temperature and high-pressure core testing.

[0100] In the embodiment of the present invention, the specific process of using the high-temperature and high-pressure core testing device to implement high-temperature and high-pressure core testing can refer to the process of using the high-temperature and high-pressure core testing device to implement high-temperature and high-pressure core testing in Example 1. The repeated parts will not be repeated here.

[0101] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. The present disclosure is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and variations may be made without departing from the scope of the present disclosure. The scope of the present disclosure is limited solely by the appended claims. Thus, to the extent such modifications and variations fall within the scope of the claims and their equivalents, the present disclosure is intended to include such modifications and variations.

Claims

1. A high temperature and high pressure core testing device, characterized in that: It includes a pressure control mechanism, a drainage mechanism, a heating device, an observation device and a core holding chamber; The core holding chamber is suitable for holding cores; The drainage mechanism is connected to the core holding chamber and is suitable for inputting liquid into the core holding chamber; The pressure control mechanism includes an oil cylinder, a hydraulic pump, a hydraulic source, an accumulator and a gas cylinder; The hydraulic source is connected to the hydraulic pump, a piston is provided in the oil cylinder, the upper end of the oil cylinder is connected to the hydraulic pump, and the lower end of the oil cylinder is connected to the core holding chamber. The hydraulic pump can pump hydraulic oil into the oil cylinder to push the piston to pressurize the core holding chamber; An air bag is provided in the accumulator, the air bag is connected to the gas cylinder, and the accumulator is connected to the oil cylinder. The gas in the gas cylinder can flow into the air bag to discharge the hydraulic oil in the accumulator into the oil cylinder, and the gas in the air bag can be discharged to suck the hydraulic oil in the oil cylinder into the accumulator. The heating device is arranged below the core holding chamber and is suitable for heating the core holding chamber; The observation device is arranged on the side of the core storage chamber and is suitable for observing the core storage chamber; The high-temperature and high-pressure core testing device further includes an exhaust mechanism; The exhaust mechanism includes a stop valve and an exhaust valve connected by pipelines; The stop valve pipeline is connected to the upper part of the core storage chamber, and when the stop valve and the exhaust valve are opened, the gas in the core storage chamber can be discharged; The drainage mechanism includes a water tank, a filter, an electric pump, a high-pressure valve and a relief valve; The water tank, the filter screen, the electric pump, the high-pressure valve and the core holding chamber are sequentially connected by pipelines; The overflow valve is connected to the outlet of the electric pump and the water tank respectively.

2. The high-temperature and high-pressure core testing device according to claim 1, characterized in that: The core holding chamber comprises an upper shell, a transparent window and a lower shell; The transparent window is arranged between the upper shell and the lower shell.

3. The high-temperature and high-pressure core testing device according to claim 2, characterized in that: The observation device includes a light emitter and a macro camera; The light emitter and the macro camera face the transparent window.

4. The high-temperature and high-pressure core testing device according to claim 1, characterized in that: A control valve is provided between the oil cylinder and the hydraulic pump; The control valve is used to control the on / off of the fluid path between the oil cylinder and the hydraulic pump.

5. The high-temperature and high-pressure core testing device according to claim 4, characterized in that: A first pressure gauge is provided between the hydraulic pump and the control valve.

6. The high-temperature and high-pressure core testing device according to claim 1, characterized in that: The heating device includes an adjustable heating wire, an AC power supply, a switch, a temperature sensor and a fuse which are electrically connected in sequence.

7. The high-temperature and high-pressure core testing device according to claim 1, characterized in that: The high-temperature and high-pressure core testing device further includes a temperature and pressure sensor and a second pressure gauge communicated with the core containing chamber.

8. The high-temperature and high-pressure core testing device according to claim 1, characterized in that: A charging valve is provided between the gas cylinder and the accumulator.

9. A high-temperature and high-pressure core testing method, using the high-temperature and high-pressure core testing device according to any one of claims 1 to 8, characterized in that: include: Place the core into the core holding chamber and turn on the observation device; Inflating the air bag with gas from the gas cylinder so that the air bag reaches a first preset pressure; injecting liquid into the core holding chamber through the drainage mechanism until the gas in the core holding chamber is completely discharged; Pumping hydraulic oil into the oil cylinder through a hydraulic pump to push the piston down to the bottom of the oil cylinder; heating the core holding chamber by a heating device so that the temperature inside the core holding chamber reaches a preset temperature, and pumping hydraulic oil into the oil cylinder by a hydraulic pump until the pressure inside the core holding chamber reaches a second preset pressure; The gas in the airbag is slowly released to suck the hydraulic oil in the oil cylinder into the accumulator. The pressure in the oil cylinder changes accordingly, the piston moves upward, and the pressure in the core holding chamber slowly decreases. The core oil discharge is observed and recorded by the observation device to determine the pressure at the time of core oil discharge.

10. Use of the high-temperature and high-pressure core testing device according to any one of claims 1 to 8 in high-temperature and high-pressure core testing.

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