A high-temperature and high-pressure gas well annulus pressure simulation and control experimental device

Abstract

The present invention discloses a high-temperature, high-pressure gas well annulus pressure simulation and control experimental device, comprising a gas cylinder, a high-temperature, high-pressure autoclave, a heating device, a liquid storage tank, a liquid injection pipeline, a liquid discharge pipeline, an exhaust pipeline, and a data acquisition and control system. The gas cylinder is connected to the high-temperature, high-pressure autoclave via the gas injection pipeline. The high-temperature, high-pressure autoclave comprises a body, a lid, and a side cover. The body is provided with a main chamber and a side chamber, which are interconnected and have mutually perpendicular axes. The top of the main chamber is connected to the lid, and the end of the side chamber is connected to the side cover. The side chamber is located in the middle of the main chamber, and is provided with a first clamp and a second clamp for clamping a sample to be tested. The side chamber is connected to the exhaust pipeline. The heating device is connected to the body. The liquid storage tank is connected to the liquid injection pipeline via a pressure pump. The liquid discharge pipeline is connected to the bottom of the main chamber. The data acquisition and control system comprises a connected integrated controller and a computer. The present invention can conduct annulus pressure simulation and control research, providing technical support for gas well production.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and natural gas drilling fluid engineering, and in particular to a high-temperature and high-pressure gas well annulus pressure simulation and control experimental device. Background Art

[0002] In recent years, with the rapid economic development of my country and the awakening of environmental awareness, the demand for clean fossil energy sources, such as natural gas, has also increased. As natural gas exploration and development advances into deep and ultra-deep, high-temperature, and high-pressure formations, the problem of annular pressure is becoming increasingly serious, posing new challenges to the safe production of high-temperature, high-pressure gas wells. During the production process of high-temperature, high-pressure gas wells, annular pressure increases, primarily due to fluid thermal expansion and well barrier failure and leakage, resulting in annular pressure. High-pressure production can lead to problems such as tubing failure and wellhead failure. Excessive leakage can even cause safety issues such as gas poisoning and natural gas explosions.

[0003] Currently, domestic gas fields have implemented a series of measures to address annular pressure in gas wells, including compressible foam filling, rupture disks, and reducing wellbore temperatures. However, due to the limitations of field testing, the effectiveness of these measures cannot be directly observed. Furthermore, the current lack of an indoor simulation device capable of simultaneously testing multiple control technologies hinders research on annular pressure simulation and control. Therefore, a new experimental device for simulating and controlling annular pressure in high-temperature, high-pressure gas wells is needed. Summary of the Invention

[0004] In view of the above problems, the present invention aims to provide a high-temperature and high-pressure gas well annulus pressure simulation and control experimental device.

[0005] The technical solutions of the present invention are as follows:

[0006] A high-temperature and high-pressure gas well annulus pressure simulation and control experimental device, including a gas cylinder, a high-temperature and high-pressure autoclave, a heating device, a liquid storage tank, a liquid injection pipeline, a liquid discharge pipeline, an exhaust pipeline, and a data acquisition and control system;

[0007] The gas cylinder is connected to the high-temperature autoclave through a gas injection pipeline, and the gas injection pipeline is sequentially provided with a gas cylinder pressure gauge, a gas injection valve, and a main chamber pressure gauge;

[0008] The high-temperature and high-pressure autoclave comprises a autoclave body, and an autoclave cover and a side cover detachably connected to the autoclave body, wherein a main chamber and a side chamber are provided in the autoclave body, which are in communication and have axes perpendicular to each other, the top of the main chamber is connected to the autoclave cover, and the end of the side chamber is connected to the side cover; the side chamber is located in the middle of the main chamber, and a clamp 1 and a clamp 2 for clamping a sample to be tested are provided in the side chamber, and both the clamp 1 and the clamp 2 are provided with a fluid channel, and after the sample to be tested is clamped, the fluid in the main chamber passes through the fluid channel of the clamp 1, the sample to be tested, and the fluid channel of the clamp 2 in sequence into a cavity formed between the clamp 2 and the side cover, and the cavity is connected to the exhaust pipeline, which is provided with a side chamber pressure gauge and a pressure relief valve in sequence;

[0009] The heating device is connected to the kettle body and is used to heat the kettle body; the liquid storage tank is connected to the injection pipeline through a pressure pump, and the injection pipeline is provided with an injection valve; the discharge pipeline is connected to the bottom of the main chamber and is provided with a discharge valve;

[0010] The data acquisition and control system includes a connected integrated controller and a computer, and the gas injection valve, main chamber pressure gauge, heating device, side chamber pressure gauge, pressure relief valve, liquid injection valve, and pressure pump are respectively connected to the integrated controller.

[0011] Preferably, the outer surface of the kettle body is provided with a thermal insulation sleeve.

[0012] Preferably, a visual window is provided on the side cover.

[0013] Preferably, the side cover is made of sapphire glass.

[0014] Preferably, the clamp 1 and the clamp 2 are respectively threadedly connected to the inner wall of the side chamber.

[0015] Preferably, the heating device is a heating rod.

[0016] Preferably, the injection line is connected to the bottom of the main chamber.

[0017] Preferably, the sample to be tested is any one of a seal, a core, a cement ring, a casing thread, and a rupture disk.

[0018] The beneficial effects of the present invention are:

[0019] The present invention provides technical support for gas well exploitation by configuring the kettle body into a main chamber and a side chamber that are connected, arranging a fixture in the side chamber, and using different test samples to perform gas well annular pressure simulation and control research. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a structural schematic diagram of the experimental device for simulating and controlling annular pressure in high-temperature and high-pressure gas wells according to the present invention.

[0022] Numbers in the figure: 1-gas cylinder, 2-gas cylinder pressure gauge, 3-gas injection line, 4-gas injection valve, 5-main chamber pressure gauge, 6-heating device, 7-kettle cover, 8-kettle body, 9-thermal insulation sleeve, 10-fixture 1, 11-fixture 2, 12-sample to be tested, 13-side cover, 14-liquid injection line, 15-liquid injection valve, 16-pressure pump, 17-liquid storage tank, 18-side chamber pressure gauge, 19-pressure relief valve, 20-exhaust line, 21-liquid discharge valve, 22-liquid discharge line, 23-integrated controller, 24-computer. DETAILED DESCRIPTION

[0023] The present invention is further described below with reference to the accompanying drawings and examples. It should be noted that, in the absence of conflict, the embodiments in this application and the technical features in the embodiments can be combined with each other. It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as those commonly understood by those of ordinary skill in the art to which this application belongs. The use of similar words such as "include" or "comprising" in the present invention means that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0024] like Figure 1 As shown, the present invention provides a high-temperature and high-pressure gas well annulus pressure simulation and control experimental device, including a gas cylinder 1, a high-temperature and high-pressure autoclave, a heating device 6, a liquid storage tank 17, a liquid injection pipeline 14, a liquid discharge pipeline 22, an exhaust pipeline 20, and a data acquisition and control system;

[0025] The gas cylinder 1 is connected to the high-temperature autoclave through a gas injection line 3, and the gas injection line 3 is provided with a gas cylinder pressure gauge 2, a gas injection valve 4, and a main chamber pressure gauge 5 in sequence;

[0026] The high-temperature and high-pressure autoclave includes a autoclave body 8 and an autoclave cover 7 and a side cover 13 detachably connected to the autoclave body 8. The autoclave body 8 is provided with a main chamber and a side chamber that are interconnected and whose axes are perpendicular to each other. The top of the main chamber is connected to the autoclave cover 7, and the end of the side chamber is connected to the side cover 13. The side chamber is located in the middle of the main chamber. A clamp 10 and a clamp 2 11 for clamping a sample 12 to be tested are provided in the side chamber. Both the clamp 10 and the clamp 2 11 are provided with fluid channels. After the sample 12 to be tested is clamped, the fluid in the main chamber passes through the fluid channel of the clamp 10, the sample 12 to be tested, and the fluid channel of the clamp 2 11 in sequence and enters the cavity formed between the clamp 2 11 and the side cover 13. The cavity is connected to the exhaust pipeline 20. The exhaust pipeline 20 is provided with a side chamber pressure gauge 18 and a pressure relief valve 19 in sequence.

[0027] The heating device 6 is connected to the kettle body 8 and is used to heat the kettle body 8; the liquid storage tank 17 is connected to the injection pipeline 14 through the pressure pump 16, and the injection pipeline 14 is provided with an injection valve 15; the discharge pipeline 22 is connected to the bottom of the main chamber and is provided with a discharge valve 21;

[0028] The data acquisition and control system includes an integrated controller 23 and a computer 24 connected to each other. The gas injection valve 4, main chamber pressure gauge 5, heating device 6, side chamber pressure gauge 18, pressure relief valve 19, liquid injection valve 15, and pressure pump 16 are respectively connected to the integrated controller 23.

[0029] In this embodiment, the integrated controller 23 can control the opening of each valve (each valve is an electrically controlled valve), the heating temperature of the heating device 6, the pressure of the pressure pump 16, and other parameters, thereby making the experimental process more intelligent. It should be noted that the use of an integrated controller to control these subcomponents is conventional technology, and the specific structure of the integrated controller will not be detailed here.

[0030] In one specific embodiment, the kettle body and lid are made of high-strength alloy steel, capable of meeting a hermetic sealing operating pressure range of 0-70 MPa and a standard operating temperature range of 0-200°C. This enables the present invention to simulate annular pressure and evaluate the effectiveness of control measures in high-temperature and high-pressure environments up to 70 MPa and 200°C.

[0031] In one specific embodiment, the outer surface of the kettle body 8 is provided with a thermal insulation sleeve 9, and the side cover 13 is provided with a viewing window. Optionally, the side cover 13 is made of sapphire glass. In this embodiment, providing a viewing window on the side cover 13 or making the entire side cover of sapphire glass allows the experimenter to easily observe the sample 12 to be tested and the fluid in the side chamber.

[0032] In a specific embodiment, the clamp 10 and the clamp 2 11 are respectively connected to the inner wall of the side chamber by threads, the heating device 6 uses a heating rod, and the injection line 14 is connected to the bottom of the main chamber.

[0033] In a specific embodiment, the sample 12 to be tested is any one of a seal, a core, a cement ring, a casing thread, and a rupture disk.

[0034] When the test sample 12 is a seal, the main chamber and side chamber are completely separated, allowing the main chamber alone to test the control effectiveness of the compressible gas foam. Specifically, compressible gas foam is injected into the upper portion of the main chamber, and annular fluid is injected into the lower portion. The main chamber is heated by the heating device 6 to cause thermal expansion of the annular fluid. The pressure increase on the main chamber pressure gauge 5 is recorded to evaluate the control effectiveness of the injected compressible gas foam.

[0035] When the sample 12 to be tested is a core, the effectiveness of releasing the annular pressure into the formation can be tested. Specifically, a pressure pump 16 is used to pressurize the main chamber. Fluid seepage from the core sample is observed through the sapphire glass side cover 13. The pressure increase in the side chamber pressure gauge 18 is combined with the pressure to determine the effectiveness of the formation pressure relief.

[0036] When the test sample 12 is a cement sheath or casing thread, the sealing effectiveness of the cement sheath and casing threads can be tested. Specifically, an appropriate amount of liquid (not pressurized) is pre-placed in the side chamber. A gas cylinder 1 is used to pressurize the main chamber via the gas injection line 3. The temperature is raised using a heating device 6 to simulate a real downhole environment. Bubble seepage from the cement sheath or casing threads is then observed through the sapphire glass side cover 13. The sealing effectiveness of the cement sheath or casing threads is then determined using the side chamber pressure gauge 18.

[0037] When the test sample 12 is a rupture disk, the rupture disk's pressure relief performance can be tested. Specifically, a pressure pump 16 is used to increase pressure in the main chamber. The rupture disk's opening and closing status is observed through the sapphire glass side cover 13. The rupture disk's operating pressure differential and pressure relief capacity are then determined by combining the readings of the main chamber pressure gauge 5 and the side chamber pressure gauge 18.

[0038] In the above embodiment, different annular pressure simulations and evaluations of the effects of control measures can be achieved by changing the sample to be tested held by the fixture. For example, when it is necessary to test the thermal expansion coefficient of the annular fluid or the control effect of the compressible gas foam, a seal can be used to completely seal the side chamber; when it is necessary to test the control effect of the rupture disk, the sample to be tested can be replaced with a rupture disk sample; when it is necessary to test the effect of the annular pressure release to the formation, the sample to be tested can be replaced with a core sample; when it is necessary to test the sealing effect of the cement ring, the sample to be tested can be replaced with a cement ring sample; when it is necessary to test the sealing effect of the pipe string thread, the sample to be tested can be replaced with a thread sample. It should be noted that the above examples are only some typical cases, and other control methods can be tested using the device described in the present invention.

[0039] In summary, the present invention can conduct research on the simulation and control of gas well annular pressure, and is a significant improvement over the prior art.

[0040] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A high-temperature and high-pressure gas well annulus pressure simulation and control experimental device, characterized in that: Including gas cylinders, high-temperature autoclaves, heating devices, liquid storage tanks, liquid injection lines, liquid discharge lines, exhaust lines, data acquisition and control systems; The gas cylinder is connected to the high-temperature autoclave through a gas injection pipeline, and the gas injection pipeline is sequentially provided with a gas cylinder pressure gauge, a gas injection valve, and a main chamber pressure gauge; The high-temperature and high-pressure autoclave comprises a autoclave body, and an autoclave cover and a side cover detachably connected to the autoclave body, wherein a main chamber and a side chamber are provided in the autoclave body, which are in communication and have axes perpendicular to each other, the top of the main chamber is connected to the autoclave cover, and the end of the side chamber is connected to the side cover; the side chamber is located in the middle of the main chamber, and a clamp 1 and a clamp 2 for clamping a sample to be tested are provided in the side chamber, and both the clamp 1 and the clamp 2 are provided with a fluid channel, and after the sample to be tested is clamped, the fluid in the main chamber passes through the fluid channel of the clamp 1, the sample to be tested, and the fluid channel of the clamp 2 in sequence into a cavity formed between the clamp 2 and the side cover, and the cavity is connected to the exhaust pipeline, which is provided with a side chamber pressure gauge and a pressure relief valve in sequence; The heating device is connected to the kettle body and is used to heat the kettle body; the liquid storage tank is connected to the injection pipeline through a pressure pump, and the injection pipeline is provided with an injection valve; the discharge pipeline is connected to the bottom of the main chamber and is provided with a discharge valve; The data acquisition and control system includes a connected integrated controller and a computer, and the gas injection valve, main chamber pressure gauge, heating device, side chamber pressure gauge, pressure relief valve, liquid injection valve, and pressure pump are respectively connected to the integrated controller.

2. The high-temperature and high-pressure gas well annulus pressure simulation and control experimental device according to claim 1 is characterized in that: The outer surface of the kettle body is provided with a heat insulation sleeve.

3. The high-temperature and high-pressure gas well annulus pressure simulation and control experimental device according to claim 1 is characterized in that: The side cover is provided with a viewing window.

4. The high-temperature and high-pressure gas well annulus pressure simulation and control experimental device according to claim 1 is characterized in that: The side cover is made of sapphire glass.

5. The high-temperature and high-pressure gas well annulus pressure simulation and control experimental device according to claim 1 is characterized in that: The first clamp and the second clamp are respectively connected to the inner wall of the side chamber through threads.

6. The high-temperature and high-pressure gas well annulus pressure simulation and control experimental device according to claim 1 is characterized in that: The heating device adopts a heating rod.

7. The high-temperature and high-pressure gas well annulus pressure simulation and control experimental device according to claim 1 is characterized in that: The liquid injection line is communicated with the bottom of the main chamber.

8. The high-temperature and high-pressure gas well annulus pressure simulation and control experimental device according to any one of claims 1 to 7, characterized in that: The sample to be tested is any one of a seal, a rock core, a cement ring, a casing thread, and a rupture disk.

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