A multi-mode leakage simulation experimental device and method for an ultra-deep gas well production pipe string

Abstract

The present application relates to the technical field of oil and gas field development, and particularly relates to a multi-mode leakage simulation experimental device and method for a production string of an ultra-deep gas well. The technical scheme is as follows: an outer side of a wellbore temperature-pressure coupling simulation system is connected with a reservoir gas supply simulation system, a multi-mode leakage simulation assembly is installed in the middle, a reservoir-wellbore coupling interface is connected with the lower end of the production tubing, one side of the upper part of a layered sand filling seepage tank of the reservoir gas supply simulation system is connected with a confining pressure loading unit through a pipeline, the lower part is connected with a reservoir fluid supply unit, and the outlet end of the layered sand filling seepage tank is connected with the reservoir-wellbore coupling interface through a pipeline. The beneficial effects are as follows: by constructing an experimental device for coupling the reservoir and the wellbore, the multi-mode leakage simulation assembly is used to realize the body perforation leakage simulation and the thread seal failure simulation, and the simulation under the complex working conditions of the ultra-deep gas well is realized, thereby providing a scientific basis and technical support for the leakage prevention and control of the production string of the ultra-deep gas well.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field development technology, and in particular to a multi-mode leakage simulation experimental device and method for ultra-deep gas well production tubing. Background Technology

[0002] Ultra-deep gas wells (depth > 6000m, temperature > 150℃, pressure > 100MPa) are characterized by extreme formation conditions, complex wellbore structures, and unique fluid properties. During long-term production, the production tubing is highly susceptible to corrosion and perforation, as well as threaded seal failure and leakage problems due to high temperature, high pressure, and corrosive environment. This can lead to continuous annular pressure, which, if not effectively controlled, will seriously threaten the integrity of the wellbore and safe production.

[0003] Existing leakage simulation experimental devices mostly focus on the leakage simulation of a single link in the wellbore, lacking the physical coupling design between the reservoir and the wellbore, and cannot reproduce the impact of real formation seepage on wellbore leakage behavior; moreover, the leakage mode is singular, making it difficult to simulate two typical leakage scenarios on a single device: body perforation (macroscopic pores) and threaded seal failure (microscopic rough gaps), and even more so, it cannot characterize the wellbore temperature and pressure evolution law and fluid distribution characteristics after multi-mode leakage under complex working conditions.

[0004] Therefore, there is an urgent need to develop an experimental device and method for simulating multi-mode leakage of ultra-deep gas well production tubing that can achieve reservoir-wellbore coupling and cover multiple leakage scenarios. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned deficiencies in existing technologies by providing a multi-mode leakage simulation experimental device and method for ultra-deep gas well production tubing. By constructing an experimental device that couples the reservoir and the wellbore, and employing a multi-mode leakage simulation component, the invention simulates both perforation leakage and threaded seal failure, thereby simulating complex operating conditions in ultra-deep gas wells and providing a scientific basis and technical support for leakage prevention and control of production tubing in ultra-deep gas wells.

[0006] This invention discloses a multi-mode leakage simulation experimental device for ultra-deep gas well production tubing. The technical solution includes a wellbore temperature-pressure coupling simulation system, a global parameter control module, and an intelligent data acquisition module. The wellbore temperature-pressure coupling simulation system includes a production casing, an annulus, and production tubing. Production tubing is installed inside the production casing, forming an annulus between the production tubing and the production casing. One side of the wellbore temperature-pressure coupling simulation system is connected to the global parameter control module and the intelligent data acquisition module. It also includes a reservoir gas supply simulation system, a multi-mode leakage simulation component, and a reservoir-wellbore coupling interface. The wellbore temperature-pressure... The outer side of the coupling simulation system is connected to the reservoir gas supply simulation system. A multi-mode leakage simulation component is installed in the middle of the wellbore temperature and pressure coupling simulation system. The lower end of the production tubing is connected to the reservoir-wellbore coupling interface. The reservoir gas supply simulation system includes a layered sand-filled seepage tank, a confining pressure loading unit, a reservoir fluid supply unit, and a wellbore fluid outlet. The upper part of one side of the layered sand-filled seepage tank is connected to the confining pressure loading unit through a pipeline, and the lower part is connected to the reservoir fluid supply unit. The outlet end of the layered sand-filled seepage tank is connected to the reservoir-wellbore coupling interface through a pipeline. The upper end of the production tubing is connected to the reservoir fluid supply unit through the wellbore fluid outlet.

[0007] Preferably, the inner cavity of the aforementioned layered sand-filled seepage tank is equipped with a seepage monitoring array and a permeability adjustment component. The permeability adjustment component uses quartz sand or artificial rock cores of different particle sizes to achieve continuous permeability adjustment, and is matched with a porosity adjustment plate to achieve porosity adaptation. The seepage monitoring array consists of pressure sensors and flow sensors arranged in three dimensions inside the layered sand-filled seepage tank to monitor the distribution and dynamic changes of the formation seepage field inside the layered sand-filled seepage tank.

[0008] Preferably, the above-mentioned wellbore temperature and pressure coupling simulation system further includes a temperature control system, a pressure compensation valve, an armored high-temperature and high-pressure resistant data transmission optical cable, an annular fluid level monitoring sensor, a flow sensor and a PVT characteristic analyzer, an annular filling port, a bottom hole plugging device, and a wellhead sealing device. The wellhead sealing device is installed at the upper end of the production casing and the production tubing, and the bottom hole plugging device is installed at the lower end. The annular filling port is installed on the wellhead sealing device. The flow sensor, the PVT characteristic analyzer, and the pressure compensation valve are connected to the upper side of the wellhead sealing device. The temperature control system is installed on the outer side of the production casing. The annular fluid level monitoring sensor is installed at the top of the annulus of the casing and the production tubing. One end of the armored high-temperature and high-pressure resistant data transmission optical cable passes through the inner cavity of the production tubing and connects to the reservoir-wellbore coupling interface, and the other end is connected to the global parameter control module and the intelligent data acquisition module.

[0009] Preferably, the reservoir-wellbore coupling interface includes a fluid flow channel, a one-way valve, a coupling interface, a temperature compensation unit, and a filter screen. The fluid flow channel is equipped with a filter screen and a one-way valve. The upper end of the fluid flow channel is connected to the lower end of the production tubing through the coupling interface. A pressure transmission hole is provided on the coupling interface, and a temperature compensation unit is installed at the lower part of the coupling interface.

[0010] Preferably, the above-mentioned multi-mode leakage simulation component adopts a body perforation leakage simulation component or a threaded seal failure simulation component.

[0011] Preferably, the above-mentioned perforation leakage simulation component includes an external support, a linear hydraulic cylinder, a small-diameter drive rod, a perforation leakage base, a puncture rod, and a laser displacement sensor. The external support is fixed to one side of the outer wall of the production casing. The linear hydraulic cylinder and the laser displacement sensor are installed on the outside of the external support. The output end of the linear hydraulic cylinder is connected to the puncture rod through the small-diameter drive rod, and the puncture rod is located on the outside of the perforation leakage base. The perforation leakage base is installed on the outer wall of the production tubing, and an alloy sealing diaphragm is installed inside the perforation leakage base.

[0012] Preferably, the above-mentioned threaded seal failure simulation component includes a threaded connector, a titanium alloy elastic sealing sleeve, an annular drive hydraulic cylinder, and an external pump station for the annular hydraulic cylinder. The two ends of the threaded connector are installed on the production oil pipe. The threaded connector is provided with a fluid leakage channel. A titanium alloy elastic sealing sleeve is fitted on the outside of the threaded connector. The lower end of the titanium alloy elastic sealing sleeve is connected to the output end of the annular drive hydraulic cylinder, and the upper end of the titanium alloy elastic sealing sleeve is in contact with the sealing element installed on the upper part of the threaded connector. The annular drive hydraulic cylinder is connected to the external pump station for the annular hydraulic cylinder outside the production sleeve through a hydraulic pipeline.

[0013] The method of using the multi-mode leakage simulation experimental device for ultra-deep gas well production tubing mentioned in this invention includes the following steps:

[0014] First, a multi-mode leakage simulation component is installed in the middle of the wellbore temperature and pressure coupling simulation system. The multi-mode leakage simulation component adopts a body perforation leakage simulation component. The external support is fixed on one side of the outer wall of the production casing. A linear hydraulic cylinder and a laser displacement sensor are installed on the outside of the external support. The output end of the linear hydraulic cylinder is connected to the puncture rod through a small diameter drive rod. The puncture rod is located on the outside of the perforation leakage base. The perforation leakage base is installed on the outer wall of the production tubing. An alloy sealing diaphragm is installed inside the perforation leakage base.

[0015] Second, the perforation leakage simulation component is in a closed state before the annulus is pressurized, and the production tubing and the annulus are not connected. Annulus protective fluid is injected into the sealed annulus through the annulus filling port, and the top pressure compensation valve is opened to purge air until the annulus is completely filled with annulus protective fluid. The reservoir gas supply simulation system is activated, and production fluid is injected into the production tubing through the reservoir-wellbore coupling interface to maintain the pressure in the production tubing at 35 MPa, simulating the initial wellbore pressure environment. The global parameter control module is activated to control the electromagnetic induction heating unit in the temperature control system to perform a stepped temperature increase, setting the target temperature to 60℃. The intelligent data acquisition module records the pressure change of the annulus over time. As the annulus temperature rises from 25℃ to 60℃, because the thermal expansion coefficient of the annulus fluid is greater than that of the tubing and the annulus is sealed, the annulus pressure rises to the preset value.

[0016] Third, during the perforation leakage simulation: after the pressure of the annular protective fluid in the oil jacket annulus rises to the preset value, the piercing rod is driven to move axially through the linear hydraulic cylinder. The piercing rod pierces the sealing diaphragm forward, forming a leakage channel with a preset diameter. The high-pressure production fluid in the production oil pipe rapidly enters the oil jacket annulus, and the pressure of the oil jacket annulus rises rapidly from the preset value, accompanied by gas-liquid redistribution. Finally, the pressure of the oil jacket annulus stabilizes at 35MPa, forming a continuous annular pressure.

[0017] Among them, the intelligent data acquisition module collects wellbore temperature and pressure, reservoir seepage pressure, leakage flow, annular liquid level changes and gas PVT parameters in real time, and continuously collects and records the parameter change patterns of the closed annular pressure-continuous annular pressure coupling process.

[0018] The method of using the multi-mode leakage simulation experimental device for ultra-deep gas well production tubing mentioned in this invention includes the following steps:

[0019] First, the multi-mode leakage simulation component installed in the middle of the wellbore temperature and pressure coupling simulation system adopts a threaded seal failure simulation component. The two ends of the threaded joint of the threaded seal failure simulation component are installed on the production tubing. The threaded joint has a fluid leakage channel. A titanium alloy elastic sealing sleeve is fitted on the outside of the threaded joint. The lower end of the titanium alloy elastic sealing sleeve is connected to the output end of the annular drive hydraulic cylinder, and the upper end of the titanium alloy elastic sealing sleeve is in contact with the sealing element installed on the upper part of the threaded joint. The annular drive hydraulic cylinder is connected to the external pump station of the annular hydraulic cylinder outside the production casing through a hydraulic pipeline. During the pressurization of the closed annulus, the external pump station of the annular hydraulic cylinder injects high pressure into the annular drive hydraulic cylinder. The annular drive hydraulic cylinder generates axial thrust, which pushes the titanium alloy elastic sealing sleeve to generate axial elongation deformation, so that its sealing surface is pressed against the sealing element installed on the upper part of the threaded joint, forming a metal hard seal, and the production tubing and the annulus are completely isolated.

[0020] Second, the threaded seal failure simulation component is in a closed state before the annulus is pressurized, and the production tubing and the annulus are not connected. Annulus protective fluid is injected into the sealed annulus through the annulus filling port, and the top pressure compensation valve is opened to purge air until the annulus is completely filled with annulus protective fluid. The reservoir gas supply simulation system is activated, and production fluid is injected into the production tubing through the reservoir-wellbore coupling interface to maintain the pressure in the production tubing at 35 MPa, simulating the initial wellbore pressure environment. The global parameter control module is activated to control the electromagnetic induction heating unit in the temperature control system to perform a stepped temperature increase, setting the target temperature to 60℃. The intelligent data acquisition module records the pressure change of the annulus over time. As the annulus temperature rises from 25℃ to 60℃, because the thermal expansion coefficient of the annulus fluid is greater than that of the tubing and the annulus is sealed, the annulus pressure rises to the preset value.

[0021] Third, when simulating threaded seal failure: the elastic rebound is activated, and the pressure on the annular drive hydraulic cylinder is reduced by controlling the external pump station of the annular hydraulic cylinder. As the axial thrust decreases, the titanium alloy elastic sealing sleeve gradually retracts to form a micro gap due to the elastic rebound force of the material itself. The titanium alloy elastic sealing sleeve separates from the seal installed on the upper part of the threaded joint, forming an annular gap. The production fluid in the production oil pipe flows along the thread and slowly flows out from the annular gap into the oil sleeve annulus, simulating the process of threaded end face seal failure.

[0022] Unlike the sudden change in perforation leakage, the high-pressure production fluid in the production tubing slowly enters the annulus, and the pressure in the annulus slowly increases from the preset value.

[0023] Among them, the intelligent data acquisition module collects wellbore temperature and pressure, reservoir seepage pressure, leakage flow, annular liquid level changes and gas PVT parameters in real time, and continuously collects and records the parameter change patterns of the closed annular pressure-continuous annular pressure coupling process.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. This invention constructs an experimental device that couples the reservoir and the wellbore, uses a multi-mode leakage simulation component to simulate perforation leakage and threaded seal failure, and simulates the closed annulus pressure generated by thermal expansion by controlling the electromagnetic induction heating unit in the temperature control system. This achieves a three-coupling simulation of "annulus fluid thermal expansion - production tubing leakage - reservoir seepage" under complex working conditions of ultra-deep gas wells, closely matching real production conditions.

[0026] 2. This invention breaks through the limitations of conventional annular pressure prediction models under single-point or single-leakage modes, and can achieve a fine characterization of the bidirectional gas-liquid interaction and transport characteristics, wellbore temperature and pressure changes, and flow distribution characteristics under the superposition of closed annular pressure and continuous annular pressure. In summary, this invention provides a scientific basis and technical support for the prevention and control of leakage in the production tubing of ultra-deep gas wells. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the experimental apparatus of the present invention;

[0028] Figure 2 A schematic diagram of the structure of a body-perforated leakage simulation component for a multi-mode leakage simulation component;

[0029] Figure 3 A schematic diagram of the multi-mode leakage simulation component using a threaded seal failure simulation component;

[0030] Figure 4 This is a schematic diagram of the reservoir-wellbore coupling interface structure.

[0031] Figure 5 A schematic diagram of a physical simulation experiment of a closed annulus under pressure;

[0032] Figure 6 This is a schematic diagram of the pressure change when a single-point perforation leak occurs after a closed annulus is pressurized.

[0033] Figure 7 This is a schematic diagram of the pressure change when a single-point thread leakage occurs after a closed annulus is pressurized.

[0034] Figure 8 This is a schematic diagram showing the pressure changes when a two-point leak occurs after a closed annulus is pressurized.

[0035] In the diagram: 3. Multi-mode leakage simulation component; 4. Reservoir-wellbore coupling interface; 5. Global parameter control module; 6. Intelligent data acquisition module; 1-1. Layered sand-filling seepage tank; 1-2. Confining pressure loading unit; 1-3. Reservoir fluid supply unit; 1-4. Seepage monitoring array; 1-5. Permeability adjustment component; 1-6. Wellbore fluid outlet; 2-1. Production casing; 2-2. Oil casing annulus; 2-3. Production tubing; 2-4. Temperature control system; 2-5. Pressure compensation valve; 2-6. Armored high-temperature and high-pressure resistant data transmission optical cable; 2-7. Annulus level monitoring sensor; 2-8. Flow sensor and PVT features. Analyzer 2-8, Annular fluid filling port 2-9, Bottom hole plugging device 2-10, Wellhead sealing device 2-11, External support 3-1, Linear hydraulic cylinder 3-2, Small diameter drive rod 3-3, Perfluoroether O-ring 3-4, Perforation leakage base 3-5, Puncture rod 3-6, Laser displacement sensor 3-7, Threaded joint 3-8, Titanium alloy elastic sealing sleeve 3-9, Annular drive hydraulic cylinder 3-10, Annular hydraulic cylinder external pump station 3-11, Fluid flow channel 4-1, Check valve 4-2, Coupling interface 4-3, Temperature compensation unit 4-4, Filter screen 4-5. Detailed Implementation

[0036] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0037] Example 1, referring to Figures 1-4 The present invention discloses a multi-mode leakage simulation experimental device for ultra-deep gas well production tubing, comprising a wellbore temperature-pressure coupling simulation system, a global parameter control module 5, and an intelligent data acquisition module 6. The wellbore temperature-pressure coupling simulation system includes a production casing 2-1, an annulus 2-2, and a production tubing 2-3. The production tubing 2-3 is installed inside the production casing 2-1, forming an annulus 2-2 between the production tubing 2-3 and the production casing 2-1. The global parameter control module 5 and the intelligent data acquisition module 6 are connected to one side of the wellbore temperature-pressure coupling simulation system. The device also includes a reservoir gas supply simulation system, a multi-mode leakage simulation component 3, and a reservoir-wellbore coupling interface 4. An external reservoir gas supply simulation system is connected. A multi-mode leakage simulation component 3 is installed in the middle of the wellbore temperature and pressure coupling simulation system. A reservoir-wellbore coupling interface 4 is connected to the lower end of the production tubing 2-3. The reservoir gas supply simulation system includes a layered sand-filled seepage tank 1-1, a confining pressure loading unit 1-2, a reservoir fluid supply unit 1-3, and a wellbore fluid outlet 1-6. The upper part of one side of the layered sand-filled seepage tank 1-1 is connected to the confining pressure loading unit 1-2 through a pipeline, and the lower part is connected to the reservoir fluid supply unit 1-3. The outlet end of the layered sand-filled seepage tank 1-1 is connected to the reservoir-wellbore coupling interface 4 through a pipeline. The upper end of the production tubing 2-3 is connected to the reservoir fluid supply unit 1-3 through the wellbore fluid outlet 1-6.

[0038] The reservoir fluid supply unit 1-3 includes a high-pressure fluid storage tank, a constant flow pump and a fluid pretreatment module, which can supply simulated formation fluids such as methane, nitrogen and formation water, and supports the adjustment of the gas-liquid two-phase fluid ratio.

[0039] The inner cavity of the layered sand-filled seepage tank 1-1 is equipped with a seepage monitoring array 1-4 and a permeability adjustment component 1-5. The permeability adjustment component 1-5 uses quartz sand or artificial rock cores of different particle sizes to achieve continuous permeability adjustment, and is matched with a porosity adjustment plate to achieve porosity adaptation. The seepage monitoring array 1-4 is composed of pressure sensors and flow sensors arranged in three dimensions inside the layered sand-filled seepage tank 1-1 to monitor the distribution and dynamic changes of the formation seepage field inside the layered sand-filled seepage tank 1-1.

[0040] The wellbore temperature-pressure coupling simulation system mentioned in this invention also includes a temperature control system 2-4, a pressure compensation valve 2-5, an armored high-temperature and high-pressure resistant data transmission optical cable 2-6, an annular fluid level monitoring sensor 2-7, a flow sensor and PVT characteristic analyzer 2-8, an annular filling port 2-9, a bottom hole plugging device 2-10, and a wellhead sealing device 2-11. The wellhead sealing device 2-11 is installed at the upper end of the production casing 2-1 and the production tubing 2-3, and the bottom hole plugging device 2-10 is installed at the lower end. The annular filling port 2-9 is installed on the wellhead sealing device 2-11, and the flow sensor is connected to the upper side of the wellhead sealing device 2-11. The equipment includes a PVT characteristic analyzer 2-8 and a pressure compensation valve 2-5. A temperature control system 2-4 is installed on the outside of the production casing 2-1. The temperature control system 2-4 includes an electromagnetic induction heating unit and a platinum resistance temperature sensor. The electromagnetic induction heating unit is installed on the outside of the production casing 2-1, and multiple platinum resistance temperature sensors are installed at intervals. An annulus level monitoring sensor 2-7 is installed on the top of the annulus 2-2. One end of the armored high-temperature and high-pressure resistant data transmission optical cable 2-6 passes through the inner cavity of the production tubing 2-3 and connects to the reservoir-wellbore coupling interface 4. The other end is connected to the global parameter control module 5 and the intelligent data acquisition module 6.

[0041] The reservoir-wellbore coupling interface 4 mentioned in this invention includes a fluid flow channel 4-1, a one-way valve 4-2, a coupling interface 4-3, a temperature compensation unit 4-4, and a filter screen 4-5. The filter screen 4-5 and the one-way valve 4-2 are installed in the inner cavity of the fluid flow channel 4-1. The upper end of the fluid flow channel 4-1 is connected to the lower end of the production tubing 2-3 through the coupling interface 4-3. A pressure transmission hole is provided on the coupling interface 4-3. The temperature compensation unit 4-4 is installed at the lower part of the coupling interface 4-3.

[0042] Among them, the multi-mode leakage simulation component 3 mentioned in this invention adopts the body perforation leakage simulation component.

[0043] Specifically, the perforation leakage simulation component includes an external bracket 3-1, a linear hydraulic cylinder 3-2, a small-diameter drive rod 3-3, a perfluoroether O-ring 3-4, a perforation leakage base 3-5, a puncture rod 3-6, and a laser displacement sensor 3-7. The external bracket 3-1 is fixed to one side of the outer wall of the production casing 2-1. The linear hydraulic cylinder 3-2 and the laser displacement sensor 3-7 are installed on the outside of the external bracket 3-1. The output end of the linear hydraulic cylinder 3-2 is connected to the puncture rod 3-6 through the small-diameter drive rod 3-3. The puncture rod 3-6 is located on the outside of the perforation leakage base 3-5. The perforation leakage base 3-5 is installed on the outer wall of the production tubing 2-3. The perfluoroether O-ring 3-4 is installed on the outside of the perforation leakage base 3-5, and an alloy sealing diaphragm is installed inside the perforation leakage base 3-5.

[0044] The method of using the multi-mode leakage simulation experimental device for ultra-deep gas well production tubing mentioned in this invention includes the following steps:

[0045] First, a multi-mode leakage simulation component 3 is installed in the middle of the wellbore temperature and pressure coupling simulation system. The multi-mode leakage simulation component 3 adopts a body perforation leakage simulation component. The external support 3-1 is fixed on one side of the outer wall of the production casing 2-1. The linear hydraulic cylinder 3-2 and the laser displacement sensor 3-7 are installed on the outside of the external support 3-1. The output end of the linear hydraulic cylinder 3-2 is connected to the puncture rod 3-6 through the thin-diameter drive rod 3-3. The puncture rod 3-6 is located on the outside of the perforation leakage base 3-5. The perforation leakage base 3-5 is installed on the outer wall of the production tubing 2-3. An alloy sealing diaphragm is installed inside the perforation leakage base 3-5.

[0046] Second, the perforation leakage simulation component is in a closed state before the annulus 2-2 is pressurized, and the production tubing 2-3 is not connected to the annulus 2-2. Annular protective fluid is injected into the sealed annulus 2-2 through the annulus filling port 2-9, and the top pressure compensation valve 2-5 is opened to purge air until the annulus 2-2 is completely filled with annular protective fluid. The reservoir gas supply simulation system is activated, and production fluid is injected into the production tubing 2-3 through the reservoir-wellbore coupling interface 4 to maintain the pressure in the production tubing 2-3 at 35 MPa, simulating the initial wellbore pressure environment. The global parameter control module 5 is activated to control the electromagnetic induction heating unit in the temperature control system 2-4 to perform a stepped temperature increase, setting the target temperature to 60℃. The intelligent data acquisition module 6 records the pressure change of the annulus 2-2 over time. As the annulus temperature rises from 25℃ to 60℃, due to the greater thermal expansion coefficient of the annulus fluid than the tubing and the annulus being sealed, the annulus pressure rises to 22.98 MPa. MPa, its pressure change diagram is shown in reference Figure 5 ;

[0047] Third, during the perforation leakage simulation: after the pressure of the annular protective fluid in the annulus 2-2 reaches the preset value, the piercing rod 3-6 is driven axially by the linear hydraulic cylinder 3-2. The piercing rod 3-6 pierces the sealing diaphragm forward, forming a leakage channel with a preset orifice diameter. The high-pressure production fluid in the production oil pipe 2-3 rapidly enters the annulus 2-2, and the pressure in the annulus 2-2 rapidly increases from 22.98 MPa, accompanied by gas-liquid redistribution. Finally, the pressure in the annulus 2-2 stabilizes at 35 MPa, forming a continuous annular pressure. The pressure change diagram is shown in the figure. Figure 6 ;

[0048] Among them, the intelligent data acquisition module 6 collects wellbore temperature and pressure, reservoir seepage pressure, leakage flow, annular liquid level changes and gas PVT parameters in real time, and continuously collects and records the parameter change law of the closed annular pressure-continuous annular pressure coupling process.

[0049] Example 2: The multi-mode leakage simulation experimental device for ultra-deep gas well production tubing mentioned in this invention includes a wellbore temperature and pressure coupling simulation system, a global parameter control module 5, and an intelligent data acquisition module 6. The wellbore temperature and pressure coupling simulation system includes a production casing 2-1, an annulus 2-2, and a production tubing 2-3. The production tubing 2-3 is installed inside the production casing 2-1, forming an annulus 2-2 between the production tubing 2-3 and the production casing 2-1. The global parameter control module 5 and the intelligent data acquisition module 6 are connected to one side of the wellbore temperature and pressure coupling simulation system. It also includes a reservoir gas supply simulation system, a multi-mode leakage simulation component 3, and a reservoir-wellbore coupling interface 4. The reservoir gas supply simulation system is connected to the outer side of the system. A multi-mode leakage simulation component 3 is installed in the middle of the wellbore temperature and pressure coupling simulation system. The reservoir-wellbore coupling interface 4 is connected to the lower end of the production tubing 2-3. The reservoir gas supply simulation system includes a layered sand-filled seepage tank 1-1, a confining pressure loading unit 1-2, a reservoir fluid supply unit 1-3, and a wellbore fluid outlet 1-6. The upper part of one side of the layered sand-filled seepage tank 1-1 is connected to the confining pressure loading unit 1-2 through a pipeline, and the lower part is connected to the reservoir fluid supply unit 1-3. The outlet end of the layered sand-filled seepage tank 1-1 is connected to the reservoir-wellbore coupling interface 4 through a pipeline. The upper end of the production tubing 2-3 is connected to the reservoir fluid supply unit 1-3 through the wellbore fluid outlet 1-6.

[0050] The difference from Example 1 is:

[0051] The multi-mode leakage simulation component 3 mentioned in this invention adopts a threaded seal failure simulation component.

[0052] Specifically, the aforementioned threaded seal failure simulation component includes a threaded connector 3-8, a titanium alloy elastic sealing sleeve 3-9, an annular drive hydraulic cylinder 3-10, and an external pump station 3-11 for the annular hydraulic cylinder. Both ends of the threaded connector 3-8 are installed on the production oil pipe 2-3. The threaded connector 3-8 is provided with a fluid leakage channel. The titanium alloy elastic sealing sleeve 3-9 is fitted outside the threaded connector 3-8. The lower end of the titanium alloy elastic sealing sleeve 3-9 is connected to the output end of the annular drive hydraulic cylinder 3-10, and the upper end of the titanium alloy elastic sealing sleeve 3-9 is in contact with the sealing element installed on the upper part of the threaded connector 3-8. The annular drive hydraulic cylinder 3-10 is connected to the external pump station 3-11 for the annular hydraulic cylinder outside the production sleeve 2-1 via a hydraulic pipeline.

[0053] The method of using the multi-mode leakage simulation experimental device for ultra-deep gas well production tubing mentioned in this invention includes the following steps:

[0054] First, the multi-mode leakage simulation component 3 installed in the middle of the wellbore temperature and pressure coupling simulation system adopts a threaded seal failure simulation component. The two ends of the threaded joint 3-8 of the threaded seal failure simulation component are installed on the production tubing 2-3. The threaded joint 3-8 has a fluid leakage channel. A titanium alloy elastic sealing sleeve 3-9 is fitted outside the threaded joint 3-8. The lower end of the titanium alloy elastic sealing sleeve 3-9 is connected to the output end of the annular drive hydraulic cylinder 3-10, and the upper end of the titanium alloy elastic sealing sleeve 3-9 is connected to the sealing sleeve installed on the upper part of the threaded joint 3-8. The sealing element contacts and engages. The annular drive hydraulic cylinder 3-10 is connected to the external pump station 3-11 of the annular hydraulic cylinder outside the production sleeve 2-1 via a hydraulic pipeline. During the pressurization of the sealed annulus, the external pump station 3-11 of the annular hydraulic cylinder injects high pressure into the annular drive hydraulic cylinder 3-10, which generates axial thrust. This pushes the titanium alloy elastic sealing sleeve 3-9 to undergo axial elongation deformation, causing its sealing surface to press against the sealing element installed on the upper part of the threaded joint 3-8, forming a metal hard seal. The production oil pipe 2-3 is completely isolated from the annulus 2-2.

[0055] Second, the threaded seal failure simulation component is in a closed state before the annulus 2-2 is pressurized, and the production tubing 2-3 is not connected to the annulus 2-2. Annular protective fluid is injected into the sealed annulus 2-2 through the annulus filling port 2-9, and the top pressure compensation valve 2-5 is opened to purge air until the annulus 2-2 is completely filled with annular protective fluid. The reservoir gas supply simulation system is activated, and production fluid is injected into the production tubing 2-3 through the reservoir-wellbore coupling interface 4 to maintain the pressure in the production tubing 2-3 at 35 MPa, simulating the initial wellbore pressure environment. The global parameter control module 5 is activated to control the electromagnetic induction heating unit in the temperature control system 2-4 to perform a stepped temperature increase, setting the target temperature to 60℃. The intelligent data acquisition module 6 records the pressure change of the annulus 2-2 over time. As the annulus temperature rises from 25℃ to 60℃, due to the greater thermal expansion coefficient of the annulus fluid than the tubing material and the sealed annulus, the annulus pressure rises to 22.98 MPa. MPa, its pressure change diagram is shown in reference Figure 5 ;

[0056] Third, when simulating threaded seal failure: the elastic rebound is activated, and the pressure on the annular drive hydraulic cylinder 3-10 is reduced by controlling the external pump station 3-11 of the annular hydraulic cylinder. As the axial thrust decreases, the titanium alloy elastic sealing sleeve 3-9 gradually retracts to form a micro gap due to the elastic rebound force of the material itself. The titanium alloy elastic sealing sleeve 3-9 separates from the seal installed on the upper part of the threaded joint 3-8, forming an annular gap. The production fluid in the production oil pipe 2-3 flows along the thread and slowly flows out from the annular gap into the oil sleeve annulus 2-2, simulating the process of threaded end face seal failure.

[0057] Unlike the abrupt change in perforation leakage, the high-pressure production fluid in production tubing 2-3 slowly enters the annulus 2-2, causing the pressure in the annulus 2-2 to slowly increase from 22.98 MPa to 23.15 MPa. See the schematic diagram for the pressure change. Figure 7 ;

[0058] Among them, the intelligent data acquisition module 6 collects wellbore temperature and pressure, reservoir seepage pressure, leakage flow, annular liquid level changes and gas PVT parameters in real time, and continuously collects and records the parameter change law of the closed annular pressure-continuous annular pressure coupling process.

[0059] Example 3: The present invention provides a multi-mode leakage simulation experimental device for ultra-deep gas well production tubing, comprising a wellbore temperature-pressure coupling simulation system, a global parameter control module 5, and an intelligent data acquisition module 6. The wellbore temperature-pressure coupling simulation system includes a production casing 2-1, an annulus 2-2, and a production tubing 2-3. The production tubing 2-3 is installed inside the production casing 2-1, forming an annulus 2-2 between the production tubing 2-3 and the production casing 2-1. One side of the wellbore temperature-pressure coupling simulation system is connected to the global parameter control module 5 and the intelligent data acquisition module 6. It also includes a reservoir gas supply simulation system, a multi-mode leakage simulation component 3, and a reservoir-wellbore coupling interface 4. The reservoir gas supply simulation system is connected to the outer side of the system. A multi-mode leakage simulation component 3 is installed in the middle of the wellbore temperature and pressure coupling simulation system. The reservoir-wellbore coupling interface 4 is connected to the lower end of the production tubing 2-3. The reservoir gas supply simulation system includes a layered sand-filled seepage tank 1-1, a confining pressure loading unit 1-2, a reservoir fluid supply unit 1-3, and a wellbore fluid outlet 1-6. The upper part of one side of the layered sand-filled seepage tank 1-1 is connected to the confining pressure loading unit 1-2 through a pipeline, and the lower part is connected to the reservoir fluid supply unit 1-3. The outlet end of the layered sand-filled seepage tank 1-1 is connected to the reservoir-wellbore coupling interface 4 through a pipeline. The upper end of the production tubing 2-3 is connected to the reservoir fluid supply unit 1-3 through the wellbore fluid outlet 1-6.

[0060] The difference from Example 1 is:

[0061] Based on Example 1, this example arranges two sets of body perforation leakage simulation components at different axial positions of the wellbore temperature and pressure coupling simulation system. The equivalent diameter of the two perforation leakage points is 1mm, located at the upper and lower parts of the wellbore respectively. After the closed annulus is pressurized, the lower body perforation leakage simulation component and the upper body perforation leakage simulation component are opened in sequence.

[0062] Figure 8 This is a schematic diagram of the pressure change in the two-point perforation leakage provided in this embodiment. The pressure change in the annulus 2-2 is rapid. At the upper perforation leakage point, high-pressure fluid in the production oil pipe 2-3 rapidly leaks into the annulus 2-2, which is caused by gas-dominated leakage. At the lower perforation leakage point, high-pressure fluid in the production oil pipe 2-3 first rapidly leaks into the annulus 2-2, which is also caused by gas-dominated leakage. Then, liquid in the annulus 2-2 leaks into the production oil pipe 2-3, which is caused by annular liquid-dominated leakage. Finally, the annular pressure stabilizes at about 31 MPa, forming a continuous annular pressure, accompanied by a drop in the liquid level in the annulus 2-2.

[0063] The above description is merely a partial preferred embodiment of the present invention. Any person skilled in the art can modify the above-described technical solutions or modify them into equivalent technical solutions. Therefore, any simple modifications or equivalent transformations made based on the technical solutions of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A multi-mode leakage simulation experimental device for ultra-deep gas well production tubing, comprising a wellbore temperature-pressure coupling simulation system, a global parameter control module (5), and an intelligent data acquisition module (6), wherein the wellbore temperature-pressure coupling simulation system comprises a production casing (2-1), an annulus (2-2), and a production tubing (2-3), wherein the production tubing (2-3) is installed inside the production casing (2-1), and an annulus (2-2) is formed between the production tubing (2-3) and the production casing (2-1), and the global parameter control module (5) and the intelligent data acquisition module (6) are connected to one side of the wellbore temperature-pressure coupling simulation system, characterized in that: It also includes a reservoir gas supply simulation system, a multi-mode leakage simulation component (3), and a reservoir-wellbore coupling interface (4). The reservoir gas supply simulation system is connected to the outside of the wellbore temperature and pressure coupling simulation system. The multi-mode leakage simulation component (3) is installed in the middle of the wellbore temperature and pressure coupling simulation system. The reservoir-wellbore coupling interface (4) is connected to the lower end of the production tubing (2-3). The reservoir gas supply simulation system includes a layered sand-filled seepage tank (1-1), a confining pressure loading unit (1-2), a reservoir fluid supply unit (1-3), and a wellbore fluid outlet (1-6). The upper part of one side of the layered sand-filled seepage tank (1-1) is connected to the confining pressure loading unit (1-2) through a pipeline, and the lower part is connected to the reservoir fluid supply unit (1-3). The outlet end of the layered sand-filled seepage tank (1-1) is connected to the reservoir-wellbore coupling interface (4) through a pipeline. The upper end of the production tubing (2-3) is connected to the reservoir fluid supply unit (1-3) through the wellbore fluid outlet (1-6). The wellbore temperature-pressure coupling simulation system also includes a temperature control system (2-4), a pressure compensation valve (2-5), an armored high-temperature and high-pressure resistant data transmission optical cable (2-6), an annular fluid level monitoring sensor (2-7), a flow sensor and PVT characteristic analyzer (2-8), an annular filling port (2-9), a bottom hole plugging device (2-10), and a wellhead sealing device (2-11). The wellhead sealing device (2-11) is installed at the upper end of the production casing (2-1) and the production tubing (2-3), and the bottom hole plugging device (2-10) is installed at the lower end. The annular filling port (2-9) is installed at... On the wellhead sealing device (2-11), the upper side of the wellhead sealing device (2-11) is connected to a flow sensor, a PVT characteristic analyzer (2-8), and a pressure compensation valve (2-5). A temperature control system (2-4) is installed on the outside of the production casing (2-1). An annulus level monitoring sensor (2-7) is installed on the top of the oil casing annulus (2-2). One end of the armored high temperature and high pressure data transmission optical cable (2-6) passes through the inner cavity of the production tubing (2-3) and connects to the reservoir-wellbore coupling interface (4). The other end is connected to the global parameter control module (5) and the intelligent data acquisition module (6).

2. The multi-mode leakage simulation experimental device for ultra-deep gas well production tubing as described in claim 1, characterized in that: The inner cavity of the layered sand-filled seepage tank (1-1) is equipped with a seepage monitoring array (1-4) and a permeability adjustment component (1-5). The permeability adjustment component (1-5) uses quartz sand or artificial rock cores of different particle sizes to achieve continuous permeability adjustment, and is matched with a porosity adjustment plate to achieve porosity adaptation. The seepage monitoring array (1-4) is composed of pressure sensors and flow sensors arranged in three dimensions inside the layered sand-filled seepage tank (1-1) to monitor the distribution and dynamic changes of the formation seepage field inside the layered sand-filled seepage tank (1-1).

3. The multi-mode leakage simulation experimental device for ultra-deep gas well production tubing as described in claim 2, characterized in that: The reservoir-wellbore coupling interface (4) includes a fluid flow channel (4-1), a one-way valve (4-2), a coupling interface (4-3), a temperature compensation unit (4-4), and a filter screen (4-5). The filter screen (4-5) and the one-way valve (4-2) are installed in the inner cavity of the fluid flow channel (4-1). The upper end of the fluid flow channel (4-1) is connected to the lower end of the production tubing (2-3) through the coupling interface (4-3). A pressure transmission hole is provided on the coupling interface (4-3). The temperature compensation unit (4-4) is installed at the lower part of the coupling interface (4-3).

4. The multi-mode leakage simulation experimental device for ultra-deep gas well production tubing as described in claim 3, characterized in that: The multi-mode leakage simulation component (3) adopts either a body perforation leakage simulation component or a threaded seal failure simulation component.

5. The multi-mode leakage simulation experimental device for ultra-deep gas well production tubing as described in claim 4, characterized in that: The perforation leakage simulation component includes an external bracket (3-1), a linear hydraulic cylinder (3-2), a small-diameter drive rod (3-3), a perforation leakage base (3-5), a puncture rod (3-6), and a laser displacement sensor (3-7). The external bracket (3-1) is fixed to one side of the outer wall of the production casing (2-1). The linear hydraulic cylinder (3-2) and the laser displacement sensor (3-7) are installed on the outside of the external bracket (3-1). The output end of the linear hydraulic cylinder (3-2) is connected to the puncture rod (3-6) through the small-diameter drive rod (3-3). The puncture rod (3-6) is located on the outside of the perforation leakage base (3-5). The perforation leakage base (3-5) is installed on the outer wall of the production oil pipe (2-3). An alloy sealing diaphragm is installed inside the perforation leakage base (3-5).

6. The multi-mode leakage simulation experimental device for ultra-deep gas well production tubing as described in claim 4, characterized in that: The threaded seal failure simulation component includes a threaded connector (3-8), a titanium alloy elastic sealing sleeve (3-9), an annular drive hydraulic cylinder (3-10), and an external pump station for the annular hydraulic cylinder (3-11). The two ends of the threaded connector (3-8) are installed on the production oil pipe (2-3). The threaded connector (3-8) is provided with a fluid leakage channel. The titanium alloy elastic sealing sleeve (3-9) is fitted on the outside of the threaded connector (3-8). The lower end of the titanium alloy elastic sealing sleeve (3-9) is connected to the output end of the annular drive hydraulic cylinder (3-10), and the upper end of the titanium alloy elastic sealing sleeve (3-9) is in contact with the sealing element installed on the upper part of the threaded connector (3-8). The annular drive hydraulic cylinder (3-10) is connected to the external pump station for the annular hydraulic cylinder (3-11) outside the production sleeve (2-1) through a hydraulic pipeline.

7. A method of using the multi-mode leakage simulation experimental device for ultra-deep gas well production tubing as described in claim 5, characterized in that... Includes the following processes: First, a multi-mode leakage simulation component (3) is installed in the middle of the wellbore temperature and pressure coupling simulation system. The multi-mode leakage simulation component (3) adopts a body perforation leakage simulation component. The external support (3-1) is fixed on one side of the outer wall of the production casing (2-1). The linear hydraulic cylinder (3-2) and the laser displacement sensor (3-7) are installed on the outside of the external support (3-1). The output end of the linear hydraulic cylinder (3-2) is connected to the puncture rod (3-6) through the thin-diameter drive rod (3-3). The puncture rod (3-6) is located on the outside of the perforation leakage base (3-5). The perforation leakage base (3-5) is installed on the outer wall of the production tubing (2-3). An alloy sealing diaphragm is installed inside the perforation leakage base (3-5). Second, the perforation leakage simulation component is in a closed state before the annulus (2-2) is pressurized, and the production tubing (2-3) is not connected to the annulus (2-2). Annulus protection fluid is injected into the sealed annulus (2-2) through the annulus filling port (2-9), and the top pressure compensation valve (2-5) is opened to purge air until the annulus (2-2) is completely filled with annulus protection fluid. The reservoir gas supply simulation system is then started, and production flow is injected into the production tubing (2-3) through the reservoir-wellbore coupling interface (4). The pressure inside the production tubing (2-3) is maintained at 35MPa to simulate the initial wellbore pressure environment. The global parameter control module (5) is activated to control the electromagnetic induction heating unit in the temperature control system (2-4) to perform stepwise heating. The target temperature is set to 60℃. The intelligent data acquisition module (6) is used to record the pressure change of the annulus (2-2) over time. As the annulus temperature rises from 25℃ to 60℃, the annulus pressure rises to the preset value because the thermal expansion coefficient of the annulus liquid is greater than that of the tubing and the annulus is sealed. Third, during the perforation leakage simulation: after the pressure of the annular protective fluid in the oil jacket annulus (2-2) rises to the preset value, the piercing rod (3-6) is driven to move axially by the linear hydraulic cylinder (3-2). The piercing rod (3-6) pierces the sealing diaphragm forward, forming a leakage channel with a preset aperture. The high-pressure production fluid in the production oil pipe (2-3) rapidly enters the oil jacket annulus (2-2), and the pressure of the oil jacket annulus (2-2) rises rapidly from the preset value, accompanied by gas-liquid redistribution. Finally, the pressure of the oil jacket annulus (2-2) stabilizes at 35MPa, forming a continuous annular pressure. Among them, the intelligent data acquisition module (6) collects wellbore temperature and pressure, reservoir seepage pressure, leakage flow, annular liquid level change and gas PVT parameters in real time, and continuously collects and records the parameter change law of the closed annular pressure-continuous annular pressure coupling process.

8. A method of using the multi-mode leakage simulation experimental device for ultra-deep gas well production tubing as described in claim 6, characterized in that... Includes the following processes: First, the multi-mode leakage simulation component (3) installed in the middle of the wellbore temperature and pressure coupling simulation system adopts a threaded seal failure simulation component. The two ends of the threaded joint (3-8) of the threaded seal failure simulation component are installed on the production tubing (2-3). The threaded joint (3-8) is provided with a fluid leakage channel. A titanium alloy elastic sealing sleeve (3-9) is fitted on the outside of the threaded joint (3-8). The lower end of the titanium alloy elastic sealing sleeve (3-9) is connected to the output end of the annular drive hydraulic cylinder (3-10). The upper end of the titanium alloy elastic sealing sleeve (3-9) is connected to the sealing sleeve installed on the upper part of the threaded joint (3-8). The sealing element contacts and engages. The annular drive hydraulic cylinder (3-10) is connected to the external pump station (3-11) of the annular hydraulic cylinder outside the production sleeve (2-1) via a hydraulic pipeline. During the pressurization of the sealed annulus, the external pump station (3-11) of the annular hydraulic cylinder injects high pressure into the annular drive hydraulic cylinder (3-10), and the annular drive hydraulic cylinder (3-10) generates axial thrust, which pushes the titanium alloy elastic sealing sleeve (3-9) to generate axial elongation deformation, so that its sealing surface is pressed against the sealing element installed on the upper part of the threaded joint (3-8), forming a metal hard seal, and the production oil pipe (2-3) is completely isolated from the oil sleeve annulus (2-2). Second, the threaded seal failure simulation component is in a closed state before the annulus (2-2) is pressurized, and the production tubing (2-3) is not connected to the annulus (2-2). Annulus protective fluid is injected into the sealed annulus (2-2) through the annulus filling port (2-9), and the top pressure compensation valve (2-5) is opened to purge air until the annulus (2-2) is completely filled with annulus protective fluid. The reservoir gas supply simulation system is then started, and production flow is injected into the production tubing (2-3) through the reservoir-wellbore coupling interface (4). The pressure inside the production tubing (2-3) is maintained at 35MPa to simulate the initial wellbore pressure environment. The global parameter control module (5) is activated to control the electromagnetic induction heating unit in the temperature control system (2-4) to perform stepwise heating. The target temperature is set to 60℃. The intelligent data acquisition module (6) is used to record the pressure change of the annulus (2-2) over time. As the annulus temperature rises from 25℃ to 60℃, the annulus pressure rises to the preset value because the thermal expansion coefficient of the annulus liquid is greater than that of the tubing and the annulus is sealed. Third, when simulating the failure of the threaded seal: the elastic rebound is activated, and the pressure on the annular drive hydraulic cylinder (3-10) is reduced by controlling the external pump station (3-11) of the annular hydraulic cylinder. As the axial thrust decreases, the titanium alloy elastic sealing sleeve (3-9) gradually retracts to form a micro gap due to the elastic rebound force of the material itself. The titanium alloy elastic sealing sleeve (3-9) separates from the seal installed on the upper part of the threaded joint (3-8) to form an annular gap. The production fluid in the production oil pipe (2-3) flows along the thread and slowly flows out from the annular gap into the oil sleeve annulus (2-2) to simulate the process of threaded end face seal failure. Unlike the sudden change in perforation leakage, the high-pressure production fluid in the production tubing (2-3) slowly enters the annulus (2-2), and the pressure in the annulus (2-2) slowly increases from the preset value; Among them, the intelligent data acquisition module (6) collects wellbore temperature and pressure, reservoir seepage pressure, leakage flow, annular liquid level change and gas PVT parameters in real time, and continuously collects and records the parameter change law of the closed annular pressure-continuous annular pressure coupling process.

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