Device and method for measuring fractured gas reservoir-shaft coupling seepage key parameters

Abstract

The invention provides a device and method for measuring fractured gas reservoir-shaft coupling seepage key parameters, the device comprises a simulated stratum structure, a gas injection system, a drilling fluid injection system, a first outflow system and a second outflow system, the simulated stratum structure is provided with an accommodating space, and a rock core is arranged in the accommodating space; the gas injection system is communicated with the accommodating space in an openable and closable manner, and the gas injection system is provided with a first pressure detection piece and a first flow detection piece; the drilling fluid injection system is communicated with the accommodating space in an openable and closable manner, and the drilling fluid injection system is provided with a second pressure detection piece and a second flow detection piece; the first outflow system and the second outflow system are communicated with the simulated stratum structure in an openable and closable mode, the first outflow system is provided with a third flow detection piece, and the second outflow system is provided with a fourth flow detection piece. The device solves the problems that in the prior art, the condition of flow coupling of a shaft and formation fluid is not comprehensively considered, so that the device performance is poor, and the experiment effect is poor.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas drilling and production, and in particular to a device and method for measuring key parameters of fractured gas reservoir-wellbore coupled seepage. Background Art

[0002] In the existing technology, as my country's demand for oil and natural gas energy continues to increase, how to correctly and efficiently exploit fractured oil and gas reservoirs has become a major problem in the field of oil extraction. In the process of drilling fractured gas reservoirs, complex downhole accidents such as gas invasion and leakage occur from time to time, which is an important factor affecting the safety of well control operations. When leakage and gas invasion occur in fractured formations, the permeability of fractured formations will also change due to changes in formation pressure. If the key seepage parameters such as drilling fluid leakage rate, gas invasion rate and formation permeability in the coupled flow of fractured gas reservoirs and wellbores cannot be accurately predicted, the possibility of well pressure failure may increase, causing major personal safety accidents and economic losses. Therefore, it is of great significance to measure the key parameters of fractured gas reservoir-wellbore coupled seepage.

[0003] Current indoor experimental equipment generally lacks experimental devices and methods that consider the relatively comprehensive coupling of wellbore and formation fluid flow. For example, "A Wellbore Fracture Simulation Device" (CN102305045A) simulates the drilling loss process by connecting a fracture pipe to the simulated wellbore, without considering the specific conditions of the formation; the patent "Research Device for Studying the Coexistence Mechanism of Overflow and Leakage in Fracture Formations" (CN204098907U) uses a seam plate to connect the simulated wellbore and the simulated formation to evaluate the coexistence mechanism of overflow and leakage in fractured formations. Although the conditions of the wellbore and the formation are taken into account at the same time, the gas-liquid replacement of the formation fluid and the drilling fluid is not considered, resulting in the existing indoor wellbore-formation simulation device. The simulated underground conditions are not considered comprehensively, the performance of the device is poor, and the experimental results are not good.

[0004] Therefore, there are problems in the prior art that the indoor simulation device does not fully consider the coupling between the wellbore and the formation fluid flow, the device performance is poor, and the experimental effect is poor. Summary of the invention

[0005] The main purpose of the present invention is to provide a device and method for measuring key parameters of fractured gas reservoir-wellbore coupled seepage, so as to solve the problem that the indoor simulation devices in the prior art do not fully consider the coupling of wellbore and formation fluid flow, resulting in poor device performance and poor experimental results.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided a device for measuring key parameters of fracture-type gas reservoir-wellbore coupled seepage, comprising a simulated formation structure, a gas injection system, a drilling fluid injection system, a first outflow system, and a second outflow system, wherein the simulated formation structure has a containing space, and the core is arranged in the containing space; the gas injection system is connected to the containing space in an openable and closable manner, and the gas injection system has a first pressure detection component and a first flow detection component, and the first pressure detection component and the first flow detection component are arranged at the connection between the gas injection system and the simulated formation structure; the drilling fluid injection system is connected to the containing space in an openable and closable manner, and the drilling fluid injection system has a second pressure detection component and a second flow detection component; the first outflow system and the second outflow system are respectively connected to the simulated formation structure in an openable and closable manner, and the first outflow system has a third flow detection component, and the second outflow system has a fourth flow detection component.

[0007] Furthermore, the gas injection system includes a high-pressure gas tank and at least one first valve, wherein the first valve is arranged between the high-pressure gas tank and the simulated formation structure, and the first pressure detection component and the first flow detection component are both located between the first valve and the simulated formation structure.

[0008] Furthermore, the gas injection system further includes an air compressor, which is located at one end of the high-pressure gas tank away from the first valve; and / or the gas injection system further includes a dryer, which is located between the high-pressure gas tank and the first valve.

[0009] Furthermore, the drilling fluid injection system includes a pipeline, a simulated wellbore structure and a liquid storage tank, wherein the simulated wellbore structure and the simulated formation structure are connected in an openable and closable manner through the pipeline, the second flow detection component is arranged on the pipeline, and the second pressure detection component is arranged on the simulated wellbore structure; the liquid outlet of the liquid storage tank is connected to the liquid inlet of the simulated wellbore structure.

[0010] Furthermore, the drilling fluid injection system also includes at least one second valve and at least one third valve, wherein the second valve is arranged on the pipeline; and at least one third valve is arranged between the simulated wellbore structure and the fluid storage tank.

[0011] Furthermore, the liquid outlet of the simulated wellbore structure is connected to the liquid inlet of the liquid storage tank, and at least one third valve is respectively provided between the liquid outlet of the liquid storage tank and the liquid inlet of the simulated wellbore structure and between the liquid outlet of the simulated wellbore structure and the liquid inlet of the liquid storage tank.

[0012] Furthermore, the simulated wellbore structure includes a wellbore body and a simulated drill rod, wherein a first flow channel is formed inside the simulated drill rod, the liquid outlet of the liquid storage tank is connected to the first flow channel, the simulated drill rod is arranged inside the wellbore body and forms a second flow channel between the simulated drill rod and the inner wall of the wellbore body, the first flow channel and the second flow channel are connected, and the second flow channel is respectively connected to the pipeline and the liquid inlet of the liquid storage tank.

[0013] Furthermore, the second pressure detecting member is connected to an end of the second flow channel close to the pipeline.

[0014] Further, the first outflow system includes a gas-liquid separator and at least one fourth valve, and the gas-liquid separator and the fourth valve are respectively arranged between the third flow detection component and the simulated formation structure; and / or the second outflow system includes a liquid tank and at least one fifth valve, the liquid tank is arranged on the side of the fourth flow detection component away from the simulated formation structure, and at least one fifth valve is arranged between the fourth flow detection component and the simulated formation structure.

[0015] According to another aspect of the present invention, a method for measuring key parameters of fractured gas reservoir-wellbore coupled seepage is provided, and the method for measuring key parameters of fractured gas reservoir-wellbore coupled seepage is performed using the above-mentioned device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage. The method for measuring key parameters of fractured gas reservoir-wellbore coupled seepage includes disconnecting the connection between the simulated formation structure and the gas injection system and the drilling fluid injection system; determining an experimental method; connecting the gas injection system and the simulated formation structure; adjusting the pressure of the drilling fluid injection system and the pressure at the connection between the simulated formation structure and the gas injection system according to the experimental method; connecting the drilling fluid injection system and the simulated formation structure; determining the leakage amount Q according to the experimental method l Or the gas intrusion Q g ; According to the upper leakage Q l Or the gas intrusion Q g Determine the permeability K of the core within the simulated formation structure.

[0016] Furthermore, the experimental methods include leakage test and gas invasion test. When conducting leakage test, the pressure P of drilling fluid injection system is 井 Greater than the pressure P at the connection between the simulated formation structure and the gas injection system 地 ; When conducting gas invasion experiments, the pressure of the drilling fluid injection system is P 井 Less than the pressure P at the connection between the simulated formation structure and the gas injection system 地 .

[0017] Furthermore, when conducting a leakage experiment, the first outflow system of the device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage is closed; when conducting a gas invasion experiment, the second outflow system of the device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage is closed.

[0018] Furthermore, when conducting a leakage experiment, the leakage amount Q l =Equal to the difference between the flow rate Q3 detected by the second flow detection element of the drilling fluid injection system and the flow rate Q4 detected by the fourth flow detection element of the second outflow system, and the permeability of the core Where A is the bottom area of ​​the core, in cm 2 , Δp=P 井 -P地 , in MPa, μ is the drilling fluid viscosity, in mpa·s, L is the core length, in cm; when conducting gas invasion experiments, the gas invasion amount Q g = equal to the difference between the flow rate Q1 detected by the first flow detection device of the gas injection system and the flow rate Q2 detected by the third flow detection device of the first outflow system, and the permeability of the core Where A is the core bottom area, in cm 2 , Pa is the atmospheric pressure of the day, the unit is MPa, μ is the air viscosity, the unit is mPa·s, and L is the core length, the unit is cm.

[0019] By applying the technical solution of the present invention, a device for measuring key parameters of fracture-type gas reservoir-wellbore coupled seepage includes a simulated formation structure, a gas injection system, a drilling fluid injection system, a first outflow system, and a second outflow system, wherein the simulated formation structure has a containing space, and the core is arranged in the containing space; the gas injection system is connected to the containing space in an openable and closable manner, and the gas injection system has a first pressure detection component and a first flow detection component, and the first pressure detection component and the first flow detection component are arranged at the connection between the gas injection system and the simulated formation structure; the drilling fluid injection system is connected to the containing space in an openable and closable manner, and the drilling fluid injection system has a second pressure detection component and a second flow detection component; the first outflow system and the second outflow system are respectively connected to the simulated formation structure in an openable and closable manner, and the first outflow system has a third flow detection component, and the second outflow system has a fourth flow detection component.

[0020] The device for measuring the key parameters of fractured gas reservoir-wellbore coupled seepage in this scheme simulates the process of fractured gas reservoir-wellbore coupled seepage. The experimental equipment has relatively comprehensive considerations on the coupling of the drilling fluid injection system and the simulated formation structure fluid flow, mainly including the leakage of the drilling fluid injection system into the simulated formation structure, the invasion of gas from the simulated formation structure into the drilling fluid injection system, changing the pressure of the drilling fluid injection system and the simulated formation structure to simulate the gas invasion and leakage process, measuring the pressure and flow at the entrance of the simulated formation structure, the pressure and flow in the drilling fluid injection system, and the flow of the first outflow system and the second outflow system, and recording the key parameters in the experimental process. The simulation device has better performance and the experimental data is closer to the real value, which provides a data reference for the well pressure work of low permeability fractured gas reservoirs under real working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0022] Figure 1A schematic structural diagram of a device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage according to an optional embodiment of the present invention is shown.

[0023] The above drawings include the following reference numerals:

[0024] 10. Simulated formation structure; 11. Accommodation space; 20. Gas injection system; 21. First pressure detection component; 22. First flow detection component; 23. High-pressure gas tank; 24. First valve; 25. Air compressor; 26. Dryer; 30. Drilling fluid injection system; 31. Second pressure detection component; 32. Second flow detection component; 33. Pipeline; 331. Second gas phase flowmeter; 34. Simulated wellbore structure; 341. Wellbore body; 342. Simulated drill pipe; 3421. First flow channel; 343. Second flow channel; 35. Liquid storage tank; 36. Second valve; 37. Third valve; 38. Second liquid phase flowmeter; 39. Third liquid phase flowmeter ;310, water pump;40, first outflow system;41, third flow detection element;42, gas-liquid separator;43, fourth valve;50, second outflow system;51, fourth flow detection element;52, liquid tank;53, fifth valve;2p, second pressure gauge;3p, third pressure gauge;4p, fourth pressure gauge;5p, fifth pressure gauge;6p, sixth pressure gauge;7p, seventh pressure gauge;9p, ninth pressure gauge;10p, tenth pressure gauge;1t, first temperature sensor;2t, second temperature sensor;3t, third temperature sensor;4t, fourth temperature sensor;5t, fifth temperature sensor;6t, sixth temperature sensor;2, core. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In order to solve the problem that the indoor simulation devices in the prior art do not fully consider the coupling of wellbore and formation fluid flow, resulting in poor device performance and poor experimental results, the present invention provides a device and method for measuring key parameters of fractured gas reservoir-wellbore coupled seepage.

[0027] like Figure 1As shown, a device for measuring key parameters of fracture-type gas reservoir-wellbore coupled seepage includes a simulated formation structure 10, a gas injection system 20, a drilling fluid injection system 30, a first outflow system 40 and a second outflow system 50, wherein the simulated formation structure 10 has a containing space 11, and the core 2 is arranged in the containing space 11; the gas injection system 20 is connected to the containing space 11 in an openable and closable manner, and the gas injection system 20 has a first pressure detection component 21 and a first flow detection component 22, and the first pressure detection component 21 and the first flow detection component 22 are arranged at the connection between the gas injection system 20 and the simulated formation structure 10; the drilling fluid injection system 30 is connected to the containing space 11 in an openable and closable manner, and the drilling fluid injection system 30 has a second pressure detection component 31 and a second flow detection component 32; the first outflow system 40 and the second outflow system 50 are respectively connected to the simulated formation structure 10 in an openable and closable manner, and the first outflow system 40 has a third flow detection component 41, and the second outflow system 50 has a fourth flow detection component 51.

[0028] The device for measuring the key parameters of the coupled seepage of the fractured gas reservoir and the wellbore in the present scheme simulates the process of the coupled seepage of the fractured gas reservoir and the wellbore. The experimental equipment has relatively comprehensive considerations on the coupling of the fluid flow between the drilling fluid injection system 30 and the simulated formation structure 10, mainly including the leakage of the drilling fluid injection system 30 into the simulated formation structure 10, the invasion of gas into the drilling fluid injection system 30 by the simulated formation structure 10, the change of the pressure of the drilling fluid injection system 30 and the simulated formation structure 10 to realize the simulation of the gas invasion and leakage process, the measurement of the pressure and flow at the inlet of the simulated formation structure 10, the pressure and flow in the drilling fluid injection system 30, and the flow of the first outflow system 40 and the second outflow system 50, and the recording of the key parameters in the experimental process. The performance of the simulation device is better, and the experimental data is closer to the real value, which provides a data reference for the well pressure work of the low permeability fractured gas reservoir under real working conditions.

[0029] like Figure 1 As shown, the gas injection system 20 includes a high-pressure gas tank 23 and at least one first valve 24, the first valve 24 is arranged between the high-pressure gas tank 23 and the simulated formation structure 10, and the first pressure detection component 21 and the first flow detection component 22 are both located between the first valve 24 and the simulated formation structure 10. In this way, the communication between the high-pressure gas tank 23 and the simulated formation structure 10 can be controlled by the first valve 24 to ensure that the gas injection system 20 and the accommodating space 11 can be openably and closably connected, and the first pressure detection component 21 and the first flow detection component 22 are both located between the first valve 24 and the simulated formation structure 10, ensuring that no matter whether the first valve 24 is in an open state or a closed state, the first pressure detection component 21 and the first flow detection component 22 can monitor the pressure value and flow value at the connection between the accommodating space 11 and the gas injection system 20.

[0030] It should be noted that, in this embodiment, the pressure value P detected by the first pressure detection element 21 is 地 , the flow value Q1 detected by the first flow detection element 22.

[0031] Preferably, the first flow detection component 22 is a gas flow meter.

[0032] like Figure 1 As shown, the gas injection system 20 also includes an air compressor 25, which is located at one end of the high-pressure gas tank 23 away from the first valve 24; in this way, the air compressor 25 compresses the air and flows it into the high-pressure gas tank 23, and then opens the first valve 24 to allow the high-pressure air to flow into the simulated formation structure 10, so as to pressurize the containing space 11 and simulate the actual pressure conditions of the core 2 in the formation.

[0033] like Figure 1 As shown, the gas injection system 20 further includes a dryer 26, which is located between the high-pressure gas tank 23 and the first valve 24. In this way, the high-pressure gas flowing into the simulated formation structure 10 is ensured to be dry gas, preventing a large amount of moisture contained in the gas from affecting the accuracy of the experimental data measurement.

[0034] like Figure 1 As shown, the drilling fluid injection system 30 includes a pipeline 33, a simulated wellbore structure 34 and a liquid storage tank 35, wherein the simulated wellbore structure 34 is openably connected to the simulated formation structure 10 through the pipeline 33, the second flow detection component 32 is arranged on the pipeline 33, and the second pressure detection component 31 is arranged on the simulated wellbore structure 34; the liquid outlet of the liquid storage tank 35 is connected to the liquid inlet of the simulated wellbore structure 34. In this way, the pipeline 33 is opened to connect the simulated wellbore structure 34 with the simulated formation structure 10, so that the drilling fluid of the drilling fluid injection system 30 flows into the accommodating space 11 through the pipeline 33 and flows out through the second outflow system 50, or the high-pressure gas of the gas injection system 20 flows into the accommodating space 11 and flows out through the drilling fluid injection system 30 and the first outflow system 40. The second flow detection component 32 is used to detect the flow Q2 on the pipeline 33, and the second pressure detection component 31 is used to detect the pressure P of the simulated wellbore structure 34. 井 .

[0035] Preferably, the second flow detection component 32 is a liquid phase flow meter.

[0036] like Figure 1As shown, the drilling fluid injection system 30 also includes at least one second valve 36 and at least one third valve 37, wherein the second valve 36 is arranged on the pipeline 33; and at least one third valve 37 is arranged between the simulated wellbore structure 34 and the liquid storage tank 35. Thus, by controlling the switch of the second valve 36, the connection and disconnection between the simulated wellbore structure 34 and the simulated formation structure 10 can be controlled, and by controlling the opening of the third valve 37, the pressure P in the simulated wellbore structure 34 can be adjusted. 井 .

[0037] It should be noted that, in this embodiment, a second gas flow meter 331 is also provided on the pipeline 33. The second gas flow meter 331 is arranged close to the simulated formation structure 10 relative to the second flow detection component 32. There are two second valves 36, and the two second valves 36 are respectively located on the opposite sides of the second gas flow meter 331 and the second flow detection component 32.

[0038] like Figure 1 As shown, the liquid outlet of the simulated wellbore structure 34 is connected to the liquid inlet of the liquid storage tank 35, and at least one third valve 37 is provided between the liquid outlet of the liquid storage tank 35 and the liquid inlet of the simulated wellbore structure 34, and between the liquid outlet of the simulated wellbore structure 34 and the liquid inlet of the liquid storage tank 35. In this way, the drilling fluid in the liquid storage tank 35 flows into the interior of the simulated wellbore structure 34, and the drilling fluid flows back into the liquid storage tank 35 through the simulated wellbore structure 34, thereby realizing the circulation of the drilling fluid. The third valve 37 provided between the liquid outlet of the liquid storage tank 35 and the liquid inlet of the simulated wellbore structure 34 can control the flow rate of the drilling fluid flowing from the liquid storage tank 35 into the simulated wellbore structure 34, and the third valve 37 provided between the liquid outlet of the simulated wellbore structure 34 and the liquid inlet of the liquid storage tank 35 can control the flow rate of the drilling fluid flowing from the simulated wellbore structure 34 back to the liquid storage tank 35, thereby controlling the pressure P in the simulated wellbore structure 34. 井 .

[0039] Preferably, in this embodiment, two third valves 37 are arranged between the liquid outlet of the liquid storage tank 35 and the liquid inlet of the simulated wellbore structure 34, and the two third valves 37 are both spherical valves; the third valve 37 between the liquid outlet of the simulated wellbore structure 34 and the liquid inlet of the liquid storage tank 35 is an electric regulating valve.

[0040] It should be noted that, in this embodiment, the drilling fluid injection system 30 further includes a second liquid phase flowmeter 38 and a third liquid phase flowmeter 39, wherein the second liquid phase flowmeter 38 is disposed between the liquid outlet of the liquid storage tank 35 and the liquid inlet of the simulated wellbore structure 34, and the third liquid phase flowmeter 39 is disposed between the liquid outlet of the simulated wellbore structure 34 and the liquid inlet of the liquid storage tank 35. The second liquid phase flowmeter 38 is used to detect the liquid flow rate flowing into the simulated wellbore structure 34, and the third liquid phase flowmeter 39 is used to detect the liquid flow rate flowing out of the simulated wellbore structure 34.

[0041] It should be noted that, in this embodiment, the drilling fluid injection system 30 also includes a water pump 310, which is arranged between the liquid outlet of the liquid storage tank 35 and the liquid inlet of the simulated wellbore structure 34. The water pump 310 is connected to the liquid outlet of the liquid storage tank 35 to provide power for the drilling fluid to flow in the drilling fluid injection system 30.

[0042] like Figure 1 As shown, the simulated wellbore structure 34 includes a wellbore body 341 and a simulated drill rod 342, wherein a first flow channel 3421 is formed inside the simulated drill rod 342, and the liquid outlet of the liquid storage tank 35 is connected to the first flow channel 3421. The simulated drill rod 342 is arranged inside the wellbore body 341 and forms a second flow channel 343 between the inner wall of the wellbore body 341. The first flow channel 3421 and the second flow channel 343 are connected, and the second flow channel 343 is respectively connected to the pipeline 33 and the liquid inlet of the liquid storage tank 35. In this way, the drilling fluid flows from the liquid outlet of the liquid storage tank 35 through the first flow channel 3421 and the second flow channel 343 in sequence, and flows back to the liquid storage tank 35 through the liquid inlet of the liquid storage tank 35.

[0043] like Figure 1 As shown, the second pressure detection member 31 is connected to the end of the second flow channel 343 close to the pipeline 33. In this way, the pressure value in the simulated wellbore structure 34 detected by the second pressure detection member 31 is ensured to be more accurate.

[0044] like Figure 1 As shown, the first outflow system 40 includes a gas-liquid separator 42 and at least one fourth valve 43, and the gas-liquid separator 42 and the fourth valve 43 are respectively arranged between the third flow detection component 41 and the simulated formation structure 10; in this way, the dry gas after the outflowing gas of the simulated formation structure 10 is separated by the gas-liquid separator 42 is detected by the third flow detection component 41, so as to ensure the accuracy of the flow value Q3 detected by the third flow detection component 41.

[0045] Preferably, the third flow detection component 41 is a gas flow meter.

[0046] like Figure 1 As shown, the second outflow system 50 includes a liquid tank 52 and at least one fifth valve 53. The liquid tank 52 is arranged on a side of the fourth flow detection element 51 away from the simulated formation structure 10, and at least one fifth valve 53 is arranged between the fourth flow detection element 51 and the simulated formation structure 10. In this way, the drilling fluid flowing out of the simulated formation structure 10 flows into the liquid tank 52 through the fifth valve 53 and the fourth flow detection element 51 in sequence, and the liquid tank 52 can play a role in recovering and storing the drilling fluid.

[0047] Preferably, the fourth flow detection component 51 is a liquid phase flow meter.

[0048] It should be noted that, in the present embodiment, the device for measuring the key parameters of the fractured gas reservoir-wellbore coupled seepage also includes a second pressure gauge 2p, a third pressure gauge 3p, a fourth pressure gauge 4p, a fifth pressure gauge 5p, a sixth pressure gauge 6p, a seventh pressure gauge 7p, a ninth pressure gauge 9p and a tenth pressure gauge 10p, wherein the second pressure gauge 2p and the third pressure gauge 3p are both placed on the pipeline 33, the second pressure gauge 2p is located between the simulated formation structure 10 and the second gas phase flow meter 331, the third pressure gauge 3p is located between the second flow detection component 32 and the simulated wellbore structure 34, the fourth pressure gauge 4p, the fifth pressure gauge 5p, the sixth pressure gauge 6p and the seventh pressure gauge 7p are all arranged on the simulated wellbore structure 34, the fifth pressure gauge 5p and the sixth pressure gauge 6p are connected to the end of the second flow channel 343 away from the pipeline 33, the fourth pressure gauge 4p and the seventh pressure gauge 7p are both connected to the second flow channel 343 and are located between the fifth pressure gauge 5p and the second pressure detection component 31. The ninth pressure gauge 9p and the tenth pressure gauge 10p are both arranged between the simulated wellbore structure 34 and the liquid storage tank 35, wherein the ninth pressure gauge 9p is arranged between the liquid outlet of the simulated wellbore structure 34 and the liquid inlet of the liquid storage tank 35, and the tenth pressure gauge 10p is arranged between the liquid outlet of the liquid storage tank 35 and the liquid inlet of the simulated wellbore structure 34.

[0049] It should be noted that, in the present embodiment, the device for measuring the key parameters of the fractured gas reservoir-wellbore coupled seepage also includes a first temperature sensor 1t, a second temperature sensor 2t, a third temperature sensor 3t, a fourth temperature sensor 4t, a fifth temperature sensor 5t and a sixth temperature sensor 6t, wherein the first temperature sensor 1t and the sixth temperature sensor 6t are both disposed on the pipeline 33, the first temperature sensor 1t is located between the second flow detection component 32 and the simulated wellbore structure 34, the sixth temperature sensor 6t is located between the simulated formation structure 10 and the second gas phase flowmeter 331, the second temperature sensor 2t, the third temperature sensor 3t, the fourth temperature sensor 4t, and the fifth temperature sensor 5t are all disposed on the simulated wellbore structure 34, the third temperature sensor 3t and the fourth temperature sensor 4t are both connected to the end of the second flow channel 343 away from the pipeline 33, the second temperature sensor 2t and the fifth temperature sensor 5t are both connected to the second flow channel 343 and are located between the third temperature sensor 3t and the second pressure detection component 31.

[0050] It should be noted that, in this embodiment, the device for measuring the key parameters of fractured gas reservoir-wellbore coupling seepage also includes a data acquisition system, which monitors the temperature and pressure of the wellbore body 341 entrance and exit and the simulated formation structure 10 entrance and exit in real time, the gas and liquid flow rate on each pipeline, and transmits the monitored temperature, pressure, flow rate and other data to the computer. Preferably, the data acquisition system is respectively connected to the first pressure detection member 21, the first flow detection member 22, the second pressure detection member 31, the second flow detection member 32, the second gas phase flowmeter 331, the second liquid phase flowmeter 38, the third liquid phase flowmeter 39, the third flow detection member 41, the fourth flow detection member 51, the second pressure gauge 2p, the third pressure gauge 3p, the fourth pressure gauge 4p, the fifth pressure gauge 5p, the sixth pressure gauge 6p, the seventh pressure gauge 7p, the ninth pressure gauge 9p and the tenth pressure gauge 10p, the first temperature sensor 1t, the second temperature sensor 2t, the third temperature sensor 3t, the fourth temperature sensor 4t, the fifth temperature sensor 5t and the sixth temperature sensor 6t.

[0051] The method for measuring the key parameters of fractured gas reservoir-wellbore coupled seepage is measured using the above-mentioned device for measuring the key parameters of fractured gas reservoir-wellbore coupled seepage. The method for measuring the key parameters of fractured gas reservoir-wellbore coupled seepage includes: disconnecting the simulated formation structure 10 from the gas injection system 20 and the drilling fluid injection system 30; determining the experimental method; connecting the gas injection system 20 and the simulated formation structure 10; adjusting the pressure of the drilling fluid injection system 30 and the pressure at the connection between the simulated formation structure 10 and the gas injection system 20 according to the experimental method; connecting the drilling fluid injection system 30 and the simulated formation structure 10; determining the leakage amount Q according to the experimental method l Or the gas intrusion Q g ; According to the upper leakage Q l Or the gas intrusion Q g The permeability K of the core within the simulated formation structure 10 is determined.

[0052] Before using the device for measuring the key parameters of fractured gas reservoir-wellbore coupled seepage in the present scheme, the connection between the simulated formation structure 10 and the gas injection system 20 and the drilling fluid injection system 30 is disconnected. After the experimental mode is determined, the gas injection system 20 in the device for measuring the key parameters of fractured gas reservoir-wellbore coupled seepage is connected to the simulated formation structure 10, and the pressure inside the accommodation space 11 is pressurized to simulate the pressure on the core 2 in the formation, and the pressure value P is detected by the first pressure detection member 21 at the connection between the simulated formation structure 10 and the gas injection system 20. 地 , adjust the pressure of the drilling fluid injection system 30, and detect the pressure value P through the second pressure detection element 31 井The drilling fluid injection system 30 and the simulated formation structure 10 are connected, and the flow value Q1 is detected by the first flow detection element 22, the flow value Q2 is detected by the second flow detection element 32, the flow value Q3 is detected by the third flow detection element 41 of the first outflow system 40, and the flow value Q4 is detected by the fourth flow detection element 51 of the second outflow system 50. The leakage amount Q is determined according to the experimental method. l Or the gas intrusion Q g , according to the upper leakage Q l Or the gas intrusion Q g Determine the permeability K of the core in the simulated formation structure 10. The present invention simulates the process of fractured gas reservoir-wellbore coupled seepage, and the experimental equipment takes relatively comprehensive considerations on the coupling of wellbore and formation fluid flow, mainly including the situation of wellbore drilling fluid leakage into the formation and formation gas intrusion into the wellbore, and records the key parameters in the experimental process. The performance of the simulation device is better, and the experimental data is closer to the real value, which provides a data reference for the well killing work of low permeability fractured gas reservoirs under real working conditions.

[0053] Furthermore, the experimental method includes a leakage test and a gas invasion test. When the leakage test is performed, the pressure P of the drilling fluid injection system 30 is 井 Greater than the pressure P at the connection between the simulated formation structure 10 and the gas injection system 20 地 When the gas invasion experiment is carried out, the pressure P of the drilling fluid injection system 30 井 is less than the pressure P at the connection between the simulated formation structure 10 and the gas injection system 20 地 Thus, when a leakage test is conducted, the drilling fluid of the drilling fluid injection system 30 flows into the accommodation space 11 through the pipeline 33 and flows out through the second outflow system 50 . When a gas invasion test is conducted, the high-pressure gas of the gas injection system 20 flows into the accommodation space 11 and flows out through the drilling fluid injection system 30 and the first outflow system 40 .

[0054] Furthermore, when a leakage test is conducted, the first outflow system 40 of the device for measuring the key parameters of fractured gas reservoir-wellbore coupled seepage is closed; when a gas invasion test is conducted, the second outflow system 50 of the device for measuring the key parameters of fractured gas reservoir-wellbore coupled seepage is closed. In this way, when a leakage test is conducted, it is ensured that the drilling fluid passing through the simulated formation structure 10 flows out through the second outflow system 50, and when a gas invasion test is conducted, it is ensured that the gas passing through the simulated formation structure 10 flows out through the first outflow system 40.

[0055] Furthermore, when conducting a leakage experiment, the leakage amount Q l = is equal to the difference between the flow rate Q2 detected by the second flow rate detection element 32 of the drilling fluid injection system 30 and the flow rate Q4 detected by the fourth flow rate detection element 51 of the second outflow system 50, and the permeability of the core Where A is the bottom area of ​​core 2, in cm 2 , Δp=P 井 -P 地 , in MPa, μ is the drilling fluid viscosity, in mpa·s, L is the core 2 length, in cm; when conducting gas invasion experiments, the gas invasion amount Q g = equal to the difference between the flow rate Q1 detected by the first flow rate detection element 22 of the gas injection system 20 and the flow rate Q3 detected by the third flow rate detection element 41 of the first outflow system 40, and the permeability of the core Where A is the bottom area of ​​core 2, in cm 2 , Pa is the atmospheric pressure of the day, unit is MPa, μ is the air viscosity, unit is mpa·s, L is the length of core 2, unit is cm. Thus, when conducting a leakage test, the leakage amount Q l =Q2-Q4, and penetration The leakage rate and permeability of the core can be calculated when the drilling fluid in the wellbore leaks into the formation; when the gas invasion experiment is carried out, the gas invasion volume Q g =Q1-Q3, and the permeability of the core The core loss rate and permeability can be calculated in the case of formation gas intrusion into the wellbore.

[0056] The method for measuring the key parameters of fractured gas reservoir-wellbore coupled seepage is as follows:

[0057] Example 1: Dropout Experiment

[0058] (1) Before the experiment, all valves were closed and the drilling fluid with set parameters was injected into the liquid storage tank 35; the bottom area of ​​the core 2 was measured as A, the length was L, and the viscosity of the drilling fluid was μ;

[0059] (2) Slowly open the third valve 37 provided between the liquid outlet of the liquid storage tank 35 and the liquid inlet of the simulated wellbore structure 34, and between the liquid outlet of the simulated wellbore structure 34 and the liquid inlet of the liquid storage tank 35;

[0060] (3) Turn on the water pump 310, and the drilling fluid in the liquid storage tank 35 is pumped into the first flow channel 3421 of the wellbore body 341 through the water pump 310 and the third valve 37. The drilling fluid is returned through the second flow channel 343, and is returned to the liquid storage tank 35 through another third valve 37 and the third liquid phase flow meter 39. The pressure in the simulated wellbore structure 34 is adjusted by adjusting the multiple third valves 37, and the indication P of the second pressure detection element 31 is read. 井 ;

[0061] (4) Turn on the air compressor 25 and the dryer 26, slowly open the first valve 24, connect the gas injection system 20 with the simulated formation structure 10, give the core 2 a certain confining pressure, and read the instrument reading P of the first flow detection component 22. 地 , thereby simulating the formation pressure. Strictly control the formation pressure to be less than the wellbore pressure, that is, P 地 <P 井 The first valve 24 is closed, and the second valve 36 is slowly opened, so that a part of the drilling fluid in the second flow channel 343 flows from the pipeline 33 into the accommodation space 11 and passes through the core 2, and then flows out from the core 2 through the fourth flow detection element 51 to the liquid tank 52;

[0062] (5) Read the drilling fluid flow rates Q2 and Q4 through the second flow detection element 32 and the fourth flow detection element 51; read the drilling fluid flow rates Q5 and Q6 through the second liquid phase flow meter 38 and the third liquid phase flow meter 39;

[0063] (6) Read the pressures Pl1, Pl2, Pl3, Pl4, Pl5, Pl6, Pl7, and Pl8 through the second pressure gauge 2p, the third pressure gauge 3p, the fourth pressure gauge 4p, the fifth pressure gauge 5p, the sixth pressure gauge 6p, the seventh pressure gauge 7p, the ninth pressure gauge 9p, and the tenth pressure gauge 10p;

[0064] (7) Reading temperatures Tl1, Tl2, Tl3, Tl4, Tl5, Tl6 through the first temperature sensor 1t, the second temperature sensor 2t, the third temperature sensor 3t, the fourth temperature sensor 4t, the fifth temperature sensor 5t, and the sixth temperature sensor 6t;

[0065] (8) Keeping the flow rate of the drilling fluid unchanged, adjusting the third valve 37, changing the pressure of the simulated wellbore structure 34, and repeating steps (4) to (7) to collect experimental data under different wellbore-formation pressure differences;

[0066] (9) Based on the data obtained from the above experiments, the core permeability K is calculated as follows:

[0067] According to the drilling fluid flow rates Q2 and Q4 measured in step (5), the leakage volume Q l ,

[0068] Q l =Q3-Q4

[0069] In the formula, Q l is the leakage amount, in cm 3 / s.

[0070] The bottom area A, length L, drilling fluid viscosity μ of the core 2 measured in step (1), and P measured in steps (3) and (4) are 井 , P地 And the calculated leakage Q l , according to West's law The core permeability K can be obtained,

[0071]

[0072] Where K is the permeability and A is the core bottom area in cm 2 , Δp is the pressure difference between the two ends of the core, the unit is MPa, μ is the viscosity of the drilling fluid, the unit is mpa·s, and L is the core length, the unit is cm.

[0073] (10) Repeat the above leakage experiment by changing the drilling fluid displacement, density, viscosity, and wellbore pressure, and measure the leakage rate and formation permeability changes under different flow conditions.

[0074] By simulating the coupled seepage of the wellbore and fractured formation, changing the pressure at both ends of the simulated formation so that the wellbore pressure is greater than the simulated formation pressure, the simulation of the leakage process is realized, the temperature and pressure of the wellbore inlet and outlet and the simulated formation inlet and outlet, the gas-liquid flow rate on each pipeline are measured, and then the permeability change of the core under different pressure and formation conditions is calculated by Darcy's law, and the fractured gas reservoir-wellbore coupled seepage mechanism is studied. Through the leakage experiment designed by the present invention, the experimental simulation of the coupled seepage of the fractured gas reservoir-wellbore can be realized, the temperature and pressure of the wellbore inlet and outlet and the simulated formation inlet and outlet, the gas-liquid flow rate on each pipeline can be accurately measured, and the change of the core permeability can be obtained. At the same time, by replacing different cores or adjusting the pressure at both ends of the simulated formation, the key parameters of the coupled seepage of the fractured gas reservoir-wellbore under different formation conditions can be compared, and the response law of the key parameters of the fractured formation seepage with the wellbore flow characteristics can be obtained.

[0075] Example 2: Gas Intrusion Experiment

[0076] (1) Before the experiment, all valves were closed and the drilling fluid with set parameters was injected into the liquid storage tank 35; the bottom area A, length L, and drilling fluid viscosity μ of the core 2 were measured;

[0077] (2) Turn on the air compressor 25 to inject gas into the high-pressure gas tank 23. After the high-pressure gas tank 23 is full of gas, turn on the dryer 26;

[0078] (3) Slowly open the first valve 24, and the gas enters the core 2, giving the core 2 a certain confining pressure, thereby simulating the formation pressure, and reading the instrument reading P of the first flow detection component 22. 地 ;

[0079] (4) Turn on the water pump 310, and the drilling fluid in the liquid storage tank 35 is pumped into the first flow channel 3421 of the wellbore body 341 through the water pump 310 and the third valve 37. The drilling fluid is returned through the second flow channel 343, and is returned to the liquid storage tank 35 through another third valve 37 and the third liquid phase flow meter 39. The pressure of the simulated wellbore structure 34 is adjusted by adjusting the multiple third valves 37, and the indication P of the second pressure detection element 31 is read. 井 ; Strictly control the wellbore pressure to be less than the formation pressure, that is, P 井 <P 地 ;

[0080] (5) Slowly open the second valve 36 on the pipeline 33, and the gas begins to flow from the simulated formation structure 10 into the second flow channel 343 in the wellbore body 341;

[0081] (6) Open the fourth valve 43, and the remaining gas flows out of the core 2 into the gas-liquid separator 42 and then discharged into the atmosphere;

[0082] (7) Reading the gas flow rates Q1 and Q3 through the first flow detection element 22 and the third flow detection element 41, and reading the gas flow rate Q7 through the second gas phase flow meter 331;

[0083] (8) Read the pressures Pl1, Pl2, Pl3, Pl4, Pl5, Pl6, Pl7, and Pl8 through the second pressure gauge 2p, the third pressure gauge 3p, the fourth pressure gauge 4p, the fifth pressure gauge 5p, the sixth pressure gauge 6p, the seventh pressure gauge 7p, the ninth pressure gauge 9p, and the tenth pressure gauge 10p;

[0084] (9) Reading temperatures Tl1, Tl2, Tl3, Tl4, Tl5, Tl6 through the first temperature sensor 1t, the second temperature sensor 2t, the third temperature sensor 3t, the fourth temperature sensor 4t, the fifth temperature sensor 5t, and the sixth temperature sensor 6t;

[0085] (10) Keeping the flow rate of the drilling fluid unchanged, adjusting the third valve 37, changing the pressure of the simulated wellbore structure 34, and repeating steps (4) to (7) to collect experimental data under different wellbore-formation pressure differences;

[0086] (11) The core permeability K is calculated based on the data obtained from the above experiments. The method is as follows:

[0087] According to the gas flow rates Q1 and Q3 measured in step (7), the gas intrusion amount Q g ,

[0088] Q g =Q1-Q3

[0089] In the formula, Q g is the gas intrusion volume, cm3 / s.

[0090] The bottom area A, length L, drilling fluid viscosity μ of the core 2 measured in step (1), and P measured in steps (3) and (4) are 井 , P 地 And the calculated gas intrusion amount Q g , we can get the core permeability K,

[0091]

[0092] Where K is the permeability and A is the core bottom area in cm 2 , Pa is the atmospheric pressure of the day, the unit is MPa, μ is the air viscosity, the unit is mPa·s, and L is the core length, the unit is cm.

[0093] (12) Change the drilling fluid displacement, density, viscosity, and wellbore pressure, repeat the above experiment, and measure the changes in gas invasion rate and formation permeability under different flow conditions.

[0094] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0095] (1) It can realize the experimental simulation of fractured gas reservoir-wellbore coupled seepage, accurately measure the temperature and pressure of the wellbore entrance and exit and the simulated formation entrance and exit, and the gas and liquid flow rate on each pipeline, and then derive the change of core permeability.

[0096] (2) By replacing different cores or adjusting the pressure at both ends of the simulated formation, the key parameters of fractured gas reservoir-wellbore coupled seepage under different formation conditions can be compared, and the response law of the key parameters of fractured formation seepage with the wellbore flow characteristics can be obtained.

[0097] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0098] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0099] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0100] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0101] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage, characterized in that: include: A simulated stratum structure (10), wherein the simulated stratum structure (10) has a containing space (11), and a core (2) is arranged in the containing space (11); a gas injection system (20), the gas injection system (20) being in openable and closable communication with the accommodation space (11), the gas injection system (20) comprising a first pressure detection component (21) and a first flow detection component (22), the first pressure detection component (21) and the first flow detection component (22) being arranged at a connection between the gas injection system (20) and the simulated formation structure (10); A drilling fluid injection system (30), the drilling fluid injection system (30) being in openable and closable communication with the accommodating space (11), the drilling fluid injection system (30) comprising a second pressure detection component (31) and a second flow detection component (32); a first outflow system (40); A second outflow system (50), wherein the first outflow system (40) and the second outflow system (50) are respectively connected to the simulated formation structure (10) in an openable and closable manner, and the first outflow system (40) has a third flow detection component (41), and the second outflow system (50) has a fourth flow detection component (51).

2. The device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage according to claim 1, characterized in that: The gas injection system (20) comprises: High pressure gas tank (23); At least one first valve (24), wherein the first valve (24) is arranged between the high-pressure gas tank (23) and the simulated formation structure (10), and the first pressure detection component (21) and the first flow detection component (22) are both located between the first valve (24) and the simulated formation structure (10).

3. The device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage according to claim 2, characterized in that: The gas injection system (20) further comprises: an air compressor (25), the air compressor (25) being located at an end of the high-pressure gas tank (23) away from the first valve (24); and / or A dryer (26), wherein the dryer (26) is located between the high-pressure gas tank (23) and the first valve (24).

4. The device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage according to any one of claims 1 to 3, characterized in that: The drilling fluid injection system (30) comprises: Pipeline (33); a simulated wellbore structure (34), the simulated wellbore structure (34) being in openable and closable communication with the simulated formation structure (10) via the pipeline (33), the second flow detection element (32) being arranged on the pipeline (33), and the second pressure detection element (31) being arranged on the simulated wellbore structure (34); A liquid storage tank (35), wherein the liquid outlet of the liquid storage tank (35) is connected to the liquid inlet of the simulated wellbore structure (34).

5. The device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage according to claim 4, characterized in that: The drilling fluid injection system (30) further comprises: at least one second valve (36), wherein the second valve (36) is arranged on the pipeline (33); At least one third valve (37), at least one third valve (37) is provided between the simulated wellbore structure (34) and the liquid storage tank (35).

6. The device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage according to claim 5, characterized in that: The liquid outlet of the simulated wellbore structure (34) is connected to the liquid inlet of the liquid storage tank (35), and at least one third valve (37) is respectively provided between the liquid outlet of the liquid storage tank (35) and the liquid inlet of the simulated wellbore structure (34), and between the liquid outlet of the simulated wellbore structure (34) and the liquid inlet of the liquid storage tank (35).

7. The device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage according to claim 4, characterized in that: The simulated wellbore structure (34) comprises: Wellbore body(341); A simulated drill rod (342) is provided, wherein a first flow channel (3421) is formed inside the simulated drill rod (342), a liquid outlet of the liquid storage tank (35) is connected to the first flow channel (3421), the simulated drill rod (342) is arranged inside the wellbore body (341) and forms a second flow channel (343) with the inner wall of the wellbore body (341), the first flow channel (3421) and the second flow channel (343) are connected, and the second flow channel (343) is respectively connected to the pipeline (33) and the liquid inlet of the liquid storage tank (35).

8. The device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage according to claim 7, characterized in that: The second pressure detection member (31) is connected to an end of the second flow channel (343) close to the pipeline (33).

9. The device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage according to any one of claims 1 to 3, characterized in that: The first outflow system (40) comprises a gas-liquid separator (42) and at least one fourth valve (43), and the gas-liquid separator (42) and the fourth valve (43) are respectively arranged between the third flow detection element (41) and the simulated formation structure (10); and / or The second outflow system (50) comprises a liquid tank (52) and at least one fifth valve (53); the liquid tank (52) is arranged on a side of the fourth flow detection component (51) away from the simulated formation structure (10); and at least one fifth valve (53) is arranged between the fourth flow detection component (51) and the simulated formation structure (10).

10. A method for measuring key parameters of fractured gas reservoir-wellbore coupled seepage, characterized in that: The device for measuring the key parameters of fractured gas reservoir-wellbore coupled seepage is used as described in any one of claims 1 to 9. The method for measuring the key parameters of fractured gas reservoir-wellbore coupled seepage comprises: Disconnecting the simulated formation structure (10) from the gas injection system (20) and the drilling fluid injection system (30); Determine the experimental method; Connecting the gas injection system (20) and the simulated formation structure (10); According to the experimental method, the pressure of the drilling fluid injection system (30) and the pressure at the connection between the simulated formation structure (10) and the gas injection system (20) are adjusted; connecting the drilling fluid injection system (30) and the simulated formation structure (10); The leakage amount Q is determined according to the experimental method l Or the gas intrusion Q g ; According to the above leakage Q l Or the gas intrusion amount Q g The permeability K of the core in the simulated formation structure (10) is determined.

11. The method for measuring key parameters of fractured gas reservoir-wellbore coupled seepage according to claim 10, characterized in that: The experimental methods include leakage test and gas intrusion test. When the leakage test is performed, the pressure P of the drilling fluid injection system (30) is 井 greater than the pressure P at the connection between the simulated formation structure (10) and the gas injection system (20) 地 ; When the gas invasion experiment is performed, the pressure P of the drilling fluid injection system (30) is 井 is less than the pressure P at the connection between the simulated formation structure (10) and the gas injection system (20) 地 .

12. The method for measuring key parameters of fractured gas reservoir-wellbore coupled seepage according to claim 11, characterized in that: When the leakage test is performed, the first outflow system (40) of the device for measuring the key parameters of fractured gas reservoir-wellbore coupled seepage is closed; When the gas invasion experiment is carried out, the second outflow system (50) of the device for measuring key parameters of fractured gas reservoir-wellbore coupled seepage is closed.

13. The method for measuring key parameters of fractured gas reservoir-wellbore coupled seepage according to claim 12, characterized in that: When the leakage experiment is performed, the leakage amount Q l is equal to the difference between the flow rate Q2 detected by the second flow rate detection element (32) of the drilling fluid injection system (30) and the flow rate Q4 detected by the fourth flow rate detection element (51) of the second outflow system (50), and the permeability of the core Where A is the bottom area of ​​the core (2), in cm 2 , Δp=P 井 -P 地 , in MPa, μ is the drilling fluid viscosity in mpa·s, L is the length of the core (2) in cm; When the gas intrusion experiment is performed, the gas intrusion amount Q g is equal to the difference between the flow rate Q1 detected by the first flow rate detection element (22) of the gas injection system (20) and the flow rate Q3 detected by the third flow rate detection element (41) of the first outflow system (40), and the permeability of the core Where A is the bottom area of ​​the core (2), in cm 2 , Pa is the atmospheric pressure of the day, unit is MPa, μ is the air viscosity, unit is mPa·s, and L is the length of the core (2), unit is cm.

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