Device and method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution

Abstract

The present invention provides a device and method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution, the device includes a high-pressure reciprocating pump, an air compressor, a gas flowmeter, a first liquid flowmeter, a second liquid flowmeter, a wellhead pressure sensor, a bottom hole pressure sensor, a gas supply leakage test pipeline, a discharge valve and a simulation experiment pipeline, wherein the simulation experiment pipeline includes a coaxially arranged simulated wellbore and a simulated drill pipe; the bottom of the simulated wellbore is provided with a first and a second formation simulation hole and a water injection hole; the high-pressure reciprocating pump is connected to the water injection hole to pump liquid; the air compressor is connected to the gas supply leakage test pipeline through the second pipeline to pump gas into the formation simulation hole; the wellhead pressure sensor and the bottom hole pressure sensor are arranged at the top and bottom of the simulated wellbore. The present invention has the advantages of being able to conduct drilling fluid leakage single-phase wellbore-formation coupled flow experiments, as well as leakage coexistence, gas invasion wellbore-formation coupled multiphase flow experiments, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas drilling, and in particular to a device and method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution. Background Art

[0002] In the development of deep fractured carbonate reservoirs, accurately understanding the complex multiphase flow characteristics and pressure variations in the wellbore under the conditions of fractured formation-wellbore multiphase coupled flow is a prerequisite for solving wellbore pressure control and realizing a series of technologies such as safe and active pressure-managed drilling in deep carbonate formations, intelligent well control and risk-free drilling in fractured formations, plugging while drilling, reservoir evaluation while drilling, and reservoir protection. Currently, most research on the multiphase coupled flow patterns in fractured formations and wellbores is carried out by establishing a mathematical model of the formation-wellbore multiphase coupled flow and performing numerical calculations in combination with appropriate boundary conditions to obtain the wellbore pressure distribution pattern.

[0003] Regarding the multiphase coupled flow patterns in fractured formations and wellbores, current research focuses on gas invasion and well-killing processes at fixed gas flow rates. Application number: CN200820080025.7, titled "Oil and Gas Well Overflow and Leakage Experimental Device," discloses an oil and gas well overflow and leakage experimental device consisting of a wellbore with a piston, a transparent fracture-simulating glass window, and a reservoir tube. The wellbore comprises a circular wellbore with a piston, a screw at its lower end, and a screw connected to the piston at its upper end. The transparent fracture-simulating glass window consists of two plexiglass windows fixed parallel to and sealed at the seams between the wellbore and reservoir tube. The two plexiglass windows are connected to the wellbore and reservoir tube at their respective ends. A quick-connect connector is fixed to the wall of the reservoir tube, and a gas source interface is fixed to the top of the reservoir tube. This device can realistically simulate the reservoir drilling process and observe gas invasion, well leakage, and gravity displacement phenomena during well control operations. In "Flow Experiment and Simulation of Gas-Liquid Gravity Replacement in Fractures", Dai Cheng, Li Gao, et al. used a visualized formation-wellbore coupled flow experimental frame to simulate the gas-liquid gravity replacement phenomenon under real fractures.

[0004] Regarding the characteristics of complex multiphase flow and pressure variations in wellbores, Wei Na, Meng Yingfeng, Li Gao, and others established mathematical models for steady-state gas-liquid multiphase flow under underbalanced normal drilling and transient gas-liquid two-phase flow in stopped-circulation wellbores. Based on the Shi drift model, they established a transient prediction model for annular two-phase flow. Using numerical calculation methods and experimental research, they obtained bottomhole pressures and dynamic response characteristics between various flow parameters under conditions such as constant-volume continuous gas invasion, variable-volume continuous gas invasion, single-stream gas invasion, intermittent gas invasion, and pressure-controlled drilling in thin and thick reservoirs. The main shortcoming of these experimental devices or studies is that they fail to combine the study of formation-wellbore coupled flow with the characteristics of complex multiphase flow in the wellbore and the laws of pressure variation to develop a wellbore pressure distribution model under formation-wellbore multiphase coupled flow conditions, making it difficult to meet the needs of on-site drilling operations. Summary of the Invention

[0005] The present invention aims to address at least one of the aforementioned deficiencies in the prior art. For example, one object of the present invention is to provide an experimental testing device capable of studying the evolution of wellbore pressure under conditions of formation gas production, drilling fluid loss, and spillage. Another object of the present invention is to provide an experimental testing method for studying the distribution of wellbore pressure under conditions of multiphase coupled formation-wellbore flow.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a device for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution, the device comprising a high-pressure reciprocating pump, an air compressor, a gas flow meter, a first liquid flow meter, a second liquid flow meter, a wellhead pressure sensor, a bottom hole pressure sensor, a first pipeline, a second pipeline, a third pipeline, a gas supply leakage test pipeline, a discharge valve and a simulation experiment pipeline, wherein the simulation experiment pipeline comprises a simulation wellbore and a simulation drill pipe, the lower part of the simulation drill pipe is inserted into the simulation wellbore and is coaxially arranged with the simulation wellbore, and the top of the simulation drill pipe is sealed to form a A first cavity opening downward, the top of the simulated wellbore is sealed with the outer wall of the simulated drill pipe and the bottom of the simulated wellbore is sealed, a second cavity is formed between the inner wall of the simulated wellbore and the outer wall of the simulated drill pipe, and the second cavity is communicated with the first cavity; a first formation simulation hole, a second formation simulation hole and a water injection hole are provided at the bottom of the simulated wellbore, and the first formation simulation hole, the second formation simulation hole and the water injection hole are respectively communicated with the second cavity; a discharge hole is also provided at the top of the simulated wellbore, and the discharge hole is connected to the discharge valve through a third pipeline; the high-pressure reciprocating pump is connected to the The water injection hole is connected, and the first liquid flow meter is arranged on the first pipeline; the air compressor is connected to the air supply leakage test pipeline through the second pipeline, and the gas flow meter is arranged on the second pipeline; the air supply leakage test pipeline includes a fourth pipeline, a fifth pipeline, a sixth pipeline, a seventh pipeline, a first air intake valve, a second air intake valve, a first leakage valve, a second leakage valve and a second liquid flow meter, wherein one end of the fourth pipeline is connected to the second pipeline, and the other end is connected to the first formation simulation hole, and one end of the fifth pipeline is connected to the second pipeline, and the other end is connected to the second formation simulation hole ; The first air inlet valve is arranged on the fourth pipeline, and the second air inlet valve is arranged on the fifth pipeline; one end of the sixth pipeline is connected to the second liquid flow meter, and the other end is connected to the part of the fourth pipeline located between the first air inlet valve and the first formation simulation hole; one end of the seventh pipeline is connected to the second liquid flow meter, and the other end is connected to the part of the fifth pipeline located between the second air inlet valve and the second formation simulation hole; the first loss valve is arranged on the sixth pipeline, and the second loss valve is arranged on the seventh pipeline; the wellhead pressure sensor is arranged on the upper part of the simulated wellbore, and the bottom hole pressure sensor is arranged at the bottom of the simulated wellbore.

[0007] In an exemplary embodiment of one aspect of the present invention, the device may further include a data acquisition module, which is respectively connected to the gas flow meter, the first liquid flow meter, the second liquid flow meter, the wellhead pressure sensor, and the bottom hole pressure sensor to collect pressure and flow data.

[0008] In an exemplary embodiment of one aspect of the present invention, the device may also include an eighth pipeline, a third air intake valve and a pressure-stabilizing container, one end of the eighth pipeline is connected to the air compressor, and the other end is connected to the discharge valve, the pressure-stabilizing container is arranged on the eighth pipeline, and the third air intake valve is arranged on the eighth pipeline and located before the pressure-stabilizing container.

[0009] In an exemplary embodiment of one aspect of the present invention, the device may further include a first pressure sensor and a second pressure sensor, wherein the first pressure sensor is disposed on the fourth pipeline and the second pressure sensor is disposed on the fifth pipeline.

[0010] In an exemplary embodiment of one aspect of the present invention, the device may further include a gas pressure regulating valve, which is provided on the second pipeline and located between the air compressor and the gas flow meter to control the pressure and flow of the gas experimental medium.

[0011] In an exemplary embodiment of one aspect of the present invention, the device may further include a throttle valve, a solenoid valve and a third pressure sensor, wherein the throttle valve, the solenoid valve and the third pressure sensor are arranged on a third pipeline, and the solenoid valve is arranged between the discharge hole and the throttle valve, and the third pressure sensor is arranged between the throttle valve and the discharge valve.

[0012] In an exemplary embodiment of one aspect of the present invention, the simulated wellbore may be made of a transparent material, the length of the simulated wellbore may be 20 to 50 m, and the diameter of the simulated wellbore may be 120 to 200 mm.

[0013] In an exemplary embodiment of an aspect of the present invention, the length of the simulated drill rod may be 20 to 50 m, and the diameter of the simulated drill rod may be 40 to 110 mm.

[0014] In an exemplary embodiment of one aspect of the present invention, the pressure resistance range of the simulation experiment pipeline may be 1 to 15 MPa.

[0015] In an exemplary embodiment of one aspect of the present invention, the device may also include an axial pressure sensor and an axial pressure sensor, the axial pressure sensor may include 5 to 10 pressure sensors evenly distributed along the axial direction of the simulated wellbore, and the circumferential pressure sensor may include 2 to 5 pressure sensors evenly distributed along the circumference of the simulated wellbore.

[0016] In an exemplary embodiment of an aspect of the present invention, the diameters of the first formation simulation perforations and the second formation simulation perforations may be equal to the actual formation equivalent diameters.

[0017] Another aspect of the present invention provides a method for simulating wellbore pressure distribution in formation-wellbore multiphase coupled flow, which can be implemented by the device for simulating wellbore pressure distribution in formation-wellbore multiphase coupled flow as described above, and the method comprises the steps of:

[0018] When conducting a single-phase leakage experiment, a liquid-phase experimental working medium is injected into the simulated experimental pipeline through the first pipeline by a high-pressure reciprocating pump, and the first liquid flowmeter measures the injection amount of the liquid-phase experimental working medium. The liquid-phase experimental working medium flows from the bottom of the simulated wellbore to the upper part of the simulated wellbore, and is discharged to the outside through the discharge valve via the discharge hole on the simulated wellbore through the third pipeline; the first leakage valve and / or the second leakage valve are opened, and the first air inlet valve and the second air inlet valve are closed. The liquid-phase experimental working medium enters the second liquid flowmeter through the first formation simulation hole, the fourth pipeline, and the sixth pipeline and / or enters the second liquid flowmeter through the second formation simulation hole, the fifth pipeline, and the seventh pipeline, and the liquid-phase working medium leakage amount is measured before being discharged to the outside; the wellhead pressure and the bottomhole pressure during the single-phase leakage experiment are measured by the wellhead pressure sensor and the bottomhole pressure sensor;

[0019] When conducting a gas-liquid two-phase flow experiment with gas intrusion and leakage, the liquid phase experimental working medium is injected into the simulation experimental pipeline through the first pipeline by a high-pressure reciprocating pump, and the first liquid flowmeter measures the injection amount of the liquid phase experimental working medium. The liquid phase experimental working medium flows from the bottom of the simulation wellbore to the upper part of the simulation wellbore, and is discharged to the outside through the discharge hole on the simulation wellbore through the third pipeline from the discharge valve; the first air inlet valve and the second leakage valve are opened, and the first leakage valve and the second air inlet valve are closed, or the second air inlet valve and the first leakage valve are opened, and the second leakage valve and the first air inlet valve are closed, and the gas experimental working medium is injected into the simulation experimental pipeline through the second pipeline by the air compressor. The fourth pipeline or the fifth pipeline is injected into the simulation experimental pipeline, and the injection amount of the gas experimental working fluid is measured by the gas flowmeter; the liquid phase experimental working fluid enters the second liquid flowmeter through the second formation simulation hole, the fifth pipeline, and the seventh pipeline or through the first formation simulation hole, the fourth pipeline, and the sixth pipeline, and the leakage amount of the liquid experimental working fluid is measured; the gas content is calculated by the liquid leakage amount measured by the second liquid flowmeter and the gas working fluid injection amount measured by the gas flowmeter; the wellhead pressure and the bottom hole pressure during the gas-liquid two-phase flow experiment with gas invasion and leakage coexisting are measured by the wellhead pressure sensor and the bottom hole pressure sensor.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] (1) The present invention provides a wellbore pressure distribution device for simulating formation-wellbore multiphase coupled flow, which can be used to conduct single-phase wellbore-formation coupled flow experiments with drilling fluid loss, as well as wellbore-formation coupled multiphase flow experiments with overflow and gas invasion, and truly simulate the complex material exchange between the wellbore and the formation during the drilling process;

[0022] (2) The present invention provides a method for simulating the wellbore pressure distribution of formation-wellbore multiphase coupled flow. By changing the wellhead back pressure, leakage pressure, gas injection volume and injection pressure, the relationship between leakage volume, gas invasion volume and wellhead back pressure, gas injection pressure and gas content can be explored, and the pressure evolution law of the entire wellbore can be obtained, which provides a theoretical basis for petroleum engineering to calculate the bottom hole pressure change law when drilling into the production layer with high precision and realize safe active pressure control drilling operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other objects and / or features of the present invention will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0024] Figure 1 A schematic structural diagram of an exemplary embodiment of a device for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution according to the present invention is shown;

[0025] Figure 2 A schematic structural diagram showing another exemplary embodiment of the device for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution of the present invention is shown;

[0026] Figure 3 Shown Figure 1 Schematic diagram of the structure of the simulation experiment pipeline;

[0027] Figure 4 Shows Shows Figure 3 Bottom view of .

[0028] Description of reference numerals:

[0029] 1. High-pressure reciprocating pump, 2. Water inlet valve, 3. Air compressor, 4. Gas pressure regulating valve, 5. Gas flow meter, 6. First air inlet valve, 7. Second air inlet valve, 8. First leakage valve, 9. Second leakage valve, 10. First liquid flow meter, 11. Third air inlet valve, 12. Pressure stabilizing container, 13. Discharge valve, 14. Throttle valve, 15. Solenoid valve, 16. Simulated experimental pipeline, 16-1. Simulated wellbore, 16-2. Simulated drill pipe, 16-3. First formation simulation hole, 16-4. Second formation simulation hole, 16-5. Pressure measurement hole, 16-6. Water injection hole, 17. Second liquid flowmeter, A1. First pressure sensor, A2. Second pressure sensor, A3. Bottom hole pressure sensor, A4. Wellhead pressure sensor, A5. Third pressure sensor, 18. First pipeline, 19. Second pipeline, 20. Third pipeline, 21. Fourth pipeline, 22. Fifth pipeline, 23. Sixth pipeline, 24. Seventh pipeline, 25. Eighth pipeline, 26. Data acquisition module. DETAILED DESCRIPTION

[0030] The following describes in detail the apparatus and method for simulating formation-wellbore multiphase coupled flow pressure distribution according to the present invention, in conjunction with exemplary embodiments. It should be noted that terms such as "first," "second," "third," "fourth," "fifth," "sixth," "seventh," and "eighth," are used solely for ease of description and distinction and should not be construed as indicating or implying relative importance. Terms such as "upper," "lower," "inner," and "outer" are used solely for ease of description and to establish relative orientation or positional relationships, and do not indicate or imply that the components referred to must occupy a specific orientation or position.

[0031] Figure 1 A schematic structural diagram of an exemplary embodiment of a device for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution according to the present invention is shown; Figure 2 A schematic structural diagram showing another exemplary embodiment of the device for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution of the present invention is shown; Figure 3 Shown Figure 1 Schematic diagram of the structure of the simulation experiment pipeline; Figure 4 Shows Shows Figure 3 Bottom view of .

[0032] In a first exemplary embodiment of the present invention, as Figure 1 As shown, the device for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution includes a high-pressure reciprocating pump 1, an air compressor 3, a gas flowmeter 5, a first liquid flowmeter 10, a second liquid flowmeter 17, a wellhead pressure sensor A4, a bottom hole pressure sensor A3, a first pipeline 18, a second pipeline 19, a third pipeline 20, a gas supply leakage test pipeline, a discharge valve 13 and a simulation experiment pipeline 16.

[0033] The simulated experimental pipeline 16 includes a simulated wellbore 16-1 and a simulated drill pipe 16-2. The lower portion of the simulated drill pipe 16-2 is inserted into the simulated wellbore 16-1 and is coaxially arranged with the simulated wellbore 16-1. The top of the simulated drill pipe 16-2 is sealed to form a first cavity with an opening facing downward. The top of the simulated wellbore 16-1 is sealed to the outer wall of the simulated drill pipe 16-2 and the bottom of the simulated wellbore 16-1 is sealed. A second cavity is formed between the inner wall of the simulated wellbore and the outer wall of the simulated drill pipe, and the second cavity is connected to the first cavity. Specifically, the simulated experimental pipeline 16 is composed of the simulated wellbore 16-1 and the simulated drill pipe 16-2 arranged inside and outside, wherein the simulated wellbore 16-1 is an outer tube and the simulated drill pipe 16-2 is an inner tube, and the simulated drill pipe 16-2 is a distance higher than the simulated wellbore 16-1. For example, the length of the portion of the simulated drill pipe not inserted into the simulated wellbore can be 1 to 16 meters.

[0034] In this embodiment, if Figure 1 and Figure 3-4As shown, the bottom of the simulated wellbore 16-1 is provided with a first formation simulation hole 16-3, a second formation simulation hole 16-4, and a water injection hole 16-6. The first formation simulation hole 16-3, the second formation simulation hole 16-4, and the water injection hole 16-6 are respectively connected to the second cavity. Specifically, four holes are provided at the bottom of the simulated wellbore 16-1: the first formation simulation hole 16-3, the second formation simulation hole 16-4, the pressure measurement hole 16-5, and the water injection hole 16-6. These holes are used to simulate the formation and install pressure measuring instruments. Among them, the first formation simulation hole 16-3 and the second formation simulation hole 16-4 are used to simulate the formation, and their diameters are equal to the equivalent diameter of the real formation. The pressure measurement hole 16-5 is used to install the bottomhole pressure sensor A3 for measuring the bottomhole pressure, and the water injection hole 16-6 is used to inject liquid experimental fluid into the simulated experimental pipeline.

[0035] In this embodiment, if Figure 1 As shown, a discharge hole is further provided at the upper portion of the simulated wellbore 16 - 1 , and the discharge hole is connected to the discharge valve 13 through a third pipeline 20 to discharge the liquid phase experimental medium.

[0036] In this embodiment, the high-pressure reciprocating pump 1 is connected to the water injection hole 16-6 through the first pipeline 18 to pump the liquid-phase experimental working fluid into the simulation experimental pipeline 16, and the first liquid flowmeter 10 is arranged on the first pipeline 18 to measure the injection amount of the liquid-phase experimental working fluid.

[0037] In this embodiment, the air compressor 3 is connected to the air supply leakage test pipeline through the second pipeline 19, and the gas flow meter 5 is arranged on the second pipeline 19 to measure the injection amount of the gas phase experimental working medium.

[0038] In this embodiment, if Figure 1As shown, the gas supply leakage test pipeline includes a fourth pipeline 21, a fifth pipeline 22, a sixth pipeline 23, a seventh pipeline 24, a first air inlet valve 6, a second air inlet valve 7, a first leakage valve 8, a second leakage valve 9, and a second liquid flowmeter 17. The fourth pipeline 21 has one end connected to the second pipeline 19 and the other end connected to the first formation simulation hole 16-3. The fifth pipeline 22 has one end connected to the second pipeline 19 and the other end connected to the second formation simulation hole 16-4. The first air inlet valve 6 is provided on the fourth pipeline 21, and the second air inlet valve 7 is provided on the fifth pipeline 22. The sixth pipeline 23 has one end connected to the second liquid flowmeter 17 and the other end connected to the portion of the fourth pipeline 21 between the first air inlet valve 6 and the first formation simulation hole 16-3. The seventh pipeline 24 has one end connected to the second liquid flowmeter 17 and the other end connected to the portion of the fifth pipeline 22 between the second air inlet valve 7 and the second formation simulation hole 16-4. The first leakage valve 8 is located on the sixth pipeline 23, and the second leakage valve 9 is located on the seventh pipeline 24. Specifically, the gaseous experimental fluid enters the simulation experimental pipeline 16 through two parallel channels, one from the first formation simulation hole 16-3 and the other from the second formation simulation hole 16-4. Both channels are equipped with inlet valves to control the opening and closing of the channels. Simultaneously, the two channels are respectively connected to a second liquid flowmeter 17, enabling the second liquid flowmeter 17 to measure the amount of liquid experimental fluid lost through the first formation simulation hole 16-3 and / or the second formation simulation hole 16-4.

[0039] In this embodiment, the wellhead pressure sensor A4 is disposed at the upper portion of the simulated wellbore 16 - 1 , and the bottomhole pressure sensor A3 is disposed at the bottom of the simulated wellbore 16 - 1 to measure the wellhead pressure and the bottomhole pressure during the experiment.

[0040] In a second exemplary embodiment of the present invention, as Figure 2 As shown, the device for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution includes a high-pressure reciprocating pump 1, an air compressor 3, a gas flowmeter 5, a first liquid flowmeter 10, a second liquid flowmeter 17, a wellhead pressure sensor A4, a bottom hole pressure sensor A3, a first pipeline 18, a second pipeline 19, a third pipeline 20, a gas supply leakage test pipeline, a pressure stabilizing container 12, a discharge valve 13, a data acquisition module 26 and a simulation experiment pipeline 16.

[0041] Among them, the simulated experimental pipeline 16 includes a simulated wellbore 16-1 and a simulated drill rod 16-2, the lower part of the simulated drill rod 16-2 is inserted into the simulated wellbore 16-1 and is coaxially arranged with the simulated wellbore 16-1, the top of the simulated drill rod 16-2 is sealed to form a first cavity opening downward, the top of the simulated wellbore 16-1 is sealed with the outer wall of the simulated drill rod 16-2 and the bottom of the simulated wellbore 16-1 is sealed, and a second cavity is formed between the inner wall of the simulated wellbore and the outer wall of the simulated drill rod, and the second cavity is connected to the first cavity. Specifically, the simulated experimental pipeline 16 is composed of the simulated wellbore 16-1 and the simulated drill rod 16-2 arranged inside and outside, wherein the simulated wellbore 16-1 is an outer tube, the simulated drill rod 16-2 is an inner tube, and the simulated drill rod 16-2 is a distance higher than the simulated wellbore 16-1. For example, the length of the portion of the simulated drill rod that is not inserted into the simulated wellbore can be 1 to 16 meters. In this embodiment, if Figure 2 and Figure 3-4 As shown, the bottom of the simulated wellbore 16-1 is provided with a first formation simulation hole 16-3, a second formation simulation hole 16-4, and a water injection hole 16-6. The first formation simulation hole 16-3, the second formation simulation hole 16-4, and the water injection hole 16-6 are all connected to the second cavity. Specifically, four holes are provided at the bottom of the simulated wellbore 16-1: the first formation simulation hole 16-3, the second formation simulation hole 16-4, the pressure measurement hole 16-5, and the water injection hole 16-6. These holes are used to simulate the formation and install pressure measuring instruments. Among them, the first formation simulation hole 16-3 and the second formation simulation hole 16-4 are used to simulate the formation, and their diameters are equal to the equivalent diameter of the real formation. The pressure measurement hole 16-5 is used to install the bottomhole pressure sensor A3 for measuring the bottomhole pressure, and the water injection hole 16-6 is used to inject liquid experimental fluid into the simulated experimental pipeline.

[0042] In this embodiment, if Figure 2 As shown, a discharge hole is further provided at the upper portion of the simulated wellbore 16 - 1 , and the discharge hole is connected to the discharge valve 13 through a third pipeline 20 to discharge the liquid phase experimental medium.

[0043] In this embodiment, the high-pressure reciprocating pump 1 is connected to the water injection hole 16-6 through the first pipeline 18 to pump the liquid-phase experimental working fluid into the simulation experimental pipeline 16, and the first liquid flowmeter 10 is arranged on the first pipeline 18 to measure the injection amount of the liquid-phase experimental working fluid.

[0044] In this embodiment, the air compressor 3 is connected to the air supply leakage test pipeline through the second pipeline 19, and the gas flow meter 5 is arranged on the second pipeline 19 to measure the injection amount of the gas phase experimental working medium.

[0045] The gas supply leakage test pipeline includes a fourth pipeline 21, a fifth pipeline 22, a sixth pipeline 23, a seventh pipeline 24, a first air intake valve 6, a second air intake valve 7, a first leakage valve 8, a second leakage valve 9, and a second liquid flowmeter 17. The fourth pipeline 21 has one end connected to the second pipeline 19 and the other end connected to the first formation simulation hole 16-3. The fifth pipeline 22 has one end connected to the second pipeline 19 and the other end connected to the second formation simulation hole 16-4. The first air intake valve 6 is provided on the fourth pipeline 21, and the second air intake valve 7 is provided on the fifth pipeline 22. The sixth pipeline 23 has one end connected to the second liquid flowmeter 17 and the other end connected to the portion of the fourth pipeline 21 between the first air intake valve 6 and the first formation simulation hole 16-3. The seventh pipeline 24 has one end connected to the second liquid flowmeter 17 and the other end connected to the portion of the fifth pipeline 22 between the second air intake valve 7 and the second formation simulation hole 16-4. The first leakage valve 8 is located on the sixth pipeline 23, and the second leakage valve 9 is located on the seventh pipeline 24. Specifically, the gaseous experimental fluid enters the simulation experimental pipeline 16 through two parallel channels, one from the first formation simulation hole 16-3 and the other from the second formation simulation hole 16-4. Both channels are equipped with inlet valves to control the opening and closing of the channels. Simultaneously, the two channels are respectively connected to a second liquid flowmeter 17, enabling the second liquid flowmeter 17 to measure the amount of liquid experimental fluid lost through the first formation simulation hole 16-3 and / or the second formation simulation hole 16-4.

[0046] In this embodiment, if Figure 2 As shown, the device also includes a pressure-stabilizing container 12. The pressure-stabilizing container 12 is connected to the air compressor 3 and the discharge valve 13 through the eighth pipeline 25. Among them, one end of the eighth pipeline 25 is connected to the outlet pipeline of the air compressor 3, and the other end is connected to the wellhead pipeline of the discharge valve 13. The pressure-stabilizing container 12 is arranged on the eighth pipeline 25, and the third air inlet valve 11 is arranged before the pressure-stabilizing container 12 to control the pressure and flow of the gas-phase working medium entering the pressure-stabilizing container 12. By setting up a pressure-stabilizing container, the pressure of the test system can be kept stable, ensuring that the gas injection pressure and gas injection volume of the experimental system are not affected by changes in the working state of the air compressor. At the same time, it can also prevent liquid backflow due to operational errors without affecting the operation of the air compressor and causing danger.

[0047] In this embodiment, the wellhead pressure sensor A4 is set at the top of the simulated wellbore 16-1, and the bottomhole pressure sensor A3 is set at the bottom of the simulated wellbore 16-1 to measure the wellhead pressure and bottomhole pressure during the experiment. The data acquisition module 26 is respectively connected to the gas flowmeter 5, the first liquid flowmeter 10, the second liquid flowmeter 17, the wellhead pressure sensor A4, and the bottomhole pressure sensor A3 to collect data such as the pressure of the simulated experimental pipeline and the liquid phase experimental working fluid injection amount, the gas phase experimental working fluid injection amount, and the liquid phase experimental working fluid leakage amount during the experiment. For example, the data acquisition module can be a computer, which can collect and display data such as the bottomhole pressure and wellhead pressure, as well as the liquid phase experimental working fluid injection amount, the gas phase experimental working fluid injection amount, and the liquid phase experimental working fluid leakage amount.

[0048] In this exemplary embodiment, Figure 2 As shown, the device may further include a first pressure sensor A1 and a second pressure sensor A2 on the basis of the above-mentioned first exemplary embodiment, wherein the first pressure sensor A1 is arranged on the fourth pipeline 21 to measure the pressure of the gaseous working fluid or the liquid working fluid in the fourth pipeline, and the second pressure sensor A2 is arranged on the fifth pipeline 22 to measure the pressure of the gaseous working fluid or the liquid working fluid in the fifth pipeline.

[0049] In this exemplary embodiment, Figure 2 As shown, the device can further include a gas pressure regulating valve 4 on the basis of the above-mentioned first exemplary embodiment. The gas pressure regulating valve 4 is arranged on the second pipeline 19 and located between the air compressor 3 and the gas flow meter 5 to control the pressure and flow of the injected gas experimental working fluid.

[0050] In this exemplary embodiment, Figure 2 As shown, the device may further include a throttle valve 14, a solenoid valve 15, and a third pressure sensor A5. The throttle valve 14, the solenoid valve 15, and the third pressure sensor A5 are arranged on the third pipeline 20, with the solenoid valve 15 arranged between the discharge hole and the throttle valve 14, and the third pressure sensor A5 arranged between the throttle valve 14 and the discharge valve 13. Here, the solenoid valve 15 is used to adjust the opening of the throttle valve 14 to control the pressure of the simulated experiment pipeline 16.

[0051] In this exemplary embodiment, the simulated wellbore can be made of a transparent material, have a length of 20 to 50 meters, and a diameter of 120 to 200 mm. For example, the simulated wellbore is made of fiberglass reinforced plastic, has a length of 36 meters, and a diameter of 160 mm.

[0052] In this exemplary embodiment, the length of the simulated drill rod may be 20 to 50 m, and the diameter of the simulated drill rod may be 40 to 110 mm.

[0053] In this exemplary embodiment, the pressure range of the simulation test pipeline can be 0-15 MPa. In this exemplary embodiment, the device can also include an axial pressure sensor and an axial pressure sensor ( Figure 1 and Figure 2 (not shown) the axial pressure sensors may include 5 to 10 pressure sensors evenly distributed along the axial direction of the simulated wellbore, and the circumferential pressure sensors may include 2 to 5 pressure sensors evenly distributed along the circumference of the simulated wellbore. By providing these axial and circumferential pressure sensors, the axial direction and axial pressure variations of the wellbore during the simulation experiment can be measured.

[0054] In this exemplary embodiment, the diameters of the first formation simulation hole and the second formation simulation hole may be equal to the actual formation equivalent diameter to better simulate the formation.

[0055] In a third exemplary embodiment of the present invention, a method for simulating wellbore pressure distribution of formation-wellbore multiphase coupled flow is provided. The method may be implemented by the apparatus for simulating wellbore pressure distribution of formation-wellbore multiphase coupled flow described in the first or second exemplary embodiment, and the method comprises the following steps:

[0056] The steps for conducting a single-phase spill experiment include:

[0057] Open the water inlet valve 2, close the first air inlet valve 6, the second air inlet valve 7, the first leakage valve 8, and the second leakage valve 9. Use the high-pressure reciprocating pump 1 to inject the liquid experimental fluid into the simulated experimental pipeline 16 through the first pipeline 18. Simultaneously, the first liquid flowmeter 10 measures the injection volume of the liquid experimental fluid. The liquid experimental fluid flows from the bottom of the simulated wellbore 16-1 to the top of the simulated wellbore 16-1, then through the discharge hole in the simulated wellbore 16-1, through the third pipeline 20, and finally out of the discharge valve 13 to the outside.

[0058] Open the first leakage valve 8 and / or the second leakage valve 9, and close the first air inlet valve 6 and the second air inlet valve 7. The liquid-phase experimental fluid enters the second liquid flowmeter 17 after passing through the first formation simulation hole 16-3, the fourth pipeline 21, and the sixth pipeline 23, and / or enters the second liquid flowmeter 17 after passing through the second formation simulation hole 16-4, the fifth pipeline 22, and the seventh pipeline 24. The second liquid flowmeter 17 measures the amount of liquid-phase fluid loss and then discharges it to the outside. The wellhead pressure and bottomhole pressure during the single-phase leakage experiment are measured using the wellhead pressure sensor A4 and the bottomhole pressure sensor A3. That is, during a one-way leakage experiment, the liquid-phase experimental fluid can be passed through the first formation simulation hole 16-3, the second formation simulation hole 16-4, or both the first and second formation simulation holes 16-3, 16-4.

[0059] The gas-liquid two-phase flow experiment with gas intrusion and leakage includes the following steps:

[0060] A high-pressure reciprocating pump 1 injects a liquid experimental fluid into the simulated experimental pipeline 16 via the first pipeline 18. Simultaneously, a first liquid flowmeter 10 measures the injected amount of the liquid experimental fluid. The liquid experimental fluid flows from the bottom of the simulated wellbore 16-1 to the top of the simulated wellbore 16-1, then through the discharge hole in the simulated wellbore 16-1, through the third pipeline 20, and finally out of the discharge valve 13.

[0061] Open the first air inlet valve 6 and the second leakage valve 9, and close the first leakage valve 8 and the second air inlet valve 7. Use the air compressor 3 to inject the gaseous experimental working medium into the simulated experimental pipeline 16 through the second pipeline 19 and then the fourth pipeline 21. The gaseous experimental working medium injection volume is measured by the gas flowmeter 5. The liquid-phase experimental working medium enters the second liquid flowmeter 17 through the second formation simulation hole 16-4, the fifth pipeline 22, and the seventh pipeline 24. The liquid experimental working medium is measured and discharged to the outside. Alternatively, open the second air inlet valve 7 and the first leakage valve 8, close the second leakage valve 9 and the first air inlet valve 6, and use the air compressor 3 to inject the gaseous experimental working medium into the simulated experimental pipeline 16 through the fifth pipeline 22. The gaseous experimental working medium injection volume is measured by the gas flowmeter 5. The liquid-phase experimental working medium enters the second liquid flowmeter 17 through the first formation simulation hole 16-3, the fourth pipeline 21, and the sixth pipeline 23. The liquid experimental working medium is measured and discharged to the outside. That is, when conducting a gas-liquid two-phase flow experiment with gas invasion and leakage, the gas phase working fluid can only enter from one of the first formation simulation holes 16-3 or the second formation simulation holes 16-4, and correspondingly, the liquid phase experimental working fluid can only leak out from the second formation simulation holes 16-4 or the first formation simulation holes 16-3.

[0062] The gas content is calculated by the liquid loss measured by the second liquid flowmeter and the gas injection rate measured by the gas flowmeter. The gas content calculation formula is:

[0063]

[0064] Where: α g is the gas content, %; Q g is the gas injection volume, m 3 / h;Q l is the injection volume, m 3 / h.

[0065] The wellhead pressure and bottomhole pressure during the single-phase leakage experiment were measured by the wellhead pressure sensor A4 and the bottomhole pressure sensor A3.

[0066] In summary, the beneficial effects of the present invention include at least one of the following:

[0067] (1) The present invention provides a wellbore pressure distribution device for simulating formation-wellbore multiphase coupled flow, which can be used to conduct single-phase wellbore-formation coupled flow experiments with drilling fluid loss, as well as wellbore-formation coupled multiphase flow experiments with overflow and gas invasion, and truly simulate the complex material exchange between the wellbore and the formation during the drilling process;

[0068] (2) The present invention provides a method for simulating the wellbore pressure distribution of formation-wellbore multiphase coupled flow. By changing the wellhead back pressure, leakage pressure, gas injection volume and injection pressure, the relationship between leakage volume, gas invasion volume and wellhead back pressure, gas injection pressure and gas content can be explored, and the pressure evolution law of the entire wellbore can be obtained, which provides a theoretical basis for petroleum engineering to calculate the bottom hole pressure change law when drilling into the production layer with high precision and realize safe active pressure control drilling operations.

[0069] Although the present invention has been described above with reference to the exemplary embodiments and the accompanying drawings, it will be apparent to those skilled in the art that various modifications may be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution, characterized in that: The method is implemented by simulating a formation-wellbore multiphase coupled flow wellbore pressure distribution device, the device comprising a high-pressure reciprocating pump, an air compressor, a gas flow meter, a first liquid flow meter, a second liquid flow meter, a wellhead pressure sensor, a bottom hole pressure sensor, a first pipeline, a second pipeline, a third pipeline, a gas supply leakage test pipeline, a discharge valve and a simulation experiment pipeline, wherein: The simulated experimental pipeline includes a simulated wellbore and a simulated drill pipe, the lower part of the simulated drill pipe is inserted into the simulated wellbore and is coaxially arranged with the simulated wellbore, the top of the simulated drill pipe is sealed to form a first cavity opening downward, the top of the simulated wellbore is sealed with the outer wall of the simulated drill pipe and the bottom of the simulated wellbore is sealed, a second cavity is formed between the inner wall of the simulated wellbore and the outer wall of the simulated drill pipe, and the second cavity is connected with the first cavity; The bottom of the simulated wellbore is provided with a first formation simulation hole, a second formation simulation hole and a water injection hole, and the first formation simulation hole, the second formation simulation hole and the water injection hole are respectively connected to the second cavity; The upper part of the simulated wellbore is also provided with a discharge hole, and the discharge hole is connected to the discharge valve through a third pipeline; The high-pressure reciprocating pump is connected to the water injection hole through a first pipeline, and the first liquid flow meter is arranged on the first pipeline; The air compressor is connected to the air supply leakage test pipeline through a second pipeline, and the gas flow meter is arranged on the second pipeline; The gas supply leakage test pipeline includes a fourth pipeline, a fifth pipeline, a sixth pipeline, a seventh pipeline, a first air intake valve, a second air intake valve, a first leakage valve, a second leakage valve and a second liquid flow meter, wherein: One end of the fourth pipeline is connected to the second pipeline, and the other end is connected to the first formation simulation hole; one end of the fifth pipeline is connected to the second pipeline, and the other end is connected to the second formation simulation hole; The first intake valve is arranged on the fourth pipeline, and the second intake valve is arranged on the fifth pipeline; One end of the sixth pipeline is connected to the second liquid flow meter, and the other end is connected to a portion of the fourth pipeline located between the first air inlet valve and the first formation simulation hole; One end of the seventh pipeline is connected to the second liquid flow meter, and the other end is connected to the portion of the fifth pipeline located between the second air inlet valve and the second formation simulation hole; The first leakage valve is arranged on the sixth pipeline, and the second leakage valve is arranged on the seventh pipeline; The wellhead pressure sensor is arranged at the upper part of the simulated wellbore, and the bottom hole pressure sensor is arranged at the bottom of the simulated wellbore; The method comprises the steps of: When conducting a single-phase leakage experiment, a liquid phase experimental medium is injected into the simulation experimental pipeline through the first pipeline by a high-pressure reciprocating pump, and the first liquid flowmeter measures the injection amount of the liquid phase experimental medium. The liquid phase experimental medium flows from the bottom of the simulation wellbore to the upper part of the simulation wellbore, and is discharged to the outside from the discharge valve through the discharge hole on the simulation wellbore through the third pipeline; The first leakage valve and / or the second leakage valve are opened, the first air inlet valve and the second air inlet valve are closed, and the liquid phase experimental working fluid enters the second liquid flow meter through the first formation simulation hole, the fourth pipeline and the sixth pipeline and / or enters the second liquid flow meter through the second formation simulation hole, the fifth pipeline and the seventh pipeline, and the liquid phase working fluid leakage is measured and then discharged to the outside; The wellhead pressure and bottom hole pressure are measured by the wellhead pressure sensor and the bottom hole pressure sensor during the single-phase leakage experiment; When conducting a gas-liquid two-phase flow experiment with gas intrusion and leakage, a liquid phase experimental medium is injected into the simulation experimental pipeline through the first pipeline by a high-pressure reciprocating pump, and the first liquid flowmeter measures the injection amount of the liquid phase experimental medium. The liquid phase experimental medium flows from the bottom of the simulation wellbore to the upper part of the simulation wellbore, and is discharged to the outside from the discharge valve through the discharge hole on the simulation wellbore through the third pipeline; Open the first air intake valve and the second leakage valve, close the first leakage valve and the second air intake valve, or open the second air intake valve and the first leakage valve, close the second leakage valve and the first air intake valve, inject the gaseous experimental medium into the simulation experimental pipeline through the second pipeline and then the fourth pipeline or the fifth pipeline through the air compressor, and measure the injection amount of the gaseous experimental medium through the gas flow meter; The liquid phase experimental working fluid enters the second liquid flow meter through the second formation simulation hole, the fifth pipeline, and the seventh pipeline or through the first formation simulation hole, the fourth pipeline, and the sixth pipeline to measure the leakage of the liquid experimental working fluid; Calculate the gas content by using the liquid leakage measured by the second liquid flowmeter and the gas working medium injection amount measured by the gas flowmeter; The wellhead pressure and bottom hole pressure were measured by wellhead pressure sensor and bottom hole pressure sensor in the gas-liquid two-phase flow experiment with gas invasion and leakage.

2. The method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution according to claim 1, characterized in that: The device also includes a data acquisition module, which is respectively connected to the gas flow meter, the first liquid flow meter, the second liquid flow meter, the wellhead pressure sensor, and the bottom hole pressure sensor to collect pressure and flow data.

3. The method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution according to claim 1, characterized in that: The device also includes an eighth pipeline, a third air intake valve and a pressure-stabilizing container. One end of the eighth pipeline is connected to the air compressor, and the other end is connected to the discharge valve. The pressure-stabilizing container is arranged on the eighth pipeline, and the third air intake valve is arranged on the eighth pipeline and is located before the pressure-stabilizing container.

4. The method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution according to claim 1, characterized in that: The device further comprises a first pressure sensor and a second pressure sensor, wherein the first pressure sensor is arranged on the fourth pipeline and the second pressure sensor is arranged on the fifth pipeline.

5. The method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution according to claim 1, characterized in that: The device also includes a gas pressure regulating valve, which is arranged on the second pipeline and located between the air compressor and the gas flow meter to control the pressure and flow of the gas experimental working medium.

6. The method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution according to claim 1, characterized in that: The device also includes a throttle valve, a solenoid valve and a third pressure sensor, wherein the throttle valve, the solenoid valve and the third pressure sensor are arranged on a third pipeline, and the solenoid valve is arranged between the discharge hole and the throttle valve, and the third pressure sensor is arranged between the throttle valve and the discharge valve.

7. The method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution according to claim 1, characterized in that: The simulated wellbore is made of transparent material, the length of the simulated wellbore is 20~50m, and the diameter of the simulated wellbore is 120~200mm.

8. The method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution according to claim 1, characterized in that: The length of the simulated drill rod is 20-50 m, and the diameter of the simulated drill rod is 40-110 mm.

9. The method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution according to claim 1, characterized in that: The pressure resistance range of the simulation experimental pipeline is 1~15Mpa.

10. The method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution according to claim 1, characterized in that: The device also includes an axial pressure sensor and a circumferential pressure sensor. The axial pressure sensor includes 5 to 10 pressure sensors evenly distributed along the axial direction of the simulated wellbore, and the circumferential pressure sensor includes 2 to 5 pressure sensors evenly distributed along the circumference of the simulated wellbore.

11. The method for simulating formation-wellbore multiphase coupled flow wellbore pressure distribution according to claim 1, characterized in that: The diameters of the first formation simulation hole and the second formation simulation hole are equal to the actual formation equivalent diameter.

Images