An experimental apparatus for simulating simultaneous spilling and channeling of a formation and a wellbore and a method of using the same

Abstract

The present application relates to the field of oil and gas development drilling engineering, and is an experimental device for simulating overflow and leakage coexistence of formation and wellbore coupling and a use method thereof. The former includes a wellbore simulation unit, a drilling fluid circulation unit and a simulation medium injection unit. The wellbore simulation unit includes a wellbore and a drill string. The present application is mainly used for simulating the influence law of overflow and leakage parameters and drilling fluid physical property parameters on wellbore fluid flow parameters when overflow and leakage coexistence conditions occur in fractured formation and permeable formation. The experimental device can help the research of deepwater drilling and well control methods when overflow and leakage coexistence occurs. Compared with the existing experimental equipment, the present application can simulate the actual formation and wellbore coupling condition in the drilling process and the overflow or leakage condition of different types of formation. Not only can the abnormal conditions under various formation conditions be simulated, but also the experimental results are more in line with the change law of wellbore fluid under actual working conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas development drilling engineering, and is an overflow and leakage coexisting experimental device simulating the coupling of a formation and a wellbore and a use method thereof. BACKGROUND

[0002] Under the condition of an oil and gas reservoir, a deep-sea seabed has the characteristics of loose deposition and low formation cementation strength, a three-pressure profile of a deep formation forms a narrow safety density window, and accidents such as well leakage, well kick and overflow and leakage coexistence are prone to occur due to the high-temperature and high-pressure environment of the deep formation. Therefore, deepwater drilling has great safety risks, and overflow and leakage coexistence and other abnormal working conditions are prone to occur in the wellbore. At present, the main solution to the problem of overflow and leakage coexistence in the wellbore is to use fine pressure control drilling or circulating plugging well control technology. However, the related engineering experience is limited due to the difference in engineering geological conditions, and therefore has great limitations in popularization and application to other blocks.

[0003] A Chinese patent document with publication number CN205654336U discloses a complex working condition simulation experimental device for fractured formations, which includes a simulated wellbore unit, a simulated fracture unit and a simulated formation unit. The sidewall of the simulated wellbore unit is provided with a wellbore through hole, and the sidewall of the simulated formation unit is provided with a formation through hole. The wellbore through hole and the formation through hole are communicated through the simulated fracture unit. The complex working condition simulation experimental device for fractured formations further includes an adjusting member for adjusting the flow area of the wellbore through hole.

[0004] A Chinese patent document with publication number CN201184130Y discloses an overflow and leakage experimental device for oil and gas wells, which mainly consists of a wellbore with a piston, a transparent fracture simulation glass window and a storage cylinder. The wellbore part has a piston in a circular wellbore. A threaded hole seat is fixed at the lower end of the circular wellbore. A screw rod is arranged on the threaded hole seat. A tapered roller bearing is installed on the upper end of the screw rod. The lower end of the screw rod is connected to the upper end of the piston through the tapered roller bearing. A flange plate is arranged on the upper end surface of the circular wellbore, which can fix the connecting wellbore at different heights. The transparent fracture simulation glass window is composed of two organic glass windows which are fixed in parallel on the cracks of the wellbore and the storage cylinder and are sealed. The two ends of the two organic glass windows are sealed by a metal frame and fastening bolts. The two ends of the two organic glass windows are connected to the wellbore and the storage cylinder, respectively. The upper and lower end surfaces of the two organic glass windows are sealed. The storage cylinder is in a cylindrical shape. The upper and lower ends of the storage cylinder are sealed. An upper quick connector is fixed on the upper pipe wall of the storage cylinder. A lower quick connector is fixed on the lower pipe wall of the storage cylinder. The quick connectors are connected to pipelines. A gas source interface is fixed on the top end of the storage cylinder, which can connect the pipelines to provide high-pressure gas for the storage cylinder.

[0005] In the process of wellbore overflow and leakage coexistence control, the wellbore fluid flow is affected by the formation condition, wellbore pressure and fluid flow state. In order to carry out mechanism analysis and experimental research, the influence effect of the coupling of the formation and the wellbore needs to be considered. The current domestic research on wellbore overflow and leakage coexistence is investigated. The research results show that the related experiments mainly consider the gravity displacement effect and the single-phase or two-phase flow under the gas invasion condition, and the research on the formation of the overflow and leakage position in the well is relatively insufficient. Therefore, the research on the complex flow law of the coupling of the formation and the wellbore is lacking. SUMMARY

[0006] The application provides an overflow and leakage coexistence experimental device simulating the coupling of the formation and the wellbore and a use method thereof, which overcomes the shortcomings of the prior art, and effectively solves the problem that the research on the formation of the overflow and leakage position in the well lacks the research on the complex flow law of the coupling of the formation and the wellbore.

[0007] One of the technical solutions of the application is realized by the following measures: an overflow and leakage coexistence experimental device simulating the coupling of the formation and the wellbore, which comprises a wellbore simulation unit, a drilling fluid circulation unit and a simulation medium injection unit. The wellbore simulation unit comprises a wellbore and a drill string, the lower part of the drill string is sleeved outside the wellbore, and a closed annular drilling fluid circulation cavity is formed between the lower part of the drill string and the inner side of the wellbore. The drilling fluid circulation unit comprises a circulation tank and a plunger pump. The inlet of the plunger pump is fixedly communicated with the outlet of the circulation tank, and the outlet of the plunger pump is fixedly communicated with the upper end of the drill string. A first circulation pipeline is fixedly communicated between the upper part of the drilling fluid circulation cavity and the upper part of the circulation tank. A back pressure gauge, an annulus pressure gauge and a bottom hole pressure gauge are sequentially arranged outside the wellbore from top to bottom. A first simulation pipeline is fixedly communicated between the lower part of the wellbore and the lower part of the circulation tank. A first control valve is arranged on the first simulation pipeline. The simulation medium injection unit comprises a gas storage tank, a compressor and a formation fluid storage tank. A second simulation pipeline is fixedly communicated between the lower part of the wellbore and the formation fluid storage tank. A second control valve is arranged on the second simulation pipeline. A third simulation pipeline is fixedly communicated between the second simulation pipeline corresponding to the position between the second control valve and the wellbore and the outlet of the gas storage tank. A third control valve is installed on the third simulation pipeline. The outlet of the compressor is fixedly communicated with the inlet of the gas storage tank.

[0008] The following is a further optimization or / and improvement of the above-mentioned one of the technical solutions of the application:

[0009] A first throttle valve can be installed on the above-mentioned first circulation pipeline. A first flowmeter is installed on the first circulation pipeline corresponding to the position between the first throttle valve and the wellbore. A second circulation pipeline is fixedly communicated between the inlet of the plunger pump and the lower part of the circulation tank. A second throttle valve is installed on the second circulation pipeline. A third circulation pipeline is fixedly communicated between the outlet of the plunger pump and the upper end of the drill string. A second flowmeter is installed on the third circulation pipeline.

[0010] The wellbore outside corresponding to the position below the annular gap pressure gauge can be provided with a flow divider and a flow collector at intervals, the flow divider and the flow collector are both tubular structures with closed ends, at least one interval-provided flow dividing pipe is fixedly communicated between the flow divider and the lower part of the wellbore outside, the second simulation pipeline is fixedly communicated between the flow divider and the formation fluid storage tank, at least one interval-provided flow collecting pipe is fixedly communicated between the flow collector and the lower part of the wellbore outside, the first simulation pipeline is fixedly communicated between the flow collector and the circulating tank, and a third flow meter is installed on the first simulation pipeline corresponding to the position between the first control valve and the circulating tank.

[0011] The first control valve, the second control valve and the third control valve can all be throttle valves.

[0012] A fourth flow meter can be installed on the flow dividing pipe, and a formation pressure gauge is installed on the flow dividing pipe corresponding to the position between the fourth flow meter and the wellbore.

[0013] A fifth flow meter can be installed on the second simulation pipeline corresponding to the position between the second control valve and the third simulation pipeline, the first end of the third simulation pipeline and the fifth flow meter are fixedly communicated with the second simulation pipeline, the second end of the third simulation pipeline is fixedly communicated with the outlet of the gas storage tank, and a sixth flow meter is installed on the third simulation pipeline corresponding to the position between the third control valve and the second simulation pipeline.

[0014] The device can further include a control unit and a camera, and the camera is arranged on the upper part of the wellbore outside, the camera, the first flow meter, the second flow meter, the third flow meter, the fourth flow meter, the fifth flow meter, the sixth flow meter, the back pressure gauge, the annular gap pressure gauge, the bottom hole pressure gauge and the formation pressure gauge are all connected with the control unit.

[0015] The second technical scheme of the application is realized by the following measures: a use method of an experimental device for simulating overflow and leakage coexistence of a formation and a wellbore, including the following steps:

[0016] Step one, close the first control valve, the second control valve and the third control valve, pour the configured drilling fluid into the circulating tank, and fill the drilling fluid into the drilling fluid circulation cavity through the plunger pump;

[0017] Step two, pour the gas into the simulation medium injection unit, and open the third control valve;

[0018] Step three, start the plunger pump, circulate the drilling fluid between the drilling fluid circulation cavity and the circulating tank, and record the back pressure gauge reading, the annular gap pressure gauge reading and the bottom hole pressure gauge reading when the back pressure gauge reading is stable;

[0019] Step four, open the first control valve, the drilling fluid part through the first simulation pipeline into the circulating tank, after the bottom hole pressure gauge stable, record the back pressure pressure gauge, annulus pressure gauge and bottom hole pressure gauge, close the third control valve, open the second control valve, the formation fluid reservoir to the drilling fluid circulation cavity injection formation fluid, after the flow stable, record the back pressure pressure gauge, annulus pressure gauge and bottom hole pressure gauge;

[0020] Step five, adjust the second control valve opening, formation fluid into the drilling fluid circulation cavity, record the bottom hole pressure gauge;

[0021] Step six, if the formation fluid is gas, then inject gas into the drilling fluid circulation cavity, if the simulation first spray after the leakage condition, then repeat step two, step three and step five, if the simulation first leak after the spray condition, then repeat step two, step three and step four;

[0022] Step seven, if the simulation of permeable formation overflow and leakage condition, then repeat steps two to five.

[0023] The following is a further optimization or / and improvement of the above technical scheme two:

[0024] The above step four is: adjust the opening of the first control valve, the drilling fluid part through the first simulation pipeline into the circulating tank, after the third flow gauge and the bottom hole pressure gauge stable, record the back pressure pressure gauge, annulus pressure gauge and bottom hole pressure gauge;

[0025] Close the third control valve, open the second control valve, the formation fluid reservoir to the drilling fluid circulation cavity injection formation fluid, slowly close the first control valve, adjust the opening of the second control valve, after the fourth flow gauge stable to the target overflow, record the back pressure pressure gauge, annulus pressure gauge and bottom hole pressure gauge, at the same time through the camera record the phase image of the drilling fluid and the drilling fluid flow rate.

[0026] The above step five is: adjust the opening of the second control valve, the formation fluid from the formation fluid reservoir into the drilling fluid circulation cavity under the action of differential pressure, when the third flow gauge stable to the target overflow, record the back pressure pressure gauge, annulus pressure gauge and bottom hole pressure gauge, at the same time through the camera record the phase image of the drilling fluid and the drilling fluid flow rate;

[0027] Slowly close the second control valve, adjust the opening of the first control valve, when the third flow gauge stable to the target leakage, record the back pressure pressure gauge, annulus pressure gauge and bottom hole pressure gauge, at the same time through the camera record the phase image of the drilling fluid and the drilling fluid flow rate.

[0028] The third step is specifically adjusting the first throttle valve and the second throttle valve, starting the plunger pump, circulating the drilling fluid between the drilling fluid circulation cavity and the circulation tank, and recording the back pressure gauge reading, the annular pressure gauge reading and the bottom hole pressure gauge reading when the second flow meter reading and the back pressure gauge reading are stable.

[0029] The seventh step is specifically repeating the second to fifth steps to control the opening degrees of the first control valve, the second control valve and the third control valve so that the changes of the loss, the overflow and the gas invasion are within the set range.

[0030] The application provides an overflow and loss coexistence experimental device for simulating the coupling of a formation and a wellbore, which is mainly used for simulating the change state of the wellbore liquid column pressure, the wellbore fluid flow rate and the flow pattern with the change of the loss and the gas invasion, the influence of the overflow and loss parameters and the drilling fluid physical property parameters on the wellbore fluid flow parameters and the like when the overflow and loss coexistence condition occurs in the fractured formation and the permeable formation. The experimental device can make up for the shortage of the overflow and loss coexistence indoor experimental equipment and research method under the coupling of the formation and the wellbore, and can help the research of the deep water drilling and the well control method when the overflow and loss coexistence occurs. Compared with the existing experimental equipment, the application can simulate the actual coupling of the formation and the wellbore in the drilling process and the overflow or loss condition of different types of formations, can not only realize the simulation of the abnormal condition of multiple formation conditions, but also make the experimental results more consistent with the change law of the wellbore fluid under the actual working condition. BRIEF DESCRIPTION OF DRAWINGS

[0031] ATTACHMENT Figure 1 The figure is a schematic view of the front structure of the best embodiment of the application.

[0032] The codes in the figure are as follows: 1 is a wellbore, 2 is a drill string, 3 is a drilling fluid circulation cavity, 4 is a circulation tank, 5 is a plunger pump, 6 is a first circulation pipeline, 7 is a back pressure gauge, 8 is an annular pressure gauge, 9 is a bottom hole pressure gauge, 10 is a first simulation pipeline, 11 is a first control valve, 12 is a gas storage tank, 13 is a compressor, 14 is a formation fluid storage tank, 15 is a second simulation pipeline, 16 is a second control valve, 17 is a third simulation pipeline, 18 is a third control valve, 19 is a first throttle valve, 20 is a first flow meter, 21 is a second circulation pipeline, 22 is a second throttle valve, 23 is a third circulation pipeline, 24 is a second flow meter, 25 is a flow divider, 26 is a flow combiner, 27 is a flow dividing pipe, 28 is a flow combining pipe, 29 is a third flow meter, 30 is a fourth flow meter, 31 is a formation pressure gauge, 32 is a fifth flow meter, 33 is a sixth flow meter, 34 is a control unit, and 35 is a camera. DETAILED DESCRIPTION

[0033] The present invention is not limited to the following embodiments, and specific implementation methods can be determined based on the technical solutions of the present invention and actual conditions.

[0034] In the present invention, for the convenience of description, the relative position relationship of each component is described based on the Figure 1 The positional relationships of front, back, top, bottom, left, and right are described in the layout of the manual. Figure 1 The layout direction is determined by the

[0035] The present invention will be further described below in conjunction with the embodiments and accompanying drawings:

[0036] Example 1: As shown in the attached Figure 1 As shown, the leakage coexistence experimental device for simulating the coupling of formation and wellbore includes a wellbore simulation unit, a drilling fluid circulation unit and a simulated medium injection unit. The wellbore simulation unit includes a wellbore 1 and a drill string 2. The outer side of the lower part of the drill string 2 is sleeved in the wellbore 1. A closed annular drilling fluid circulation chamber 3 is formed between the outer side of the lower part of the drill string 2 and the inner side of the wellbore 1. The drilling fluid circulation unit includes a circulation tank 4 and a plunger pump 5. The inlet of the plunger pump 5 is fixedly connected to the outlet of the circulation tank 4. The outlet of the plunger pump 5 is fixedly connected to the upper end of the drill string 2. A first circulation pipeline 6 is fixedly connected between the upper part of the drilling fluid circulation chamber 3 and the upper part of the circulation tank 4. A back pressure gauge 7, an annular pressure gauge 8 and a bottom hole pressure gauge 9 are arranged on the outside of the wellbore 1 from top to bottom. A first simulation pipeline 10 is fixedly connected between the outer side of the lower part and the lower part of the circulation tank 4, and a first control valve 11 is provided on the first simulation pipeline 10. The simulation medium injection unit includes a gas storage tank 12, a compressor 13 and a formation fluid storage tank 14. A second simulation pipeline 15 is fixedly connected between the outer side of the lower part of the wellbore 1 and the formation fluid storage tank 14, and a second control valve 16 is provided on the second simulation pipeline 15. A third simulation pipeline 17 is fixedly connected between the second simulation pipeline 15 corresponding to the position between the second control valve 16 and the wellbore 1 and the outlet of the gas storage tank 12, and a third control valve 18 is installed on the third simulation pipeline 17. The outlet of the compressor 13 and the inlet of the gas storage tank 12 are fixedly connected.

[0037] According to the requirement, the circulating tank 4 can be a box structure with an open upper end or a known tank, a first circulating pipeline 6 is fixedly communicated between the upper part of the drilling fluid circulating cavity 3 and the upper inlet of the circulating tank 4, a first simulation pipeline 10 is fixedly communicated between the lower part of the wellbore 1 and the lower inlet of the circulating tank 4, the first control valve 11, the second control valve 16 and the third control valve 18 are all throttle valves, the wellbore 1 is made of transparent pressure-bearing glass, the upper end of the wellbore 1 is fixedly and sealingly installed with the outer side of the upper part of the drill string 2 through a ring-shaped cover plate, the cover plate is provided with an outlet communicated with the drilling fluid circulating cavity 3, the first circulating pipeline 6 is fixedly communicated between the outlet of the cover plate and the circulating tank 4, and the lower part of the wellbore 1 can be provided with a simulated fracture communicated with the drilling fluid circulating cavity 3. The second simulation pipeline 15 is fixedly communicated between the simulated fracture of the lower part of the wellbore 1 and the formation fluid storage tank 14.

[0038] The outlet and the inlet of the gas storage tank 12 can be the same or different, the outer side of the wellbore 1 is sequentially fixedly communicated with a first connecting short pipe, a second connecting short pipe and a third connecting short pipe from top to bottom, the back pressure gauge 7, the annular pressure gauge 8 and the bottom hole pressure gauge 9 are respectively installed at the end of the first connecting short pipe, the second connecting short pipe and the third connecting short pipe, the bottom hole pressure gauge 9 is used for measuring the pressure at the bottom of the wellbore 1 (the lower end of the drilling fluid circulating cavity 3), the back pressure gauge 7 is used for measuring the back pressure at the upper end of the wellbore 1 (the upper end of the drilling fluid circulating cavity 3), and the annular pressure gauge 8 is used for measuring the fluid pressure at the middle depth of the annular space of the wellbore 1 (the middle part of the drilling fluid circulating cavity 3), the circulating tank 4 is used for storing drilling fluid, the circulating tank 4 is provided with a liquid injection port, which facilitates the injection of drilling fluid into the circulating tank 4, the drilling fluid is injected into the drill string 2 through the plunger pump 5 to simulate the injection of drilling fluid in the drilling process, the formation fluid storage tank 14 stores simulated formation fluid, the gas storage tank 12 stores compressed gas prepared by the compressor 13, the simulated formation fluid can be injected into the drilling fluid circulating cavity 3 through the second simulation pipeline 15 and the simulated fracture at the lower part of the wellbore 1, and the compressed gas is injected into the drilling fluid circulating cavity 3 through the third simulation pipeline 17, the second simulation pipeline 15 and the simulated fracture at the lower part of the wellbore 1.

[0039] The application provides an overflow and loss coexistence experimental device simulating the coupling of a formation and a wellbore, which is mainly used for simulating the change state of the liquid column pressure, the fluid flow rate and the flow pattern of the wellbore 1 with the loss amount and the gas invasion amount, the influence of the overflow loss parameters and the drilling fluid physical property parameters on the fluid flow parameters of the wellbore 1 when the overflow and loss coexistence conditions occur in the fractured formation and the permeable formation, and the like. The experimental device can make up for the shortage of the overflow and loss coexistence indoor experimental equipment and research method under the coupling of the formation and the wellbore, and can help the research on the deep water drilling and the well control method when the overflow and loss coexistence occurs. Compared with the existing experimental equipment, the application can simulate the actual coupling of the formation and the wellbore in the drilling process and the overflow or loss conditions of different types of formation, can not only realize the simulation of the abnormal conditions of various formation conditions, but also make the experimental results more consistent with the change law of the wellbore fluid under the actual working condition.

[0040] According to actual needs, the overflow and loss coexistence experimental device simulating the coupling of the formation and the wellbore can be further optimized or / and improved:

[0041] Embodiment two: as the optimization of the above-mentioned embodiments, as shown in the accompanying drawings, the first circulation pipeline 6 is provided with a first throttle valve 19, the first circulation pipeline 6 at the position corresponding to the first throttle valve 19 and the wellbore 1 is provided with a first flowmeter 20, the inlet of the plunger pump 5 is fixedly communicated with the lower part of the circulation tank 4 through a second circulation pipeline 21, the second circulation pipeline 21 is provided with a second throttle valve 22, the outlet of the plunger pump 5 is fixedly communicated with the upper end of the drill string 2 through a third circulation pipeline 23, and the third circulation pipeline 23 is provided with a second flowmeter 24. Figure 1 The inlet of the plunger pump 5 is fixedly communicated with the lower part of the circulation tank 4 through the second circulation pipeline 21, the second flowmeter 24 is used for reading and recording the drilling fluid injection flow rate, the drilling fluid injection flow rate is adjusted through the second throttle valve 22, the drilling fluid flows back to the circulation tank 4 through the first circulation pipeline 6, the flowback flow rate can be controlled through the first throttle valve 19, and the flowback flow rate value is read through the first flowmeter 20.

[0042] Embodiment three: as the optimization of the above-mentioned embodiments, as shown in the accompanying drawings, the first circulation pipeline 6 is provided with a first throttle valve 19, the first circulation pipeline 6 at the position corresponding to the first throttle valve 19 and the wellbore 1 is provided with a first flowmeter 20, the inlet of the plunger pump 5 is fixedly communicated with the lower part of the circulation tank 4 through a second circulation pipeline 21, the second circulation pipeline 21 is provided with a second throttle valve 22, the outlet of the plunger pump 5 is fixedly communicated with the upper end of the drill string 2 through a third circulation pipeline 23, and the third circulation pipeline 23 is provided with a second flowmeter 24.

[0043] Figure 1 ​As shown, a diverter 25 and a confluence 26 are provided at intervals on the outer side of the wellbore 1 corresponding to the position below the annulus pressure gauge 8. Both the diverter 25 and the confluence 26 are tubular structures with closed ends. At least one diverter pipe 27 is fixedly connected between the diverter 25 and the outer side of the lower part of the wellbore 1. The second simulation pipeline 15 is fixedly connected between the diverter 25 and the formation fluid storage tank 14. At least one confluence pipe 28 is fixedly connected between the confluence 26 and the outer side of the lower part of the wellbore 1. The first simulation pipeline 10 is fixedly connected between the confluence 26 and the circulation tank 4. A third flowmeter 29 is installed on the first simulation pipeline 10 corresponding to the position between the first control valve 11 and the circulation tank 4; a fourth flowmeter 30 is installed on the diverter pipe 27, and a formation pressure gauge 31 is installed on the diverter pipe 27 corresponding to the position between the fourth flowmeter 30 and the wellbore 1.

[0044] There are two horizontally arranged shunt pipes 27 fixedly connected to the outer side of the lower part of the wellbore 1 at upper and lower intervals, and two horizontally arranged confluence pipes 28 fixedly connected to the outer side of the lower part of the wellbore 1 at upper and lower intervals. In this way, a simulated crack can be set on the outer side of the lower part of the wellbore 1, and the simulated crack is connected to the shunt pipes 27 and the confluence pipes 28 in a one-to-one correspondence. The second control valve 16, the third flowmeter 29 and the fourth flowmeter 30 facilitate the simulation of formation leakage conditions. When the second control valve 16 is opened, the pressure difference at both ends of the confluence pipe 28 (the end close to the wellbore 1 and the end away from the wellbore 1) can realize the simulation of leakage conditions. The shunt pipe 27 is connected to the gas storage tank 12 and the formation fluid storage tank 14. Gas and formation fluid are injected into the drilling fluid circulation chamber 3 through the shunt pipe 27 to simulate gas invasion and formation fluid overflow conditions in the well. The fourth flowmeter 30 can read the flow rate of gas invasion and overflow, and the formation pressure gauge 31 can collect simulated formation pressure.

[0045] Example 4: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a fifth flowmeter 32 is installed on the second simulation pipeline 15 corresponding to the position between the second control valve 16 and the third simulation pipeline 17, the first end of the third simulation pipeline 17 is fixedly connected to the second simulation pipeline 15 between the fifth flowmeter 32 and the diverter 25, the second end of the third simulation pipeline 17 is fixedly connected to the outlet of the gas storage tank 12, and a sixth flowmeter 33 is installed on the third simulation pipeline 17 corresponding to the position between the third control valve 18 and the second simulation pipeline 15.

[0046] The second control valve 16 can control the flow rate of the formation fluid injected into the drilling fluid circulation cavity 3, the fifth flow meter 32 can obtain the flow rate of the formation fluid injected into the fracture (drilling fluid circulation cavity 3), the third control valve 18 can control the flow rate of the gas injected into the drilling fluid circulation cavity 3, the sixth flow meter 33 can obtain the flow rate of the gas injected into the fracture (drilling fluid circulation cavity 3), and by switching the second control valve 16 and the third control valve 18, the working condition of injecting gas into the simulated fracture or injecting formation fluid into the simulated fracture can be controlled.

[0047] Embodiment five: as an optimization of the above-mentioned embodiments, as shown in the accompanying Figure 1 The wellbore 1 is provided with a camera 35 outside the upper part, and the camera 35, the first flow meter 20, the second flow meter 24, the third flow meter 29, the fourth flow meter 30, the fifth flow meter 32, the sixth flow meter 33, the back pressure gauge 7, the annular pressure gauge 8, the bottom hole pressure gauge 9 and the formation pressure gauge 31 are all connected with the control unit 34.

[0048] According to the requirements, the back pressure gauge 7, the annular pressure gauge 8, the bottom hole pressure gauge 9 and the formation pressure gauge 31 are all existing known pressure sensors, the first control valve 11, the second control valve 16, the third control valve 18, the first throttle valve 19 and the second throttle valve 22 are all existing known electric throttle valves, the first control valve 11, the second control valve 16, the third control valve 18, the first throttle valve 19 and the second throttle valve 22 are all connected with the control unit 34, the camera 35 is an existing known technology such as a high-speed camera, and the control unit 34 is an existing known technology such as an upper computer.

[0049] The control unit 34 obtains the drilling fluid loss rate, the formation fluid overflow rate, the formation pressure and the bottom hole pressure through the flow meters and pressure gauges, adjusts the throttle valve opening degree through the control unit 34 to adjust the loss and overflow flow rate, adjusts the opening and closing of the first control valve 11 to realize the switching of the loss and overflow state, adjusts the opening and closing of the second control valve 16 and the third control valve 18 to realize the conversion of the gas invasion and the formation fluid overflow state, and the camera 35 observes the drilling fluid flow pattern and flow rate change in the wellbore 1; the data obtained by the flow meters, pressure gauges and camera 35 are all stored in the control unit 34.

[0050] Embodiment six: as shown in the accompanying Figure 1 The use method of the overflow and loss coexistence experimental device for coupling the simulated formation and the wellbore includes the following steps:

[0051] Step one: close the first control valve 11, the second control valve 16 and the third control valve 18, inject the configured drilling fluid into the circulation tank 4, and fill the drilling fluid circulation cavity 3 with the drilling fluid through the plunger pump 5;

[0052] Step two, inject gas into the simulation medium injection unit, open the third control valve 18;

[0053] Inject the simulated formation fluid into the formation fluid storage tank 14; start the compressor 13, inject gas into the gas storage tank 12, and close the compressor 13 when the pressure in the gas storage tank 12 reaches the set value, then open the third control valve 18;

[0054] Step three, start the plunger pump 5, circulate the drilling fluid between the drilling fluid circulation cavity 3 and the circulation tank 4, and record the back pressure gauge 7, annulus pressure gauge 8 and bottom hole pressure gauge 9 when the back pressure gauge 7 is stable;

[0055] Step four, open the first control valve 11, part of the drilling fluid flows into the circulation tank 4 through the first simulation pipeline 10, and record the back pressure gauge 7, annulus pressure gauge 8 and bottom hole pressure gauge 9 when the bottom hole pressure gauge 9 is stable, close the third control valve 18, open the second control valve 16, and inject the formation fluid from the formation fluid storage tank 14 into the drilling fluid circulation cavity 3, and record the back pressure gauge 7, annulus pressure gauge 8 and bottom hole pressure gauge 9 when the flow is stable;

[0056] Step five, adjust the opening of the second control valve 16, and record the bottom hole pressure gauge 9 when the formation fluid enters the drilling fluid circulation cavity 3;

[0057] Step six, if the formation fluid is gas, inject gas into the drilling fluid circulation cavity 3, if the simulation is first spurt and then leak, repeat steps two, three and five, if the simulation is first leak and then spurt, repeat steps two, three and four;

[0058] Step seven, if the simulation is overflow and leakage of permeable formation, repeat steps two to five.

[0059] The present application reflects the influence of the coupling conditions of the formation and the wellbore on the fluid flow in the wellbore, and realizes the simulation of overflow and leakage conditions by controlling and adjusting the pressure provided by the formation fluid storage tank 14 and the gas storage tank 12, and then controlling the overflow and leakage flow size by controlling the opening of the manifold switch (second control valve 16 and third control valve 18) for simulating leakage and overflow, and realizing the simulation of drilling fluid circulation in the drilling process by the drilling fluid flow at the upper end inlet of the drill string 2 and the drilling fluid flow at the upper end outlet of the wellbore 1, and realizing the simulation of overflow and leakage types under different formation conditions by adjusting the fluid flow size, and analyzing the change law of fluid pressure and flow state in the wellbore 1 by simulating the overflow and leakage conditions, which provides a research basis for early detection of drilling anomalies in the drilling process.

[0060] The use method of the overflow and leakage coexisting experimental device for simulating the coupling of the formation and the wellbore can be further optimized or / and improved according to actual needs.

[0061] Embodiment seven: as an optimization of the above-mentioned embodiments, as shown in FIG. 7, step four is specifically as follows: the opening of the first control valve 11 is adjusted, the drilling fluid flows into the circulating tank 4 through the first simulation pipeline 10, and after the readings of the third flowmeter 29 and the bottom hole pressure gauge 9 are stable, the readings of the back pressure gauge 7, the annular pressure gauge 8 and the bottom hole pressure gauge 9 are recorded respectively. Figure 1

[0062] The third control valve 18 is closed, the second control valve 16 is opened, the formation fluid storage tank 14 injects formation fluid into the drilling fluid circulating cavity 3, the first control valve 11 is slowly closed, the opening of the second control valve 16 is adjusted, and after the reading of the fourth flowmeter 30 is stable to the target overflow, the readings of the back pressure gauge 7, the annular pressure gauge 8 and the bottom hole pressure gauge 9 are recorded respectively, and the phase image and the flow rate of the drilling fluid are recorded by the camera 35.

[0063] The opening of the first control valve 11 is adjusted, the drilling fluid in the wellbore 1 flows to the first simulation pipeline 10 under the pressure difference between the two ends of the first simulation pipeline 10, and returns to the circulating tank 4 through the first simulation pipeline 10, and after the readings of the third flowmeter 29 and the bottom hole pressure gauge 9 are stable, the readings of the back pressure gauge 7, the annular pressure gauge 8 and the bottom hole pressure gauge 9 are recorded respectively, the third control valve 18 is closed, the opening of the first control valve 11 is adjusted to gradually reduce the amount of drilling fluid loss until the first control valve 11 is closed, the second control valve 16 is opened, the leakage condition is converted to the overflow condition, the opening of the second control valve 16 is adjusted, the reading of the fourth flowmeter 30 on the simulation fracture is observed at the same time, and after the reading of the fourth flowmeter 30 is stable to the target overflow, the readings of the back pressure gauge 7, the annular pressure gauge 8 and the bottom hole pressure gauge 9 are recorded respectively, and the phase image and the flow rate of the drilling fluid are recorded by the camera 35, so as to realize the simulation of the first leakage and then spouting condition.

[0064] Embodiment eight: as an optimization of the above-mentioned embodiments, as shown in FIG. 8, step five is specifically as follows: the opening of the second control valve 16 is adjusted, the formation fluid enters the drilling fluid circulating cavity 3 under the action of the pressure difference, and after the reading of the third flowmeter 29 is stable to the target overflow, the readings of the back pressure gauge 7, the annular pressure gauge 8 and the bottom hole pressure gauge 9 are recorded respectively, and the phase image and the flow rate of the drilling fluid are recorded by the camera 35. Figure 1

[0065] ​​Slowly close the second control valve 16, adjust the opening of the first control valve 11, when the third flow meter 29 shows a stable target leakage, record the back pressure gauge 7, annulus pressure gauge 8 and bottom hole pressure gauge 9, and record the phase image of the drilling fluid and the flow rate of the drilling fluid through the camera 35.

[0066] Adjust the opening of the second control valve 16, simulate the flow of the formation fluid into the second simulation pipeline 15 from the formation fluid storage tank 14 under the action of pressure difference, through the flow divider 25, the flow divider pipe 27 and the simulated fracture into the drilling fluid circulation cavity 3, adjust the opening of the second control valve 16, until the third flow meter 29 shows a stable target overflow speed, record the back pressure gauge 7, annulus pressure gauge 8 and bottom hole pressure gauge 9, and record the phase image of the drilling fluid and the flow rate of the drilling fluid through the camera 35; adjust the opening of the second control valve 16 to gradually reduce the flow until the second control valve 16 is closed, adjust the opening of the first control valve 11, and observe the third flow meter 29, when the third flow meter 29 shows a stable target leakage speed, record the back pressure gauge 7, annulus pressure gauge 8 and bottom hole pressure gauge 9, and record the phase image of the drilling fluid and the flow rate of the drilling fluid through the camera 35, so as to realize the simulation of the first leakage and then the overflow working condition.

[0067] Example nine: as an optimization of the above-mentioned examples, as shown in the accompanying drawings Figure 1 Step three is specifically: adjust the first throttle valve 19 and the second throttle valve 22, start the plunger pump 5, and circulate the drilling fluid between the drilling fluid circulation cavity 3 and the circulation tank 4, when the second flow meter 24 and the back pressure gauge 7 show a stable value, record the back pressure gauge 7, annulus pressure gauge 8 and bottom hole pressure gauge 9.

[0068] Adjust the first throttle valve 19 and the second throttle valve 22, start the plunger pump 5, adjust the opening of the second throttle valve 22 and the first throttle valve 19 to control the drilling fluid injection flow and the wellhead drilling fluid flowback flow, the drilling fluid enters the upper end of the drill string 2 through the second circulation pipeline 21 and the third circulation pipeline 23, enters the wellbore 1 from the lower end of the drill string 2, and returns along the drilling fluid circulation cavity 3, after the wellbore 1 is filled with drilling fluid, the drilling fluid enters the first circulation pipeline 6 from the upper end of the wellbore 1, and flows back to the circulation tank 4 through the first circulation pipeline 6, after the plunger pump 5 is started, the drilling fluid circulates, when the first flow meter 20 and the second flow meter 24 show a stable value, record the back pressure gauge 7, annulus pressure gauge 8 and bottom hole pressure gauge 9.

[0069] Example ten: as an optimization of the above-mentioned examples, as shown in the accompanying drawings Figure 1As shown, step seven is specifically: if the overflow and loss conditions of the simulated permeable formation are simulated, steps two to five are repeated, the opening degrees of the first control valve 11, the second control valve 16 and the third control valve 18 are controlled, so that the changes of the loss amount, the overflow amount and the gas invasion amount are within the set range.

[0070] For the overflow and loss conditions of the permeable formation, steps two to five are repeated, the opening degrees of the first control valve 11, the second control valve 16 and the third control valve 18 are controlled, so that the loss amount, the overflow amount and the gas invasion amount are controlled within a smaller range, and the overflow and loss coexistence conditions of the permeable formation are simulated.

[0071] For the research of different drilling fluids and formation fluids, the drilling fluid required for the experiment can be replaced, the formation fluid is simulated, and steps one to five are repeated, the overflow amount and the loss amount are adjusted, and the experimental data are recorded.

[0072] The above technical features respectively constitute embodiments of the present application, have strong adaptability and best implementation effect, and can increase or decrease unnecessary technical features according to actual needs to meet the needs of different situations.

Claims

1. A method of using an overflow coexistence experimental device that simulates a formation and wellbore coupling, the method comprising: The overflow and leakage coexistence experimental device simulating the coupling of a formation and a wellbore comprises a wellbore simulation unit, a drilling fluid circulation unit and a simulated medium injection unit, the wellbore simulation unit comprises a wellbore and a drill string, the lower part of the drill string is sleeved outside the wellbore, a closed annular drilling fluid circulation cavity is formed between the lower part of the drill string and the inner side of the wellbore, the drilling fluid circulation unit comprises a circulating tank and a plunger pump, the inlet of the plunger pump is fixedly communicated with the outlet of the circulating tank, the outlet of the plunger pump is fixedly communicated with the upper end of the drill string, a first circulation pipeline is fixedly communicated between the upper part of the drilling fluid circulation cavity and the upper part of the circulating tank, the outer side of the wellbore is sequentially provided with a back pressure gauge, an annular space pressure gauge and a bottom hole pressure gauge from top to bottom, a first simulation pipeline is fixedly communicated between the lower part of the outer side of the wellbore and the lower part of the circulating tank, a first control valve is arranged on the first simulation pipeline, the simulated medium injection unit comprises a gas storage tank, a compressor and a formation fluid storage tank, a second simulation pipeline is fixedly communicated between the lower part of the outer side of the wellbore and the formation fluid storage tank, a second control valve is arranged on the second simulation pipeline, a third simulation pipeline is fixedly communicated between the second simulation pipeline corresponding to the position between the second control valve and the wellbore and the outlet of the gas storage tank, a third control valve is installed on the third simulation pipeline, and the outlet of the compressor is fixedly communicated with the inlet of the gas storage tank; A first throttle valve is installed on the first circulation pipeline, a first flowmeter is installed on the first circulation pipeline corresponding to the position between the first throttle valve and the wellbore, a second circulation pipeline is fixedly communicated between the inlet of the plunger pump and the lower part of the circulating tank, a second throttle valve is installed on the second circulation pipeline, a third circulation pipeline is fixedly communicated between the outlet of the plunger pump and the upper end of the drill string, and a second flowmeter is installed on the third circulation pipeline; A flow divider and a flow combiner are separately arranged on the outer side of the wellbore corresponding to the position below the annular space pressure gauge, the flow divider and the flow combiner are both tubular structures with closed two ends, at least one interval arranged flow divider pipe is fixedly communicated between the flow divider and the lower part of the outer side of the wellbore, the second simulation pipeline is fixedly communicated between the flow divider and the formation fluid storage tank, at least one interval arranged flow combiner pipe is fixedly communicated between the flow combiner and the lower part of the outer side of the wellbore, the first simulation pipeline is fixedly communicated between the flow combiner and the circulating tank, and a third flowmeter is installed on the first simulation pipeline corresponding to the position between the first control valve and the circulating tank; The first control valve, the second control valve and the third control valve are all throttle valves; A fourth flowmeter is installed on the flow divider pipe corresponding to the position between the fourth flowmeter and the wellbore, and a formation pressure gauge is installed on the flow divider pipe corresponding to the position between the fourth flowmeter and the wellbore; A fifth flowmeter is installed on the second simulation pipeline corresponding to the position between the second control valve and the third simulation pipeline, the first end of the third simulation pipeline and the second simulation pipeline between the fifth flowmeter and the flow divider are fixedly communicated, the second end of the third simulation pipeline and the outlet of the gas storage tank are fixedly communicated, and a sixth flowmeter is installed on the third simulation pipeline corresponding to the position between the third control valve and the second simulation pipeline. The control unit and the camera are further included, the camera is arranged outside the upper part of the wellbore, and the camera, the first flowmeter, the second flowmeter, the third flowmeter, the fourth flowmeter, the fifth flowmeter, the sixth flowmeter, the back pressure gauge, the annular pressure gauge, the bottom hole pressure gauge and the formation pressure gauge are all connected with the control unit; The use method of the overflow and loss coexistence experimental device for simulating the coupling of a formation and a wellbore comprises the following steps: Step one, close the first control valve, the second control valve and the third control valve, pour the prepared drilling fluid into the circulating tank, and fill the drilling fluid circulation cavity with the drilling fluid through the plunger pump; Step two, pour the gas into the simulated medium injection unit, and open the third control valve; Step three, start the plunger pump, circulate the drilling fluid between the drilling fluid circulation cavity and the circulating tank, and record the back pressure gauge reading, the annular pressure gauge reading and the bottom hole pressure gauge reading when the back pressure gauge reading is stable; Step four, open the first control valve, part of the drilling fluid flows into the circulating tank through the first simulation pipeline, record the back pressure gauge reading, the annular pressure gauge reading and the bottom hole pressure gauge reading when the bottom hole pressure gauge reading is stable, close the third control valve, open the second control valve, and pour the formation fluid from the formation fluid storage tank into the drilling fluid circulation cavity, record the back pressure gauge reading, the annular pressure gauge reading and the bottom hole pressure gauge reading when the flow is stable; Step five, adjust the opening degree of the second control valve, and record the bottom hole pressure gauge reading when the formation fluid enters the drilling fluid circulation cavity; Step six, if the formation fluid is gas, pour the gas into the drilling fluid circulation cavity, if the simulated condition is first spouting and then leaking, repeat steps two, three and five, and if the simulated condition is first leaking and then spouting, repeat steps two, three and four; Step seven, if the simulated condition is overflow and loss of a permeable formation, repeat steps two to five.

2. The method of claim 1, wherein Step four is specifically: adjust the opening degree of the first control valve, part of the drilling fluid flows into the circulating tank through the first simulation pipeline, record the back pressure gauge reading, the annular pressure gauge reading and the bottom hole pressure gauge reading when the third flowmeter reading and the bottom hole pressure gauge reading are stable; Close the third control valve, open the second control valve, pour the formation fluid from the formation fluid storage tank into the drilling fluid circulation cavity, slowly close the first control valve, adjust the opening degree of the second control valve, record the back pressure gauge reading, the annular pressure gauge reading and the bottom hole pressure gauge reading when the fourth flowmeter reading is stable to the target overflow flow, and record the phase image of the drilling fluid and the flow rate of the drilling fluid through the camera at the same time.

3. The method of using an analog formation and wellbore coupled spill-and- leak coexistence laboratory apparatus of claims 1 or 2, wherein Step five is specifically: adjust the opening degree of the second control valve, the formation fluid enters the drilling fluid circulation cavity from the formation fluid storage tank under the action of the pressure difference, record the back pressure gauge reading, the annular pressure gauge reading and the bottom hole pressure gauge reading when the third flowmeter reading is stable to the target overflow flow, and record the phase image of the drilling fluid and the flow rate of the drilling fluid through the camera at the same time. Slowly close the second control valve, adjust the opening of the first control valve, when the third flow meter reading is stable to the target loss, record the back pressure pressure gauge reading, annulus pressure gauge reading and bottom hole pressure gauge reading respectively, and record the drilling fluid phase image and drilling fluid flow rate through the camera at the same time.

4. The method of claim 1 or 2, wherein Step three is specifically: adjusting the first throttle valve and the second throttle valve, starting the plunger pump, circulating the drilling fluid between the drilling fluid circulation cavity and the circulation tank, and recording the back pressure pressure gauge reading, the annulus pressure gauge reading and the bottom hole pressure gauge reading respectively when the second flow meter reading and the back pressure pressure gauge reading are stable; Or / and, step seven is specifically: if the overflow and loss conditions of the permeable formation are simulated, steps two to five are repeated, the opening of the first control valve, the second control valve and the third control valve is controlled, so that the change of the loss, the overflow and the gas invasion is within the set range.

5. The method of claim 3, wherein Step three is specifically: adjusting the first throttle valve and the second throttle valve, starting the plunger pump, circulating the drilling fluid between the drilling fluid circulation cavity and the circulation tank, and recording the back pressure pressure gauge reading, the annulus pressure gauge reading and the bottom hole pressure gauge reading respectively when the second flow meter reading and the back pressure pressure gauge reading are stable; Or / and, step seven is specifically: if the overflow and loss conditions of the permeable formation are simulated, steps two to five are repeated, the opening of the first control valve, the second control valve and the third control valve is controlled, so that the change of the loss, the overflow and the gas invasion is within the set range.

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