Test bench and test method for observing disturbance characteristics during hydrate rotary drilling

Abstract

The invention discloses a disturbance characteristic observation test bench, which is used for observing the disturbance characteristic in the process of hydrate rotary drilling, and relates to the technical field of hydrate testing, and comprises: a hydrate generation unit, a detachable hydrate pressure-maintaining drilling cabin, a ball valve pressure-maintaining unit and a tracer particle trajectory tracking unit, wherein the hydrate generation unit comprises a hydrate generation barrel, and the hydrate generation barrel is used for reacting and generating hydrates with metal tracer particles; the detachable hydrate pressure-maintaining drilling cabin has a closed cavity, and a drilling rig is arranged in the cavity, and the drilling rig is used for drilling into hydrates with metal tracer particles; the ball valve pressure-maintaining unit is arranged between the hydrate pressure-maintaining drilling cabin and the hydrate generation unit, and is used for controlling the connection and sealing of the two; the tracer particle trajectory tracking unit is used for detecting, tracking and displaying the trajectory of the metal tracer particles in the hydrate generation barrel.

Description

Technical Field

[0001] The invention relates to the technical field of hydrate testing, and in particular to a disturbance characteristic observation test bench and a testing method during hydrate rotary drilling. Background Art

[0002] Natural gas hydrate is a crystalline solid substance formed by gas molecules (mainly methane) and water under certain temperature and pressure conditions, commonly known as "combustible ice". The occurrence environment of natural gas hydrate is mainly under the permafrost layer in high-latitude areas and under the continental shelf extending from the continent to the ocean within a few hundred meters. Its reserves are abundant, clean, and have extremely high resource value. At the same time, the physical and chemical conditions of hydrate accumulation are good, and it is considered to be a huge potential alternative resource for fossil fuels. Therefore, natural gas hydrate has been a research hotspot in the scientific community and the oil and gas industry in recent years. In addition to being a new type of green, low-carbon and efficient energy, hydrates have also attracted much attention from the scientific community in terms of studying global climate change, marine geological disasters, and marine engineering safety. For research in these areas, the most direct and effective way is to obtain complete, undisturbed in-situ samples of natural gas hydrates on the seabed and conduct further experimental analysis.

[0003] During the drilling process of natural gas hydrate formations, when the formation is disturbed by drilling, it is easy to be squeezed and deformed like soil, and soil particles will also be dislocated. Local soil particles will fall into the original voids, causing volume deformation of the soil, which will lead to changes in important formation parameters such as porosity, permeability, and saturation. In this case, during the coring process, part of the soil is squeezed into the core tube to become the core, part is squeezed into the voids, and part is lost with the drilling fluid, so the formation disturbance within a certain range around the drilling will be very serious.

[0004] Due to the special properties of natural gas hydrates, their occurrence state, destruction mechanism and changes in physical and mechanical properties are very different from those of conventional seabed sediments, which also greatly affect the results of natural gas hydrate exploration and exploitation. The reserves of natural gas hydrates are generally explored by wave velocity logging. However, during the drilling process, the strata around the well will produce large plastic deformation due to the influence of stratum disturbance. The plastic deformation caused by this disturbance brings large errors to the results of wave velocity logging, and even causes the measured natural gas hydrate reserves to be far from the real data, and cannot correctly reflect the occurrence state of hydrates in the stratum; in addition, the disturbance may cause the temperature and pressure field to change, causing the hydrate to decompose, which will not only lead to poor integrity of the hydrate sample and reduce the value of further research, but also cause changes in reservoir strength and stress state, leading to engineering problems such as reservoir sand production, well wall collapse, stratum subsidence and landslides.

[0005] From the sampling tool point of view, in order to ensure that the sample can always maintain the original pressure of the sample and will not cause the gas phase components to disperse and the organic components to decompose, the physical properties of the sample will not be destroyed by the pressure release, and the internal fluid will not volatilize and lose due to changes in temperature and pressure. Therefore, in the exploration and sampling of natural gas hydrates, the pressure-maintaining sampling device is mainly used. The hydrate pressure-maintaining sampling device is divided into a pressure-in type pressure-maintaining sampling device and a rotary pressure-maintaining sampling device. The pressure-in type pressure-maintaining sampling device generally increases the pump pressure in the drill pipe to a certain extent, cuts off the pin, and pushes the inner door of the drill bit into the formation at the same time. This method is suitable for the sampling of submarine natural gas hydrates in soft formations. For the sampling of natural gas hydrates in medium-hard or hard formations, a rotary pressure-maintaining sampling device is generally used. This sampling device drives the sampling drill bit to rotate through the outer tube to drill, and the core gradually enters the core tube to complete the sampling. Among them, the single penetration of the pressure-type sampling device is about 1m, while the single penetration of the rotary pressure-type sampling device can reach 3m under the same outer tube assembly and bottom drilling tool combination. More single penetration length means higher efficiency and lower cost. It can be seen that the rotary pressure-type sampling device has more advantages in obtaining the length of hydrate samples. Therefore, it is necessary to study the changing law of the disturbance characteristics of natural gas hydrate under rotary drilling conditions. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a disturbance characteristic observation test platform during hydrate rotary drilling. In the high-pressure and low-temperature drilling test of hydrate, it uses X-rays to track the trajectory of metal tracer particles, displays the real-time position of the metal tracer particles on the X-ray detector, and transmits the movement trajectory of the metal tracer particles to the corresponding computer software through the data signal line, so as to study the change law of the disturbance characteristics of natural gas hydrate under drilling conditions. The present invention also provides a disturbance characteristic test method during hydrate rotary drilling, which can detect the movement trajectory of metal tracer particles in the synthesized hydrate.

[0007] To achieve the above object, the present invention can be carried out by adopting the following technical solutions:

[0008] A disturbance characteristic observation test bench is used to observe the disturbance characteristics during hydrate rotary drilling, comprising:

[0009] A hydrate generation unit, comprising a hydrate generation barrel, wherein the hydrate generation barrel is used to react and generate hydrates with metal tracer particles;

[0010] A detachable hydrate pressure-maintaining drilling chamber, which has a closed cavity, and a drilling rig is arranged in the cavity, and the drilling rig is used to drill into the hydrate with metal tracer particles;

[0011] A ball valve pressure-maintaining unit, which is arranged between the hydrate pressure-maintaining drilling chamber and the hydrate generation unit, and is used to control the connection and sealing between the two; and

[0012] The tracer particle trajectory tracking unit is used to detect, track and display the trajectory of the metal tracer particles in the hydrate generation barrel.

[0013] The disturbance characteristic observation test bench as described above, further, the hydrate pressure-maintaining drilling chamber includes a fixed frame sleeve, a lift, a vertical pressure rod and a lift motor, the fixed frame sleeve is fixed with the lift, the lift is connected with the vertical pressure rod that can move up and down in the height direction, the lower end of the vertical pressure rod is connected to the drilling rig, the lift motor is used to drive the lift, thereby driving the drilling rig to move up and down in its height direction; the drilling rig includes a drilling rig motor, a reducer, a drill rod and a drill bit, the output end of the drilling rig motor is connected to the drill rod through the reducer, and the drill bit is provided at the lower end of the drill rod.

[0014] As described above, the disturbance characteristic observation test bench, further, the ball valve pressure maintaining unit comprises a ball valve body and a ball valve control rod, wherein the ball valve control rod is used to control the flipping of the ball valve body to control the opening and closing of the ball valve.

[0015] The disturbance characteristic observation test bench as described above further includes a control and detection unit, and the control and detection unit includes:

[0016] A first temperature sensor is disposed in the hydrate formation unit and is used to receive a control instruction from a temperature controller and detect an ambient temperature of hydrate formation;

[0017] A first pressure sensor, which is disposed in the hydrate formation unit and is used to detect the environmental pressure of hydrate formation;

[0018] A motor controller, which is connected to the lifting platform motor and the drilling rig motor control signal;

[0019] A computer controller connected to the motor controller, the first temperature sensor, and the first pressure sensor control signal; and,

[0020] Program software running on the computer controller.

[0021] The disturbance characteristic observation test bench as described above, further, the tracer particle trajectory tracking unit comprises:

[0022] An X-ray diffractometer, which is used to emit electromagnetic waves of a specific wavelength to the hydrate generation barrel;

[0023] an X-ray detector for displaying the real-time position of metal tracer particles of hydrates in the hydrate generation barrel; and,

[0024] Digital image processing (DIC) is used to process the real-time position data of metal tracer particles and display the moving trajectory of the metal tracer particles on the screen of a computer controller.

[0025] The disturbance characteristic observation test bench as described above, further, the hydrate pressure-maintaining drilling chamber further comprises:

[0026] A second temperature sensor, which is used to detect the ambient temperature in the hydrate pressure-maintaining drilling chamber;

[0027] The second pressure sensor is used to detect the environmental pressure in the hydrate pressure-maintaining drilling chamber.

[0028] The disturbance characteristic observation test bench as described above, further, the hydrate generation unit is provided with a second air inlet with an electromagnetic valve, a second air outlet, a water inlet and a water outlet.

[0029] The disturbance characteristic observation test bench as described above, further, the hydrate generation barrel is made of organic glass or special glass that is light-transmissive and has strength that meets set requirements.

[0030] As described above, the disturbance characteristic observation test bench, further, the hydrate generation unit, the hydrate pressure-maintaining drilling chamber and the ball valve pressure-maintaining unit are connected by a plurality of flange-type end covers, the plurality of end covers are fixed by locking screws, and sealing rings are provided inside the end covers.

[0031] The present invention also provides a method for testing disturbance characteristics during hydrate rotary drilling, which comprises the following steps:

[0032] Install the hydrate generation unit, the pressure-maintaining ball valve unit, and the unit for placing metal tracer particles in sequence from bottom to top;

[0033] Adding water to the hydrate generation unit, and gradually increasing the pressure inside the hydrate generation unit to a set pressure, and opening the second gas inlet and the second gas outlet to allow the natural gas to circulate inside the hydrate generation unit;

[0034] Adjust the temperature of the hydrate formation unit to the set temperature, keep the pressure-maintaining ball valve unit connected, and add the required metal tracer particles layer by layer evenly during the hydrate formation process;

[0035] After the hydrate containing the metal tracer particles is generated, the pressure-maintaining ball valve unit is closed;

[0036] After ensuring the phase stability of the hydrate, the unit for placing the metal tracer particles is removed and replaced with a hydrate pressure-maintaining drilling cabin, the pressure in the hydrate pressure-maintaining drilling cabin is increased to be consistent with the pressure inside the hydrate generation unit, and the pressure-maintaining ball valve unit is opened to allow the internal space of the hydrate pressure-maintaining drilling cabin to be connected with the internal space of the hydrate generation unit;

[0037] The drilling rig is lowered and the X-ray diffractometer and X-ray detector are started simultaneously to observe in real time the movement trajectory of the metal tracer particles inside the hydrate sample during rotary drilling. The movement trajectory of the metal tracer particles is parameterized and displayed on the screen of the computer controller.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. The test bench of the present invention draws on the particle tracking method of blood or pipeline fluid in the medical and industrial fields, and adds metal tracer particles layer by layer in the hydrate formation process. After the hydrate is generated, in the high-pressure and low-temperature drilling test of the hydrate, the trajectory of the metal particles is tracked by X-rays, the real-time position of the metal tracer particles is displayed on the X-ray detector, and the movement trajectory of the metal tracer particles is transmitted to the corresponding computer software through the data signal line, so as to study the change law of the disturbance characteristics of natural gas hydrate under drilling conditions.

[0040] 2. The test bench of the present invention adopts a modular design. The hydrate generation unit at the bottom can create a high-pressure and low-temperature generation environment for hydrates to form natural gas hydrates containing metal tracer particles. The hydrate pressure-maintaining drilling cabin at the top can also perform separate pressurization and pressure relief operations. The middle pressure-maintaining ball valve device can maintain the pressure inside the hydrate generation unit when the hydrate pressure-maintaining drilling cabin is installed or disassembled, and at the same time, ensure the connectivity of the entire internal space of the device when conducting hydrate drilling and disturbance performance tests.

[0041] 3. After the disturbance performance test of the hydrate rotary drilling process is completed, the hydrate pressure-maintaining drilling chamber can be dismantled while keeping the hydrate phase unchanged and replaced with other experimental equipment to prepare for the later study of the mechanical properties of hydrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 This is a schematic diagram of the structure of the disturbance characteristic observation test bench before the test according to an embodiment of the present invention;

[0044] Figure 2 It is a schematic diagram of the structure of the disturbance characteristic observation test bench in the test according to the embodiment of the present invention.

[0045] Among them: 1. first sealing end cover; 2. vertical pressure rod; 3. hydrate pressure-maintaining drilling chamber; 4. elevator; 5. first gas outlet; 6. displacement sensor; 7. fixed frame; 8. drilling rig motor; 9. reducer; 10. drill pipe; 11. drill bit; 12. second sealing end cover; 13. ball valve body; 14. second gas outlet; 15. temperature controller; 16. X-ray diffractometer; 17. hydrate sample; 18. X-ray diffractometer fixed frame; 19. water inlet; 20. time domain reflection Shooting needle; 21. Test bench frame; 22. Second temperature sensor; 23. Lifting platform motor; 24. Second pressure sensor; 25. Power line and signal line; 26. First air inlet; 27. Sealing ring; 28. Ball valve control rod; 29. ​​Third sealing end cover; 30. Temperature and pressure sensor; 31. Iron ring; 32. Rubber barrel; 33. Water outlet; 34. Hydrate generation barrel; 35. Computer controller; 36. X-ray detector; 37. Second air inlet; 38. Hydrate fixing seat. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0047] Example:

[0048] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations of the embodiments of the present invention are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0049] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0050] In the description of the present invention, "multiple" means at least two, such as two, three, etc., unless otherwise clearly defined. In addition, unless otherwise clearly defined and defined, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0052] See also Figure 1 to Figure 2 The present invention provides a disturbance characteristic observation test platform during hydrate rotary drilling, which draws on the particle tracking method of blood or pipeline fluid in the medical and industrial fields. By adding metal tracer particles layer by layer evenly during the hydrate generation process, after the hydrate is generated, the trajectory of the metal tracer particles is tracked by X-rays during the high-pressure and low-temperature drilling test of the hydrate, and the real-time position of the metal tracer particles is displayed on the X-ray detector 36, and the movement trajectory of the metal tracer particles is transmitted to the corresponding computer software through the data signal line, so as to study the change law of the disturbance characteristics of natural gas hydrate under drilling conditions. At the same time, after the disturbance performance test of the hydrate rotary drilling process is completed, the hydrate pressure-maintaining drilling cabin 3 of this test platform can be dismantled while keeping the hydrate phase unchanged, and replaced with other experimental equipment, so as to prepare for the later study of the mechanical properties of hydrates.

[0053] See also Figure 1 , Figure 1 A test bench for observing disturbance characteristics during hydrate rotary drilling is shown, which includes: a hydrate generation unit, a detachable hydrate pressure-maintaining drilling cabin 3, a ball valve pressure-maintaining unit and a tracer particle trajectory tracking unit. The hydrate generation unit includes a hydrate generation barrel 34, and the hydrate generation barrel 34 is used to react and generate hydrates with metal tracer particles; the detachable hydrate pressure-maintaining drilling cabin 3 has a closed cavity, and a drilling rig is arranged in the cavity, and the drilling rig is used to drill into hydrates with metal tracer particles; the ball valve pressure-maintaining unit is arranged between the hydrate pressure-maintaining drilling cabin 3 and the hydrate generation unit, and is used to control the connection and closure of the two; the tracer particle trajectory tracking unit is used to detect, track and display the trajectory of the metal tracer particles in the hydrate generation barrel 34. It can be understood that the test bench of the present invention adopts a modular design. The hydrate generation unit at the bottom can create a high-pressure and low-temperature generation environment for hydrates to form natural gas hydrates containing metal tracer particles inside. The upper hydrate pressure-maintaining drilling cabin 3 can also perform separate pressurization and pressure relief operations. The middle pressure-maintaining ball valve device can maintain the pressure inside the hydrate generation unit when the hydrate pressure-maintaining drilling cabin 3 is installed or disassembled, and at the same time, ensure the connectivity of the entire internal space of the device when conducting hydrate drilling and disturbance performance tests.

[0054] As an optional implementation, in some embodiments, the hydrate pressure-maintaining drilling chamber 3 includes a fixed frame sleeve 7, a lift 4, a vertical pressure rod 2 and a lift motor 23. The fixed frame sleeve 7 is fixed with a lift 4, and the lift 4 is connected with a vertical pressure rod 2 that can move up and down in the height direction. The lower end of the vertical pressure rod 2 is connected to the drilling rig, and the lift motor 23 is used to drive the lift 4, thereby driving the drilling rig to move up and down in its height direction; the drilling rig includes a drilling motor 8, a reducer 9, a drill rod 10 and a drill bit 11. The output end of the drilling motor 8 is connected to the drill rod 10 through the reducer 9, and the lower end of the drill rod 10 is provided with a drill bit 11. Further, the ball valve pressure-maintaining unit includes a ball valve body 13 and a ball valve control rod 28, and the ball valve control rod 28 is used to control the flipping of the ball valve body 13 to control the opening and closing of the ball valve.

[0055] In this embodiment, a fixed frame sleeve 7 is arranged inside the hydrate pressure-maintaining drilling chamber 3 to fix the elevator 4 and the drilling rig. This test bench drives the elevator 4 through the elevator motor 23, thereby driving the drilling rig to move up and down. At the same time, the drill rod 10 and the drill bit 11 at the lower end can be controlled by the drilling rig motor 8 to rotate at a predetermined speed. Preferably, the hydrate pressure-maintaining drilling chamber 3 also includes a displacement sensor 6, which can be arranged on the elevator motor 23, and is used to detect the distance that the vertical pressure rod 2 descends. Before the test of this test bench, the ball valve is closed, such as Figure 1When the test bench is in use, the ball valve control rod 28 controls the ball valve body 13 to flip, and the ball valve is opened. Figure 2 As shown, at this time, the lifting platform motor 23 drives the lift 4 to gradually lower the drilling rig to the top of the generated hydrate sample 17, and then starts the drilling rig motor 8 to drive the drill rod 10 and the drill bit 11 at the lower end to rotate at a predetermined speed, and at the same time turns on the tracer particle trajectory tracking unit to achieve real-time observation of the movement trajectory of the metal tracer particles inside the sample during the rotary drilling process of the hydrate. Further, the shell of the hydrate pressure-maintaining drilling cabin 3 is also provided with a first air inlet 26 and a first air outlet 5, which can perform separate pressurization and depressurization operations on the hydrate pressure-maintaining drilling cabin 3. Further, the hydrate pressure-maintaining drilling cabin 3 also includes: a second temperature sensor 22 and a second pressure sensor 24, the second temperature sensor 22 is used to detect the ambient temperature in the hydrate pressure-maintaining drilling cabin 3; the second pressure sensor 24 is used to detect the ambient pressure in the hydrate pressure-maintaining drilling cabin 3. Furthermore, it also includes a first sealing end cover 1, a second sealing end cover 12 and a third sealing cover. The first sealing end cover 1 is located at the upper part of the hydrate pressure-maintaining drilling chamber 3, and the first sealing end cover 1 is a solid circle. The second sealing end cover 12 and the third sealing end cover 29 are located at the upper and lower ends of the ball valve pressure-maintaining unit, and the second sealing end cover 12 and the third sealing end cover 29 are both provided with through holes. The design of the three sealing end covers can not only ensure the sealing of the test bench, but also facilitate the drilling rig of the hydrate pressure-maintaining drilling chamber 3 to smoothly pass through the second sealing end cover 12 and the third sealing end cover 29 after the ball valve pressure-maintaining unit is opened, and fall on the surface of the synthesized hydrate sample 17 for rotation. In addition, a rubber barrel 32 with an iron ring 31 is also provided around the hydrate sample 17 generated in this embodiment, which can play a certain role in fixing the shape of the generated hydrate sample 17.

[0056] As an optional implementation, in some embodiments, a control and detection unit is also included, and the control and detection unit includes: a first temperature sensor, a first pressure sensor, a motor controller, a computer controller 35, and a program software running on the computer controller 35. The first temperature sensor is arranged in the hydrate generation unit, and is used to receive the control instruction issued by the temperature controller 15 to detect the ambient temperature of hydrate generation; the first pressure sensor is arranged in the hydrate generation unit, and is used to detect the ambient pressure of hydrate generation; the motor controller is connected to the control signal of the lifting platform motor 23 and the drilling rig motor 8; the computer controller 35 is connected to the control signal of the motor controller, the first temperature sensor, and the first pressure sensor. In this embodiment, the computer controller 35 is connected to various sensors and controllers through power lines and signal lines 25. By setting various sensors, the temperature, pressure, etc. in the device can be accurately monitored. By setting various controllers, the test process of the device can be accurately controlled, thereby ensuring the accuracy of the test results. It should be noted that the temperature and pressure sensor 30 is only schematically drawn in the accompanying drawings to represent the first temperature sensor and the first pressure sensor.

[0057] As an optional implementation, in some embodiments, the tracer particle trajectory tracking unit includes: an X-ray diffractometer 16, an X-ray detector 36, and a digital image processing method DIC, wherein the X-ray diffractometer 16 is used to emit electromagnetic waves of a specific wavelength to the hydrate generation barrel 34; the X-ray detector 36 is used to display the real-time position of the metal tracer particles of the hydrate in the hydrate generation barrel 34; the digital image processing method DIC is used to process the real-time position data of the metal tracer particles and display the moving trajectory of the metal tracer particles on the screen of the computer controller 35. Exemplarily, the X-ray diffractometer 16 and the X-ray detector 36 can be placed at appropriate distances before and after the hydrate generation unit, respectively. The X-ray diffractometer 16 can also be placed on the X-ray diffractometer fixing frame 18, which is conducive to maintaining the stability of the X-ray diffractometer 16, and the height of the X-ray diffractometer 16 can also be adjusted by adjusting the height of the X-ray diffractometer fixing frame 18.

[0058] As an optional implementation, in some embodiments, the hydrate generation unit is provided with a second air inlet 37, a second air outlet 14, a water inlet 19 and a water outlet 33 with an electromagnetic valve. Specifically, by providing the second air inlet 37, the second air outlet 14, the water inlet 19 and the water outlet 33 with an electromagnetic valve, a high-pressure and low-temperature hydrate generation environment can be created in the hydrate generation unit. Further, the hydrate generation barrel 34 adopts organic glass or special glass that is light-transmissive and has a strength that meets the set requirements. Specifically, in order to meet the needs of other experimental visibility in the later stage and to achieve the effect of pressure and heat preservation, the material of the hydrate generation barrel 34 needs to be selected from thick organic glass or special glass with good light transmittance and high strength. For example, Pasmo special transparent material can be selected. This transparent material has an optical transparency of up to 90%, is resistant to low temperature and high pressure, and can even operate under ultra-high pressure conditions of more than 200MPa by selecting a suitable thickness. Furthermore, the hydrate generation unit further includes a hydrate fixing seat 38 and a time domain reflection needle 20. The hydrate fixing seat 38 is arranged on the time domain reflection needle 20. The time domain reflection needle 20 is used to detect the water content of the generated hydrate.

[0059] As an optional implementation, in some embodiments, the hydrate generation unit, the hydrate pressure-maintaining drilling cabin 3 and the ball valve pressure-maintaining unit are connected by a plurality of flange-type end covers, the plurality of end covers are fixed by locking screws, and a sealing ring 27 is provided inside the end cover. In this embodiment, the upper and lower ends of the hydrate generation unit, the hydrate pressure-maintaining drilling cabin 3 and the ball valve pressure-maintaining unit are connected by flange-type end covers, the end covers are fixed by locking screws, and are sealed by sealing rings 27, so that the device can be easily placed on the test bench stand 21 for installation and disassembly.

[0060] The present invention also provides a method for testing disturbance characteristics during hydrate rotary drilling, which comprises the following steps:

[0061] The hydrate generation unit, the pressure-maintaining ball valve unit and the unit for placing metal tracer particles are installed in sequence from bottom to top.

[0062] Water is added to the hydrate generation unit, and the pressure inside the hydrate generation unit is gradually increased to a set pressure through an air compressor, and the second air inlet 37 and the second air outlet 14 are opened to allow natural gas to circulate inside the hydrate generation unit.

[0063] The temperature of the hydrate formation unit is adjusted to a set temperature by the temperature controller 15. Preferably, the temperature is lowered to about 2°C, the pressure-maintaining ball valve unit is kept connected, and the required metal tracer particles are added uniformly layer by layer during the hydrate formation process.

[0064] After the hydrate containing the metal tracer particles is generated, the pressure-maintaining ball valve unit is closed.

[0065] After ensuring the phase stability of the hydrate, the unit used to place the metal tracer particles is removed and replaced with the hydrate pressure-maintaining drilling cabin 3. After the connection is completed, the hydrate pressure-maintaining drilling cabin 3 is pressurized to be consistent with the internal pressure of the hydrate generation unit, and the pressure-maintaining ball valve unit is opened to allow the internal space of the hydrate pressure-maintaining drilling cabin 3 to be connected with that of the hydrate generation unit.

[0066] The drilling rig is lowered and the X-ray diffractometer 16 and the X-ray detector 36 are started simultaneously to observe in real time the movement trajectory of the metal tracer particles inside the sample during the rotary drilling process of the hydrate, and the movement trajectory of the metal tracer particles is parameterized by the digital image processing method DIC technology and displayed on the screen of the computer controller 35.

[0067] After the hydrate drilling disturbance test is completed, the drilling rig is lifted into the hydrate pressure-maintaining drilling chamber 3 by the elevator 4, and the ball valve control rod 28 is turned to close the pressure-maintaining ball valve unit. Thereafter, the pressure in the upper hydrate pressure-maintaining drilling chamber 3 is released. After the pressure is released, the upper hydrate pressure-maintaining drilling chamber 3 and the drilling rig and other equipment are removed by unscrewing the locking screws between the devices, and replaced with other experimental instruments to be tested, completing the switching of the test module of the experimental device under the pressure-maintaining state.

[0068] After the hydrate is generated, the test method uses X-rays to track the trajectory of metal particles during the high-pressure and low-temperature drilling test of the hydrate, and displays the real-time position of the metal tracer particles on the X-ray detector 36, and transmits the movement trajectory of the metal tracer particles to the corresponding computer software through the data signal line, so as to study the change law of the disturbance characteristics of natural gas hydrate under drilling conditions. At the same time, after the disturbance performance test of the hydrate rotary drilling process is completed, the hydrate pressure-maintaining drilling chamber 3 can be dismantled while keeping the hydrate phase unchanged, and replaced with other experimental equipment, so as to prepare for the later study of the mechanical properties of hydrates.

[0069] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0070] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made based on the essence of the content of the present invention should be included in the protection scope of the present invention.

Claims

1. A disturbance characteristic observation test bench, used to observe the disturbance characteristics during hydrate rotary drilling, characterized in that: include: A hydrate generation unit, comprising a hydrate generation barrel, wherein the hydrate generation barrel is used to react and generate hydrates with metal tracer particles; A detachable hydrate pressure-maintaining drilling chamber, which has a closed cavity, and a drilling rig is arranged in the cavity, and the drilling rig is used to drill into hydrates with metal tracer particles; wherein the hydrate pressure-maintaining drilling chamber comprises a fixed frame sleeve, a lift, a vertical pressure rod and a lifting platform motor, the fixed frame sleeve is fixed with the lift, the lift is connected with the vertical pressure rod that can move up and down in the height direction, the lower end of the vertical pressure rod is connected to the drilling rig, and the lifting platform motor is used to drive the lift, thereby driving the drilling rig to move up and down in its height direction; the drilling rig comprises a drilling rig motor, a reducer, a drill rod and a drill bit, the output end of the drilling rig motor is connected to the drill rod through the reducer, and the lower end of the drill rod is provided with the drill bit; A ball valve pressure-maintaining unit, which is arranged between the hydrate pressure-maintaining drilling chamber and the hydrate generation unit, and is used to control the connection and sealing between the two; and A tracer particle trajectory tracking unit is used to detect, track and display the trajectory of the metal tracer particles in the hydrate generation barrel, wherein the tracer particle trajectory tracking unit includes: An X-ray diffractometer, which is used to emit electromagnetic waves of a specific wavelength to the hydrate generation barrel; an X-ray detector for displaying the real-time position of metal tracer particles of hydrates in the hydrate generation barrel; and, Digital image processing (DIC) is used to process the real-time position data of metal tracer particles and display the moving trajectory of the metal tracer particles on the screen of a computer controller.

2. The disturbance characteristic observation test bench according to claim 1, characterized in that: The ball valve pressure maintaining unit comprises a ball valve body and a ball valve control rod, wherein the ball valve control rod is used to control the flipping of the ball valve body to control the opening and closing of the ball valve.

3. The disturbance characteristic observation test bench according to claim 1, characterized in that: It also includes a control and detection unit, which includes: A first temperature sensor is disposed in the hydrate formation unit and is used to receive a control instruction from a temperature controller and detect an ambient temperature of hydrate formation; A first pressure sensor, which is disposed in the hydrate formation unit and is used to detect the environmental pressure of hydrate formation; A motor controller, which is connected to the lifting platform motor and the drilling rig motor control signal; A computer controller connected to the motor controller, the first temperature sensor, and the first pressure sensor control signal; and, Program software running on the computer controller.

4. The disturbance characteristic observation test bench according to claim 1, characterized in that: The hydrate pressure-maintaining drilling chamber also includes: A second temperature sensor, which is used to detect the ambient temperature in the hydrate pressure-maintaining drilling chamber; The second pressure sensor is used to detect the environmental pressure in the hydrate pressure-maintaining drilling chamber.

5. The disturbance characteristic observation test bench according to claim 1, characterized in that: The hydrate generating unit is provided with a second air inlet with an electromagnetic valve, a second air outlet, a water inlet and a water outlet.

6. The disturbance characteristic observation test bench according to claim 1, characterized in that: The hydrate forming barrel is made of light-transmissive organic glass or special glass with strength meeting set requirements.

7. The disturbance characteristic observation test bench according to claim 1, characterized in that: The hydrate generation unit, the hydrate pressure-maintaining drilling chamber and the ball valve pressure-maintaining unit are connected via a plurality of flange-type end covers, the plurality of end covers are fixed via locking screws, and sealing rings are arranged inside the end covers.

8. A method for testing disturbance characteristics during hydrate rotary drilling, applicable to the disturbance characteristics observation test bench as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: Install the hydrate generation unit, the pressure-maintaining ball valve unit, and the unit for placing metal tracer particles in sequence from bottom to top; Adding water to the hydrate generation unit, and gradually increasing the pressure inside the hydrate generation unit to a set pressure, and opening the second gas inlet and the second gas outlet to allow the natural gas to circulate inside the hydrate generation unit; Adjust the temperature of the hydrate formation unit to the set temperature, keep the pressure-maintaining ball valve unit connected, and add the required metal tracer particles layer by layer evenly during the hydrate formation process; After the hydrate containing the metal tracer particles is generated, the pressure-maintaining ball valve unit is closed; After ensuring the phase stability of the hydrate, the unit for placing the metal tracer particles is removed and replaced with a hydrate pressure-maintaining drilling cabin, the pressure in the hydrate pressure-maintaining drilling cabin is increased to be consistent with the pressure inside the hydrate generation unit, and the pressure-maintaining ball valve unit is opened to allow the internal space of the hydrate pressure-maintaining drilling cabin to be connected with the internal space of the hydrate generation unit; The drilling rig is lowered and the X-ray diffractometer and X-ray detector are started simultaneously to observe in real time the movement trajectory of the metal tracer particles inside the hydrate sample during rotary drilling. The movement trajectory of the metal tracer particles is parameterized and displayed on the screen of the computer controller.

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