LU101573B1

LU101573B1 - Hydrate Triaxial Experimental Equipment

Info

Publication number: LU101573B1
Application number: LU101573A
Authority: LU
Inventors: Jie Guo; Fengshan Ma; Haijun Zhao; Qihao Sun; Guang Li; Xuelei Feng; Xueliang Duan; Shuaiqi Liu
Original assignee: Inst Geology & Geophysics Cas
Priority date: 2019-07-10
Filing date: 2019-12-27
Publication date: 2020-04-17

Abstract

The invention discloses a hydrate triaxial experimental equipment, comprising a rack, a pressure chamber, an upper pressure component, a lower pressure component, an enclosing pressure component, a detection mechanism for natural gas content and a measuring mechanism for hydrate saturation; the pressure chamber is installed on the rack, a work chamber is provided inside the pressure chamber, and the pressure chamber is provided with an enclosing pressure exit, an air inlet and an exhaust port; the upper pressure component and the lower pressure component are installed inside the work chamber, and an axial extensometer is connected to the upper pressure component and/or the lower pressure component; the enclosing pressure component is communicated with the enclosing pressure exit, and the object to be tested is arranged with a radial extensometer; the detection mechanism for natural gas content is connected with the air inlet and the exhaust port respectively; the measuring mechanism for hydrate saturation is communicated with the work chamber. In the invention, the displacement and deformation of the object to be tested are detected by the axial extensometer and radial extensometer, and the content change of the natural gas content and saturation of the object to be tested are detected by the detection mechanism for natural gas content and measuring mechanism for hydrate saturation respectively. The detection is comprehensive and more accurate.

Description

Hydrate Triaxial Experimental Equipment lu101573 .

Technical field ; The invention relates to the technical field of testing natural gas hydrate bearing : sediments, particularly relates to a hydrate triaxial experimental equipment. : Background art : The hydrate bearing sediments are metastable structures with complex mechanical ; behavior characteristics. The exploitation process often involves hydrate phase | transformation, particle migration, damage of cementation structure and other ] microstructural changes. It is necessary to carry out the particle size Physical : mechanism analysis starting from micro level to determine the formation mechanism | of geological disasters such as stratum subsidence and submarine landslide caused A by natural gas hydrate decomposition. | Sediment and uniaxial and triaxial compression of rock, as well as seepage and : high-low temperature coupling tests are important test methods for testing sediments ; and rocks, which can accurately measure various indicators of natural gas hydrates. lt | is very important for unconventional energy exploitation. There are many kinds of | existing gas hydrate test equipments, but there are design defects, resulting in | inaccurate measurement results. | Invention summary f The purpose of the invention is to provide a hydrate triaxial experimental equipment to | solve the problem of inaccurate measurement results of existing hydrate experimental | equipments. | In order to achieve the above purpose, the technical solution proposed in the invention 4 is as follows: | A hydrate triaxial experimental equipment, comprises: Ë À rack; à A pressure chamber installed on the rack, a work chamber is provided inside the a pressure chamber, and the pressure chamber is provided with an enclosing pressure ë exit, an air inlet and an exhaust port communicating with the work chamber; 0 An upper pressure component and a lower pressure component installed in the work | chamber, wherein the object to be tested is installed between the upper pressure , component and the lower pressure component, and an axial extensometer is |connected to the upper pressure component and/or the lower pressure component. u101573 | An enclosing pressure component communicated with the enclosing pressure exit, and the enclosing pressure component is configured to apply radial pressure to the | object to be tested, which is provided with a radial extensometer: .

A detection mechanism for natural gas content communicated with the air inlet and the exhaust port respectively; | A measuring mechanism for hydrate saturation communicated with the work chamber. : According to the hydrate triaxial experimental equipment provided in the invention, the / displacement and deformation of the object to be tested are detected by the axial / extensometer and radial extensometer, and the content change of the natural gas content and saturation of the object to be tested are detected by the detection | mechanism for natural gas content and measuring mechanism for hydrate saturation ; respectively. The detection is comprehensive and more accurate. : Further, the hydrate triaxial experimental equipment according to the above ; embodiment of the invention may have the following additional technical features: | According to an example of the invention, a lifting mechanism is installed on the upper | rack; the lifting mechanism is movably connected with the pressure chamber to drive ; the pressure chamber to move up and down. | According to an example of the invention, the lifting mechanism comprises a É connecting frame and a first linear reciprocating device; the connecting frame is ' connected with the rack; the first linear reciprocating device is installed on the ; connecting frame, and connected with the pressure chamber to drive the pressure A chamber to move up and down. | According to an example of the invention, the rack is provided with a fixed rail and a | lifting rail; the pressure chamber is installed on the lifting rail, and when the lifting rail is . raised or descended to the preset position, the fixed rail is connected with the lifting | rail, so that the pressure chamber can move in the preset direction of the fixed rail and | the lifting rail. | According to an example of the invention, the lifting rail comprises a rail board and a | second linear reciprocating device; the second linear reciprocating device is installed | on the rack; the rail board is installed on the second linear reciprocating device and | lifted and lowered driven by the second linear reciprocating device. | According to an example of the invention, the pressure chamber comprises a cylinder | and a base, the bottom of the cylinder is provided with an opening and the cylinder is | installed on the base to form the work chamber, and the cylinder is movably |connected with the base. lu101573 | According to an example of the invention, the bottom of the cylinder is provided with a | first coupling flange extending outwards; the upper base is provided with a second ; coupling flange extending outwards, which is parallel and against the first coupling ; flange; the first coupling flange and the second coupling flange are connected by a | clamp. : According to an example of the invention, the enclosing pressure component | comprises a first duplex pump, a second duplex pump, a return valve, a process valve, | and a enclosing pressure control valve; | The first duplex pump is respectively pipeline connected with the return valve and the | process valve, and the return valve and the process valve are pipeline connected with | the work chamber respectively; : The second duplex pump is pipeline connected with the enclosing pressure control | valve, which is pipeline connected with the enclosing pressure exit, and a | thermodetector is provided on the pipeline between the enclosing pressure control ; valve and the enclosing pressure exit. | According to an example of the invention, the detection mechanism for natural gas | content comprises a methane gas cylinder, a constant pressure-speed pump, a | back-pressure valve, a flow meter, and a separation and a balance; ' The methane gas cylinder is pipeline connected with the constant pressure-speed ; pump, which is pipeline connected with the air inlet, and an alarm is provided on the | pipeline between the constant pressure-speed pump and the air inlet; : The separator is installed on the balance, the flow meter and the back pressure valve | are respectively pipeline connected with the separator, and the back pressure valve is ] pipeline connected with the exhaust port. | According to an example of the invention, the measuring mechanism for hydrate i; saturation comprises an acoustic testing device. F The above additional advantages will be partly set forth in the following description, .

and part will be apparent from the following description or from the embodiments of , the invention. [ Brief description of the drawings È FIG. 1 is a structural schematic diagram of a hydrate triaxial experimental equipment | according to an embodiment of the invention; | FIG. 2 is a front view of the rack and pressure chamber in an embodiment of the '

invention; lu101573 FIG. 3 is a side view of the rack and pressure chamber in an embodiment of the : invention; FIG. 4 is a structural schematic diagram of the pressure chamber according to an | embodiment of the invention. } In the drawings, the part list represented by each number is as follows: ;

1. Rack; 11, Motor; 12, Lifting mechanism; 121, Connecting frame; 122, The first linear ; reciprocating device; 13, Lifting rail, 131, Rail board; 132, The second linear È reciprocating device; |

2. Pressure chamber; 21. Cylinder; 211. The first connecting flange; 212. Lug; 22. ; Base; 221. The second connecting flange; 23. Clamp; 24. Enclosing pressure exit; 25. : Air inlet; 26. Exhaust port; |

3. Upper pressure component; 31. Axial extensometer, A

4. Lower pressure component; 41. Radial extensometer; :

5. Enclosing pressure component; 51. The first duplex pump; 52. The second duplex | pump; 53. Return valve; 54. Process valve; 55. Enclosing pressure control valve; 56. | Thermodetector; |

6. Detection mechanism for natural gas content; 61. Methane gas cylinder; 62. | Constant pressure-speed pump; 63. Back-pressure valve; 64. Flow meter; 65. .

Separator; 66. Balance; |

7. Measuring mechanism for hydrate saturation; :

8. Object to be tested. ' Embodiments } The principles and characteristics of the invention are described below in combination ; with the drawings. The examples are only used to explain the invention, not to limit the | scope of the invention. A Referring to FIG. 1, a hydrate triaxial experimental equipment is provided in the | embodiment, comprising a rack 1, a pressure chamber 2, an upper pressure à component 3, a lower pressure component 4, a enclosing pressure component 5, À | detection mechanism for natural gas content 6, and a measuring mechanism for l hydrate saturation 7 and other specific structures. 8 The rack 1 in the embodiment can be regarded as a square-shaped frame structure | with a preset height, and with a space for accommodating the pressure chamber 2 | therein, and a motor 11 is installed on the upper part of the rack 1, to drive the upper |pressure component 3 to move downwards. lu101573 | In the embodiment, the pressure chamber 2 is installed in the space above the rack 1, and a work chamber is arranged inside the pressure chamber 2. The pressure ; chamber 2 is provided with an enclosing pressure exit 24, an air inlet 25 and an ! exhaust port 26 communicated with the work chamber; referring to FIG. 2-4, the | pressure chamber 2 in the embodiment comprises a cylinder 21 and a base 22, and ; the cylinder 21 is a bottom opening structure which is installed on the base 22, to form a work chamber together with the base 22. Preferably, in order to facilitate the installation of the upper pressure component 3 and the lower pressure component 4 ; and other structures in the work chamber, the cylinder 21 and the base 22 are ; designed to be movably connected in the embodiment. ; Specifically, the removable connection between the cylinder 21 and the base 22 can ; be achieved with the following structure: the bottom of the cylinder 21 is provided with à a first coupling flange 211 extending outwards; the upper part of the base 22 is | provided with a second coupling flange 221 extending outwards, which is parallel and ! against the first coupling flange 211; the first coupling flange 211 and the second : coupling flange 221 are connected by a clamp 23. ' In the embodiment, the upper pressure component 3 and the lower pressure 3 component 4 are installed in the work chamber, and the object 8 to be tested is : installed between the upper pressure component 3 and the lower pressure component | 4, which are used to apply an axial pressure to the object 8 to be tested, in which the ! axial direction can be understood as the axial direction of the motor 11 described | above, or as up and down in the drawing. The upper pressure component 3 is | connected with an axial extensometer 31, which is used to detect the axial .

deformation and displacement data of the object 8 to be tested under the action of the | upper pressure component 3 and the lower pressure component 4. The upper | pressure component 3 and the lower pressure component 4 in the embodiment can be Ë selected from any one of the prior art, therefore the structure is not described in detail | in the embodiment. | The axial extensometer 31 in the embodiment preferably comprises a magnetic | displacement sensor, an amplifier and a recorder. The magnetic displacement sensor | has the advantages of high precision, high stability, high reliability, strong | anti-interference ability and low power consumption, etc. which is the best | displacement test sensor currently. | The enclosing pressure component 5 in the embodiment is communicated with the :

enclosing pressure exit 24, and the enclosing pressure component 5 is used to applylu101573 1 a radial pressure to the object 8 to be tested, which is provided with a radial / extensometer 41. The extensometer 41 in the embodiment specifically comprises a hydraulic sensor, an amplifier, and a recorder. ; The detection mechanism 6 for natural gas content in the embodiment is ! communicated with the air inlet 25 and the exhaust port 26 respectively, for detecting ) the content change of natural gas of the object 8 to be tested; the measuring | mechanism 7 for hydrate saturation is communicated with the work chamber for ! detecting the hydrate saturation of the object 8 to be tested; the specific structure of 2 detection mechanism 6 for natural gas content and the measuring mechanism 7 for ; hydrate saturation are given in the following description. ; According to the above structural description, the hydrate triaxial experimental | equipment provided in the embodiment detects the displacement and deformation of .

the object 8 to be tested through the axial extensometer 31 and the radial } extensometer 41, and detects the content change of natural gas and the saturation of } the object 8 to be tested through detection mechanism 6 for natural gas content and | the measuring mechanism 7 for hydrate saturation respectively. The detection is : comprehensive and more accurate. | Based on the above structure, in order to facilitate the installation of the pressure .

chamber 2 at the specified working position of the rack 1, to make the pressure | chamber 2 at a preset height, to facilitate the installation of the object 8 to be tested, | axial extensometer 31 and radial extensometer 41, etc, referring to FIG. 2 and 3, in | the embodiment, a lifting mechanism 12 is installed on the upper part of the rack 1. | The lifting mechanism 12 is movably connected to the cylinder 21 of the pressure | chamber 2 to drive the pressure chamber 2 to move up and down. É Specifically, the lifting mechanism 12 in the embodiment comprises a connecting . frame 121 and a first linear reciprocating device 122; the connecting frame 121 is | connected with the rack 1; the first linear reciprocating device 122 is installed on the ! connecting frame 121, which is connected with the pressure chamber 2, to drive the | pressure chamber 2 to move up and down. The first linear reciprocating device 122 . may be a cylinder or an electric cylinder or an oil hydraulic cylinder, and the cylinder of | the first linear reciprocating device 122 is installed on the connecting frame 121 and | the piston rod of the first linear reciprocating device 122 is movably connected with the | cylinder 21 of the pressure chamber 2. Specifically, it may be a lug 212 arranged on | the cylinder 21, a hook provided at the bottom of the piston rod and other structures to ’

achieve the connection between both. lu101573 | Further, in order to facilitate the horizontal movement and adjustment in the vertical / direction of the pressure chamber 2 to abut the first linear reciprocating device 122. In /

the embodiment, a fixed rail (not shown in the FIG) and a lifting rail 13 are also :

arranged on the rack 1; the pressure chamber 2 is installed on the lifting rail 13, and when the lifting rail 13 is raised or descended to the preset position, the fixed rail is connected with the lifting rail 13, so that the pressure chamber 2 can move in the preset direction of the fixed rail and the lifting rail 13. Specifically, the lifting rail 13 in the embodiment comprises a rail board 131 and a :

second linear reciprocating device 132; the second linear reciprocating device 132 is installed on the rack 1; the rail board 131 is installed on the second linear / reciprocating device 132, and is lifted and lowered driven by the second linear . reciprocating device 132. ]

The second linear reciprocating device 132 in the embodiment may also be a cylinder |}

or an electric cylinder or an oil hydraulic cylinder.

The cylinder of the second linear } reciprocating device 132 is installed on the rack 1, and the piston rod of the second 7 reciprocating device is connected with the rail board 131. |

As shown in FIG. 1 , the enclosing component 5 in the embodiment specifically | comprises a first duplex pump 51 , a second duplex pump 52 , a return valve 53 , a Aprocess valve 54 and an enclosing pressure control valve 55; in which, the first duplex | pump 51 is pipeline connected with the return valve 53 and the process valve 54 | respectively, and the return valve 53 and the process valve 54 are pipeline connected àto the work chamber respectively; the second duplex pump 52 in the embodiment is | pipeline connected with the enclosing pressure control valve 55, which is pipeline )

connected with the enclosing pressure exit 24, and a thermodetector 56 is provided on | the pipeline between the enclosing pressure control valve 55 and enclosing pressure 2exit 24. ;

The enclosing pressure component 5 in the embodiment opens the enclosing | pressure control vaive 55 when the oil is fed, and the second duplex pump 52 draws |the pressurized oil in the oil tank into a high pressure oil chamber, then shuts down the | enclosing pressure control valve 55, and a servo actuator injects the pressurized oil |into the pressure chamber 2. When the oil is discharged, the first duplex pump 51 is | unloaded firstly, to open the return valve 53, and the compressed air enters into the | pressure chamber 2 through an air inlet 25 of the pressure chamber 2, to discharge |the pressurized oil from the enclosing pressure exit 24, and the pressurized oil returns |to the oil tank for sedimentation and filtration.

The oil is injected into the pressurelu101573 / chamber 2 through the second duplex pump 52 as necessary for the next experiment. ;

The detection mechanism 6 for natural gas content of the embodiment specifically ; comprises a methane gas cylinder 61, a constant pressure- speed pump 62, a back Ëpressure valve 63, a flow meter 64, a separator 6 and a balance 66; in which, the : methane gas cylinder 61 of the embodiment is pipeline connected with the constant : pressure-speed pump 62, which is pipeline connected with the air inlet 25. An alarm ; device is arranged on the pipeline between the constant pressure-speed pump 62 and >air inlet 25; the separator 65 in the embodiment is installed on the balance 66, and the |flow meter 64 and the back pressure valve 63 are pipeline connected with the ; separator 65 respectively, and the back pressure valve 63 is pipeline connected with ithe exhaust port 26. :

The hydrate saturation measurement of the present in the embodiment uses acoustic | measurement, ie. the hydrate saturation mechanism comprises an acoustic test :

device.

Specifically, the acoustic test device in the embodiment consists of a function | generator, a signal amplifier, an acoustic component, an oscilloscope and a computer | processing module, etc. (the above specific parts not shown in the FIG). Compared Àwith the ground stratum, it has higher longitudinal and transverse wave velocity, and |this characteristic is used to determine whether there is hydrate or saturation.

The !

acoustic parameters during the in-situ generation and decomposition of hydrate under | the conditions of actual temperature and pressure are obtained to establish the } relationship between the saturation and elastic parameters of gas hydrate and sound ' velocity. | Further, the hydrate triaxial experimental equipment in the embodiment further ;

comprises a control system (not shown in the FIG.), which is electrically connected | with the enclosing pressure mechanism, detection mechanism 6 for natural gas | content and hydrate saturation mechanism, to send the control command to the action | parts of the mechanism, accept the data detected by the sensor of the mechanism, °and process and analyze the data to obtain an experimental result. ;

The control system adopts the advanced adaptive fuzzy PID control algorithm, which ; can achieve on-line precise closed-loop control of system parameter control quantity, land achieve functions such as constant velocity loading and unloading, constant force |and constant displacement, etc.

At the same time, the control interface of the user | system parameters is provided, through which the user can set the system control |parameters to adapt to different control environment, which has good flexibility. ;

The control system has two independent electro-hydraulic servo valve controlu101573 | channels.

During the test, various control rates and control functions can be switched | between each other.

Each actuator can control the servo valve simultaneously or / separately according to the test requirements, ensuring the synchronous or | asynchronous control of the entire loading system, which greatly improves the stability | of the test system. | A data acquisition system has 9 high-precision 24-bit A/D conversion pressure, | displacement and deformation acquisition channels, which can achieve the accuracy | within +0.1% of the indicated value.

The e data acquisition speed reaches 10KHz, which can collect the current sensor signal quickly, so that the closed-loop control | module can better perform real-time closed-loop control. | In the description of the invention, it is understood that the orientation or positional | relationship indicated by the terms "inside", "outside", etc. is based on the orientation | or positional relationship shown in the drawings, merely for convenience of description | of the invention and simplified description, rather than indicating or implying that the | device referred must have a particular orientation, constructed and operated in a | particular orientation, which cannot be understood as limit to the invention. | Furthermore, the terms "the first" and "the second" are used for descriptive purposes / only, which are not to be understood as indicating or implying a relative importance or implicitly indicating the number of technical features indicated.

Therefore, the features | defining with "the first" or "the second" may express or implicitly comprise one or | multiple of the features.

In the description of the invention, the meaning of "multiple" is | two or more unless otherwise expressly defined. | In the invention, unless otherwise expressly specified and defined, the terms | "installed", "communicated" and "connected", etc. shall be understood broadly, and for | example, may be a fixed connection, a removable connection or integrating.

For those | skilled in the art, the specific meanings of the terms in the invention can be understood | in accordance with specific conditions.

Although the embodiments of the invention have been shown and described, it is understood that the above-described embodiments are illustrative which cannot be understood as limit of the invention.

Changes, variations, substitutes and modifications | of the above-described embodiments may be made by those skilled in the art within | the scope of the invention. mm a eee

Claims

Claims lu101573

1. À hydrate triaxial experimental equipment, is characterized by comprising: A rack; A pressure chamber installed on the rack, a work chamber is provided inside the pressure chamber, and the pressure chamber is provided with an enclosing pressure exit, an air inlet and an exhaust port communicating with the work chamber: An upper pressure component and a lower pressure component installed in the work chamber, wherein the object to be tested is installed between the upper pressure component and the lower pressure component, and an axial extensometer is connected to the upper pressure component and/or the lower pressure component. An enclosing pressure component communicated with the enclosing pressure exit, and the enclosing pressure component is configured to apply radial pressure to the | object to be tested, which is provided with a radial extensometer, A detection mechanism for natural gas content communicated with the air inlet and the exhaust port respectively; A measuring mechanism for hydrate saturation communicated with the work chamber. |

2. The hydrate triaxial experimental equipment according to claim 1, is characterized in that a lifting mechanism is installed on the upper rack; the lifting mechanism is movably connected with the pressure chamber to drive the pressure chamber to move up and down.

3. The hydrate triaxial experimental equipment according to claim 2, is characterized | in that the lifting mechanism comprises a connecting frame and a first linear reciprocating device; the connecting frame is connected with the rack; the first linear | reciprocating device is installed on the connecting frame, and connected with the pressure chamber to drive the pressure chamber to move up and down.

4. The hydrate triaxial experimental equipment according to claim 1, is characterized in that the rack is provided with a fixed rail and a lifting rail; the pressure chamber is installed on the lifting rail, and when the lifting rail is raised or descended to the preset position, the fixed rail is connected with the lifting rail, so that the pressure chamber | can move in the preset direction of the fixed rail and the lifting rail. |

5. The hydrate triaxial experimental equipment according to claim 4, is characterized in that the lifting rail comprises a rail board and a second linear reciprocating device; the second linear reciprocating device is installed on the rack; the rail board is installed on the second linear reciprocating device, and is lifted and lowered driven by mer A EEEthe second linear reciprocating device. lu101573 |

6. The hydrate triaxial experimental equipment according to any one of claims 1 to 5, | is characterized in that the pressure chamber comprises a cylinder and a base, the bottom of the cylinder is provided with an opening and the cylinder is installed on the base to form the work chamber, and the cylinder is movably connected with the base.

7. The hydrate triaxial experimental equipment according to claim 6, is characterized in that the bottom of the cylinder is provided with a first coupling flange extending outwards; the upper base is provided with a second coupling flange extending outwards, which is parallel and against the first coupling flange; the first coupling flange and the second coupling flange are connected by a clamp. |

8. The hydrate triaxial experimental equipment according to any one of claims 1 to 5, is characterized in that the enclosing pressure component comprises a first duplex pump, a second duplex pump, a return valve, a process valve, and a enclosing | pressure control valve; | The first duplex pump is respectively pipeline connected with the return valve and the ! process valve, and the return valve and the process valve are pipeline connected with | the work chamber respectively; | The second duplex pump is pipeline connected with the enclosing pressure control | valve, which is pipeline connected with the enclosing pressure exit, and a } thermodetector is provided on the pipeline between the enclosing pressure control | valve and the enclosing pressure exit. |

9. The hydrate triaxial experimental equipment according to any one of claims 1 to 5, | is characterized in that the detection mechanism for natural gas content comprises a | methane gas cylinder, a constant pressure-speed pump, a back-pressure valve, a flow | meter, and a separation and a balance; | The methane gas cylinder is pipeline connected with the constant pressure-speed | pump, which is pipeline connected with the air inlet, and an alarm is provided on the | pipeline between the constant pressure-speed pump and the air inlet; 1 The separator is installed on the balance, the flow meter and the back pressure valve are respectively pipeline connected with the separator, and the back pressure valve is | pipeline connected with the exhaust port. |

10. The hydrate triaxial experimental equipment according to any one of claims 1 to 5, ; is characterized in that the measuring mechanism for hydrate saturation comprises an / acoustic testing device. /