CN110487697B - Supercritical carbon dioxide injection coal rock mechanical property test and fracturing experiment device - Google Patents
Supercritical carbon dioxide injection coal rock mechanical property test and fracturing experiment device Download PDFInfo
- Publication number
- CN110487697B CN110487697B CN201910690960.8A CN201910690960A CN110487697B CN 110487697 B CN110487697 B CN 110487697B CN 201910690960 A CN201910690960 A CN 201910690960A CN 110487697 B CN110487697 B CN 110487697B
- Authority
- CN
- China
- Prior art keywords
- pressure
- pump
- pressing plate
- confining
- pore
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000011435 rock Substances 0.000 title claims abstract description 54
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 title claims abstract description 46
- 238000012360 testing method Methods 0.000 title claims abstract description 37
- 239000003245 coal Substances 0.000 title claims abstract description 26
- 229910002092 carbon dioxide Inorganic materials 0.000 title claims abstract description 23
- 239000001569 carbon dioxide Substances 0.000 title claims abstract description 23
- 238000002474 experimental method Methods 0.000 title claims abstract description 16
- 238000002347 injection Methods 0.000 title claims abstract description 15
- 239000007924 injection Substances 0.000 title claims abstract description 15
- 239000011148 porous material Substances 0.000 claims abstract description 65
- 238000000034 method Methods 0.000 claims abstract description 30
- 230000008569 process Effects 0.000 claims abstract description 23
- 238000012544 monitoring process Methods 0.000 claims abstract description 17
- 238000012545 processing Methods 0.000 claims abstract description 11
- 239000000523 sample Substances 0.000 claims description 78
- 238000007789 sealing Methods 0.000 claims description 67
- 238000011144 upstream manufacturing Methods 0.000 claims description 29
- 238000006073 displacement reaction Methods 0.000 claims description 20
- 230000035699 permeability Effects 0.000 claims description 20
- 239000007788 liquid Substances 0.000 claims description 18
- 239000012530 fluid Substances 0.000 claims description 13
- 230000035882 stress Effects 0.000 claims description 9
- 230000001052 transient effect Effects 0.000 claims description 9
- 238000010438 heat treatment Methods 0.000 claims description 7
- 238000009792 diffusion process Methods 0.000 claims description 6
- 230000009471 action Effects 0.000 claims description 4
- 230000006355 external stress Effects 0.000 claims description 3
- 230000001550 time effect Effects 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 claims description 2
- 230000008859 change Effects 0.000 claims description 2
- 238000003556 assay Methods 0.000 claims 1
- 230000008878 coupling Effects 0.000 abstract description 9
- 238000010168 coupling process Methods 0.000 abstract description 9
- 238000005859 coupling reaction Methods 0.000 abstract description 9
- 239000007787 solid Substances 0.000 abstract description 9
- 230000001360 synchronised effect Effects 0.000 abstract description 5
- 239000007789 gas Substances 0.000 description 17
- 230000001808 coupling effect Effects 0.000 description 5
- 238000013461 design Methods 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 239000003345 natural gas Substances 0.000 description 2
- 239000003208 petroleum Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009530 blood pressure measurement Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000009919 sequestration Effects 0.000 description 1
- 230000000638 stimulation Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
- G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
- G01N15/082—Investigating permeability by forcing a fluid through a sample
- G01N15/0826—Investigating permeability by forcing a fluid through a sample and measuring fluid flow rate, i.e. permeation rate or pressure change
Abstract
The invention relates to the technical field of rock mechanical property test under a multi-physical field coupling environment, and provides a supercritical carbon dioxide injection coal rock mechanical property test and fracturing experiment device which comprises a confining pressure system, a shaft pressure system, a pore pressure system, a temperature control system and an information acquisition and processing system; the confining pressure system, the shaft pressure system and the pore pressure system can simultaneously provide confining pressure, shaft pressure and pore pressure for the experimental sample; the temperature control system provides temperature control for the experimental sample; the information acquisition and processing system acquires and processes real-time data of the confining pressure system, the shaft pressure system and the pore pressure system. According to the invention, under a heat-fluid-solid coupling environment, the shaft pressure system, the confining pressure system, the pore pressure system and the temperature control system are organically combined, so that synchronous implementation of various loading amounts in the experimental process and real-time synchronous monitoring of monitoring amounts are realized; reasonable structure and wide application prospect.
Description
Technical Field
The invention relates to the technical field of rock mechanical property testing in a multi-physical field coupling environment, in particular to a supercritical carbon dioxide injection coal rock mechanical property testing and fracturing experimental device.
Background
The problems of coal rock mechanical response under the coupling actions of a temperature field, a fluid seepage field and a stress field are all related to the fracturing and yield increasing development process of coal bed gas, shale gas, compact gas and petroleum reservoir and the carbon dioxide geological sequestration engineering. In recent years, research institutions and scholars in many countries internationally began fracturing stimulation operations for petroleum, natural gas and unconventional natural gas using supercritical carbon dioxide as a fracturing medium. The interaction between the coal rock and the supercritical carbon dioxide under the heat-fluid-solid coupling environment is further studied, and the full stress-strain-permeability-acoustic emission response curve of the coal rock in the supercritical carbon dioxide injection process is studied, so that the method has important scientific significance for further understanding the action mechanism of the coal rock and the supercritical carbon dioxide and promoting the technical progress of China in the field of supercritical carbon dioxide fracturing of the coal rock. However, the existing triaxial experiment machine can only meet the permeability test under the fluid-solid condition or the stress-strain test under the fluid-solid coupling condition, but a temperature control system, a confining pressure system, a shaft pressure system and a pore pressure system are not organically combined together, so that the requirement of the full stress-strain-permeability-acoustic emission process curve research under the laboratory fluid-solid coupling environment is difficult to meet.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a device for testing the mechanical properties of coal rock injected with supercritical carbon dioxide and fracturing experiments, wherein the coal rock (an experimental sample) is in a set heat-fluid-solid coupling environment by controlling a temperature control system, a confining pressure system, a shaft pressure system and a pore pressure system; then, the permeability test based on the transient method is realized by using the pressure setting of the upstream air pump and the downstream air pump in the permeability test of the transient method; the deformation and acoustic emission events of the coal rock in the experimental process are synchronously monitored in real time through a displacement sensor (LVDT) and an acoustic emission acquisition device; therefore, the multi-field coupling effect and the interaction mechanism of the supercritical carbon dioxide coal rock under the heat flow solid coupling effect are deeply researched and understood.
The invention adopts the following technical scheme:
the device for testing the mechanical properties of the supercritical carbon dioxide injection coal rock and carrying out fracturing experiments comprises a confining pressure system, a shaft pressure system, a pore pressure system, a temperature control system and an information acquisition and processing system;
the confining pressure system, the shaft pressure system and the pore pressure system can simultaneously provide confining pressure, shaft pressure and pore pressure for the experimental sample; the temperature control system provides temperature control for the experimental sample; the information acquisition and processing system acquires and processes real-time data of the confining pressure system, the shaft pressure system and the pore pressure system.
Further, the confining pressure system comprises an outer pipe, an inner flexible pipe, a confining pressure control pressure pump and a confining pressure control valve;
the inner flexible pipe is fixedly arranged in an outer pipe cavity, and the outer pipe cavity is filled with first liquid; the confining pressure control pressure pump is connected with the cavity of the outer tube through the confining pressure control valve; placing an experimental sample inside the inner flexible tube; the confining pressure control pressure pump controls the pressure of the first liquid in the outer tube cavity, and the pressure of the first liquid is transmitted to the experimental sample through the inner flexible tube to form confining pressure of the experimental sample.
Further, the fixing mode of the outer tube and the inner flexible tube is as follows: the both ends of outer tube all set up the counter-force base, counter-force base threaded connection in the tip of outer tube, holder threaded connection in the counter-force base, interior flexible pipe's 2 ends cup joint respectively in 2 the holder.
Further, the axial pressure system comprises a first sealing pressing plate, a second sealing pressing plate, an axial pressure control pump and an axial pressure control valve;
the first sealing pressing plate and the second sealing pressing plate are arranged in the inner flexible pipe, and a closed space formed by the first sealing pressing plate, the second sealing pressing plate and the inner flexible pipe is used for placing an experimental sample; the first sealing pressing plate is fixedly connected with the clamp holder, and the second sealing pressing plate can slide in the inner flexible pipe;
the second sealing pressing plate, the inner flexible pipe and the airtight space among the clamp holder form an axial pressure cavity, the axial pressure cavity is filled with second liquid, and the axial pressure control pump is connected with the axial pressure cavity through the axial pressure control valve; the axial pressure control pump controls the pressure of the second liquid in the axial pressure cavity, and the second sealing pressing plate slides in the inner flexible pipe under the drive of the second liquid pressure to squeeze the experimental sample and provide axial pressure for the experimental sample.
Further, the pore pressure system comprises an air source, an upstream pressure pump, a downstream pressure pump and a pore pressure control pump;
the first sealing pressing plate and the second sealing pressing plate are respectively provided with a through hole; the upstream pressure pump applies upstream pressure to the experimental sample through a through hole arranged on the first sealing pressing plate, and the downstream pressure pump applies downstream pressure to the experimental sample through a through hole arranged on the second sealing pressing plate;
the air source is connected with a pore pressure control pump, and the pore pressure control pump is respectively connected with an upstream pressure pump and a downstream pressure pump.
Further, the temperature control system comprises a temperature control box, a heating device, a temperature sensor and a support seat;
the outer tube, the inner flexible tube and the experimental sample are all arranged in the temperature control box, a heating device and a temperature sensor are arranged on the inner wall of the temperature control box, and the support is used for supporting the outer tube.
Further, the information acquisition and processing system comprises the temperature sensor, a displacement sensor, an acoustic emission acquisition device and a computer;
the displacement sensor is arranged on the second sealing pressing plate and is used for measuring the displacement of the experimental sample;
the acoustic emission acquisition device comprises an acoustic emission probe and an acoustic emission acquisition instrument; the acoustic emission probe is arranged on the first sealing pressing plate and/or the second sealing pressing plate and is connected to the acoustic emission acquisition instrument through a data transmission line;
the computer is respectively connected with the temperature sensor, the displacement sensor and the acoustic emission acquisition instrument;
the computer collects the confining pressure, the axial pressure and the pore pressure of the experimental sample at the same time.
Further, the first sealing pressing plate and the second sealing pressing plate are both O-shaped or double O-shaped. The design of the O-shaped sealing pressing plate structure is mainly designed aiming at fracturing fluid with larger viscosity such as water, so that the fracturing fluid can be effectively prevented from overflowing and the like; the design of the double-O-shaped sealing pressing plate structure is mainly designed aiming at fracturing fluid with smaller viscosity such as carbon dioxide, supercritical carbon dioxide and the like, and the sealing function of fracturing fluid in the fracturing process is realized.
Further, the experimental device further comprises a vacuumizing device, and the vacuumizing device provides a vacuum environment for the experimental sample.
The invention also provides a method for carrying out experiments by using the experimental device, which comprises the following steps:
firstly, connecting all pipelines of an experimental device well, and performing air tightness test; carrying out vacuumizing operation on the experimental device by using a vacuumizing device;
secondly, setting the temperature of the temperature control box to 40 ℃ by utilizing a temperature control system, and ensuring that CO is injected 2 CO at a pressure of greater than 7.38MPa 2 Phase transition occurs to a supercritical state;
thirdly, applying confining pressure of 1MPa to the rock sample by using a confining pressure control pressure pump of a confining pressure system to ensure that the rock sample is in a stable confining pressure state; applying an axial pressure of 1MPa to the rock test sample by the axial pressure control pump, applying an pore pressure of 1MPa to the rock test sample by the upstream pressure pump, the downstream pressure pump and the pore pressure control pump, and checking the overall air tightness of the system again;
and step four, increasing the confining pressure, the shaft pressure and the pore pressure by using the confining pressure system, the shaft pressure system and the pore pressure control system step by step, and carrying out transient permeability test by using the pressure difference of the upstream pressure pump and the downstream pressure pump at different stress levels. Meanwhile, the displacement sensor is used for monitoring the deformation of the coal rock in the loading process, and the acoustic emission acquisition system is used for monitoring acoustic emission information of rock experiment samples; considering the time effect of gas diffusion in the rock test sample in the gas injection process, continuously monitoring the permeability for 48 hours at each confining pressure, axial pressure and pore pressure level, so that the gas diffusion in the rock test sample is balanced, and a permeability evolution curve with time under different stress levels is obtained;
fifthly, keeping the pressure of the confining pressure control pressure pump to 15MPa and the pressure of the axial pressure control pump to 15MPa unchanged, gradually increasing the gas injection pressure through the pore pressure control pump, controlling the temperature by utilizing a temperature sensor, monitoring the axial deformation of a sample by utilizing a displacement sensor, and monitoring an acoustic emission event by an acoustic emission acquisition system; and testing the permeability values of the coal and the rock under the action of different pore pressures to obtain a full stress-strain-permeability-acoustic emission curve under the condition of unchanged external stress.
The beneficial effects of the invention are as follows:
1. the organic combination of the shaft pressure system, the confining pressure system, the pore pressure system and the temperature control system is realized under the heat-fluid-solid coupling environment.
2. The phase change of the carbon dioxide can be accurately controlled by utilizing the temperature control system and the fluid pressure control system, so that the mechanical property test of the multi-field coupling effect of the supercritical carbon dioxide injection coal rock is realized.
3. And the upstream and downstream two-stage pressure pumps arranged in the fluid pressure control system are utilized to realize the upstream and downstream pressure difference of the rock sample, and the transient permeability test of the ultra-low permeability rock is carried out.
4. And designing an O-shaped and double O-shaped pressing plate sealing device, realizing an indoor small-size coal rock fracturing experiment, synchronously monitoring acoustic emission signals in the fracturing process, and deeply grasping the coal rock cracking and breaking mechanism in a heat flow solid coupling environment.
5. The temperature control system, the surrounding rock system, the shaft pressure system, the pore pressure system and the information acquisition system are integrated in the computer software control system and are controlled uniformly; therefore, synchronous implementation of various loading amounts in the experimental process is realized, and real-time synchronous monitoring of the monitoring amount is realized.
Drawings
Fig. 1 is a schematic structural diagram of an experimental apparatus in an embodiment of the invention.
Fig. 2 is a schematic diagram of a temperature control system.
FIG. 3 is a schematic view of the structure of an O-shaped sealing pressing plate.
FIG. 4 is a schematic view of a double O-ring seal platen.
In the figure: 1-a counter-force base; 2-an outer tube; 3-an inner flexible tube; 41-a first sealing platen; 42-a second sealing platen; 5-a clamp holder; 6-a temperature sensor; 7, a temperature control box; 8-supporting the support; 9-displacement sensor (LVDT); 10-heating device; 11-a computer; 12-an acoustic emission acquisition device; 13-confining pressure control pressure pump; 14-confining pressure control valve (V1); 15-an axial pressure control valve (V2); 16-an upstream pressure pump; 17-a downstream pressure pump; 18-vacuumizing device; 19-an axial pressure control pump; 20-a pressure sensor; 21-a connection interface; 22-air source; 23-pore pressure control pump.
Detailed Description
Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the technical features or combinations of technical features described in the following embodiments should not be regarded as being isolated, and they may be combined with each other to achieve a better technical effect. In the drawings of the embodiments described below, like reference numerals appearing in the various drawings represent like features or components and are applicable to the various embodiments.
As shown in FIG. 1, the device for testing the mechanical properties of the multi-field coupling effect of the supercritical carbon dioxide injection coal rock and the fracturing experiment comprises a confining pressure system, a shaft pressure system, a pore pressure system, a temperature control system and an information acquisition and processing system;
the confining pressure system, the shaft pressure system and the pore pressure system can simultaneously provide confining pressure, shaft pressure and pore pressure for the experimental sample; the temperature control system provides temperature control for the experimental sample; the information acquisition and processing system acquires and processes real-time data of the confining pressure system, the shaft pressure system and the pore pressure system.
The confining pressure system provides different magnitudes of hoop stress for rock sample samples in the experimental process; as a specific implementation manner, the confining pressure system comprises an outer pipe 2, an inner flexible pipe 3, a confining pressure control pressure pump 13 and a confining pressure control valve 14; the inner flexible pipe 3 is fixedly arranged in the cavity of the outer pipe 2, and the cavity of the outer pipe 2 is filled with first liquid; the confining pressure control pressure pump 13 is connected with the cavity of the outer tube 2 through the confining pressure control valve 14; placing an experimental sample inside the inner flexible tube 3; the confining pressure control pressure pump 13 controls the pressure of the first liquid in the cavity of the outer tube 2, and the pressure of the first liquid is transmitted to the experimental sample through the inner flexible tube 3 to form confining pressure of the experimental sample.
The fixing between the outer tube 2 and the inner flexible tube 3 may take various ways, and preferably, the fixing manner of the outer tube 2 and the inner flexible tube 3 is as follows: the two ends of the outer tube 2 are provided with reaction bases 1, the reaction bases 1 are in threaded connection with the end parts of the outer tube 2, the holders 5 are in threaded connection with the reaction bases 1, and the 2 ends of the inner flexible tube 3 are respectively sleeved with 2 holders 5.
The axial pressure system provides axial stress with different magnitudes for the experimental sample, and preferably comprises a first sealing pressing plate 41, a second sealing pressing plate 42, an axial pressure control pump 19 and an axial pressure control valve 15; the first sealing pressing plate 41 and the second sealing pressing plate 42 are arranged in the inner flexible pipe 3, and a closed space formed by the first sealing pressing plate 41, the second sealing pressing plate 42 and the inner flexible pipe 3 is used for placing an experimental sample; the first sealing pressing plate 41 is fixedly connected with the clamp holder 5, and the second sealing pressing plate 42 can slide in the inner flexible pipe 3; the second sealing pressing plate 42, the inner flexible pipe 3 and the clamp holder 5 form an axial pressure cavity, the axial pressure cavity is filled with second liquid, and the axial pressure control pump 19 is connected with the axial pressure cavity through the axial pressure control valve 15; the axial pressure control pump 19 controls the pressure of the second liquid in the axial pressure cavity, and the second sealing pressing plate 42 slides in the inner flexible tube 3 under the driving of the second liquid pressure to squeeze the experimental sample, so as to provide the axial pressure for the experimental sample. Preferably, the first sealing platen 41 and the second sealing platen 42 may be O-type or double O-type, as shown in fig. 3 and 4. The design of the O-shaped sealing pressing plate structure is mainly designed aiming at fracturing fluid with larger viscosity such as water, so that the fracturing fluid can be effectively prevented from overflowing and the like; the design of the double-O-shaped sealing pressing plate structure is mainly designed aiming at fracturing fluid with smaller viscosity such as carbon dioxide, supercritical carbon dioxide and the like, and the sealing function of fracturing fluid in the fracturing process is realized.
The pore pressure control system is used for realizing the internal pore and fracture pressurization and the transient permeability test of the rock experimental sample; the pore pressure system comprises a gas source 22, an upstream pressure pump 16, a downstream pressure pump 17 and a pore pressure control pump 23; the first sealing pressing plate 41 and the second sealing pressing plate 42 are respectively provided with a through hole; the upstream pressure pump 16 applies an upstream pressure to the test sample through a through hole provided on the first sealing pressing plate 41, and the downstream pressure pump 17 applies a downstream pressure to the test sample through a through hole provided on the second sealing pressing plate 42; the gas source 22 is connected to a pore pressure control pump 23, which pore pressure control pump 23 is connected to the upstream pressure pump 16 and the downstream pressure pump 17, respectively. In use, the gas source 22 provides gas at a pressure to the pore pressure control pump 23; at this time, the pore pressure control pump 23 can perform secondary pressurization on the gas in the pump, and load the gas to a pressure value required by the experiment; the pore pressure control pump 23 is connected with the upstream pressure pump 16 and the downstream pressure pump 17, and provides a certain pressure to the upstream pressure pump 16 and the downstream pressure pump 17; the upstream pressure pump 16 and the downstream pressure pump 17 make the respective pressures reach the pressure difference required by the experiment through the pressurizing devices of the upstream pressure pump and the downstream pressure pump, thereby realizing the transient method permeability measurement of the experimental sample.
As shown in fig. 2, the temperature control system is configured to make the experimental sample (rock sample) and the fluid in the loading system in a set constant temperature state, so as to ensure that carbon dioxide can be changed into a supercritical state in the experimental process, and the temperature control system comprises a temperature control box 7, a heating device 10, a temperature sensor 6 and a support 8; the outer tube 2, the inner flexible tube 3 and the experimental sample are all arranged in the temperature control box 7, a heating device 10 and a temperature sensor 6 are arranged on the inner wall of the temperature control box 7, and the support 8 is used for supporting the outer tube 2. The temperature control box 7 is also provided with a connecting interface 21 for a pipeline to enter the temperature control box 7. The connecting interface 21 has a certain sealing effect, mainly ensures the constant temperature in the temperature control box 7, is embedded in the temperature control box 7, and has threads at both ends, so that the connecting interface 21 can be respectively connected with devices inside and outside the temperature control box 7.
The information acquisition system is used for realizing real-time and synchronous collection of physical quantities in the whole experimental device loading and testing process; the information acquisition and processing system comprises the temperature sensor 6, a displacement sensor 9, an acoustic emission acquisition device 12 and a computer 11; the displacement sensor 9 is arranged on the second sealing pressing plate 42 and is used for measuring the displacement of the experimental sample; the computer 11 is respectively connected with the temperature sensor 6, the displacement sensor 9 and the acoustic emission acquisition device 12; the computer also collects the confining pressure, the shaft pressure and the pore pressure of the experimental sample, and pressure measurement is achieved through the pressure sensor 20.
The working flow of the experimental device is as follows:
and in the first step, connecting all pipelines of the experimental device, and performing air tightness test. The experimental setup was then vacuum operated using the vacuum apparatus 18.
Secondly, the temperature of the temperature control box 7 is set to 40 ℃ by utilizing a temperature control system, so that when CO is injected 2 CO at a pressure of greater than 7.38MPa 2 Phase transition to the supercritical state will occur.
And thirdly, applying confining pressure of 1MPa to the rock sample by using a confining pressure control pressure pump 13 of a confining pressure system and the like, so as to ensure that the rock sample is in a stable confining pressure state. An axial pressure of 1MPa is applied to the rock sample by the axial pressure control pump 19 of the axial pressure system and the like, and an pore pressure of 1MPa is applied to the rock sample by the pore pressure system upstream pressure pump 16, downstream pressure pump 17 and pore pressure control pump 23 in this order, and the overall air tightness of the system is checked again.
And step four, increasing confining pressure, shaft pressure and pore pressure by utilizing the confining pressure system, the shaft pressure system and the pore pressure control system step by step, and carrying out transient permeability test by utilizing pressure differences of the upstream pressure pump 16 and the downstream pressure pump 17 at different stress levels. Meanwhile, the deformation of the coal and rock in the loading process is monitored by using a displacement sensor (LVDT) 9, and information such as rock sample acoustic emission is monitored by using an acoustic emission acquisition system 12. Considering the time effect of gas diffusion in the rock sample during the gas injection process, the permeability is continuously monitored for 48h (diffusion balance of gas in the rock sample) at each confining pressure, axial pressure and pore pressure level, and a permeability evolution curve with time under different stress levels is obtained.
And fifthly, keeping the pressure of the confining pressure control pressure pump 13 and the pressure of the axial pressure control pump (19) to be 15MPa unchanged, gradually increasing the gas injection pressure (pore pressure) through the pore pressure control pump 23, controlling the system to be stable by utilizing the temperature sensor 6, monitoring the axial deformation by the displacement sensor (LVDT) 9, monitoring the acoustic emission event by the acoustic emission acquisition system 12, and testing the coal rock permeability value under the action of different pore pressures to obtain a full stress-strain-permeability-acoustic emission curve under the condition of unchanged external stress.
Although a few embodiments of the present invention have been described herein, those skilled in the art will appreciate that changes can be made to the embodiments herein without departing from the spirit of the invention. The above-described embodiments are exemplary only, and should not be taken as limiting the scope of the claims herein.
Claims (5)
1. The device for testing the mechanical properties of the supercritical carbon dioxide injection coal rock and the fracturing experiment is characterized by comprising a confining pressure system, a shaft pressure system, a pore pressure system, a temperature control system, an information acquisition and processing system and a vacuumizing device;
the confining pressure system, the shaft pressure system and the pore pressure system can simultaneously provide confining pressure, shaft pressure and pore pressure for the experimental sample; the temperature control system provides temperature control for the experimental sample; the information acquisition and processing system acquires and processes real-time data of the confining pressure system, the shaft pressure system and the pore pressure system; the vacuumizing device provides a vacuum environment for the experimental sample;
the pore pressure system comprises an air source, an upstream pressure pump, a downstream pressure pump and a pore pressure control pump; the upstream pressure pump applies upstream pressure to the experimental sample, and the downstream pressure pump applies downstream pressure to the experimental sample; the upstream pressure pump and the downstream pressure pump enable the respective pressure to reach the pressure difference required by the experiment through the self-pressurizing device, so that the transient method of the experimental sample is realized for measuring the permeability; the air source is connected with a pore pressure control pump, and the pore pressure control pump is respectively connected with an upstream pressure pump and a downstream pressure pump;
the confining pressure system comprises an outer pipe, an inner flexible pipe, a confining pressure control pressure pump and a confining pressure control valve;
the inner flexible pipe is fixedly arranged in an outer pipe cavity, and the outer pipe cavity is filled with first liquid; the confining pressure control pressure pump is connected with the cavity of the outer tube through the confining pressure control valve; placing an experimental sample inside the inner flexible tube; the confining pressure control pressure pump controls the pressure of the first liquid in the outer tube cavity, and the pressure of the first liquid is transmitted to the experimental sample through the inner flexible tube to form confining pressure of the experimental sample;
the axial pressure system comprises a first sealing pressing plate, a second sealing pressing plate, an axial pressure control pump and an axial pressure control valve;
the first sealing pressing plate and the second sealing pressing plate are arranged in the inner flexible pipe, and a closed space formed by the first sealing pressing plate, the second sealing pressing plate and the inner flexible pipe is used for placing an experimental sample; the first sealing pressing plate is fixedly connected with the clamp holder, and the second sealing pressing plate can slide in the inner flexible pipe;
the second sealing pressing plate, the inner flexible pipe and the airtight space among the clamp holder form an axial pressure cavity, the axial pressure cavity is filled with second liquid, and the axial pressure control pump is connected with the axial pressure cavity through the axial pressure control valve; the axial pressure control pump controls the pressure of second liquid in the axial pressure cavity, and the second sealing pressing plate slides in the inner flexible pipe under the drive of the second liquid pressure to extrude the experimental sample so as to provide axial pressure for the experimental sample;
the temperature control system is used for enabling the experimental sample and the fluid in the loading system to be in a set constant temperature state, so that carbon dioxide phase change is ensured to be in a supercritical state in the experimental process; the temperature control system comprises a temperature control box, a heating device, a temperature sensor and a support seat; the temperature control box is provided with a connecting interface for a pipeline to enter the temperature control box; the connecting interface has a sealing function and is used for guaranteeing the constant temperature in the temperature control box;
the outer tube, the inner flexible tube and the experimental sample are all arranged in the temperature control box, a heating device and a temperature sensor are arranged on the inner wall of the temperature control box, the support is used for supporting the outer tube,
the method for carrying out the experiment by using the experimental device comprises the following steps:
firstly, connecting all pipelines of an experimental device well, and performing air tightness test; carrying out vacuumizing operation on the experimental device by using a vacuumizing device;
secondly, setting the temperature of the temperature control box to 40 ℃ by utilizing a temperature control system, and ensuring that CO is injected 2 CO at a pressure of greater than 7.38MPa 2 The phase changes intoIs in a supercritical state;
thirdly, applying confining pressure of 1MPa to the rock sample by using a confining pressure control pressure pump of a confining pressure system to ensure that the rock sample is in a stable confining pressure state; applying an axial pressure of 1MPa to the rock test sample by the axial pressure control pump, applying an pore pressure of 1MPa to the rock test sample by the upstream pressure pump, the downstream pressure pump and the pore pressure control pump, and checking the overall air tightness of the system again;
step four, increasing confining pressure, shaft pressure and pore pressure by using a confining pressure system, a shaft pressure system and a pore pressure control system step by step, and carrying out transient permeability test by using pressure differences of an upstream pressure pump and a downstream pressure pump at different stress levels; meanwhile, the displacement sensor is used for monitoring the deformation of the coal rock in the loading process, and the acoustic emission acquisition system is used for monitoring acoustic emission information of rock experiment samples; considering the time effect of gas diffusion in the rock test sample in the gas injection process, continuously monitoring the permeability for 48 hours at each confining pressure, axial pressure and pore pressure level, so that the gas diffusion in the rock test sample is balanced, and a permeability evolution curve with time under different stress levels is obtained;
fifthly, keeping the pressure of the confining pressure control pressure pump to 15MPa and the pressure of the axial pressure control pump to 15MPa unchanged, gradually increasing the gas injection pressure through the pore pressure control pump, controlling the temperature by utilizing a temperature sensor, monitoring the axial deformation of a sample by utilizing a displacement sensor, and monitoring an acoustic emission event by an acoustic emission acquisition system; and testing the permeability values of the coal and the rock under the action of different pore pressures to obtain a full stress-strain-permeability-acoustic emission curve under the condition of unchanged external stress.
2. The experimental set-up according to claim 1, wherein the outer tube and the inner flexible tube are fixed in the following manner: the both ends of outer tube all set up the counter-force base, counter-force base threaded connection in the tip of outer tube, holder threaded connection in the counter-force base, interior flexible pipe's 2 ends cup joint respectively in 2 the holder.
3. The experimental device according to claim 1, wherein the first sealing pressing plate and the second sealing pressing plate are provided with through holes; the upstream pressure pump applies upstream pressure to the experimental sample through the through hole arranged on the first sealing pressing plate, and the downstream pressure pump applies downstream pressure to the experimental sample through the through hole arranged on the second sealing pressing plate.
4. The experimental device according to claim 1, wherein the information acquisition processing system comprises the temperature sensor, a displacement sensor, an acoustic emission acquisition device, a computer;
the displacement sensor is arranged on the second sealing pressing plate and is used for measuring the displacement of the experimental sample;
the acoustic emission acquisition device comprises an acoustic emission probe and an acoustic emission acquisition instrument; the acoustic emission probe is arranged on the first sealing pressing plate and/or the second sealing pressing plate and is connected to the acoustic emission acquisition instrument through a data transmission line;
the computer is respectively connected with the temperature sensor, the displacement sensor and the acoustic emission acquisition instrument;
the computer collects the confining pressure, the axial pressure and the pore pressure of the experimental sample at the same time.
5. The assay device of claim 1, wherein the first sealing platen and the second sealing platen are both O-shaped or double O-shaped.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910690960.8A CN110487697B (en) | 2019-07-29 | 2019-07-29 | Supercritical carbon dioxide injection coal rock mechanical property test and fracturing experiment device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910690960.8A CN110487697B (en) | 2019-07-29 | 2019-07-29 | Supercritical carbon dioxide injection coal rock mechanical property test and fracturing experiment device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110487697A CN110487697A (en) | 2019-11-22 |
| CN110487697B true CN110487697B (en) | 2023-12-19 |
Family
ID=68548601
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910690960.8A Active CN110487697B (en) | 2019-07-29 | 2019-07-29 | Supercritical carbon dioxide injection coal rock mechanical property test and fracturing experiment device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110487697B (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111006947A (en) * | 2019-12-12 | 2020-04-14 | 东北大学 | Acoustic emission testing device and method for supercritical carbon dioxide fracturing simulation test |
| CN111144030B (en) * | 2020-01-03 | 2022-08-09 | 西南石油大学 | Circulating supercritical CO 2 Performance analysis method of coaxial heat exchanger for developing geothermal energy |
| CN111220525B (en) * | 2020-01-20 | 2022-01-28 | 中南大学 | Supercritical carbon dioxide rock fracture seepage device under high-temperature and high-pressure conditions |
| CN111220478B (en) * | 2020-01-20 | 2021-09-14 | 中南大学 | High-temperature high-pressure supercritical carbon dioxide rock core cracking test device |
| CN113445975B (en) * | 2020-03-26 | 2023-07-25 | 中国石油天然气股份有限公司 | Device and application, and underground coal gasification test system and method |
| CN112284992B (en) * | 2020-09-07 | 2021-06-22 | 合肥工业大学 | Device and method for monitoring soil body mechanical response whole process in gas permeation process |
| CN112858108B (en) * | 2021-03-12 | 2023-01-10 | 中国石油大学(华东) | Convection and diffusion experimental device and method for variable sample cavity under temperature and pressure conditions |
| CN113188895B (en) * | 2021-05-21 | 2022-08-16 | 长沙理工大学 | Side slope rock test system |
| CN113505540B (en) * | 2021-06-07 | 2022-08-05 | 中国船舶重工集团公司第七一九研究所 | Supercritical carbon dioxide PCHE multi-field coupling rapid prediction method, device and medium |
| CN113607620B (en) * | 2021-07-27 | 2022-08-02 | 东北大学 | Experimental device and method for carbon dioxide directional fracturing and permeability testing |
| CN113702247A (en) * | 2021-09-01 | 2021-11-26 | 中国矿业大学(北京) | Microwave heating displacement experimental device and clamping system thereof |
| CN115236217B (en) * | 2022-06-17 | 2023-07-21 | 北京科技大学 | Triaxial confining pressure coal body oxidation heating characteristic measuring device and method |
| CN115238553B (en) * | 2022-07-27 | 2023-03-10 | 北京科技大学 | Method and system for dividing dangerous area of buried pipeline leakage erosion |
| CN116046519B (en) * | 2022-11-25 | 2023-08-11 | 中南大学 | Rock triaxial pneumatic coupling single/double crack initiation and propagation test device and method |
| CN117079533B (en) * | 2023-10-16 | 2024-01-19 | 中国石油大学(华东) | CO accounting for reservoir stress time-varying effects 2 Experimental device for water layer buries |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101839841A (en) * | 2010-04-08 | 2010-09-22 | 西南石油大学 | Adsorption/desorption experimental apparatus and method for gas in rock pore |
| CN101975823A (en) * | 2010-10-14 | 2011-02-16 | 北京科技大学 | Method and device for detecting and analyzing multiband acoustic emission of rock fragile materials |
| RU2558838C1 (en) * | 2014-07-02 | 2015-08-10 | Общество с ограниченной ответственностью "Научно-исследовательский институт природных газов и газовых технологий-Газпром ВНИИГАЗ" | Modelling and estimating active storage capacity of underground gas storage in water-bearing fractured porous structures |
| CN107246998A (en) * | 2017-07-19 | 2017-10-13 | 中国石油大学(北京) | A kind of supercritical carbon dioxide rock core pressure break clamper under pore pressure saturation |
| CN108444848A (en) * | 2018-06-27 | 2018-08-24 | 辽宁工程技术大学 | Coal seam containing gas rupture process many reference amounts experimental rig under static-dynamic coupling |
| CN110057739A (en) * | 2019-04-28 | 2019-07-26 | 太原理工大学 | High temperature and pressure coal petrography supercritical carbon dioxide pressure break-creep-seepage flow test device |
| CN110057740A (en) * | 2019-04-28 | 2019-07-26 | 太原理工大学 | High temperature and pressure coal petrography supercritical carbon dioxide pressure break-creep-seepage tests method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5261267A (en) * | 1991-09-20 | 1993-11-16 | Chevron Research And Technology Company | Method and apparatus for rock property determination using pressure transient techniques and variable volume vessels |
-
2019
- 2019-07-29 CN CN201910690960.8A patent/CN110487697B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101839841A (en) * | 2010-04-08 | 2010-09-22 | 西南石油大学 | Adsorption/desorption experimental apparatus and method for gas in rock pore |
| CN101975823A (en) * | 2010-10-14 | 2011-02-16 | 北京科技大学 | Method and device for detecting and analyzing multiband acoustic emission of rock fragile materials |
| RU2558838C1 (en) * | 2014-07-02 | 2015-08-10 | Общество с ограниченной ответственностью "Научно-исследовательский институт природных газов и газовых технологий-Газпром ВНИИГАЗ" | Modelling and estimating active storage capacity of underground gas storage in water-bearing fractured porous structures |
| CN107246998A (en) * | 2017-07-19 | 2017-10-13 | 中国石油大学(北京) | A kind of supercritical carbon dioxide rock core pressure break clamper under pore pressure saturation |
| CN108444848A (en) * | 2018-06-27 | 2018-08-24 | 辽宁工程技术大学 | Coal seam containing gas rupture process many reference amounts experimental rig under static-dynamic coupling |
| CN110057739A (en) * | 2019-04-28 | 2019-07-26 | 太原理工大学 | High temperature and pressure coal petrography supercritical carbon dioxide pressure break-creep-seepage flow test device |
| CN110057740A (en) * | 2019-04-28 | 2019-07-26 | 太原理工大学 | High temperature and pressure coal petrography supercritical carbon dioxide pressure break-creep-seepage tests method |
Non-Patent Citations (1)
| Title |
|---|
| 马德宜.瞬态渗透法.《灰色预测模型及其在岩石渗流中的应用》.吉林大学出版社,2018, * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110487697A (en) | 2019-11-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110487697B (en) | Supercritical carbon dioxide injection coal rock mechanical property test and fracturing experiment device | |
| CN105510142B (en) | A kind of axle crushing test device of coal petrography multiphase different fluid three and test method | |
| CN101813604B (en) | Device for testing durability of water pressure resistant grouted rock | |
| CN106896043B (en) | True triaxial stress Imitating crack initiation and the device for evaluating fisstured flow | |
| CN102778554B (en) | Experimental device for improving permeability of shale gas storage layer in supercritical CO2 fracturing process | |
| CN103776979B (en) | A kind of coal seam water infusion suppresses analog detection method and the device of desorption of mash gas effect | |
| CN106896044B (en) | The multifunction experiment apparatus and method of supercritical carbon dioxide displacement coal bed methane | |
| CN110907334B (en) | Device and method for measuring radial flow oil-water relative permeability of conglomerate full-diameter core | |
| CN103674822A (en) | Gas and liquid two-phase flow loop corrosion experiment device | |
| CN101907586A (en) | High-temperature high-pressure clamp for testing rock core by nuclear magnetic resonance | |
| CN203643307U (en) | Gas-liquid two-phase loop corrosion experiment device | |
| CN203035188U (en) | Test experimental device for adhering sand casing pipe cement bond strength | |
| CN110018057A (en) | A kind of microseism-shear-seepage coupling test device and test method | |
| CN109946215A (en) | A kind of original position coal body gas absorption amount test simulator | |
| US11885186B2 (en) | High-temperature and high-pressure drilling fluid inhibition evaluation device and usage method thereof | |
| CN105241750A (en) | Pressing head system for indoor triaxial hydrofracture experiment | |
| CN203178164U (en) | Coal rock porosity-permeability electro-acoustic stress-strain combined measurement device under pressurization heating | |
| CN110529107A (en) | Coal seam strain, seepage flow, displacement and jet stream integrated experiment device and method | |
| CN114216785A (en) | Multi-field multi-phase variable frequency fracturing test device for large-size true triaxial coal rock mass | |
| CN112881230A (en) | Shale gas vibration desorption test evaluation device and method | |
| CN204214835U (en) | High Temperature High Pressure Crack Sealing plugging simulation apparatus | |
| CN109187926B (en) | Three-axis seepage test device for fractured coal rock mass and desorption-diffusion-seepage test system | |
| Zhu et al. | An experimental apparatus for supercritical CO2 fracturing of shale: system design and application tests | |
| CN202795075U (en) | Quantitative control device for releasing high-pressure fluid | |
| CN113622906B (en) | Testing device and testing method for simulating mechanical properties of ocean energy soil-well interface in hydrate exploitation process |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |