CN114062142A - High-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method - Google Patents
High-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method Download PDFInfo
- Publication number
- CN114062142A CN114062142A CN202111446968.3A CN202111446968A CN114062142A CN 114062142 A CN114062142 A CN 114062142A CN 202111446968 A CN202111446968 A CN 202111446968A CN 114062142 A CN114062142 A CN 114062142A
- Authority
- CN
- China
- Prior art keywords
- gas
- water
- pressure
- test piece
- electric pulse
- 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.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
- G01N3/10—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by pneumatic or hydraulic pressure
-
- 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
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
- G01N3/04—Chucks
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0016—Tensile or compressive
- G01N2203/0019—Compressive
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/0089—Biorheological properties
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Abstract
The invention discloses a high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method, which comprises the following steps: manufacturing a cylindrical test piece; step b: installing a test piece into a circular tube-shaped pressure chamber and connecting pipelines among systems; step c: operating the axial pressure loading module and the confining pressure loading module in sequence; step d: operating a water-gas two-phase seepage system; d, the stress of the water pressure and the air pressure applied to the test piece is less than the axial pressure and the confining pressure applied to the test piece in the step c; step e: operating the high-voltage electric pulse fracturing operation system to perform high-voltage pulse discharge to fracture the test piece; step f: and (f) detecting the flow change curves of the water and gas fluid of the test piece in the pressure-maintaining stress environment through a flow data acquisition module, respectively implementing the step f before and after the step e, judging the effect of the high-voltage electric pulse fracturing test piece by comparing the flow data of the water and gas fluid measured by the liquid flow meter and the gas flow meter in the previous and later steps, and performing a high-voltage electric pulse in-situ anti-reflection gas-containing reservoir two-phase seepage test.
Description
Technical Field
The invention relates to the field of coal bed gas (mine gas) exploitation, in particular to a high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method.
Background
The high-voltage electric pulse rock breaking technology is used as a novel reservoir permeability increasing technology and is rapidly and widely applied to the fields of oil gas exploitation, mineral processing, coal bed gas exploitation and the like in recent decades. The cracking effect of the high-voltage electric pulse is to crush the solid by using the shock wave generated in the discharge process and the mechanical effect caused by the high temperature generated in the plasma channel. In the technical field of coal bed permeability increase, the high-voltage electric pulse coal bed permeability increase technology has a series of advantages of low energy consumption, high efficiency and the like compared with the conventional coal bed permeability increase technology. At present, the high-voltage electric pulse technology has a certain effect in field application in the aspect of increasing the permeability of a coal seam, but the basic theoretical research of the permeability increasing of the coal seam caused by high-voltage electric pulse is still in an exploration stage.
Water-gas two-phase seepage is a common situation in the process of exploiting coal bed gas. In the process of coal bed gas exploitation, because the coal bed gas in the coal rock mass pore channel is desorbed and diffused by drainage and depressurization induction, the coal bed gas is transported from high potential energy to low potential energy in the fractured rock mass through osmosis. The underground water is discharged to reduce the pressure of the coal bed, the gas adsorbed in the coal rock mass begins to be separated and desorbed from the surface of the micropores, the concentration of the desorbed gas is higher near the desorption surface than that of the coal bed gas in the cracks, the coal bed gas can diffuse from a pore-microcrack system to the crack space under the corresponding concentration gradient, and the water-gas two-phase seepage condition can occur in the cracks of the rock mass due to the extensive existence of the underground water. The flowing rule of water and coal bed gas in coal is mainly related to the relative permeability of the water and the coal bed gas in a coal bed, and the permeability directly determines the exploitation effect of the coal bed gas. The control effect of the underground water on occurrence migration of the coal bed gas is obvious, and the seepage of the coal bed gas and the underground water affects each other. The research on the water-gas two-phase seepage characteristics of coal containing coal bed gas has important theoretical significance and engineering practice effect on the development and utilization of the coal bed gas.
Although the existing electric pulse fracturing and permeability increasing system realizes the research on high-voltage electric pulse fracturing coal bodies to a certain extent, the in-situ permeability increasing seepage and real-time information acquisition of a loaded test piece in the test process cannot be realized, the information acquisition amount in the test process is small, the research on the action response mechanism in the electric pulse fracturing coal body process is limited, and the ground stress environment of a coal rock body which is exploited deeply is difficult to simulate.
Disclosure of Invention
The invention aims to provide a high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method which is wider in simulation range, simple to operate and accurate in test data, and can simulate gas-bearing reservoir fracture water-gas two-phase in-situ seepage.
Therefore, the technical scheme adopted by the invention is as follows: a high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method comprises the following steps:
step a: manufacturing a cylindrical test piece;
step b: installing a test piece into a circular tube-shaped pressure chamber, and connecting pipelines among systems, wherein the pipelines include a confining pressure loading module and an axial pressure loading module;
step c: operating the axial pressure loading module and the confining pressure loading module in sequence to apply axial pressure and confining pressure to the test piece;
step d: operating a water-gas two-phase seepage system to apply water and gas pressure to the test piece; d, the stress of the water pressure and the air pressure applied to the test piece is constantly smaller than the axial pressure and the confining pressure applied to the test piece in the step c, and the hydraulic oil of the axial pressure and the confining pressure caused by overlarge pressure is prevented from being immersed into the test piece;
step e: operating the high-voltage electric pulse fracturing operation system to perform high-voltage pulse discharge to fracture the test piece;
step f: the flow data acquisition module is used for detecting the flow change curves of the water and gas fluid of the test piece in the pressure-maintaining stress environment, the step f is implemented before and after the step e respectively, the flow data of the water and gas fluid measured by the liquid flow meter and the gas flow meter in the previous and next steps are compared, so that the effect of the high-voltage electric pulse cracking test piece is judged, and the larger the flow difference value of the water and gas fluid in the previous and next steps is, the better the effect of the high-voltage electric pulse cracking test piece is proved.
Preferably, step c comprises: step c 1: hydraulic oil is output by using the shaft pressure pump, the hydraulic oil flowing out of the shaft pressure pump flows through two different shaft pressure pipelines to reach the corresponding oil cylinders, and the hydraulic oil reaching the oil cylinders pushes the multi-stage slide rods to carry out shaft pressure transmission to the test piece, so that equal stress is loaded on the upper end and the lower end of the test piece simultaneously;
step c 2: and (3) outputting hydraulic oil by using a confining pressure pump, enabling the hydraulic oil flowing out of the confining pressure pump to flow through two different confining pressure pipelines to reach the pressure chamber, closing a confining pressure channel after the pressure chamber is filled with the hydraulic oil, and applying confining pressure to the periphery of the test piece by the hydraulic oil with pressure in the pressure chamber.
More preferably, step d comprises: step d 1: opening the gas tank and the water pressure pump, setting pressurized water and gas containing different water-gas volume ratios to reach the water-gas channel through the gas pipeline and the water pressure pipeline respectively, and loading target water-gas mixed pressure for the test piece;
step d 2: continuously providing target water and gas fluid pressure for the test piece and keeping for a certain time;
step d 3: the total mixed pressure of water and gas circulation is adjusted or the percentage of gas is adjusted, and the influence of different water and gas two-phase permeation pressure conditions and different gas volume ratios on the crack water and gas two-phase permeation characteristics is respectively researched.
More preferably, step e is divided into: step e 1: communicating a high-voltage pulse power supply with the positive electrode of the high-voltage capacitor through a first lead segment;
step e 2: connecting the positive electrode of the high-voltage capacitor with a conductive bolt connected with an electrode needle at the upper end of the test piece through a second lead segment, and connecting the negative electrode of the high-voltage capacitor with a conductive bolt connected with an electrode needle at the lower end of the test piece through a third lead segment;
step e 3: the input energy is controlled by adjusting the voltage and current input values in the circuit according to the requirements, so that high-voltage electric pulses with different energies are generated to crack the test piece;
step e 4: operating the high-voltage electric pulse signal monitoring module to record the curves of pulse voltage and current of the second lead segment in the high-voltage electric pulse discharging process;
step e 5: after the pulse discharge of the high-voltage electric pulse generation module is finished, the grounding discharge rod is operated to sequentially contact the positive electrode and the negative electrode of the high-voltage capacitor, and the residual electric energy remained in the circuit is released.
Further preferably, the high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method is based on a high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test device and comprises a stress loading system, a high-voltage electric pulse fracturing operation system and a water-gas two-phase seepage system;
the stress loading system comprises a pressure chamber, an axial pressure loading module and a confining pressure loading module; the pressure chamber is of a circular tube structure, and a test piece is arranged in the middle of the pressure chamber; the axial compression loading module comprises an axial compression pump, a first slide bar, a second slide bar, a third slide bar, a fourth slide bar, a fifth slide bar, an oil cylinder and an axial compression pipeline, wherein the first slide bar, the second slide bar, the third slide bar, the fourth slide bar, the fifth slide bar, the oil cylinder and the axial compression pipeline are symmetrically arranged at the upper end and the lower end of a test piece and are sequentially connected; the confining pressure loading module comprises a confining pressure pump, an isolation rubber sleeve and two confining pressure pipelines, wherein two confining pressure channels are symmetrically formed in the side wall of the pressure chamber from top to bottom, one end of each confining pressure pipeline is connected with the confining pressure pump, the other end of each confining pressure pipeline is connected into the inner cavity of the test piece through the corresponding confining pressure channel to provide confining pressure for the periphery of the test piece, the isolation rubber sleeve is wrapped outside the two first slide bars and the test piece, and a sealing ring is arranged between the isolation rubber sleeve and the first slide bars to prevent hydraulic oil from being immersed into the test piece through the upper end and the lower end of the isolation rubber sleeve;
the high-voltage electric pulse fracturing operation system comprises a high-voltage electric pulse generating module, a high-voltage electric pulse signal monitoring module and a protection module; the high-voltage electric pulse generating module comprises a high-voltage pulse power supply, a high-voltage capacitor, a high-voltage electric pulse switch, a first lead section, a second lead section, a third lead section, an electrode needle and an air-guiding liquid-guiding conductive bolt; the high-voltage pulse power supply charges the high-voltage capacitor through the first lead segment, the upper end and the lower end of the test piece are both provided with an electrode needle and an air-guiding and liquid-guiding conductive bolt, one end of the electrode needle is abutted against the test piece, the other end of the electrode needle sequentially and coaxially penetrates through the first slide bar, the second slide bar and the third slide bar and then is inserted into a blind hole of the fourth slide bar, one end of the air-guiding and liquid-guiding conductive bolt is connected with the electrode needle, the other end of the air-guiding and liquid-guiding conductive bolt transversely penetrates out of the fourth slide bar, the upper air-guiding and liquid-guiding conductive bolt is connected with the anode of the high-voltage capacitor through the second lead segment, the lower air-guiding and liquid-guiding conductive bolt is connected with the cathode of the high-voltage capacitor through the third lead segment, and the second lead segment is connected with a high-voltage pulse switch in series; the high-voltage electric pulse signal monitoring module comprises a Rogowski coil, a high-voltage probe and an oscilloscope, the Rogowski coil is sleeved on the third lead section, the high-voltage probe is connected in series on the third lead section, and the Rogowski coil and monitoring signals of the high-voltage probe are connected to the oscilloscope through signal transmission lines; the protection module comprises an electromagnetic shielding field and is used for isolating high-energy static electricity generated by a high-voltage electric pulse fracturing operation system in the electromagnetic shielding field;
the water-gas two-phase seepage system comprises a water-gas pressure loading module and a flow data acquisition module, wherein the water-gas pressure loading module comprises a gas tank, a water pressure pump, a gas pipeline, a water pressure pipeline, a water-gas pipeline and a water-gas collection container, the diameter of the electrode needle is smaller than the inner diameter of the sliding rod which penetrates through the electrode needle to form the water-gas channel, the two water-gas channels are tightly attached to a test piece, the gas-guiding and liquid-guiding conducting bolt is of a hollow rod structure, the inner side end of the gas-guiding and liquid-guiding conducting bolt located above the gas-gas pressure loading module is communicated with the water-gas channel, the outer side end of the gas-guiding and liquid-guiding conducting bolt located below the gas-gas loading module is connected with the water-gas channel through the water-gas pipeline, the inner side end of the gas-guiding and liquid-gas-guiding conducting bolt located below the gas-gas loading module is communicated with the water-gas channel, and the outer side end of the water-gas tank is connected with the water outlet of the water pressure pump through the water pressure pipeline; the flow data acquisition module comprises a gas flowmeter arranged on a gas pipeline and a liquid flowmeter arranged on a water pressure pipeline.
The high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test device has the following technical characteristics:
(1) the stress loading system comprises a pressure chamber, an axial pressure loading module and a confining pressure loading module, the rest parts except an axial pressure pump, a confining pressure pump, an axial pressure pipeline and an axial pressure pipeline form a core holder whole body, the whole core holder is integrally arranged on an insulating fixed base, and a high-voltage electric pulse fracturing operation system and a water-gas two-phase seepage system are combined on the basis, so that a water-gas two-phase real-time seepage test can be carried out after high-voltage electric pulses in a pressure maintaining state and a loading process, the influence on a test piece in the process of stress unloading and test piece assembling and disassembling is avoided, the macro-micro analysis can be conveniently carried out on coal bodies more accurately, and the research result can provide advanced and reliable support for the anti-reflection technology of a high-voltage coal bed and the basic research of coal bed gas exploitation;
(2) the core holder is detachably arranged on the insulating fixed base, can be transferred or used for nuclear magnetic resonance detection and the like in a pressure maintaining state, provides a foundation for multi-aspect analysis of a test piece, and further provides a more complete basic theoretical analysis condition for the high-voltage electric pulse coal bed permeability increasing technology;
(3) the multistage slide bar is combined with the oil cylinder to provide equal axial pressure loading for the test piece, the slide bar with the larger diameter is ensured to be in sliding fit with the pressure chamber, the slide bar with the smaller diameter can reduce the influence of pipe wall friction on the axial pressure loading, the hole is formed in the side wall of the oil cylinder, and the transmission of the axial pressure is realized through the multistage slide bar, so that the processing and the replacement of a single slide bar are facilitated, and the disassembly and the assembly of the test piece in the test process are facilitated; holes are formed in the upper end and the lower end of the pressure chamber at intervals to serve as confining pressure supply channels, and an isolation rubber sleeve and a sealing ring are combined to prevent hydraulic oil from being immersed into a test piece through the upper end and the lower end of the isolation rubber sleeve, so that the structure is simple, and loading is reliable; the axial pressure loading ingeniously utilizes the side wall opening of the oil cylinder, the confining pressure loading ingeniously utilizes the side wall opening of the pressure chamber, the whole layout is reasonable, compact, simple and easy to control, the confining pressure and the axial pressure loaded at the same time are high, the research on high-voltage electric pulse fracturing of coal rock mass under the deep stress environment can be carried out, the maximum 100kV high-voltage electric pulse output is realized, the maximum confining pressure is 60MPa, and the maximum confining pressure is far higher than the condition that the current can only meet the 25kV high-voltage electric pulse output and is below 10 MPa;
(4) the upper end and the lower end of the test piece are both provided with an electrode needle and an air guide liquid guide conductive bolt, so that high-voltage electric pulses are introduced into the test piece, the electrode needle and the air guide liquid guide conductive bolt are both installed by utilizing multistage transmission slide bars, and all the slide bars for installing the electrode needle are high-density insulating bars in consideration of insulation; in addition, the key part of the whole system is arranged in an electromagnetic shielding field and used for isolating high-energy static electricity generated by a high-voltage electric pulse fracturing operation system, and the system is safe and reliable.
(5) The air guide liquid guide conductive bolt is a hollow rod made of a conductive material, can conduct electricity and conduct air and liquid, forms a water-gas channel by limiting the diameter of an electrode needle to be smaller than the inner diameter of a sliding rod which penetrates through the hollow rod, and is tightly attached to a test piece, so that air guide and liquid guide are carried out, the space structure is fully and skillfully utilized for arrangement, and the whole system structure is more compact and reasonable.
Preferably, the gas pipeline and the water pressure pipeline are respectively provided with a one-way valve, the gas pipeline, the water pressure pipeline and the water-gas pipeline are respectively provided with a stop valve, and the gas tank, the water pressure pump, the axial pressure pump and the confining pressure pump are arranged outside the electromagnetic shielding field.
Preferably, the electrode needle is provided with a platform for inserting the air-guiding and liquid-guiding conductive bolt for surface-mounted conduction, and the air-guiding and liquid-guiding conductive bolt is separated from the fourth slide bar by a stainless steel sealing sleeve; the diameter of the air guide liquid guide conductive bolt is larger than the width of a platform arranged on the electrode needle, or a communicating hole is arranged on the side wall of the inner side end of the air guide liquid guide conductive bolt, so that the hollow part of the air guide liquid guide conductive bolt is communicated with the water-gas channel; the air inlet and the water inlet of the air guide and liquid guide conductive bolt positioned below form a Y-shaped channel with the hollow part. If the air guide liquid guide conductive bolt is in point contact with the electrode needle, the contact point position can generate discharge in the electric pulse process, and the surface-mounted installation is adopted, so that the electric arc generated by point contact is effectively prevented from influencing the discharge effect.
Preferably, the first sliding rod, the second sliding rod, the third sliding rod and the fourth sliding rod are high-density insulating rods, and the axial compression pump adopts a displacement precision injection pump with a servo control system.
In order to ensure the electricity safety in the test process, the first lead section, the second lead section and the third lead section are wrapped by insulating materials meeting the 100kV insulation standard, and the joints of the second lead section and the third lead section and the air-guiding liquid-guiding conductive bolts are completely wrapped by insulating tapes meeting the 100kV insulation standard.
Preferably, the end part of the electrode needle, which is in contact with the test piece, is designed into a circular truncated cone shape, and the other end of the electrode needle is tightly abutted through a compression spring arranged in a blind hole of the fourth sliding rod, so that the test piece of the electrode needle is ensured to be tightly attached all the time.
Preferably, a positioning circular truncated cone is arranged at the center of the top of the insulating fixing base, and a positioning groove for the positioning circular truncated cone to be inserted into is formed at the center of the bottom of the oil cylinder at the lower end.
Preferably, the contact position of the fourth slide bar and the fifth slide bar is installed in a matched mode through a positioning circular truncated cone and a positioning groove.
Preferably, before loading, the far end of the second slide bar is flush with the end of the pressure chamber, the confining pressure channel is opposite to the near end of the second slide bar, the axial pressure channel is opposite to the far end of the fifth slide bar, and the near end of the fifth slide bar extends out of the oil cylinder.
Preferably, the outer diameter of the stainless steel sealing sleeve is enlarged at the far end position to be used as a flanging, and the flanging just covers the outer wall of the fourth sliding rod, so that the pressing-in installation is convenient, and the pressing-in is controlled to be in place through the flanging; the stainless steel sealing sleeve has small inner diameter near end and large far end, and a step surface is formed in the middle of the length; correspondingly, the section of the air guide and liquid guide conductive bolt in the fourth slide bar is small at the near end and large at the far end; and the section of the air-guiding, liquid-guiding and electric-conducting bolt, which is positioned outside the fourth sliding rod, is provided with a circumferential groove for winding and connecting the corresponding second wire section or third wire section.
The invention has the beneficial effects that: and performing a two-phase seepage test of the permeability-increasing gas-bearing reservoir by simulating an electric pulse action coal body test under different stresses, different voltages and other conditions and simulating a high-voltage electric pulse fracturing coal body physical test under the coupling action of multiple physical fields. The development rule and the phase response characteristics of the pore cracks after the gas-containing coal high-voltage electric pulse technology is acted are accurately and deeply researched, the internal mechanism and the essence of multi-field coupling of an electric field, a stress field and the like in the action process are disclosed, and theoretical support and engineering parameter guidance are provided for using the high-voltage electric pulse to crack the coal body and improving the exploitation efficiency of the coal bed gas.
Drawings
FIG. 1 is a schematic structural diagram of a high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test device.
FIG. 2 is a cross-sectional view of a pressure chamber of a high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test device.
Fig. 3 is a partially enlarged view of a in fig. 2.
Fig. 4 is a partially enlarged view of B in fig. 2.
The device comprises a test piece 1, a pressure chamber 2, a shaft-pressure pump 3, an oil cylinder 4, a shaft-pressure pipeline 5, a first slide rod 6, a second slide rod 7, a third slide rod 8, a fourth slide rod 9, a fifth slide rod 10, a confining pressure pump 11, an isolating rubber sleeve 12, a confining pressure pipeline 13, a sealing ring 14, a high-voltage pulse power supply 15, a high-voltage capacitor 16, a high-voltage electric pulse switch 17, a first lead section 18, a second lead section 19, a third lead section 20, an electrode needle 21, an air-guide liquid-guide conductive bolt 22, a stainless steel sealing sleeve 23, a Rogowski coil 24, a high-voltage probe 25, an oscilloscope 26, an electromagnetic shielding field 27, a gas tank 28, a water pressure pump 29, a gas pipeline 30, a water pressure pipeline 31, a water-gas pipeline 32, a water-gas pipeline 33, a compression spring 34 water-gas collecting container 35, a gas flowmeter 36, a liquid flowmeter 37, a one-way valve 38 and an insulating fixing base 39.
Detailed Description
The invention will be further illustrated by the following examples in conjunction with the accompanying drawings:
referring to fig. 1-4, a high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test device mainly comprises a stress loading system, a high-voltage electric pulse fracturing operation system and a water-gas two-phase seepage system.
The stress loading system mainly comprises a pressure chamber 2, an axial pressure loading module and a confining pressure loading module.
The axial compression loading module is composed of an axial compression pump 3, a first slide bar 6, a second slide bar 7, a third slide bar 8, a fourth slide bar 9, a fifth slide bar 10, an oil cylinder 4 and an axial compression pipeline 5 which are symmetrically arranged at the upper end and the lower end of the test piece 1 and are sequentially connected. The second slide bar 7 is in sliding fit with the pressure chamber 2, the diameters of the first slide bar 6, the third slide bar 8 and the fourth slide bar 9 are all smaller than the diameter of the second slide bar 7, and the fifth slide bars 10 extend into the corresponding oil cylinders 4 to be in sliding fit. A shaft pressure channel 4a is formed in the side wall of the oil cylinder 4, one end of a shaft pressure pipeline 5 is connected with the shaft pressure pump 3, the other end of the shaft pressure pipeline is connected into the corresponding oil cylinder 4 through the shaft pressure channel 4a, and shaft pressure which is equal to the shaft pressure of the test piece 1 is provided for the test piece 1 through all the slide bars (a first slide bar 6, a second slide bar 7, a third slide bar 8, a fourth slide bar 9 and a fifth slide bar 10 transmit the shaft pressure in sequence).
In order to prevent high-voltage electric energy from dissipating, the first slide bar 6, the second slide bar 7, the third slide bar 8 and the fourth slide bar 9 are high-density insulating bars. In order to realize accurate control of axial compression loading, the axial compression pump 3 adopts a displacement precision injection pump with a servo control system. In addition, the contact position of the fourth slide bar 9 and the fifth slide bar 10 is installed in a matching way through a positioning circular table and a positioning groove.
When the axial pressure is loaded, hydraulic oil flowing out of the axial pressure pump flows through the axial pressure pipeline to reach the oil cylinder, the hydraulic oil reaching the oil cylinder pushes the multi-stage slide rods to be sequentially transmitted to the test piece, and the effect of loading the axial pressure is achieved.
The confining pressure loading module comprises a confining pressure pump 11, an isolation rubber sleeve 12, two confining pressure pipelines 13 and the like. Two confining pressure channels 2a are symmetrically arranged on the side wall of the pressure chamber 2 up and down, one end of a confining pressure pipeline 13 is connected with a confining pressure pump 11, and the other end of the confining pressure pipeline is connected into the inner cavity of the test piece 1 through the corresponding confining pressure channel 2a to provide confining pressure for the periphery of the test piece 1. In order to enhance the sealing effect and ensure the smooth proceeding of the test, the isolation rubber sleeve 12 is wrapped outside the two first sliding rods 6 and the test piece 1, and a sealing ring 14 is arranged between the isolation rubber sleeve 12 and the first sliding rods 6 to prevent the hydraulic oil from immersing into the test piece 1 through the upper end and the lower end of the isolation rubber sleeve 12, so that the high-voltage electric pulse fails to discharge the test piece.
When confining pressure is loaded, hydraulic oil flows through a confining pressure pipeline through a confining pressure pump to reach a pressure chamber, a confining pressure channel is closed after the pressure chamber is filled with the hydraulic oil, and the confined pressure is applied to the periphery of a test piece by the hydraulic oil with pressure in the pressure chamber.
Preferably, before loading, the far end of the second slide bar 7 is flush with the end of the pressure chamber 2, the confining pressure channel 2a is opposite to the near end of the second slide bar 7, the axial pressure channel 4a is opposite to the far end of the fifth slide bar 10, and the near end of the fifth slide bar 10 extends out of the oil cylinder 4, so that the installation and control are convenient.
The high-voltage electric pulse fracturing operation system mainly comprises a high-voltage electric pulse generating module, a high-voltage electric pulse signal monitoring module and a protection module.
The high-voltage electric pulse generating module consists of a high-voltage pulse power supply 15, a high-voltage capacitor 16, a high-voltage electric pulse switch 17, a first lead section 18, a second lead section 19, a third lead section 20, an electrode needle 21 and an air-guiding, liquid-guiding and electric-conducting bolt 22. A high voltage pulsed power supply 15 charges a high voltage capacitor 16 through a first wire segment 18. The upper and lower ends of the test piece 1 are equipped with an electrode needle 21 and an air guide, liquid guide and conductive bolt 22. One end of the electrode needle 21 is abutted against the test piece 1, and the other end of the electrode needle is inserted into a blind hole of the fourth slide bar 9 after sequentially coaxially penetrating through the first slide bar 6, the second slide bar 7 and the third slide bar 8. A blind hole is formed in the fourth slide bar 9, and through holes are formed in the first slide bar 6, the second slide bar 7 and the third slide bar 8 for the electrode needle 21 to pass through. One end of the air guide and liquid guide conductive bolt 22 is connected with the electrode needle 21, the other end of the air guide and liquid guide conductive bolt transversely penetrates out of the fourth sliding rod 9, the upper air guide and liquid guide conductive bolt 22 is connected with the positive electrode of the high-voltage capacitor 16 through the second lead section 19, and the lower air guide and liquid guide conductive bolt 22 is connected with the negative electrode of the high-voltage capacitor 16 through the third lead section 20. The second wire segment 19 is connected in series with a high-voltage electric pulse switch 17.
Preferably, the first, second and third wire segments 18, 19, 20 are wrapped with an insulating material meeting the insulation standard of 100kV, and the joints between the second and third wire segments 19, 20 and the air and liquid guiding conductive bolts 22 are completely wrapped with an insulating tape meeting the insulation standard of 100 kV.
In addition, the end part of the electrode needle 21, which is in contact with the test piece 1, is designed into a circular truncated cone shape, the other end of the electrode needle 21 is tightly propped against the test piece through a compression spring 33 installed in a blind hole of the fourth sliding rod 9, the electrode needle is ensured to be in close contact with the test piece, and the electrode is prevented from damaging the end part of the test piece in the axial compression loading process while discharging in a concentrated manner. The electrode needles at the upper and lower ends of the test piece need to be made of metal materials with good electrical conductivity.
The electrode needle 21 is provided with a platform for inserting the air guide and liquid guide conductive bolt 22 for surface-mounted conduction, and the air guide and liquid guide conductive bolt 22 is separated from the fourth slide bar 9 by a stainless steel sealing sleeve 23. The outer diameter of the stainless steel sealing sleeve 23 is enlarged at the far end position to be used as a flanging 23a, and the flanging 23a just covers the outer wall of the fourth sliding rod 9; the stainless steel sealing sleeve 23 has a small inner diameter near end and a large distal end, and a step surface is formed in the middle of the length; correspondingly, the section of the air-guiding liquid-guiding conducting bolt 22 located in the fourth sliding rod 9 is small at the near end and large at the far end; the section of the air, liquid and electricity conducting bolt 22 outside the fourth sliding rod 9 is provided with a circumferential groove 22a for winding and connecting the corresponding second wire segment 19 or third wire segment 20.
The high-voltage electric pulse signal monitoring module consists of a Rogowski coil 24, a high-voltage probe 25 and an oscilloscope 26. The Rogowski coil 24 is sleeved on the third lead section 20, and the high-voltage probe 25 is connected in series on the third lead section 20 to test a circuit voltage change signal in the high-voltage pulse discharging process. The monitoring signals of the Rogowski coil 24 and the high-voltage probe 25 are connected to an oscilloscope 26 through signal transmission lines. The Rogowski coil and the high-voltage probe monitoring signal are transmitted to the oscilloscope through the signal transmission line, the waveforms of the pulse current and the pulse voltage are displayed on the screen of the oscilloscope and stored into a data file, comparison and analysis of historical pulse current and voltage data are conveniently carried out, and the optimal pulse current and voltage waveform of the high-voltage electric pulse fracturing test piece is determined. And subsequently, the optimal pulse current and voltage waveform are reduced by adjusting the discharge form of the high-voltage electric pulse generation module, so that the parameter reduction of the optimal high-voltage electric pulse cracking effect of the test piece is realized.
Because the induction of the Rogowski coil is sensitive, the place where the Rogowski coil is not easy to touch in the test process is selected as much as possible, and meanwhile, the Rogowski coil and the second lead segment keep a certain distance, so that the electromagnetic interference in the pulse current signal data acquisition process is reduced.
The main body of the protection module is an electromagnetic shielding field 27, and because high-energy static electricity generated by the high-voltage electric pulse cracking operation system can threaten the life of a human body, the electromagnetic shielding field needs to be established, the high-energy static electricity generated by the high-voltage electric pulse cracking operation system generated in the test process is isolated in the electromagnetic shielding field, and the health and safety of operators in the test process are guaranteed.
In addition, the pressure chamber 2 is detachably mounted on the insulating fixing base 39, a positioning circular truncated cone is arranged at the center of the top of the insulating fixing base 39, and a positioning groove for the positioning circular truncated cone to be inserted is formed at the center of the bottom of the oil cylinder 4 at the lower end.
The high-voltage pulse power supply is connected with the high-voltage capacitor through the first lead segment, the input energy of the high-voltage pulse circuit system can be controlled by adjusting the voltage and current input values in the input circuit according to requirements during experiments, so that high-voltage electric pulses with different energies are generated to carry out pulse discharge fracturing on a test piece, and the optimal fracturing parameters of a coal layer containing gas are determined by comparing the fracturing effects of the different high-voltage pulse input energies on the test piece. In the process of charging the high-voltage capacitor, the charging current and voltage can be remotely operated and adjusted, and the safety and reliability of the test process are ensured.
The high-voltage capacitor adopts a mode of parallel connection of combined capacitors and a method of selecting capacity, and changes capacitance parameters in the high-voltage electric pulse circuit by changing the number of different access capacitors.
The high-voltage electric pulse switch is connected with the second lead segment in series, and the release of the high-voltage electric pulse to the energy of the test piece is realized by controlling the closing of the high-voltage electric pulse switch. After the high-voltage pulse power supply charges the voltage meeting the test requirement to the high-voltage capacitor, the high-voltage electric pulse switch is closed, so that the high-voltage capacitor releases specific high-voltage pulse energy to act on the test piece in a short time. The frequency of the pulse discharge action of the high-voltage pulse energy on the test piece can be controlled by controlling the closing frequency of the high-voltage electric pulse switch, so that the research on the cracking effect of the test piece by the high-voltage pulse energy with specific frequency is realized.
The water-gas two-phase seepage system consists of a water-gas pressure loading module and a flow data acquisition module.
The water pressure loading module mainly comprises a gas tank 28, a water pressure pump 29, a gas pipeline 30, a water pressure pipeline 31, a water-gas pipeline 32 and a water-gas collecting container 34. The diameter of the electrode needle 21 is smaller than the inner diameter of the slide rod, so that a water vapor channel is formed between the electrode needle and the slide rod. Both water and gas channels are tightly attached to the test piece 1. The air guide, liquid guide and electric conduction bolt 22 is of a hollow rod structure, and is hollow for water vapor to pass through. The inner end of the upper air guide and liquid guide conductive bolt 22 is communicated with the upper water vapor channel, and the outer end is connected with a water vapor collecting container 34 through a water vapor pipeline 32. The inner side end of the air guide and liquid guide conductive bolt 22 positioned below is communicated with the water-gas channel below, and the outer side end is respectively provided with an air inlet and a water inlet; wherein the air inlet is connected with the air outlet of the air tank 28 through an air pipeline 30, and the water inlet is connected with the water outlet of the hydraulic pump 29 through a hydraulic pipeline 31. The flow data acquisition module comprises a gas flowmeter 35 arranged on the gas pipeline 30 and a liquid flowmeter 36 arranged on the water pressure pipeline 31.
Preferably, the gas pipeline 30 and the water pressure pipeline 31 are respectively provided with a one-way valve 37, the gas pipeline 30, the water pressure pipeline 31 and the water vapor pipeline 32 are respectively provided with a stop valve 38, and the gas tank 28, the water pressure pump 29, the axial pressure pump 3 and the confining pressure pump 11 are arranged outside the electromagnetic shielding field 27.
In addition, the electrode needle 21 is provided with a platform for inserting the air guiding and liquid guiding conductive bolt 22 for surface-mounted conduction, thereby conducting electricity. The air guide, liquid guide and electric conduction bolt 22 is separated from the fourth sliding rod 9 by a stainless steel sealing sleeve 23. The diameter of the air guide liquid guide conductive bolt 22 is larger than the width of the platform arranged on the electrode needle 21, or a communicating hole is arranged on the side wall of the inner side end of the air guide liquid guide conductive bolt 22, so that the hollow part of the air guide liquid guide conductive bolt 22 is communicated with the water-gas channel. The air inlet and the water inlet of the air guide and liquid guide conductive bolt 22 positioned below and the hollow form a Y-shaped channel.
In the process of a water-gas two-phase seepage characteristic test, coal bed gas containing certain pressure is released from a gas tank and reaches the gas inlet of a gas guide and liquid guide conducting bolt below through a gas pipeline, a pressure-containing water body flows out of a pressure pump and reaches the water inlet of the gas guide and liquid guide conducting bolt through a water pressure pipeline, the pressure-containing gas and the pressure-containing water body are mixed in the hollow of the gas guide and liquid guide conducting bolt, and a water-gas mixed fluid passes through an electrode needle below and forms a water-gas channel with a sliding rod penetrating through the hollow of the gas guide and liquid guide conducting bolt to reach the lower end of a test piece. Different two-phase seepage pressure is provided for the test piece by adjusting the water-air volume ratio provided by the air tank and the water pressure pump. The water-vapor mixed fluid which seeps through the test piece reaches the top end of the test piece from the bottom end of the test piece, a water-vapor channel is formed between the upper electrode needle and the sliding rod, and the hollow water-vapor pipeline of the air guide liquid guide conductive bolt flows into the water-vapor collecting container.
In the single-phase fluid seepage characteristic test, the research on the coal body fracturing at the high-voltage electric pulse position under different gas pressures can be simulated by adjusting the valve of the gas tank, and the coal body fracturing test under the high-voltage electric pulse condition under different fluid pressure conditions can be carried out by adjusting the water outlet flow of the hydraulic pump, so that the test device has more comprehensive engineering condition simulation capability.
A high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method is based on the high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test device and comprises the following steps:
step a: and (5) manufacturing a cylindrical test piece.
Step b: and installing the test piece into the circular-tube-shaped pressure chamber, and connecting pipelines among systems, wherein the pipelines comprise a confining pressure loading module and an axial pressure loading module.
Step c: and operating the axial pressure loading module and the confining pressure loading module in sequence to apply axial pressure and confining pressure to the test piece.
The step c comprises the following steps:
step c 1: hydraulic oil is output by using the shaft pressure pump, the hydraulic oil flowing out of the shaft pressure pump flows through two different shaft pressure pipelines to reach the corresponding oil cylinders, and the hydraulic oil reaching the oil cylinders pushes the multi-stage slide rods to carry out shaft pressure transmission to the test piece, so that equal stress is loaded on the upper end and the lower end of the test piece simultaneously;
step c 2: and (3) outputting hydraulic oil by using a confining pressure pump, enabling the hydraulic oil flowing out of the confining pressure pump to flow through two different confining pressure pipelines to reach the pressure chamber, closing a confining pressure channel after the pressure chamber is filled with the hydraulic oil, and applying confining pressure to the periphery of the test piece by the hydraulic oil with pressure in the pressure chamber.
Step d: operating a water-gas two-phase seepage system to apply water and gas pressure to the test piece; and d, keeping the stress of the water pressure and the air pressure applied to the test piece smaller than the axial pressure and the confining pressure applied to the test piece in the step c, and preventing the hydraulic oil of the axial pressure and the confining pressure from being immersed into the test piece due to overlarge pressure.
Step d comprises the following steps:
step d 1: opening the gas tank and the water pressure pump, setting pressurized water and gas containing different water-gas volume ratios to reach the water-gas channel through the gas pipeline and the water pressure pipeline respectively, and loading target water-gas mixed pressure for the test piece;
step d 2: continuously providing target water and gas fluid pressure for the test piece and keeping for a certain time;
step d 3: the total mixed pressure of water and gas circulation is adjusted or the percentage of gas is adjusted, and the influence of different water and gas two-phase permeation pressure conditions and different gas volume ratios on the crack water and gas two-phase permeation characteristics is respectively researched.
Step e: and operating the high-voltage electric pulse fracturing operation system to perform high-voltage pulse discharge to fracture the test piece.
Step e comprises the following steps:
step e 1: communicating a high-voltage pulse power supply with the positive electrode of the high-voltage capacitor through a first lead segment;
step e 2: connecting the positive electrode of the high-voltage capacitor with a conductive bolt connected with an electrode needle at the upper end of the test piece through a second lead segment, and connecting the negative electrode of the high-voltage capacitor with a conductive bolt connected with an electrode needle at the lower end of the test piece through a third lead segment;
step e 3: the input energy is controlled by adjusting the voltage and current input values in the circuit according to the requirements, so that high-voltage electric pulses with different energies are generated to crack the test piece; the voltage in the high-voltage electric pulse voltage monitoring signal display circuit is lower than 0.4kV to mark the end of high-voltage electric pulse discharge, and the next operation can be carried out.
Step e 4: operating the high-voltage electric pulse signal monitoring module to record the curves of pulse voltage and current of the second lead segment in the high-voltage electric pulse discharging process; the current in the electric pulse breakdown process can reach thousands of amperes, a common instrument cannot meet the measurement requirement, and special high-voltage equipment is required, so that a high-voltage probe is adopted to monitor the pulse voltage curve of the high-voltage electric pulse discharge loop, a Rogowski coil is adopted to monitor the current curve of the high-voltage electric pulse discharge loop, and the current curve is stored in an oscilloscope through a data transmission line and displayed on a screen of the oscilloscope. And subsequently, the optimal pulse current and voltage waveform are reduced by adjusting the discharge form of the high-voltage electric pulse generation module, so that the optimal high-voltage electric pulse cracking effect of the test piece 1 is subjected to parameter reduction.
Step e 5: after the pulse discharge of the high-voltage electric pulse generation module is finished, the grounding discharge rod is operated to sequentially contact the positive electrode and the negative electrode of the high-voltage capacitor, and the residual electric energy remained in the circuit is released.
Step f: the flow data acquisition module is used for detecting the flow change curves of the water and gas fluid of the test piece in the pressure-maintaining stress environment, the step f is implemented before and after the step e respectively, the flow data of the water and gas fluid measured by the liquid flow meter and the gas flow meter in the previous and next steps are compared, so that the effect of the high-voltage electric pulse cracking test piece is judged, and the larger the flow difference value of the water and gas fluid in the previous and next steps is, the better the effect of the high-voltage electric pulse cracking test piece is proved.
In the scheme, the axle pressure loading module, the confining pressure loading module, the high-voltage electric pulse generating module and the high-voltage electric pulse signal monitoring module are all required to be grounded, so that static electricity generated by discharge of high-voltage electric pulses in the device is completely communicated underground.
At the moment that the high-voltage electric pulse fractures the test piece, because the second lead section, the third lead section, the electrode needle, the test piece, the high-voltage capacitor and the high-voltage electric pulse switch form a closed circuit, bright electric arcs can be generated at a closed contact of the high-voltage electric pulse switch, and the normal phenomenon is achieved.
Claims (10)
1. A high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method is characterized by comprising the following steps of:
step a: manufacturing a cylindrical test piece;
step b: installing a test piece into a circular tube-shaped pressure chamber, and connecting pipelines among systems, wherein the pipelines include a confining pressure loading module and an axial pressure loading module;
step c: operating the axial pressure loading module and the confining pressure loading module in sequence to apply axial pressure and confining pressure to the test piece;
step d: operating a water-gas two-phase seepage system to apply water and gas pressure to the test piece; d, the stress of the water pressure and the air pressure applied to the test piece is constantly smaller than the axial pressure and the confining pressure applied to the test piece in the step c, and the hydraulic oil of the axial pressure and the confining pressure caused by overlarge pressure is prevented from being immersed into the test piece;
step e: operating the high-voltage electric pulse fracturing operation system to perform high-voltage pulse discharge to fracture the test piece;
step f: the flow data acquisition module is used for detecting the flow change curves of the water and gas fluid of the test piece in the pressure-maintaining stress environment, the step f is implemented before and after the step e respectively, the flow data of the water and gas fluid measured by the liquid flow meter and the gas flow meter in the previous and next steps are compared, so that the effect of the high-voltage electric pulse cracking test piece is judged, and the larger the flow difference value of the water and gas fluid in the previous and next steps is, the better the effect of the high-voltage electric pulse cracking test piece is proved.
2. The high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method according to claim 1, wherein the step c comprises the following steps:
step c 1: hydraulic oil is output by using the shaft pressure pump, the hydraulic oil flowing out of the shaft pressure pump flows through two different shaft pressure pipelines to reach the corresponding oil cylinders, and the hydraulic oil reaching the oil cylinders pushes the multi-stage slide rods to carry out shaft pressure transmission to the test piece, so that equal stress is loaded on the upper end and the lower end of the test piece simultaneously;
step c 2: and (3) outputting hydraulic oil by using a confining pressure pump, enabling the hydraulic oil flowing out of the confining pressure pump to flow through two different confining pressure pipelines to reach the pressure chamber, closing a confining pressure channel after the pressure chamber is filled with the hydraulic oil, and applying confining pressure to the periphery of the test piece by the hydraulic oil with pressure in the pressure chamber.
3. The high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method according to claim 1, wherein the step d comprises the following steps:
step d 1: opening the gas tank and the water pressure pump, setting pressurized water and gas containing different water-gas volume ratios to reach the water-gas channel through the gas pipeline and the water pressure pipeline respectively, and loading target water-gas mixed pressure for the test piece;
step d 2: continuously providing target water and gas fluid pressure for the test piece and keeping for a certain time;
step d 3: the total mixed pressure of water and gas circulation is adjusted or the percentage of gas is adjusted, and the influence of different water and gas two-phase permeation pressure conditions and different gas volume ratios on the crack water and gas two-phase permeation characteristics is respectively researched.
4. The high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method according to claim 1, wherein the step e comprises the following steps:
step e 1: communicating a high-voltage pulse power supply with the positive electrode of the high-voltage capacitor through a first lead segment;
step e 2: connecting the positive electrode of the high-voltage capacitor with a conductive bolt connected with an electrode needle at the upper end of the test piece through a second lead segment, and connecting the negative electrode of the high-voltage capacitor with a conductive bolt connected with an electrode needle at the lower end of the test piece through a third lead segment;
step e 3: the input energy is controlled by adjusting the voltage and current input values in the circuit according to the requirements, so that high-voltage electric pulses with different energies are generated to crack the test piece;
step e 4: operating the high-voltage electric pulse signal monitoring module to record the curves of pulse voltage and current of the second lead segment in the high-voltage electric pulse discharging process;
step e 5: after the pulse discharge of the high-voltage electric pulse generation module is finished, the grounding discharge rod is operated to sequentially contact the positive electrode and the negative electrode of the high-voltage capacitor, and the residual electric energy remained in the circuit is released.
5. The high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method according to claim 1, which is based on a high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test device and comprises a stress loading system, a high-voltage electric pulse fracturing operation system and a water-gas two-phase seepage system;
the stress loading system comprises a pressure chamber (2), an axial pressure loading module and a confining pressure loading module; the pressure chamber (2) is of a circular tube structure, and a test piece (1) is arranged in the pressure chamber (2) in the middle; the axial compression loading module comprises an axial compression pump (3), a first slide bar (6), a second slide bar (7), a third slide bar (8), a fourth slide bar (9), a fifth slide bar (10), an oil cylinder (4) and an axial compression pipeline (5) which are symmetrically arranged at the upper end and the lower end of the test piece (1) and are sequentially connected, wherein the second slide bar (7) is in sliding fit with the pressure chamber (2), the diameters of the first slide bar (6), the third slide bar (8) and the fourth slide bar (9) are all smaller than that of the second slide bar (7), and the fifth slide bar (10) extends into the oil cylinder (4) which respectively corresponds to the first slide bar, the second slide bar (7), the third slide bar and the fourth slide bar (9), a shaft pressing channel (4a) is formed in the side wall of the oil cylinder (4), one end of the shaft pressing pipeline (5) is connected with the shaft pressing pump (3), the other end of the shaft pressing pipeline is connected into the corresponding oil cylinder (4) through the shaft pressing channel (4a), and the shaft pressing channel provides equal shaft pressing for the test piece (1) through all the sliding rods; the confining pressure loading module comprises a confining pressure pump (11), an isolation rubber sleeve (12) and two confining pressure pipelines (13), wherein two confining pressure channels (2a) are symmetrically formed in the side wall of the pressure chamber (2) from top to bottom, one end of each confining pressure pipeline (13) is connected with the confining pressure pump (11), the other end of each confining pressure pipeline is connected into an inner cavity of the test piece (1) through the corresponding confining pressure channel (2a) to provide confining pressure for the periphery of the test piece (1), the isolation rubber sleeve (12) is wrapped outside the two first sliding rods (6) and the test piece (1), and a sealing ring (14) is arranged between the isolation rubber sleeve (12) and the first sliding rod (6) to prevent hydraulic oil from being immersed into the test piece (1) through the upper end and the lower end of the isolation rubber sleeve (12);
the high-voltage electric pulse fracturing operation system comprises a high-voltage electric pulse generating module, a high-voltage electric pulse signal monitoring module and a protection module; the high-voltage electric pulse generating module comprises a high-voltage pulse power supply (15), a high-voltage capacitor (16), a high-voltage electric pulse switch (17), a first lead section (18), a second lead section (19), a third lead section (20), an electrode needle (21) and an air-guiding, liquid-guiding and electric-conducting bolt (22); a high-voltage pulse power supply (15) charges a high-voltage capacitor (16) through a first lead segment (18), the upper end and the lower end of a test piece (1) are respectively provided with an electrode needle (21) and an air-guide liquid-guide conductive bolt (22), one end of the electrode needle (21) is propped against the test piece (1), the other end of the electrode needle sequentially passes through a first slide bar (6), a second slide bar (7) and a third slide bar (8) coaxially and then is inserted into a blind hole of a fourth slide bar (9), one end of the air-guide liquid-guide conductive bolt (22) is connected with the electrode needle (21), the other end of the air-guide liquid-guide conductive bolt transversely passes through the fourth slide bar (9), wherein the air-guide liquid-guide conductive bolt (22) above is connected with the positive pole of the high-voltage capacitor (16) through a second lead segment (19), and the air-guide liquid-guide conductive bolt (22) below is connected with the negative pole of the high-voltage capacitor (16) through a third lead segment (20), a high-voltage electric pulse switch (17) is connected in series on the second lead segment (19); the high-voltage electric pulse signal monitoring module comprises a Rogowski coil (24), a high-voltage probe (25) and an oscilloscope (26), the Rogowski coil (24) is sleeved on the third lead segment (20), the high-voltage probe (25) is connected in series on the third lead segment (20), and monitoring signals of the Rogowski coil (24) and the high-voltage probe (25) are connected to the oscilloscope (26) through signal transmission lines; the protection module comprises an electromagnetic shielding field (27) for isolating high-energy static electricity generated by a high-voltage electric pulse fracturing operation system in the electromagnetic shielding field (27);
the water-gas two-phase seepage system comprises a water-gas pressure loading module and a flow data acquisition module, wherein the water-gas pressure loading module comprises a gas tank (28), a water pressure pump (29), a gas pipeline (30), a water pressure pipeline (31), a water-gas pipeline (32) and a water-gas collection container (34), the diameter of the electrode needle (21) is smaller than the inner diameter of the sliding rod which penetrates through the electrode needle to form a water-gas channel, the two water-gas channels are tightly attached to the test piece (1), the gas-guide liquid-guide conductive bolt (22) is of a hollow rod structure, the inner side end of the gas-guide liquid-guide conductive bolt (22) positioned above the gas-guide liquid-guide conductive bolt is communicated with the water-gas channel, the outer side end of the gas-guide liquid-guide conductive bolt (22) positioned below the gas-gas channel is respectively provided with a gas inlet and a water inlet, and the gas inlet is connected with the gas outlet of the gas tank (28) through the gas pipeline (30), the water inlet is connected with the water outlet of the hydraulic pump (29) through a hydraulic pipeline (31); the flow data acquisition module comprises a gas flowmeter (35) arranged on the gas pipeline (30) and a liquid flowmeter (36) arranged on the water pressure pipeline (31).
6. The high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method according to claim 5, characterized by comprising the following steps: the electrode needle (21) is provided with a platform for inserting the air guide and liquid guide conductive bolt (22) to perform surface-mounted conduction, and the air guide and liquid guide conductive bolt (22) is separated from the fourth sliding rod (9) through a stainless steel sealing sleeve (23); the diameter of the air guide liquid guide conductive bolt (22) is larger than the width of a platform arranged on the electrode needle (21), or a communicating hole is arranged on the side wall of the inner side end of the air guide liquid guide conductive bolt (22), so that the hollow part of the air guide liquid guide conductive bolt (22) is communicated with a water-gas channel; the air inlet and the water inlet of the air guide and liquid guide conductive bolt (22) positioned below form a Y-shaped channel with the hollow part. Check valves (37) are respectively installed on the gas pipeline (30) and the water pressure pipeline (31), stop valves (38) are respectively installed on the gas pipeline (30), the water pressure pipeline (31) and the water vapor pipeline (32), and the gas tank (28), the water pressure pump (29), the axial pressure pump (3) and the confining pressure pump (11) are installed outside the electromagnetic shielding field (27).
7. The high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method according to claim 5, characterized by comprising the following steps: the end part of the electrode needle (21) contacting the test piece (1) is designed to be in a circular truncated cone shape, and the other end of the electrode needle (21) is tightly propped against the compression spring (33) arranged in the blind hole of the fourth sliding rod (9).
8. The high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method according to claim 5, characterized by comprising the following steps: the top of the insulating fixing base (39) is provided with a positioning round table in the middle, and the bottom of the oil cylinder (4) at the lower end is provided with a positioning groove for the positioning round table to be inserted in.
9. The high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method according to claim 5, characterized by comprising the following steps: the first wire section (18), the second wire section (19) and the third wire section (20) are wrapped by insulating materials meeting the 100kV insulation standard, and the joints of the second wire section (19) and the third wire section (20) and the air-guiding, liquid-guiding and conductive bolt (22) are completely wrapped by insulating tapes meeting the 100kV insulation standard.
10. The high-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method according to claim 6, characterized by comprising the following steps: the outer diameter of the stainless steel sealing sleeve (23) is enlarged at the far end position to be used as a flanging (23a), and the flanging (23a) just covers the outer wall of the fourth sliding rod (9); the stainless steel sealing sleeve (23) is small in inner diameter near end and large in far end, and a step surface is formed in the middle of the length; correspondingly, the section of the conductive bolt (22) positioned in the fourth sliding rod (9) is small at the near end and large at the far end; and the section of the conductive bolt (22) outside the fourth sliding rod (9) is provided with a circumferential groove (22a) for winding and connecting the corresponding second wire segment (19) or third wire segment (20).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111446968.3A CN114062142B (en) | 2021-11-30 | 2021-11-30 | High-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111446968.3A CN114062142B (en) | 2021-11-30 | 2021-11-30 | High-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114062142A true CN114062142A (en) | 2022-02-18 |
| CN114062142B CN114062142B (en) | 2022-08-19 |
Family
ID=80228068
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111446968.3A Active CN114062142B (en) | 2021-11-30 | 2021-11-30 | High-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114062142B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103861202A (en) * | 2014-03-18 | 2014-06-18 | 苏州文曲生物微系统有限公司 | Device for administrating medicine by use of electroporation of hollow electrode needle |
| CN204302155U (en) * | 2014-12-03 | 2015-04-29 | 中国矿业大学 | Dynamic load effect coal body permeability detector |
| CN107014672A (en) * | 2017-03-31 | 2017-08-04 | 重庆大学 | Loaded coal rock body heat fluid structurecoupling CT triaxial pressure loading systems |
| CN107939364A (en) * | 2017-11-14 | 2018-04-20 | 中国矿业大学 | A kind of electric pulse fracturing is anti-reflection and gas porous flow integrated apparatus and method |
| CN109211753A (en) * | 2018-09-18 | 2019-01-15 | 辽宁工程技术大学 | More of rock, multiphase porous flow experimental provision under a kind of perturbation action |
| 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 |
| US20210088429A1 (en) * | 2019-09-24 | 2021-03-25 | Southwest Petroleum University | Device and Method for Evaluating Fracture Initiation and Propagation, and Stress Sensitivity of Propped Fracture |
| CN113447633A (en) * | 2021-06-25 | 2021-09-28 | 安徽理工大学 | Movable experimental device for high-voltage electric pulse induced cracking loaded coal containing gas |
| CN113504125A (en) * | 2021-07-27 | 2021-10-15 | 辽宁工程技术大学 | True triaxial physical and chemical combination coal rock permeability increasing test device and method |
-
2021
- 2021-11-30 CN CN202111446968.3A patent/CN114062142B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103861202A (en) * | 2014-03-18 | 2014-06-18 | 苏州文曲生物微系统有限公司 | Device for administrating medicine by use of electroporation of hollow electrode needle |
| CN204302155U (en) * | 2014-12-03 | 2015-04-29 | 中国矿业大学 | Dynamic load effect coal body permeability detector |
| CN107014672A (en) * | 2017-03-31 | 2017-08-04 | 重庆大学 | Loaded coal rock body heat fluid structurecoupling CT triaxial pressure loading systems |
| CN107939364A (en) * | 2017-11-14 | 2018-04-20 | 中国矿业大学 | A kind of electric pulse fracturing is anti-reflection and gas porous flow integrated apparatus and method |
| CN109211753A (en) * | 2018-09-18 | 2019-01-15 | 辽宁工程技术大学 | More of rock, multiphase porous flow experimental provision under a kind of perturbation action |
| 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 |
| US20210088429A1 (en) * | 2019-09-24 | 2021-03-25 | Southwest Petroleum University | Device and Method for Evaluating Fracture Initiation and Propagation, and Stress Sensitivity of Propped Fracture |
| CN113447633A (en) * | 2021-06-25 | 2021-09-28 | 安徽理工大学 | Movable experimental device for high-voltage electric pulse induced cracking loaded coal containing gas |
| CN113504125A (en) * | 2021-07-27 | 2021-10-15 | 辽宁工程技术大学 | True triaxial physical and chemical combination coal rock permeability increasing test device and method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114062142B (en) | 2022-08-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104535727B (en) | A kind of waterpower sandfrac system | |
| CN109323973B (en) | Experimental device for high power pulse wave induced cracking contains gas coal body | |
| CN101881158B (en) | Pipe fluid pressure pulse signal generator | |
| CN104018830B (en) | Time and space evaluation method of coal seam hydraulic fracturing effect | |
| CN109374510A (en) | A kind of servo seepage apparatus of high power pulse wave fracturing coal seam with gas | |
| CN110984962A (en) | Fluidized gas extraction monitoring method | |
| CN109323972A (en) | A kind of experimental provision of the controllable shock wave fracturing coal seam with gas of multi- scenarios method | |
| CN112485125A (en) | Tunnel model test device and method capable of controlling soil loss rate | |
| CN114062142B (en) | High-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test method | |
| US11614390B1 (en) | Real-time nondestructive observation and two-phase seepage test system for fracture of in-situ fractured gas-bearing reservoir | |
| CN114112636B (en) | In-situ fracturing gas-bearing reservoir fracture real-time nondestructive observation and two-phase seepage test system | |
| CN109374509A (en) | A kind of servo method of seepage of high power pulse wave fracturing coal seam with gas | |
| CN114062143B (en) | High-voltage electric pulse in-situ permeability-increasing gas-bearing reservoir two-phase seepage test device | |
| CN117054250B (en) | Electric pulse liquid injection fracturing coal rock electric heat fluid-solid coupling test system and method | |
| CN114135271B (en) | Real-time nondestructive observation and two-phase seepage test method for in-situ fracturing coal seam fracture | |
| CN113266347A (en) | Near-bit coal seam gas parameter while-drilling comprehensive measurement device and method | |
| CN109342298B (en) | Experimental method for high-power pulse wave induced cracking of gas-containing coal body | |
| CN109372480A (en) | A kind of movable down-hole electric generating apparatus of water injection well and method | |
| CN105319138A (en) | Device and method used for performing rock fracturing test | |
| CN114112853B (en) | Test piece holder for coal seam fracturing | |
| CN109323974A (en) | A kind of experimental method of the controllable shock wave fracturing coal seam with gas of multi- scenarios method | |
| CN114062141B (en) | High-voltage electric pulse in-situ fracturing coal seam crack real-time nondestructive observation device | |
| CN105403449A (en) | Base of rock mechanics testing machine | |
| CN210598966U (en) | Controllable shock wave blockage removal test system | |
| CN114076715B (en) | Test method for high-voltage electric pulse in-situ fracturing coal seam fracture and real-time nondestructive observation |
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 |