WO2024098509A1 - 一种真三轴水力压裂多尺度多参数协同测试装置及方法 - Google Patents

一种真三轴水力压裂多尺度多参数协同测试装置及方法 Download PDF

Info

Publication number
WO2024098509A1
WO2024098509A1 PCT/CN2022/139257 CN2022139257W WO2024098509A1 WO 2024098509 A1 WO2024098509 A1 WO 2024098509A1 CN 2022139257 W CN2022139257 W CN 2022139257W WO 2024098509 A1 WO2024098509 A1 WO 2024098509A1
Authority
WO
WIPO (PCT)
Prior art keywords
pressure
chamber
pressure plate
oil
true triaxial
Prior art date
Application number
PCT/CN2022/139257
Other languages
English (en)
French (fr)
Inventor
张平松
刘畅
欧元超
Original Assignee
安徽理工大学
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 安徽理工大学 filed Critical 安徽理工大学
Publication of WO2024098509A1 publication Critical patent/WO2024098509A1/zh

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/25—Methods for stimulating production
    • E21B43/26—Methods for stimulating production by forming crevices or fractures
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B47/00—Survey of boreholes or wells

Definitions

  • the invention relates to a hydraulic fracturing physical simulation experimental research, and is particularly suitable for a true triaxial hydraulic fracturing multi-scale multi-parameter collaborative testing device and method.
  • coal resources account for a large proportion of energy. And for a long time in the future, my country will still maintain an energy structure dominated by coal.
  • the shallow coal reserves are facing depletion, and the mining direction is gradually extending to the deep.
  • the geological environment in the deep is different from that in the shallow, and the conditions are complex, especially the characteristics of "high confining pressure, high temperature, high stress, strong aging, and strong disturbance", which makes the rock fracturing mechanism under deep water pressure still unclear, and the research on hydraulic fracturing mechanism under true triaxial action still needs to be vigorously carried out.
  • Rock fracturing is often the generation and accumulation of microcracks, which gradually form local cracks and micropores. Under the joint action of internal and external forces, local cracks and pores expand and extend to form rock cracks, holes, etc., which in turn affect the mechanical properties of the rock mass from a macroscopic perspective, resulting in rock changes such as destruction and instability.
  • the detection method is generally combined with a certain technical means to detect the structural changes of the rock specimen based on the scale of the rock specimen. The germination and expansion process of the rock specimen cracks is sensed through the acquired physical parameters. Continuous monitoring finally obtains the formation state of hydraulic fractured rock cracks and realizes the evaluation of the hydraulic fracturing effect.
  • traditional evaluation methods often only use a single test means or method, and cannot realize multi-scale and multi-parameter collaborative testing. Therefore, it is very necessary to design a true triaxial hydraulic fracturing multi-scale and multi-parameter collaborative testing device and method.
  • the purpose of the present invention is to provide a true triaxial hydraulic fracturing multi-scale and multi-parameter collaborative testing device and method, which can load the environment, combine the micro- and macro-scale, and coordinate multiple geological physical fields. At the same time, it provides an operation method and a data processing method, which plays an important role in obtaining the hydraulic fracturing mechanism of deep rock mass, monitoring the dynamic development of rock fractures, and characterizing the parameters of the degree of fracture development.
  • the present invention provides the following solutions:
  • a true triaxial hydraulic fracturing multi-scale multi-parameter collaborative testing device comprises: a frame, a true triaxial chamber, a clamping and loading device, a water supply device, an oil supply device, a CT scanning module, an electrical test module, an acoustic emission test module, a strain test module, a magnetic test module, a computer and a display screen, wherein the clamping and loading device is fixed inside the frame, the true triaxial chamber is placed inside the clamping and loading device, the clamping and loading device passes through the true triaxial chamber and is connected to a rock specimen, the oil supply device is connected to the true triaxial chamber and is used to supply oil into the true triaxial chamber, the water supply device passes through the clamping and loading device and is connected to the rock specimen and is used to provide high-pressure water for the rock specimen, the electrical test module, the acoustic emission test module, the strain test module and the magnetic test module are respectively fixed on the clamping and loading device and are connected to the rock specimen, the CT scanning module is located at the front and
  • the frame is composed of a top plate, a bottom plate and four columns, the clamping and loading device is welded at the center of the inner side of the top plate and the bottom plate, the top plate and the bottom plate are connected by the columns and fixed by bolts, and the bottom of the columns is fixed with an anti-slip pad;
  • the true triaxial chamber comprises a sealable chamber, an oil inlet and an oil outlet.
  • a rock specimen is placed inside the sealable chamber, and the sealable chamber provides a certain confining pressure for the rock specimen.
  • the sealable chamber comprises a barrel and a bottom plate. Bolt holes are provided around the lower end of the barrel to connect the barrel and the cover plate. A circular hole is provided in the center of each side of the sealable chamber for the clamping and loading device to pass through.
  • the oil inlet is provided on the upper side of the sealable chamber, and the oil outlet is provided on the bottom of the sealable chamber. The oil inlet and the oil outlet are respectively communicated with the inside of the sealable chamber.
  • the CT scanning module is composed of a CT transmitting device and a CT receiving device located at the front and rear sides of the true triaxial chamber, providing real-time scanning for the specimen, and the CT transmitting device and the CT receiving device are electrically connected to a computer respectively.
  • the clamping and loading device includes: an upper pressure supply chamber, an upper pressure column, an upper pressure plate, a lower pressure supply chamber, a lower pressure column, a lower pressure plate, a left pressure supply chamber, a left pressure column, a left pressure plate, a right pressure supply chamber, a right pressure column, a right pressure plate, a front pressure supply chamber, a front pressure column, a front pressure plate, a rear pressure supply chamber, a rear pressure column and a rear pressure plate; the upper pressure supply chamber and the lower pressure supply chamber are respectively welded at the center positions of the inner sides of the top plate and the bottom plate; the upper, lower, left, right, front and rear pressure supply chambers are respectively connected with the upper, lower, left, right, front and rear pressure columns; the front parts of the upper, lower, left, right, front and rear pressure columns are connected with the upper, lower, left, right, front and rear pressure plates; the pressure plates in all directions jointly squeeze the rock specimen to provide the rock specimen with the required experimental conditions of axial pressure and lateral pressure;
  • the upper pressure plate is provided with a circular hole to provide an inlet for the water supply device.
  • the upper, lower, left and right pressure plates are all fixed with electrical test modules, strain test modules and magnetic test modules.
  • the left and right pressure plates are fixed with acoustic emission modules.
  • the water supply device is formed by connecting an air compressor, a high-pressure air pipe, a closed water tank, and a high-pressure water supply pipe in sequence, the fracturing pipe is placed in the fracturing hole on the end face of the rock specimen, and the high-pressure water supply pipe enters the sealed chamber from the upper pressure supply chamber via the upper pressure column, and then enters the fracturing pipe from the hole of the upper pressure plate, so as to provide high-pressure water for the rock specimen;
  • the oil supply device includes an oil tank, an oil inlet pipeline and an oil outlet pipeline.
  • the oil tank is connected to the oil inlet pipeline, the oil inlet pipeline is connected to the oil inlet, the oil outlet is connected to the oil outlet pipeline, and the oil outlet pipeline is connected to the oil tank for supplying oil to the sealable chamber.
  • the electrical method test module includes a copper rod electrode, a high-strength piezoelectric ceramic sheath, a parallel electrical method module black box, and a parallel electrical method host.
  • the copper rod electrode is embedded in the upper pressure plate, the lower pressure plate, the left pressure plate and the right pressure plate, respectively.
  • the electrodes in the left pressure plate and the right pressure plate are in a "cross" shape, and 6 electrodes are evenly distributed on two orthogonal measuring lines, and also include a B electrode and an N electrode; the electrodes in the upper pressure plate and the lower pressure plate are in a "M" shape, and 6 electrodes are evenly distributed on the horizontal and vertical measuring lines, and 8 electrodes are evenly distributed on the two inclined measuring lines, and also include a B electrode and an N electrode.
  • the high-strength piezoelectric ceramic sheath is sleeved on the outside of the copper rod electrode, and the copper rod electrode is connected to the parallel electrical method module black box, the parallel electrical method module black box is electrically connected to the parallel electrical method host, and the parallel electrical method host is electrically connected to the computer.
  • the acoustic emission test module includes an acoustic emission probe, a high-strength piezoelectric ceramic sheath, and an acoustic emission instrument.
  • the acoustic emission probe is embedded in the left pressure plate and the right pressure plate, and each pressure plate has 4 acoustic emission probes distributed in a rectangular shape.
  • the high-strength piezoelectric ceramic sheath is mounted on the outside of the acoustic emission probe.
  • the acoustic emission probe is electrically connected to the acoustic emission instrument, and the acoustic emission instrument is electrically connected to a computer.
  • the strain testing module includes a strain unit and a strain gauge, wherein the strain unit is embedded in the upper pressing plate, the lower pressing plate, the left pressing plate and the right pressing plate, each pressing plate contains 4 strain units, the strain unit is electrically connected to the strain gauge, and the strain gauge is electrically connected to the computer;
  • the magnetic testing module includes a multi-turn magnetic coil and a magnetic instrument
  • the multi-turn magnetic coil is located in the upper pressure plate, the lower pressure plate, the left pressure plate and the right pressure plate, the coil material is metallic copper, the number of coil turns in each pressure plate n ⁇ [10,30], the multi-turn magnetic coil is electrically connected to the magnetic instrument, and the magnetic instrument is electrically connected to the computer.
  • a true triaxial hydraulic fracturing multi-scale multi-parameter collaborative testing method comprises the following steps:
  • Step 1 Process the retrieved rock sample and cut it into blocks with a side length of 100 mm. Then, open a fracturing hole with a diameter of 10 mm and a depth of 20 mm on the top surface of the rock specimen, place the fracturing pipe in the hole, and connect the fracturing pipe to the high-pressure water supply pipe.
  • Step 2 Install and connect the sensors on each pressure plate, connect the wires, and start each test device;
  • Step 3 Close the sealable chamber, add oil into the sealable chamber until it is full, and keep the room temperature constant;
  • Step 4 Start the water supply device, start hydraulic fracturing, and simultaneously start the CT scanning module, acoustic emission test module, strain test module and measurement test module;
  • Step 5 After the specimen is completely ruptured, stop hydraulic fracturing, return oil to the oil tank, open the sealable chamber, take out the specimen for observation and photography, and perform data processing and analysis at the same time.
  • the present invention discloses the following technical effects: the true triaxial hydraulic fracturing multi-scale multi-parameter collaborative testing device and method provided by the present invention realizes the observation of rock specimen fracture at the microscopic scale and specimen scale during the true triaxial hydraulic fracturing process; the device is equipped with four-field collaborative testing, which depicts the hydraulic fracturing process of the rock specimen from the perspectives of electrical parameters, acoustic parameters, strain parameters and magnetic parameters, and can capture the initiation and expansion of cracks inside the rock specimen through real-time monitoring of parameters, which is of great significance for the acquisition of the hydraulic fracturing mechanism of deep rock specimens; the device has high-speed acquisition and high-speed storage functions, which can capture the changes of cracks together with instantaneous parameters, which is important for obtaining rock fracture precursor information and predicting the direction of crack expansion of rock specimens.
  • the present invention can provide assistance for the acquisition of the principle of hydraulic fracturing of deep rock masses, and for the characterization of crack initiation and expansion parameters under the action of surrounding rock water pressure under mining conditions, the characteristics of rock hydraulic fracturing precursor information, and the prediction of cracks during hydraulic fracturing.
  • FIG1 is a front view of the structure of the device of the present invention.
  • FIG2 is a left side view of the device structure of the present invention.
  • FIG3 is a top view of the structure of the device of the present invention.
  • FIG4 is a schematic diagram of the distribution of sensors of the left and right pressure plates of the present invention.
  • FIG. 5 is a schematic diagram showing the distribution of sensors of the upper pressing plate and the lower pressing plate of the present invention.
  • Figure numerals 1, frame; 2, rock specimen; 3, fracturing tube; 4, sealable chamber; 5, oil inlet; 6, oil outlet; 7, upper pressure supply chamber; 8, upper pressure column; 9, upper pressure plate; 10, right pressure supply chamber; 11, right pressure column; 12, right pressure plate; 13, lower pressure supply chamber; 14, lower pressure column; 15, lower pressure plate; 16, left pressure supply chamber; 17, left pressure column; 18, left pressure plate; 19, copper rod electrode; 20, high-strength piezoelectric ceramic sheath; 21, conductor; 22, acoustic emission probe; 23, transmission line; 24, strain unit; 25, multi-turn magnetic method coil ; 26. High-pressure water supply pipe; 27. Sealed water tank; 28. High-pressure gas pipe; 29. Air compressor; 30. Oil tank; 31. Oil inlet pipeline; 32.
  • Oil outlet pipeline 33. Parallel electrical method module black box; 34. Parallel electrical method host; 35. Acoustic emitter; 36. Strain gauge; 37. Magnetic method instrument; 38. Computer; 39. Display screen; 40. Anti-slip mat; 41. Screws; 42. CT transmitter; 43. CT receiver; 44. Front supply and pressure chamber; 45. Front pressure column; 46. Front pressure plate; 47. Rear supply and pressure chamber; 48. Rear pressure column; 49. Rear pressure plate.
  • the purpose of the present invention is to provide a true triaxial hydraulic fracturing multi-scale and multi-parameter collaborative testing device and method, which has a simple structure and low computational complexity, can operate in a channel environment with frequency selective fading, fast time variation, and time domain non-stationary characteristics, has strong anti-interference ability, and is suitable for high-speed testing environments.
  • the AM method is adopted, that is, the common ground electrode N and the common power supply electrode negative electrode B are arranged separately, and the n electrodes on the measuring line automatically take turns as the power supply electrode A, and the remaining n-1 electrodes are used as electrodes M. Therefore, in the n electrode current and (n-1) ⁇ n electrode potential data. Then, the apparent resistivity value of all electrode distance combinations among the n electrodes is obtained by the three-pole method.
  • ⁇ is the apparent resistivity
  • AM is the distance between electrode A and electrode M
  • AN is the distance between electrode A and electrode N
  • BM is the distance between electrode B and electrode M
  • BN is the distance between electrode B and electrode N
  • K is the device coefficient.
  • the three-pole method refers to the three electrodes A, M, and N.
  • Formula 2 can be simplified to:
  • the elastic wave signal released by the internal defects propagates from the inside of the specimen to the surface of the specimen, generating weak vibrations.
  • These vibration signals are converted into electrical signals by the acoustic emission probe 22, and then amplified, processed and stored, and stored in the disk in the form of parameters or waveforms.
  • the propagation form of the rock specimen 2 in the rock specimen 2 it can be divided into: longitudinal wave, transverse wave and surface wave.
  • ⁇ is the density of the material
  • E is the elastic modulus of the material
  • ⁇ is the Poisson's ratio
  • G is the shear modulus of the material.
  • the signal intensity weakens.
  • the waveform amplitude of this attenuation type has an exponential relationship with the propagation distance.
  • p(x) is the amplitude of the sound wave
  • x is the propagation distance of the sound wave
  • ⁇ is the attenuation coefficient
  • p0 is the amplitude of the sound wave at the acoustic emission source.
  • the natural frequency of the steel string changes accordingly due to the different tension (stress) of the steel string.
  • the change in the pressure on the pressure box membrane can be known.
  • the rock sample 2 produces magnetic changes during the hydraulic fracturing process of the rock sample 2.
  • the magnetic parameter characterization of the rock sample 2 during the hydraulic fracturing process can be achieved.
  • a true triaxial hydraulic fracturing multi-scale multi-parameter collaborative testing device comprises: a frame 1, a true triaxial chamber, a clamping and loading device, a water supply device, an oil supply device, a CT scanning module, an electrical test module, an acoustic emission test module, a strain test module, a magnetic test module, a computer 38 and a display screen 39.
  • the clamping and loading device is fixed inside the frame 1, the true triaxial chamber is placed inside the clamping and loading device, the clamping and loading device passes through the true triaxial chamber and is connected to a rock specimen 2, and the oil supply device is connected to the true triaxial chamber for supplying the true triaxial Oil is supplied indoors, the water supply device passes through the clamping and loading device and is connected to the rock specimen 2, and is used to provide high-pressure water for the rock specimen 2.
  • the electrical test module, acoustic emission test module, strain test module and magnetic test module are respectively fixed on the clamping and loading device and connected to the rock specimen 2.
  • the CT scanning module is located at the front and back sides of the true triaxial chamber.
  • the CT scanning module, electrical test module, acoustic emission test module, strain test module and magnetic test module are connected to a computer 38, and the computer 38 is electrically connected to a display screen 39.
  • the accessories in the test area of the rock specimen 2 are made of carbon fiber materials, and the rest are made of steel materials.
  • the frame 1 is composed of a top plate, a bottom plate and four columns.
  • the clamping and loading device is welded at the center of the inner side of the top plate and the bottom plate.
  • the top plate and the bottom plate are connected by columns and fixed by bolts.
  • the bottom of the columns is fixed with an anti-slip pad 40.
  • the true triaxial chamber comprises a sealable chamber 4, an oil inlet 5 and an oil outlet 6, a rock specimen 2 is placed inside the sealable chamber 4, and the sealable chamber 4 provides a certain confining pressure for the rock specimen 2;
  • the sealable chamber 4 comprises a barrel and a bottom plate, bolt holes are provided around the lower end of the barrel to connect the barrel and the cover plate, a circular hole is provided in the center of each side of the sealable chamber 4 for the clamping and loading device to pass through, the oil inlet 5 is provided on the upper side of the sealable chamber 4, the oil outlet 6 is provided on the bottom surface of the sealable chamber 4, and the oil inlet 5 and the oil outlet 6 are respectively communicated with the inside of the sealable chamber 4;
  • the CT scanning module is composed of a CT transmitting device 42 and a CT receiving device 43 located at the front and rear sides of the true triaxial chamber, and its function is to dynamically scan the microstructural changes of the rock specimen 2 during the hydraulic fracturing process.
  • the CT transmitting device 42 and the CT receiving device 43 are electrically connected to the computer 38 respectively.
  • the clamping and loading device comprises: an upper pressure supply chamber 7, an upper pressure column 8, an upper pressure plate 9, a lower pressure supply chamber 13, a lower pressure column 14, a lower pressure plate 15, a left pressure supply chamber 16, a left pressure column 17, a left pressure plate 18, a right pressure supply chamber 10, a right pressure column 11, a right pressure plate 12, a front pressure supply chamber 44, a front pressure column 45, a front pressure plate 46, a rear pressure supply chamber 47, a rear pressure column 48 and a rear pressure plate 49, and the center positions of the inner sides of the top plate and the bottom plate are respectively welded with upper pressure supply chambers.
  • the pressure chamber 7 and the lower pressure supply chamber 13, the upper, lower, left, right, front and rear pressure supply chambers are respectively connected with upper, lower, left, right, front and rear pressure columns, the front of the upper, lower, left, right, front and rear pressure columns are connected with upper, lower, left, right, front and rear pressure plates, the upper, lower, left, right, front and rear pressure plates jointly squeeze the rock specimen 2, and provide the rock specimen 2 with the axial pressure and lateral pressure of the required experimental conditions, and the front pressure plate 46 and the rear pressure plate 49 do not contain any detection sensors;
  • the upper pressure plate 9 is provided with a circular hole to provide an inlet for the water supply device.
  • the upper, lower, left and right pressure plates are all fixed with electrical test modules, strain test modules and magnetic test modules.
  • the left and right pressure plates are fixed with acoustic emission modules.
  • the water supply device is formed by connecting an air compressor 29, a high-pressure air pipe 28, a closed water tank 27, a high-pressure water supply pipe 26, and a fracturing pipe 3 in sequence.
  • the fracturing pipe 3 is placed in the fracturing hole on the end face of the rock specimen 2.
  • the high-pressure water supply pipe 26 enters the sealable chamber 4 from the upper pressure supply chamber 7 via the upper pressure column 8, and then enters the fracturing pipe 3 from the hole of the upper pressure plate 9, so as to provide high-pressure water for the rock specimen 2.
  • the oil supply device includes an oil tank 30, an oil inlet pipeline 31 and an oil outlet pipeline 32.
  • the oil tank 30 is connected to the oil inlet pipeline 31, the oil inlet pipeline 31 is connected to the oil inlet 5, the oil outlet 6 is connected to the oil outlet pipeline 32, and the oil outlet pipeline 32 is connected to the oil tank 30.
  • the oil tank 30 supplies and stores oil for the true three-axis chamber and controls the operation of the device.
  • the electrical method test module includes a copper rod electrode 19, a high-strength piezoelectric ceramic sheath 20, a parallel electrical method module black box 33, and a parallel electrical method host 34.
  • the copper rod electrode 19 is respectively embedded in the upper pressure plate 9, the lower pressure plate 15, the left pressure plate 18 and the right pressure plate 12.
  • the electrodes in the left pressure plate 18 and the right pressure plate 12 are in a "cross" shape, and six electrodes are evenly distributed on two orthogonal measuring lines, and an electrode B and an electrode N are also included;
  • the electrodes in the upper pressure plate 9 and the lower pressure plate 15 are in a "M" shape, and six electrodes are evenly distributed on the horizontal and vertical measuring lines, and eight electrodes are evenly distributed on the two inclined measuring lines, and an electrode N is also included.
  • the high-strength piezoelectric ceramic sheath 20 is sleeved on the outside of the copper rod electrode 19, the copper rod electrode 19 and the parallel electrical method host 34 are electrically connected by a wire 21, the wire 21 is led out from the pressure plate through the pressure column and the pressure chamber, all outlets are sealed by sealing rings, the parallel electrical method host 34 is electrically connected to the computer 38, and two methods of passive testing and active testing can be used.
  • the passive test is the natural potential ( ⁇ ) acquisition
  • the active test is a method of supplying power to the electrode.
  • the acquisition parameters include electrical signals such as resistivity ( ⁇ ), current (I) and potential (U);
  • the acoustic emission test module includes an acoustic emission probe 22, a high-strength piezoelectric ceramic sheath 20, and an acoustic emission instrument 35.
  • the acoustic emission probe 22 is embedded in the left pressure plate 18 and the right pressure plate 12. There are 4 acoustic emission probes 22 on each pressure plate, which are distributed in a rectangular shape.
  • the high-strength piezoelectric ceramic sheath 20 is sleeved on the outside of the acoustic emission probe 22.
  • the acoustic emission probe 22 and the acoustic emission instrument 35 are electrically connected by a transmission line 23.
  • the transmission line 23 is derived from the pressure plate through the pressure column and the pressure chamber. All outlets are sealed by sealing rings.
  • the acoustic emission instrument 35 is electrically connected to a computer 38, and the acquisition parameters are acoustic emission signals such as frequency (f) and amplitude (D);
  • the strain test module includes a strain unit 24 and a strain gauge 36.
  • the strain unit 24 is embedded in the upper pressing plate 9, the lower pressing plate 15, the left pressing plate 18 and the right pressing plate 12.
  • Each pressing plate contains 4 strain units 24.
  • the strain unit 24 and the strain gauge 36 are electrically connected by a wire 21.
  • the wire 21 is led out from the pressing plate through the pressure column and the pressure chamber. All outlets are sealed by sealing rings.
  • the strain gauge 36 is electrically connected to the computer 38.
  • the acquisition parameter is the strain value ( ⁇ ).
  • the magnetic test module is composed of a multi-turn magnetic coil 25, a wire 21, and a magnetic instrument 37 connected in sequence.
  • the multi-turn magnetic coil 25 is located in the upper pressure plate 9, the lower pressure plate 15, the left pressure plate 18 and the right pressure plate 12.
  • the coil material is metal copper.
  • the number of coil turns in each pressure plate is n ⁇ [10,30].
  • the multi-turn magnetic coil 25 is electrically connected to the magnetic instrument 37 by the wire 21.
  • the wire 21 is led out from the pressure plate through the pressure column and the pressure chamber. All outlets are sealed by sealing rings.
  • the magnetic instrument 37 is electrically connected to the computer 38.
  • the four-field signal collection can all adopt high-frequency collection, and the collection frequency is 3MHz, and is equipped with a computer 38 for high-speed storage, so that the evolution characteristics of multiple-field signals at the moment of fracture of the rock specimen 2 can be recorded.
  • the present invention also provides a true triaxial hydraulic fracturing multi-scale multi-parameter collaborative testing method, which is applied to the true triaxial hydraulic fracturing multi-scale multi-parameter collaborative testing method, and comprises the following steps:
  • Step 2 Install and connect the sensors on each pressure plate, connect the wire 21, start each test device, and keep the sensor in good contact with the rock specimen 2 and working normally;
  • Step 3 closing the sealable chamber 4, and filling the sealable chamber 4 with oil until it is full, and the oil supply device applies uniform confining pressure based on the rock specimen 2, and keeps the room temperature constant;
  • Step 4 Start the water supply device, start hydraulic fracturing, and simultaneously start the CT scanning module, acoustic emission test module, strain test module and measurement test module to perform real-time high-frequency testing and high-speed storage;
  • Step 5 After the specimen is completely ruptured, the hydraulic fracturing is stopped, the oil tank 30 is returned to the oil tank, the sealable chamber 4 is opened, the specimen is taken out for observation and photographing, and data processing and analysis are performed at the same time.
  • the multi-scale synchronous test of the present invention is mainly reflected in the meso scale and the specimen scale.
  • the real-time scanning based on the CT scanning device can obtain the three-dimensional crack distribution of the rock specimen 2 at the meso scale.
  • Based on the multi-field test of the probe on the pressure plate the crack development and expansion of the rock specimen 2 are obtained at the specimen scale.
  • Combining the meso scale with the specimen scale is helpful for obtaining the hydraulic fracturing mechanism of the rock specimen 2.
  • the present invention can obtain the electrical parameters, acoustic emission parameters, strain parameters and magnetic parameters of the rock specimen 2 during the fracturing process, and depict the hydraulic fracturing parameter response process of the rock specimen 2 from four different field parameters.
  • the Origin software can be used to obtain the joint response characteristic curve of the four parameters.
  • the response characteristics of different parameters at different stages of hydraulic fracturing of the rock specimen 2 are different.
  • Comparative analysis of response characteristics between parameters When the present invention obtains the four field parameters, the field parameters have a certain correlation. By constructing the correlation analysis between the parameters by SPASS, the correlation between the field parameters can be further understood.
  • the correlation analysis methods include neural network, regression analysis, variance analysis, joint analysis, etc. By constructing the correlation analysis between the parameters, the joint response mechanism between the parameters can be further understood.
  • the device of the present invention can help obtain parameter response characteristics and fracture precursor information in real time through multi-scale and multi-parameter collaborative testing of the true triaxial hydraulic fracturing process. Based on multi-scale and multi-parameter, the generation and expansion of cracks in rock specimen 2 can be mathematically modeled and predicted according to massive monitoring data. This plays an important role in predicting the occurrence of fractures.
  • Construction of dynamic deformation and destruction digital core We can obtain the three-dimensional distribution of the fracture field through real-time CT scanning of the hydraulic fracturing process, and the three-dimensional distribution of the electrical parameters of the rock specimen 2 can be obtained through electrical testing. According to the scanning or parameter test results, we can construct a three-dimensional digital core.
  • the construction of a three-dimensional digital core can be a single parameter construction or a data fusion construction. Through the construction of the digital core, the visualization of the deformation, destruction, crack initiation and expansion of the rock specimen 2 is greatly improved.
  • the true triaxial hydraulic fracturing multi-scale multi-parameter collaborative testing device and method realizes the observation of rock specimen fracture at the microscopic scale and specimen scale during the true triaxial hydraulic fracturing process;
  • the device is equipped with four-field collaborative testing to describe the hydraulic fracturing process of the rock specimen from the perspectives of electrical parameters, acoustic parameters, strain parameters and magnetic parameters, and can capture the initiation and expansion of cracks inside the rock specimen through real-time monitoring of parameters, which is of great significance for obtaining the hydraulic fracturing mechanism of deep rock specimens;
  • the device has high-speed acquisition and high-speed storage functions, which can capture the changes of cracks together with instantaneous parameters, and is important for obtaining rock fracture precursor information and predicting the direction of crack expansion of rock specimens.
  • the present invention can provide assistance for obtaining the principle of hydraulic fracturing of deep rock mass, and for characterizing the parameters of crack initiation and expansion under the action of surrounding rock water pressure under mining conditions, the characteristics of rock hydraulic fracturing precursor information, and the prediction of cracks during hydraulic fracturing.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geophysics (AREA)
  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)

Abstract

一种真三轴水力压裂多尺度多参数协同测试装置和方法，该方法包括：对取回的岩样进行加工，在岩石试件（2）的顶面开设压裂口，将压裂管（3）置于孔内，连接压裂管（3）与高压供水管（26）；安置、连接各压板上的传感器，连接导线（21），启动各测试装置；封闭可密闭室仓（4），向可密闭室仓（4）内注油，至注满，且保持室温恒定；启动供水装置，开始水力压裂，同时启动各测试模块；试件完全破裂后，停止水力压裂，油箱（30）回油，打开可密闭室仓（4），取出试件观察和拍照，同时进行数据处理与分析。

Description

一种真三轴水力压裂多尺度多参数协同测试装置及方法 技术领域
本发明涉及一种水力压裂物理模拟实验研究，尤其适用于一种真三轴水力压裂多尺度多参数协同测试装置及方法。
背景技术
煤炭资源作为我国的主要一次能源，在能源占较大比重。且在未来相当长一段时间内，我国仍保持煤为主体的能源结构。随着我国经年累月的煤炭开采，浅部的煤炭储备已面临枯竭，开采方向逐渐向深部延伸。深部的地质环境与浅部相异，条件复杂，尤其是“高围压、高温、高应力、强时效、强扰动”的特点，使得深部水压作用下岩石致裂机理尚不明确，真三轴作用下水力致裂机理研究仍需大力开展。
煤系地层岩体水力压裂裂纹发育、扩展的相似模拟试验是研究围岩突水模型、瓦斯气体高效利用和裂隙岩体注浆加固的重要研究手段。
岩石致裂往往是微裂隙的产生与积累，逐渐形成局部裂隙、微孔隙，局部裂隙和孔隙在内、外力共同作用下扩展、沿伸形成岩体裂缝、孔洞等，进而从宏观上影响岩体岩石力学性质，产生破坏、失稳等岩变事件。现有技术中一般结合探测方法，从岩石试件尺度出发，采用某种技术手段对岩石试件的结构变化进行探测，通过获取的物理参数感知岩石试件裂隙萌发和扩展过程，连续的监测最终获得水力致裂岩石裂隙的形成状态，实现水力压裂效果的评价。但是传统的评价方法往往只采用单独的测试手段或方法，更无法实现多尺度、多参数协同测试。因此设计一种真三轴水力压裂多尺度多参数协同测试装置和方法是十分必要的。
发明内容
本发明的目的是提供一种真三轴水力压裂多尺度多参数协同测试装置和方法，能够加载环境、细观和宏观结合、多地质物理场协同，同时提供操作方法和数据处理方法，对深部岩体水力致裂机理获取、岩石裂隙动态发育监测和裂隙发育程度的参量表征具有重要作用。
为实现上述目的，本发明提供了如下方案：
一种真三轴水力压裂多尺度多参数协同测试装置，包括：框架、真三轴室、夹持及加载装置、供水装置、供油装置、CT扫描模块、电法测试模块、声发射测试模块、应变测试模块、磁法测试模块、计算机及显示屏，所述框架的内部固定所述夹持及加载装置，所述夹持及加载装置的内部放置所述真三轴室，所述夹持及加载装置穿过所述真三轴室与岩石试件连接，所述供油装置连接所述真三轴室，用于向真三轴室内供油，所述供水装置穿过所述夹持及加载装置与岩石试件连接，用于为岩石试件提供高压水，所述电法测试模块、声发射测试模块、应变测试模块及磁法测试模块分别固定在所述夹持及加载装置上，并与岩石试件相连接，所述CT扫描模块位于真三轴室前后两侧，所述CT扫描模块、电法测试模块、声发射测试模块、应变测试模块及磁法测试模块连接计算机，计算机电性连接显示屏；
可选的，所述框架由顶板、底板以及4根立柱组成，顶板和底板内侧面的中心位置处焊接有所述夹持及加载装置，顶板和底板由立柱连接，并由螺栓固定，所述立柱底部固定有防滑垫；
所述真三轴室包括可密闭室仓、进油口及出油口，所述可密闭室仓内部放置有岩石试件，可密闭室仓为岩石试件提供一定的围压；所述可密闭室仓包括桶体及底板，在桶体下端周围开设有螺栓孔，链接桶体与盖板，所述可密闭室仓每面中心开有圆孔，供所述夹持及加载装置通过，所述进油口设置在可密闭室仓侧面上部，所述出油口设置在可密闭室仓底面，所述进油口、出油口分别与所述可密闭室仓内部连通；
所述CT扫描模块由位于真三轴室前后两侧的CT发射装置和CT接收装置组成，为试件提供实时扫描，所述CT发射装置和CT接收装置分别电性连接计算机。
可选的，所述夹持及加载装置包括：上部供压室、上压柱、上压板、下部供压室、下压柱、下压板、左侧供压室、左压柱、左压板、右侧供压室、右压柱、右压板、前方供压室、前压柱、前压板、后方供压室、后压柱及后压板，所述顶板和底板内侧面的中心位置处分别焊接有上部供压室及下部供压室，所述上部、下部、左侧、右侧、前方、后方供压室分别连接有上、下、左、右、 前、后压柱，所述上、下、左、右、前、后压柱前部连接有上、下、左、右、前、后压板，各方位压板共同挤压岩石试件，为岩石试件试件提供所需实验条件的轴压、侧压；
所述上压板开有圆孔，为供水装置提供进口，所述上、下、左、右压板上均固定有电法测试模块、应变测试模块及磁法测试模块，所述左、右压板固定有声发射模块。
可选的，所述供水装置由空压机、高压气管、密闭水槽、高压供水管顺次连接而成，所述压裂管置于岩石试件端面的压裂孔内，所述高压供水管由上部供压室经由上压柱进入可密闭室仓，再由上压板的孔洞进入压裂管内，用于为岩石试件提供高压水；
所述供油装置包括油箱、进油管道及出油管道，所述油箱连接进油管道，所述进油管道连接所述进油口，所述出油口连接所述出油管道，所述出油管道连接油箱，用于向可密闭室仓内供油。
可选的，电法测试模块包括铜棒电极、高强度压电陶瓷护套、并行电法模块黑箱、并行电法主机，所述铜棒电极分别内嵌于上压板、下压板、左压板和右压板中，在左压板和右压板中的电极呈“十”字型，两条正交测线等间距分布6个电极，另含一个B电极和一个N电极；上压板和下压板中的电极呈“米”字形，水平和垂直向测线各等距分布6个电极，倾斜的两条测线各等距分布8个电极，另含一个B电极和一个N电极，所述高强度压电陶瓷护套套设在铜棒电极外部，所述铜棒电极连接至所述并行电法模块黑箱，所述并行电法模块黑箱电性连接并行电法主机，所述并行电法主机电性连接计算机。
可选的，声发射测试模块包括声发射探头、高强度压电陶瓷护套、声发射仪，所述声发射探头内嵌于左压板和右压板中，每块压板上矩形分布有4个声发射探头，所述高强度压电陶瓷护套套设在声发射探头外部，所述声发射探头电性连接声发射仪，所述声发射仪电性连接计算机。
可选的，应变测试模块包括应变单元、应变仪，所述应变单元内嵌于上压板、下压板、左压板和右压板中，每块压板中含4个应变单元，所述应变单元电性连接应变仪，所述应变仪电性连接计算机；
可选的，磁法测试模块包括多匝磁法线圈、及磁法仪，所述多匝磁法线圈 位于上压板、下压板、左压板和右压板中，线圈材料为金属铜，每个压板中的线圈匝数n∈[10,30]，所述多匝磁法线圈电性连接磁法仪，所述磁法仪电性连接计算机。
一种真三轴水力压裂多尺度多参数协同测试方法，包括如下步骤：
步骤1：对取回的岩样进行加工，切割尺寸为边长100mm的方块，然后在岩石试件的顶面开设直径10mm，深度20mm的压裂口，并将压裂管置于孔内，连接压裂管与高压供水管；
步骤2：安置、连接各压板上的传感器，连接导线，启动各测试装置；
步骤3：封闭可密闭室仓，向可密闭室仓内注油，注满为止，且保持室温恒定；
步骤4：启动供水装置，开始水力压裂，同时启动CT扫描模块、声发射测试模块、应变测试模块和测法测试模块；
步骤5：试件完全破裂后，停止水力压裂，油箱回油，打开可密闭室仓，取出试件观察和拍照，同时进行数据处理与分析。
根据本发明提供的具体实施例，本发明公开了以下技术效果：本发明提供的真三轴水力压裂多尺度多参数协同测试装置及方法，实现了真三轴水力压裂过程中的细观尺度和试件尺度的岩石试件破裂观测；装置设置了四场协同测试，从电性参数、声发生参数、应变参数和磁法参数等所角度描绘了岩石试件的水力致裂过程，通过参量的实时监测，可以捕捉岩石试件内部裂隙的萌发和扩展，对深部岩石试件水力致裂机理的获取意义重大；本装置具备高速采集和高速存储功能，可捕捉裂隙连同瞬间参数的变化，对获取岩石破裂前兆信息，预测岩石试件裂隙扩展方向重要重要作用。本发明可为深部岩体水力致裂原理的获取提供帮助，为采动条件下的围岩水压作用下的裂隙萌生和扩展参数表征、岩石水力致裂前兆信息的特征以及水力致裂过程中裂隙的预测提供帮助。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动性的前提下，还可以根据这些附图获得其他的附图。
图1为本发明装置结构的主视图；
图2为本发明装置结构的左视图；
图3为本发明装置结构的俯视图；
图4为本发明左压板和右压板的传感器分布示意图；
图5为本发明上压板和下压板的传感器分布示意图。
附图标记：1、框架；2、岩石试件；3、压裂管；4、可密闭室仓；5、进油口；6、出油口；7、上部供压室；8、上压柱；9、上压板；10、右侧供压室；11、右压柱；12、右压板；13下部供压室；14、下压柱；15、下压板；16、左侧供压室；17、左压柱；18、左压板；19、铜棒电极；20、高强度压电陶瓷护套；21、导线；22、声发射探头；23、传输线；24、应变单元；25、多匝磁法线圈；26、高压供水管；27、密闭水槽；28、高压气管；29、空压机；30、油箱；31、进油管道；32、出油管道；33、并行电法模块黑箱；34、并行电法主机；35、声发射仪；36、应变仪；37、磁法仪；38、计算机；39、显示屏；40、防滑垫；41、螺丝；42、CT发射装置；43、CT接收装置；44、前方供压室；45、前压柱；46、前压板；47、后方供压室；48、后压柱；49、后压板。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
本发明的目的是提供一种真三轴水力压裂多尺度多参数协同测试装置和方法，结构简单，计算复杂度低，能够在具有频率选择性衰落、快时变、时域非平稳特性的信道环境下工作，抗干扰能力强，适用于高速测试环境下。
为使本发明的上述目的、特征和优点能够更加明显易懂，下面结合附图和具体实施方式对本发明作进一步详细的说明。
本发明的技术原理：
1.并行电法监测原理
采用AM法，即公共地电极N与公共供电电极负极B单独布设，测线上n个电极自动轮流作为供电电极A，其余n-1个电极作为电极M。所以，在n个 电极电流和(n-1)×n个电极电位数据。进而，利用三极法在n个电极中的所有电极距排列组合的视电阻率值。
Figure PCTCN2022139257-appb-000001
式中，ρ为视电阻率，AM为电极A和电极M之间的距离，AN为电极A和电极N之间的距离，BM为电极B和电极M之间的距离，BN为电极B和电极N之间的距离，K为装置系数。
Figure PCTCN2022139257-appb-000002
三极法是指A、M、N三个电极，MN间距很小时，公式2可简化为：
Figure PCTCN2022139257-appb-000003
即当MN远小于AO时(O为MN中点)
Figure PCTCN2022139257-appb-000004
Figure PCTCN2022139257-appb-000005
就是过M和N两等位面的平距面积，MN则是等位面M和N之间的距离。
2.声发射监测原理
受载的岩石试件2发生损伤时，其内部产生缺陷而释放的弹性波信号经过试件内部传播到试件表面后，产生微弱的振动，这些振动信号经声发射探头22转化为电信号，再经过信号放大、处理和存储，以参数或者波形的方式存储于磁盘中。根据岩石试件2在岩石试件2中的传播形式可分为：纵波、横波和表面波。
2.1纵波
纵波(P波)的传播方向与质点振动方向一致，波速表达式为：
Figure PCTCN2022139257-appb-000006
式中，ρ为材料的密度，E为材料的弹性模量，σ为泊松比。
2.2横波
纵波(S波)的传播方向与质点振动方向垂直，波速表达式为：
Figure PCTCN2022139257-appb-000007
式中，G为材料的切变模量。
2.3声发射衰减
弹性波在介质中传播一定距离后，信号强度减弱，该种衰减类型的波形振幅与传播距离呈指数型的关系。
p(x)＝p 0e -δx  (公式7)
式中，p(x)为声波的振幅；x为声波的传播距离；δ为衰减系数；p 0为声发射源处的声波振幅。
3.应变监测原理
利用钢弦拉张力(应力)不同，其自振频率也相应变化，通过测得钢弦频率的变化，便得知压力盒膜所受压力的变化。
4.磁法监测原理
岩石试件2水力压裂过程的岩石试件2产生磁性变化，来监测这种磁性变化，可实现水力压裂过程中岩石试件2的磁性参量表征。
如图1-5所示，本发明实施例提供的一种真三轴水力压裂多尺度多参数协同测试装置，包括：框架1、真三轴室、夹持及加载装置、供水装置、供油装置、CT扫描模块、电法测试模块、声发射测试模块、应变测试模块、磁法测试模块、计算机38及显示屏39，所述框架1的内部固定所述夹持及加载装置，所述夹持及加载装置的内部放置所述真三轴室，所述夹持及加载装置穿过所述真三轴室与岩石试件2连接，所述供油装置连接所述真三轴室，用于向真三轴室内供油，所述供水装置穿过所述夹持及加载装置与岩石试件2连接，用于为岩石试件2提供高压水，所述电法测试模块、声发射测试模块、应变测试模块及磁法测试模块分别固定在所述夹持及加载装置上，并与岩石试件2相连接，所述CT扫描模块位于真三轴室前后两侧，所述CT扫描模块、电法测试模块、声发射测试模块、应变测试模块及磁法测试模块连接计算机38，计算机38电性连接显示屏39；岩石试件2测试区域内的配件材料为碳纤维材料，其余均 为钢材料；
所述框架1由顶板、底板以及4根立柱组成，顶板和底板内侧面的中心位置处焊接有所述夹持及加载装置，顶板和底板由立柱连接，并由螺栓固定，所述立柱底部固定有防滑垫40；
所述真三轴室包括可密闭室仓4、进油口5及出油口6，所述可密闭室仓4内部放置有岩石试件2，可密闭室仓4为岩石试件2提供一定的围压；所述可密闭室仓4包括桶体及底板，在桶体下端周围开设有螺栓孔，链接桶体与盖板，所述可密闭室仓4每面中心开有圆孔，供所述夹持及加载装置通过，所述进油口5设置在可密闭室仓4侧面上部，所述出油口6设置在可密闭室仓4底面，所述进油口5、出油口6分别与所述可密闭室仓4内部连通；
所述CT扫描模块由位于真三轴室前后两侧的CT发射装置42和CT接收装置43组成，其作用是动态扫描水力压裂过程的岩石试件2细观结构变化，所述CT发射装置42和CT接收装置43分别电性连接计算机38。
所述夹持及加载装置包括：上部供压室7、上压柱8、上压板9、下部供压室13、下压柱14、下压板15、左侧供压室16、左压柱17、左压板18、右侧供压室10、右压柱11、右压板12、前方供压室44、前压柱45、前压板46、后方供压室47、后压柱48及后压板49，所述顶板和底板内侧面的中心位置处分别焊接有上部供压室7及下部供压室13，所述上部、下部、左侧、右侧、前方、后方供压室分别连接有上、下、左、右、前、后压柱，所述上、下、左、右、前、后压柱前部连接有上、下、左、右、前、后压板，上、下、左、右、前、后压板共同挤压岩石试件2，为岩石试件2提供所需实验条件的轴压、侧压，前压板46和后压板49内不含任何探测传感器；
所述上压板9开有圆孔，为供水装置提供进口，所述上、下、左、右压板上均固定有电法测试模块、应变测试模块及磁法测试模块，所述左、右压板固定有声发射模块。
所述供水装置由空压机29、高压气管28、密闭水槽27、高压供水管26、压裂管3顺次连接而成，所述压裂管3置于岩石试件2端面的压裂孔内，所述高压供水管26由上部供压室7经由上压柱8进入可密闭室仓4，再由上压板9的孔洞进入压裂管3内，用于为岩石试件2提供高压水；
所述供油装置包括油箱30、进油管道31及出油管道32，所述油箱30连接进油管道31，所述进油管道31连接所述进油口5，所述出油口6连接所述出油管道32，所述出油管道32连接油箱30，油箱30为真三轴室供油和储油，控制装置的运行。
电法测试模块包括铜棒电极19、高强度压电陶瓷护套20、并行电法模块黑箱33、并行电法主机34，所述铜棒电极19分别内嵌于上压板9、下压板15、左压板18和右压板12，左压板18和右压板12中的电极呈“十”字型，两条正交测线等间距分布6个电极，另含一个B电极和一个N电极；上压板9和下压板15中的电极呈“米”字形，水平和垂直向测线各等距分布6个电极，倾斜的两条测线各等距分布8个电极，另含一个B电极和一个N电极，所述高强度压电陶瓷护套20套设在铜棒电极19外部，所述铜棒电极19与所述并行电法主机34由导线21进行电性连接，所述导线21由压板经压柱、压力室导出，所有出口均由密封圈密封，所述并行电法主机34电性连接计算机38，可采用被动测试和主动测试两种方式，被动测试为自然电位(φ)采集，主动测试为向电极供电的方法，采集参数包括电阻率(ρ)、电流(I)和电位(U)等电性信号；
声发射测试模块包括声发射探头22、高强度压电陶瓷护套20、声发射仪35，所述声发射探头22内嵌于左压板18和右压板12中，每块压板上有4个声发射探头22，矩形分布，所述高强度压电陶瓷护套20套设在声发射探头22外部，所述声发射探头22与所述声发射仪35由传输线23进行电性连接，所述传输线23由压板经压柱、压力室导出，所有出口均由密封圈密封，所述声发射仪35电性连接计算机38，采集参数为频率(f)、振幅(D)等声发射信号；
应变测试模块包括应变单元24及应变仪36，所述应变单元24内嵌于上压板9、下压板15、左压板18和右压板12中，每块压板中含4个应变单元24，所述应变单元24与所述应变仪36由导线21进行电性连接，所述导线21由压板经压柱、压力室导出，所有出口均由密封圈密封，所述应变仪36电性连接计算机38，采集参数为应变值(ε)；
磁法测试模块由多匝磁法线圈25、导线21、磁法仪37顺次连接组成，所 述多匝磁法线圈25位于上压板9、下压板15、左压板18和右压板12中，线圈材料为金属铜，每个压板中的线圈匝数n∈[10,30]，所述多匝磁法线圈25与所述磁法仪37由导线21进行电性连接，所述导线21由压板经压柱、压力室导出，所有出口均由密封圈密封，所述磁法仪37电性连接计算机38。
所述真三轴室内所有的导线21、传输线23、传感器和配件等均需满足耐压要求，且耐压值大于80MPa；
四场信号采集均可采用高频采集，采集频率为3MHz，同时配以计算机38用来高速存储，这样，可实现岩石试件2破裂瞬间多场信号演化特征的记录。
本发明还提供了一种真三轴水力压裂多尺度多参数协同测试方法，应用于上述的真三轴水力压裂多尺度多参数协同测试方法，包括如下步骤：
步骤1：对取回的岩样进行加工，切割尺寸为边长100mm的方块，然后在岩石试件2的顶面开设压裂口(φ＝10mm，d＝20mm)，并将压裂管3置于孔内，连接压裂管3与高压供水管；
步骤2：安置、连接各压板上的传感器，连接导线21，启动各测试装置，保持传感器与岩石试件2的接触良好，且正常工作；
步骤3：封闭可密闭室仓4，向可密闭室仓4内注油，注满为止，由供油装置基于岩石试件2均匀的围压，且保持室温恒定；
步骤4：启动供水装置，开始水力压裂，同时启动CT扫描模块、声发射测试模块、应变测试模块和测法测试模块，进行实时高频测试和高速存储；
步骤5：试件完全破裂后，停止水力压裂，油箱30回油，打开可密闭室仓4，取出试件观察和拍照，同时进行数据处理与分析。
数据处理与分析具体为：
1.多尺度同步测试结果的对比分析：本发明的多尺度同步测试主要体现在细观尺度和试件尺度上，基于CT扫描装置的实时扫描可以获取岩石试件2细观尺度的三维裂隙展布情况，基于压板上探头的多场测试，则在试件尺度得到岩石试件2的裂隙发育、扩展情况，将细观尺度与试件尺度相结合，对获取岩石试件2水力压裂破裂机理具有一定的帮助。
2.四场测试结果的对比分析：通过本发明可以获取岩石试件2压裂过程中的电性参数、声发射参数、应变参数以及磁性参数，从四个不同的 场参数出发，描绘岩石试件2的水力压裂参数响应过程。在以时间变量为共同变量下，可以用Origin软件获取四种参量的联合响应特征曲线。不同的参数在岩石试件2水力压裂不同阶段的响应特征是不同的，通过构建多参数评价体系，可以灵敏捕捉各阶段岩石试件2水力压裂场参数响应特征。
3.参数间的响应特征对比分析：本发明在获得四场参数时，场参数之间具备一定的相关性，通过SPASS构建参数间的相关性分析，可以进一步认识场参数间的关联度。相关性分析方法包括神经网络、回归分析、方差分析、联合分析等，通过构建参数间的相关性分析，可以进一步了解参数间的联合响应机制。
4.预测分析：本发明装置通过对真三轴水力压裂过程的多尺度、多参数协同测试，对于实时获取参数响应特征，破裂前兆信息具有一定的帮助。在多尺度、多参数基础上，可以根据海量监测数据，对岩石试件2裂隙的生成和扩展进行数学建模和预测。这对预测破裂情况的发生具有重要的作用。
5.动态变形、破坏数字岩心的构建:我们通过水力压裂过程的CT实时扫描可以获得裂隙场的三维展布，电法测试可以获取岩石试件2电性参数的三维展布等。根据扫描或者参数测试结果，我们可以构建三维数字岩心。三位数字岩心的构建可以是单一参数的构建，可以为数据融合后的构建。通过数字岩心的构建，大大提高岩石试件2的变形破坏、裂纹萌生、扩展的可视化程度。
本发明提供的真三轴水力压裂多尺度多参数协同测试装置及方法，实现了真三轴水力压裂过程中的细观尺度和试件尺度的岩石试件破裂观测；装置设置了四场协同测试，从电性参数、声发生参数、应变参数和磁法参数等所角度描绘了岩石试件的水力致裂过程，通过参量的实时监测，可以捕捉岩石试件内部裂隙的萌发和扩展，为获取深部岩石试件水力致裂机理意义重大；本装置具备高速采集和高速存储功能，可捕捉裂隙连同瞬间参数的变化，对获取岩石破裂前兆信息，预测岩石试件裂隙扩展方向重要重要作用。本发明可为深部岩体水力致裂原理的获取提供帮助，为采动条件下的围岩水压作用下的裂隙萌生和扩 展参数表征、岩石水力致裂前兆信息的特征以及水力致裂过程中裂隙的预测提供帮助。
本文中应用了具体个例对本发明的原理及实施方式进行了阐述，以上实施例的说明只是用于帮助理解本发明的方法及其核心思想；同时，对于本领域的一般技术人员，依据本发明的思想，在具体实施方式及应用范围上均会有改变之处。综上所述，本说明书内容不应理解为对本发明的限制。

Claims (9)

  1. 一种真三轴水力压裂多尺度多参数协同测试装置，其特征在于，包括：框架、真三轴室、夹持及加载装置、供水装置、供油装置、CT扫描模块、电法测试模块、声发射测试模块、应变测试模块、磁法测试模块、计算机及显示屏，所述框架的内部固定所述夹持及加载装置，所述夹持及加载装置的内部放置所述真三轴室，所述夹持及加载装置穿过所述真三轴室与岩石试件连接，所述供油装置连接所述真三轴室，用于向真三轴室内供油，所述供水装置穿过所述夹持及加载装置与岩石试件连接，用于为岩石试件提供高压水，所述电法测试模块、声发射测试模块、应变测试模块及磁法测试模块分别固定在所述夹持及加载装置上，并与岩石试件相连接，所述CT扫描模块位于真三轴室前后两侧，所述CT扫描模块、电法测试模块、声发射测试模块、应变测试模块及磁法测试模块连接计算机，计算机电性连接显示屏；
  2. 根据权利要求1所述的一种真三轴水力压裂多尺度多参数协同测试装置，其特征在于，所述框架由顶板、底板以及4根立柱组成，顶板和底板内侧面的中心位置处焊接有所述夹持及加载装置，顶板和底板由立柱连接，并由螺栓固定，所述立柱底部固定有防滑垫；
  3. 根据权利要求1所述的一种真三轴水力压裂多尺度多参数协同测试装置，其特征在于，所述真三轴室包括可密闭室仓、进油口及出油口，所述可密闭室仓内部放置有岩石试件，可密闭室仓为岩石试件提供一定的围压；所述可密闭室仓包括桶体及底板，在桶体下端周围开设有螺栓孔，链接桶体与盖板，所述可密闭室仓每面中心开有圆孔，供所述夹持及加载装置通过，所述进油口设置在可密闭室仓侧面上部，所述出油口设置在可密闭室仓底面，所述进油口、出油口分别与所述可密闭室仓内部连通；
    所述CT扫描模块由位于真三轴室前后两侧的CT发射装置和CT接收装置组成，为试件提供实时扫描，所述CT发射装置和CT接收装置分别电性连接计算机。
  4. 根据权利要求2所述的一种真三轴水力压裂多尺度多参数协同测试装置，其特征在于，所述夹持及加载装置包括：上部供压室、上压柱、上压板、下部供压室、下压柱、下压板、左侧供压室、左压柱、左压板、右侧供压室、右压柱、右压板、前方供压室、前压柱、前压板、后方供压室、后压柱及后压 板，所述顶板和底板内侧面的中心位置处分别焊接有上部供压室及下部供压室，所述上部、下部、左侧、右侧、前方、后方供压室分别连接有上、下、左、右、前、后压柱，所述上、下、左、右、前、后压柱前部连接有上、下、左、右、前、后压板，各方位压板共同挤压岩石试件，为岩石试件提供所需实验条件的轴压、侧压；
    所述上压板开有圆孔，为供水装置提供进口，所述上、下、左、右压板上均固定有电法测试模块、应变测试模块及磁法测试模块，所述左、右压板固定有声发射模块。
  5. 根据权利要求4所述的一种真三轴水力压裂多尺度多参数协同测试装置，其特征在于，所述供水装置由空压机、高压气管、密闭水槽、高压供水管顺次连接而成，所述压裂管置于岩石试件端面的压裂孔内，所述高压供水管由上部供压室经由上压柱进入可密闭室仓，再由上压板的孔洞进入压裂管内，用于为岩石试件提供高压水；
    所述供油装置包括油箱、进油管道及出油管道，所述油箱连接进油管道，所述进油管道连接所述进油口，所述出油口连接所述出油管道，所述出油管道连接油箱，用于向可密闭室仓内供油。
  6. 根据权利要求4所述的一种真三轴水力压裂多尺度多参数协同测试装置，其特征在于，电法测试模块包括铜棒电极、高强度压电陶瓷护套、并行电法模块黑箱、并行电法主机，所述铜棒电极分别内嵌于上压板、下压板、左压板和右压板中，在左压板和右压板中的电极呈“十”字型，两条正交测线等间距分布6个电极，另含一个B电极和一个N电极；上压板和下压板中的电极呈“米”字形，水平和垂直向测线各等距分布6个电极，倾斜的两条测线各等距分布8个电极，另含一个B电极和一个N电极，所述高强度压电陶瓷护套套设在铜棒电极外部，所述铜棒电极连接至所述并行电法模块黑箱，所述并行电法模块黑箱电性连接并行电法主机，所述并行电法主机电性连接计算机。
  7. 根据权利要求4所述的一种真三轴水力压裂多尺度多参数协同测试装置，其特征在于，声发射测试模块包括声发射探头、高强度压电陶瓷护套、声发射仪，所述声发射探头内嵌于左压板和右压板中，每块压板上矩形分布有4个声发射探头，所述高强度压电陶瓷护套套设在声发射探头外部，所述声发射 探头电性连接声发射仪，所述声发射仪电性连接计算机。
  8. 根据权利要求4所述的一种真三轴水力压裂多尺度多参数协同测试装置，其特征在于，应变测试模块包括应变单元、应变仪，所述应变单元内嵌于上压板、下压板、左压板和右压板中，每块压板中含4个应变单元，所述应变单元电性连接应变仪，所述应变仪电性连接计算机；
    磁法测试模块包括多匝磁法线圈、及磁法仪，所述多匝磁法线圈位于上压板、下压板、左压板和右压板中，线圈材料为金属铜，每个压板中的线圈匝数n∈[10,30]，所述多匝磁法线圈电性连接磁法仪，所述磁法仪电性连接计算机。
  9. 一种真三轴水力压裂多尺度多参数协同测试方法，应用于权利要求1-8所述的任一真三轴水力压裂多尺度多参数协同测试装置，其特征在于，包括如下步骤：
    步骤1：对取回的岩样进行加工，切割尺寸为边长100mm的方块，然后在岩石试件的顶面开设直径10mm，深度20mm的压裂口，并将压裂管置于孔内，连接压裂管与高压供水管；
    步骤2：安置、连接各压板上的传感器，连接导线，启动各测试装置；
    步骤3：封闭可密闭室仓，向可密闭室仓内注油，注满为止，且保持室温恒定；
    步骤4：启动供水装置，开始水力压裂，同时启动CT扫描模块、声发射测试模块、应变测试模块和测法测试模块；
    步骤5：试件完全破裂后，停止水力压裂，油箱回油，打开可密闭室仓，取出试件观察和拍照，同时进行数据处理与分析。
PCT/CN2022/139257 2022-11-08 2022-12-15 一种真三轴水力压裂多尺度多参数协同测试装置及方法 WO2024098509A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202211392342.3 2022-11-08
CN202211392342.3A CN115680613A (zh) 2022-11-08 2022-11-08 一种真三轴水力压裂多尺度多参数协同测试装置及方法

Publications (1)

Publication Number Publication Date
WO2024098509A1 true WO2024098509A1 (zh) 2024-05-16

Family

ID=85050793

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/139257 WO2024098509A1 (zh) 2022-11-08 2022-12-15 一种真三轴水力压裂多尺度多参数协同测试装置及方法

Country Status (2)

Country Link
CN (1) CN115680613A (zh)
WO (1) WO2024098509A1 (zh)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10150580A1 (de) * 2001-10-12 2003-05-08 Lausitzer Bergbau Verwalt Gmbh Resonant-Column-Gerät zur Bestimmung dynamischer Bodenkennziffern an Lockergesteinsproben unter Frei-Frei-Bedingungen innerhalb eines großen Spannungsintervalls
CN105547849A (zh) * 2016-03-01 2016-05-04 安徽理工大学 大尺寸层状承压岩石真三轴加卸载试验装置及测试方法
CN206740654U (zh) * 2017-05-15 2017-12-12 中国地质调查局油气资源调查中心 一种全直径页岩样品的快速综合评价装置
CN111103198A (zh) * 2019-11-22 2020-05-05 中国矿业大学(北京) 一种带ct实时扫描的真三轴水力压裂实验装置及方法
CN112985982A (zh) * 2021-02-26 2021-06-18 中国矿业大学 一种适用于真三轴加载的电法监测装置与及其使用方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10150580A1 (de) * 2001-10-12 2003-05-08 Lausitzer Bergbau Verwalt Gmbh Resonant-Column-Gerät zur Bestimmung dynamischer Bodenkennziffern an Lockergesteinsproben unter Frei-Frei-Bedingungen innerhalb eines großen Spannungsintervalls
CN105547849A (zh) * 2016-03-01 2016-05-04 安徽理工大学 大尺寸层状承压岩石真三轴加卸载试验装置及测试方法
CN206740654U (zh) * 2017-05-15 2017-12-12 中国地质调查局油气资源调查中心 一种全直径页岩样品的快速综合评价装置
CN111103198A (zh) * 2019-11-22 2020-05-05 中国矿业大学(北京) 一种带ct实时扫描的真三轴水力压裂实验装置及方法
CN112985982A (zh) * 2021-02-26 2021-06-18 中国矿业大学 一种适用于真三轴加载的电法监测装置与及其使用方法

Also Published As

Publication number Publication date
CN115680613A (zh) 2023-02-03

Similar Documents

Publication Publication Date Title
Wang et al. On the effect of stress amplitude on fracture and energy evolution of pre-flawed granite under uniaxial increasing-amplitude fatigue loads
WO2021008229A1 (zh) 一种保真环境下非接触式测量岩石波速的测试方法
CN103868993B (zh) 岩石三轴单样法多级屈服点的声学判别方法及装置
CN104198679B (zh) 一种煤岩变形破裂过程全波形同步综合监测***及方法
Zhao et al. Size effects on granite behavior under unloading rockburst test
CN105203639B (zh) 一种利用声发射法检测岩石脆度的方法
Li et al. A novel acoustic emission monitoring method of cross‐section precise localization of defects and wire breaking of parallel wire bundle
CN109613119A (zh) 一种声电渗综合监测的拟三轴压力室及试验方法
CN201653999U (zh) 一种智能超声横波纵波综合测试仪
Jia et al. Insight into rock crack propagation from resistivity and ultrasonic wave variation
Zhou et al. Dynamic mechanical properties and cracking behaviours of persistent fractured granite under impact loading with various loading rates
CN107228903A (zh) 一种用于混凝土大坝探测的水听器线阵及其制作方法
Zang et al. Experimental investigation of the fracture and damage evolution characteristics of flawed coal based on electric potential and acoustic emission parameter analyses
Chen et al. Regularity and mechanism of coal resistivity response with different conductive characteristics in complete stress–strain process
Zhang et al. Anisotropic characteristics of ultrasonic transmission velocities and stress inversion during uniaxial compression process
Yin et al. Anisotropy of quartz mica schist based on quantitative extraction of fabric information
Li et al. Study of ultrasonic wave characteristics of shale in triaxial compression tests
Zhao et al. Experimental research on the evolutionary characteristics of acoustic signals for concrete cracking under uniaxial compression
Pan et al. Study on crack propagation of the CO2 presplitting blasting empty hole effect in coal seam
WO2024098509A1 (zh) 一种真三轴水力压裂多尺度多参数协同测试装置及方法
CN110231407A (zh) 一种判断碳酸盐岩盖层有效性的方法
Wang et al. Experimental study on failure law and mechanism of red sandstone under ultrasonic vibration excitation
CN112100842B (zh) 一种识别地应力异常区及大范围测量地应力的新方法
Jia et al. The experimental research on response characteristics of coal samples under the uniaxial loading process
CN201993345U (zh) 一种混凝土结构无损测试仪

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22964974

Country of ref document: EP

Kind code of ref document: A1