CN106769517B - The experimental method of Fracture Toughness of Rocks is tested under the conditions of a kind of pore pressure - Google Patents
The experimental method of Fracture Toughness of Rocks is tested under the conditions of a kind of pore pressure Download PDFInfo
- Publication number
- CN106769517B CN106769517B CN201710095814.1A CN201710095814A CN106769517B CN 106769517 B CN106769517 B CN 106769517B CN 201710095814 A CN201710095814 A CN 201710095814A CN 106769517 B CN106769517 B CN 106769517B
- Authority
- CN
- China
- Prior art keywords
- pressure
- test piece
- confining pressure
- confining
- pore
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000011148 porous material Substances 0.000 title claims abstract description 87
- 239000011435 rock Substances 0.000 title claims abstract description 57
- 238000002474 experimental method Methods 0.000 title claims abstract description 35
- 238000012360 testing method Methods 0.000 claims abstract description 178
- 239000007788 liquid Substances 0.000 claims abstract description 71
- 239000000463 material Substances 0.000 claims abstract description 12
- 239000010720 hydraulic oil Substances 0.000 claims abstract description 11
- 238000012545 processing Methods 0.000 claims abstract description 5
- 238000007789 sealing Methods 0.000 claims description 36
- 239000000523 sample Substances 0.000 claims description 25
- 238000003825 pressing Methods 0.000 claims description 23
- 239000003921 oil Substances 0.000 claims description 22
- 238000002347 injection Methods 0.000 claims description 19
- 239000007924 injection Substances 0.000 claims description 19
- 238000010438 heat treatment Methods 0.000 claims description 13
- 229920001169 thermoplastic Polymers 0.000 claims description 11
- 239000004416 thermosoftening plastic Substances 0.000 claims description 11
- 230000006835 compression Effects 0.000 claims description 4
- 238000007906 compression Methods 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims description 3
- 238000005086 pumping Methods 0.000 claims description 3
- 235000017166 Bambusa arundinacea Nutrition 0.000 claims 6
- 235000017491 Bambusa tulda Nutrition 0.000 claims 6
- 241001330002 Bambuseae Species 0.000 claims 6
- 235000015334 Phyllostachys viridis Nutrition 0.000 claims 6
- 239000011425 bamboo Substances 0.000 claims 6
- 239000004033 plastic Substances 0.000 description 11
- 230000000087 stabilizing effect Effects 0.000 description 8
- 238000000034 method Methods 0.000 description 5
- 238000006073 displacement reaction Methods 0.000 description 4
- 238000007656 fracture toughness test Methods 0.000 description 4
- 238000007664 blowing Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000012821 model calculation Methods 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 239000003208 petroleum Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 239000012237 artificial material Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000001687 destabilization Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
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
- G01N3/12—Pressure testing
-
- 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
- G01N2203/006—Crack, flaws, fracture or rupture
- G01N2203/0067—Fracture or rupture
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The experimental method of Fracture Toughness of Rocks is tested under the conditions of a kind of pore pressure, it is characterised in that: 1) rock material is processed into the test specimen of predetermined size, carry out processing prefabricated crack to test specimen；2) test specimen is sealed between pore pressure end socket, then test specimen is placed in clamping fixture, then that clamping fixture is fixed on confining pressure is intracavitary；3) rise trolley to confining pressure cylinder pressure head and rigid frame pressure head to be adjacent to, hydraulic oil is filled to confining pressure is intracavitary, successively applies confining pressure, pore pressure to test specimen, the intracavitary liquid of confining pressure is heated to predetermined temperature, test specimen is loaded according to the loading speed of setting, record experimental data is until test specimen destroys；4) axis pressure, pore pressure, confining pressure are successively removed to test specimen, when the intracavitary liquid of confining pressure is cooled to room temperature, take out test specimen.Experimental method provided by the invention can be used in studying the influences of the factors to rock material fracture toughness such as pore pressure, confining pressure, temperature, and obtained result of study can calculate for hydraulic fracturing model provides accurate parameter support.
Description
Technical Field
The invention belongs to the field of rock mechanics in petroleum engineering, and particularly relates to an experimental method for testing fracture toughness of rocks under a pore pressure condition.
Background
The low-permeability oil and gas field in China is very rich in resources, the low-permeability reserves account for 60-70% of petroleum geological reserves explored in China in recent years, and therefore the low-permeability oil field or the ultra (ultra) low-permeability oil field can be the main resource basis for increasing the storage and the production in a period in the future. The low permeability reservoir has low porosity, low permeability, strong heterogeneity, low reserve abundance and is easy to damage, and most oil and gas wells have capacity after fracturing production increasing measures are carried out. The hydraulic fracturing technology becomes an important measure for low-permeability and ultra-low-permeability oil field transformation, and the technological level of the hydraulic fracturing technology has direct influence on the economic development of oil gas.
The fracture toughness of the rock is an index for judging whether the fracture enters a destabilization state, and is an important parameter in hydraulic fracturing design and numerical simulation. Most formation rock contains pores, the fluid in the rock pores has a certain pore pressure, and the effect of the pressure in the rock pores on its fracture toughness is significant. At the present stage, the influence of pore pressure is not considered in the research and the test of the fracture toughness of the rock material, and the fracture toughness test result of the rock material cannot reflect the real situation of the stratum. Furthermore, regardless of the effect of pore pressure inside the rock, the obtained fracture toughness test results used for model calculation will not yield accurate results. Therefore, the rock material has to be researched by a fracture toughness test under the condition of containing pore pressure.
The invention relates to an experimental method for testing fracture toughness of a rock under a pore pressure condition, which can be used for researching the influence of factors such as pore pressure, confining pressure and temperature on the fracture toughness of a rock material, and the obtained research result can provide accurate parameter support for calculation of a hydraulic fracturing model.
Disclosure of Invention
The invention relates to an experimental method for testing fracture toughness of rock under a pore pressure condition, which can be used for researching the influence of factors such as pore pressure, confining pressure and temperature on the fracture toughness of rock materials.
The technical scheme of the first aspect of the invention is as follows:
an experimental method for testing the fracture toughness of rock under the condition of pore pressure,
1. processing a rock material into a test piece with a preset size, and processing a prefabricated crack on the test piece; 2. sealing a test piece between the hole pressure end sockets, then placing the test piece into a clamping fixture, and then fixing the clamping fixture in the confining pressure cavity; 3. the trolley is lifted until the confining pressure cylinder is tightly attached to the rigid frame pressure head and generates a pre-tightening force of 0.1N-0.2N, hydraulic oil is filled into the confining pressure cylinder, confining pressure and pore pressure are sequentially applied to the test piece, liquid in the confining pressure cavity is heated to a preset temperature, the test piece is loaded according to a set loading rate, and experimental data are recorded until the test piece is damaged; 4. and removing the axial pressure, the pore pressure and the confining pressure from the test piece in sequence, and taking out the test piece when the liquid in the confining pressure cavity is cooled to room temperature.
The experimental method for testing the fracture toughness of the rock under the pore pressure condition comprises the following steps, in the step 1, the test piece is a cuboid test piece, the length of the test piece is not less than 76mm, the height of the test piece is half of the length, and the thickness of the test piece is 30 mm.
The experimental method for testing the fracture toughness of the rock under the pore pressure condition is characterized in that in the step 1, the thickness of the prefabricated crack of the test piece is not more than 1.5mm, and the length of the prefabricated crack is 0.4-0.6 times of the height of the test piece.
The experimental method for testing the fracture toughness of the rock under the pore pressure condition is as described above, wherein in step 1, the prefabricated cracks of the test piece are processed by using a wire-cut saw.
The experimental method for testing the fracture toughness of the rock under the pore pressure condition comprises the following steps that in the step 2, the test piece is heated and fixed between the two pore pressure end enclosures by adopting the thermoplastic pipes, the sealing grooves of the pore pressure end enclosures are internally provided with the sealing elements, and the sealing elements and the thermoplastic pipes are pressed by adopting the pressing elements, so that the test piece is sealed.
The experimental method for testing the fracture toughness of the rock under the pore pressure condition comprises the following steps that in the step 2, the lower end of the test piece is placed on two supporting rollers of a clamping fixture, and the supporting rollers on a pressure head of the fixture are propped against the upper end of the test piece.
The experimental method for testing the fracture toughness of the rock under the pore pressure condition comprises the following steps that in the step 2, the clamping fixture is fixed on the confining pressure cylinder base through bolts, and the confining pressure cylinder base are fixed through bolts.
The experimental method for testing the fracture toughness of the rock under the pore pressure condition comprises the following steps, in step 3, a liquid injection port and a liquid outlet are formed in the pore pressure sealing head, the test piece is sealed between the two pore pressure sealing heads, and the pore pressure is applied to the test piece by injecting liquid into the liquid injection port.
An experimental method for testing fracture toughness of rock under pore pressure conditions as described above, wherein, in step 3, the applied pore pressure should be less than the applied confining pressure.
The experimental method for testing the fracture toughness of the rock under the pore pressure condition is as described above, wherein in step 3, a heating rod is installed on the base of the confining pressure cylinder and used for heating the liquid in the confining pressure cavity.
The experimental method for testing the fracture toughness of the rock under the pore pressure condition is described above, wherein in step 3, the test piece is loaded in a displacement control manner.
The invention relates to an experimental device for testing the fracture toughness of rocks under the condition of pore pressure, which comprises a testing machine, a confining pressure cavity and a clamping fixture, wherein the testing machine comprises:
the testing machine comprises a rigid frame, wherein the confining pressure cavity is arranged in the rigid frame, the clamping fixture is arranged in the confining pressure cavity, a rigid frame pressure head is arranged at the upper end of the rigid frame of the testing machine and is used for tightly pressing the confining pressure cavity, the testing machine rigid frame below the confining pressure cavity further comprises a trolley, slide rails are arranged below the trolley, the number of the slide rails is at least two, hydraulic cylinders are arranged on the rigid frame on the inner sides of the at least two slide rails, hydraulic shafts are arranged in the hydraulic cylinders, the hydraulic cylinders and the hydraulic shafts are used for lifting or lowering the trolley, when the hydraulic cylinders and the hydraulic shafts are in a compression state, the trolley can slide along the slide rails, and the hydraulic cylinders are connected with an oil pressure pump;
the confining pressure cavity comprises a confining pressure barrel which is arranged on a confining pressure barrel base, the confining pressure barrel comprises an exhaust hole which is connected with a valve I, the confining pressure barrel base comprises a liquid injection hole which is connected with a valve II, the confining pressure barrel and the confining pressure barrel base are sealed through a sealing ring, and when liquid is injected into the confining pressure cavity, the exhaust hole is used for exhausting gas in the confining pressure cavity; when liquid in the confining pressure cavity needs to be discharged, the exhaust hole is used for pumping high-pressure gas;
the clamping fixture comprises a clamping base, wherein stand columns are arranged on the clamping base, an upper cover plate is fixed on the clamping base through four stand columns, the clamping base comprises a sliding groove, at least one supporting plate is arranged on the sliding groove, a test piece to be tested is arranged above the supporting plate, a lower plate is fixed on the clamping base through bolts, a fixture pressure head is arranged on the upper cover plate, the fixture pressure head penetrates through a through hole in the center of the upper cover plate and then contacts with the test piece to be tested, an upper ring is fixed on the outer circumference of the fixture pressure head through four positioning bolts, at least one probe hole is formed in the lower plate, a sensor is placed in the probe hole, a probe is arranged on the upper ring, the bottom of the probe is inserted into the probe hole of the lower plate, and the sensor determines the deformation of the test.
Preferably, the LVDT sensor is an abbreviation of a linear variable Differential Transformer, and belongs to a linear displacement transducer, and the LVDT sensor is an abbreviation of a linear variable Differential Transformer, and is installed in the probe hole, the upper ring is installed with a probe, and the bottom of the probe is inserted into the probe hole of the lower plate, and the LVDT sensor determines the deformation amount of the test piece by measuring the descending distance of the probe.
In any of the above schemes, preferably, the upper end surface of the support plate comprises a semicircular groove, a support roller is arranged in the groove, and the support roller can roll in the semicircular groove of the support plate.
In any one of the above aspects, preferably, the support plate is fixed to the slide groove of the clamping base by a bolt.
In any of the above schemes, preferably, the confining pressure cylinder base includes a positioning rod, the bottom edge of the confining pressure cylinder includes a positioning hole, and when the confining pressure cylinder is assembled with the confining pressure cylinder base, the positioning rod is used for aligning the confining pressure cylinder and the bolt hole on the confining pressure cylinder base.
In any of the above schemes, preferably, the hydraulic cylinder is divided into an upper pressure chamber and a lower pressure chamber by a hydraulic shaft, when liquid is filled into the lower pressure chamber, the upper pressure chamber is filled with liquid, and the hydraulic shaft rises; when liquid is filled into the upper pressure cavity, liquid is discharged from the lower pressure cavity, and the hydraulic shaft descends.
In any of the above schemes, preferably, the trolley is controlled by a hydraulic shaft to ascend and descend, and when the trolley descends to the slide rail, the trolley can slide along the slide rail.
In any of the above schemes, preferably, the confining pressure cylinder comprises a confining pressure cylinder pressure head, and the confining pressure cylinder pressure head are sealed through a sealing ring.
In any of the above schemes, preferably, the confining pressure cylinder and the confining pressure cylinder base are fixed by bolts.
In any of the above schemes, preferably, the base of the confining pressure cylinder is provided with a heating rod for heating the liquid in the confining pressure cavity.
In any of the above aspects, preferably, the clamping base is fixed on the confining pressure cylinder base by bolts.
In any of the above aspects, it is preferable that the span of the test piece is controlled by adjusting the position of the support plate on the chute, thereby adjusting the length of the test piece.
In any of the above schemes, preferably, the bottom of the fixture pressure head is provided with a groove, the groove is internally provided with a support roller, the support roller is in contact with a test piece to be tested, and more preferably, the support roller is fixed on the fixture pressure head by welding.
Preferably in any one of the above schemes, the test piece is placed between the hole pressure sealing heads, the heated plastic pipe is sleeved outside the hole pressure sealing heads and the test piece, so that the test piece and the hole pressure sealing heads are sealed together, the end part of the hole pressure sealing head is provided with a groove for placing the sealing piece, and the sealing piece and the plastic pipe are sealed by installing a compression piece outside the plastic pipe.
It is preferred in any of the above-mentioned schemes, it has notes liquid mouth and liquid outlet to open on the hole pressure head, annotate the liquid mouth with interval between the recess is not less than 8mm, and the test piece is sealed between two hole pressure heads, through annotating liquid to annotating the liquid mouth and exert pore pressure to the test piece, the tip of moulding the pipe is located annotate the liquid mouth with position between the recess is so that sealed test piece, and does not influence and annotate the liquid.
The application method of the experimental device for testing the fracture toughness of the rock under the pore pressure condition comprises the following steps: placing a test piece between hole pressure seal heads, sleeving a heated plastic pipe on the hole pressure seal heads and the outer side of the test piece, placing a sealing element in a groove at the end of the hole pressure seal head, sealing the sealing element and the plastic pipe tightly by installing a pressing element outside the plastic pipe, wherein the plastic pipe can not cover a liquid injection port, installing the sealed test piece on a supporting plate of a clamping fixture, placing the clamping fixture in a confining pressure cylinder base, connecting and sealing a confining pressure cylinder with the confining pressure cylinder base, connecting the liquid injection port of the hole pressure seal head with a pore pressure pump, connecting the confining pressure pump to a liquid injection hole of the confining pressure cylinder base, injecting liquid into the liquid injection hole of the confining pressure cylinder base through the confining pressure pump, injecting oil into the confining pressure cavity, and discharging redundant gas in the confining pressure cavity through an exhaust hole on the confining pressure cylinder;
after the confining pressure cavity is filled with oil, stopping filling the oil, closing a valve I at an injection port of a confining pressure cylinder base 5 and a valve I at an exhaust hole of a confining pressure cylinder 4, starting a confining pressure pump to pressurize the confining pressure cavity, and maintaining the set confining pressure when the set confining pressure is reached; then the pore pressure pump is started to inject liquid into the liquid injection ports of the two pore pressure seal heads 15;
finally, heating the hydraulic oil in the confining pressure cavity to a set temperature by using a heating rod;
and then starting a control recording system to record, loading the test piece according to the set loading rate, and recording experimental data until the test piece 17 is damaged.
The experimental method for testing the fracture toughness of the rock under the pore pressure condition according to the first aspect of the invention preferably adopts an experimental device for testing the fracture toughness of the rock under the pore pressure condition according to the second aspect of the invention.
Compared with the prior art, the method has the advantages that when the fracture toughness of the rock test piece is tested, confining pressure and pore pressure can be applied to the test piece, and meanwhile, the liquid in the confining pressure cavity is heated, so that the test piece is in a high-temperature environment, the environmental characteristics of high temperature, high pressure and pore pressure of stratum rock are fully simulated, and the tested fracture toughness of the rock material is more accurate. The method provided by the invention has the advantages of simple steps, convenience in operation and strong practicability, can be used for testing the fracture toughness of rock materials and artificial materials under the conditions of confining pressure, high temperature and pore pressure, obtains more accurate results, and can provide accurate fracture toughness parameters for hydraulic fracturing model calculation of oil fields and research institutions.
Drawings
The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention. Wherein,
fig. 1 is a schematic structural diagram of a preferred embodiment of an experimental apparatus for testing fracture toughness of rock under pore pressure according to a second aspect of the present invention, which may also be preferentially adopted by a preferred embodiment of the experimental method for testing fracture toughness of rock under pore pressure according to the first aspect of the present invention;
FIG. 2 is a schematic view of the overall structure of the testing machine of the embodiment shown in FIG. 1;
FIG. 3 is a schematic structural diagram of the confining pressure chamber of the embodiment shown in FIG. 1;
FIG. 4 is a schematic view of the overall structure of the clamping fixture of the embodiment shown in FIG. 1;
FIG. 5 is a schematic view of an assembly structure of the clamping fixture and the confining pressure cavity of the embodiment shown in FIG. 1;
FIG. 6 is a schematic view of a specimen seal of the embodiment shown in FIGS. 1, 4 and 5;
fig. 7 is a schematic structural view of the chuck ram 19 in the embodiment shown in fig. 4 and 5.
The reference numbers illustrate:
1. a rigid frame; 2. a rigid frame pressure head; 3. a confining pressure cylinder pressure head; 4. a confining pressure cylinder; 5. a confining pressure cylinder base; 6. positioning a rod; 7. a trolley; 8. a slide rail; 9. a hydraulic shaft; 10. a hydraulic cylinder; 11. clamping the base; 12. a column; 13. a support plate; 14. a support roller; 15. sealing the end by hole pressure; 16. a compression member; 17. a test piece; 18. an upper cover plate; 19. a clamp press head; 20. winding; 21. fixing the bolt; 22. a probe; 23. a lower plate; 111. a chute; 151. a liquid outlet; 152. and a liquid injection port.
Detailed Description
In order to more clearly understand the technical features, objects, and effects of the present invention, a detailed embodiment of the first aspect of the present invention will now be described with reference to the accompanying drawings.
Example 1
An experimental method for testing fracture toughness of rock under a pore pressure condition comprises the following steps:
1. preparation of test pieces
A rock material is cut into a cuboid test piece 17 with the length, the width and the height of 76mm, 30mm and 38mm by a rock slicer, and then a prefabricated crack with the thickness of 1mm and the length of 15mm is cut in the middle of the test piece 17 by a wire cutting saw.
2. Sealing and fixing of test pieces
Firstly, the processed test piece 17 and the two hole pressure end sockets 15 are sleeved by a thermoplastic pipe, the thermoplastic pipe covers the sealing element on the hole pressure end socket 15 but cannot cover the liquid injection port II, and then the thermoplastic pipe is blown soft by hot air blowing, and the test piece 17 and the hole pressure end sockets 15 are sealed by the thermoplastic pipe. After the thermoplastic pipe is cooled, the sealing element on the hole pressure end socket 15 and the thermoplastic pipe are pressed by the pressing element 16, so that the test piece 17 is sealed.
The test piece 17 is then placed on the two support rollers 14 of the clamping fixture, and the fixture ram 19 is placed in the upper cover plate 18 so that the support rollers 14 below the fixture ram 19 are against the test piece 17. The upper ring 20 containing the probe 22 is then secured to the fixture ram 19 by the anchor bolts 21, and the bottom of the probe is inserted into the LVDT sensor hole in the lower plate 23.
The clamping fixture is placed on the confining pressure cylinder base 5, the clamping base 11 and the confining pressure cylinder base 5 are fixed together through bolts, and the liquid injection pipeline is connected to the liquid injection port 152 of the hole pressure seal head 15. Then hoisting the confining pressure barrel 4 to the confining pressure barrel base 5 by using hoisting equipment, aligning bolt holes in the confining pressure barrel 4 to bolt holes in the confining pressure barrel base 5 by using the positioning rods 6, and fixing the confining pressure barrel 4 and the confining pressure barrel base 5 together by using bolts. And finally, pushing the trolley 7 into the rigid frame 1 of the testing machine along the slide rail 8, and aligning the concave hole at the bottom of the trolley 7 with the hydraulic shaft 9.
3. Fracture toughness test
Before testing, firstly, a pressure stabilizing source multi-channel is started to inject oil to a bottom pressure cavity of the hydraulic cylinder 10, hydraulic oil in the pressure cavity at the top of the hydraulic cylinder 10 flows back into the pressure stabilizing source, the hydraulic shaft 9 pushes the trolley 7 to move upwards, and when the confining pressure cylinder pressure head 3 is in contact with the rigid frame pressure head 2 and generates a pre-tightening force of 0.1KN, the trolley 7 stops rising.
And then, the multi-channel of the pressure stabilizing source is started to inject oil into the confining pressure cavity, and redundant gas in the confining pressure cavity is discharged through the vent holes in the confining pressure barrel 4. And after the confining pressure cavity is filled with oil, stopping filling the oil, and closing a valve at the oil filling port of the confining pressure cylinder base 5 and a valve at the exhaust hole of the confining pressure cylinder 4. And starting the confining pressure pump to pressurize the confining pressure cavity, and maintaining the confining pressure in the confining pressure cavity unchanged when the set confining pressure is reached. And starting the pore pressure pump, injecting liquid into the liquid injection port II of the pore pressure seal head 15, and maintaining the pore pressure constant when the test piece 17 is fully saturated and reaches the set pore pressure. And starting the heating rod to heat the liquid in the confining pressure cavity, so that the liquid in the confining pressure cavity reaches and maintains the set temperature.
During testing, the control recording system is started, the test piece 17 is loaded in a displacement loading mode, the test piece 17 is loaded at a loading speed of 0.01mm/min, data such as axial displacement and axial pressure are recorded, and when the test piece 17 is damaged, loading is stopped and data are recorded.
4. Dismantle test piece
And after the test piece 17 is damaged, stopping heating, and after the liquid in the confining pressure cavity is cooled to room temperature, descending the trolley 7 to enable the axial pressure applied to the test piece 17 to reach 0.1 KN. And starting the pore pressure pump, removing the pore pressure applied on the test piece 17, and then starting the confining pressure pump to remove the confining pressure. And opening a valve at a liquid inlet of the confining pressure cylinder base 5 and a valve at an exhaust hole of the confining pressure cylinder 4, connecting an exhaust pipe connected to the exhaust hole of the confining pressure cylinder 4 to a pressure stabilizing gas station, and reversely exhausting the hydraulic oil in the confining pressure cavity into a pressure stabilizing source by using air pressure.
After the hydraulic oil in the confining pressure cavity is exhausted, the trolley 7 is descended to the slide rail 8, and the trolley 7 is pushed out of the testing machine rigid frame 1. And then the confining pressure barrel 4 is disassembled, the confining pressure barrel 4 is lifted away from the trolley 7 by using hoisting equipment, and finally the test piece 17 is disassembled from the clamping fixture, so that the whole experiment process is completed.
Example 2
Fig. 1-6 show a preferred embodiment of an experimental apparatus for testing fracture toughness of rock under pore pressure conditions, which is used in the experimental method described in example 1, and comprises a testing machine, a confining pressure cavity and a clamping fixture. The testing machine comprises a testing machine rigid frame 1, a rigid frame pressure head 2, a trolley 7, a sliding rail 8, a hydraulic shaft 9 and a hydraulic cylinder 10, wherein the rigid frame pressure head 2 is installed at the upper end of the testing machine rigid frame 1, the hydraulic cylinder 10 is installed at the lower end of the testing machine rigid frame 1, the hydraulic shaft 9 is arranged in the hydraulic cylinder 10, the trolley 7 is located on a platform of the testing machine rigid frame 1, the trolley 7 is installed on the hydraulic cylinder 10, and when the hydraulic cylinder 10 descends to the lowest position, the trolley 7 can slide along the sliding rail 8; the confining pressure cavity comprises a confining pressure cylinder pressure head 3, a confining pressure cylinder 4, a confining pressure cylinder base 5 and a positioning rod 6; the clamping fixture comprises a clamping base 11, stand columns 12, supporting plates 13, supporting rollers 14, hole pressing end sockets 15, pressing pieces 16, an upper cover plate 18, a fixture pressure head 19, an upper ring 20, fixing bolts 21, probes 22 and a lower plate 23, wherein the upper cover plate 18 is fixed on the clamping base 11 through the four stand columns 12, the two supporting plates 13 are fixed on a sliding rail of the clamping base 11 through bolts, the supporting rollers 14 are placed in semicircular grooves of the supporting plates 13, the hole pressing end sockets 15 are fixed at two ends of the test pieces 17, the lower plate 23 is fixed on the clamping base 11 through the bolts, the upper ring 20 is fixed on the fixture pressure head 19 through the four fixing bolts 21, and the probes 22 are located between the upper ring 20 and the lower plate.
Further, the structure of the tester is shown in fig. 2, when loading, the hydraulic shaft 9 is pushed to move upwards by pumping liquid into the bottom pressure cavity of the hydraulic cylinder 10, so as to push the trolley 7 to move upwards; when the test machine is unloaded, liquid is pumped into the upper pressure cavity of the hydraulic cylinder 10 to push the hydraulic shaft 9 to move downwards, so that the trolley 7 is driven to move downwards, and when the trolley 7 completely contacts the upper slide rail 8, the trolley 7 can be pushed out of the test machine rigid frame 1 along the slide rail 8.
Further, the structure of the confining pressure cavity is as shown in fig. 3, a confining pressure cylinder 4 is sealed with a confining pressure cylinder pressure head 3 and a confining pressure cylinder base 5 through a sealing ring, the top of the confining pressure cylinder 4 is provided with an exhaust hole, a positioning rod 6 is positioned on the confining pressure cylinder base 5, the positioning rod 6 is used for aligning the confining pressure cylinder 4 and the confining pressure cylinder base 5, and the confining pressure cylinder 4 and the confining pressure cylinder base 5 are fixed through bolts.
Further, the structure of the clamping fixture is shown in fig. 4, as shown in fig. 5, during the test, the clamping base 11 is fixed on the confining pressure cylinder base 5 through bolts, a sliding groove 111 is formed on the clamping base 11, and the supporting plate 13 can be fixed at any position on the sliding groove 111 of the clamping base 11; the upper end of the supporting plate 13 is provided with a semicircular groove, and the supporting roller 14 can roll in the semicircular groove of the supporting plate 13; the hole pressure seal head 15 comprises a liquid outlet 151 and a liquid injection port 152, a groove is formed in the end part of the hole pressure seal head 15, and a sealing element is embedded in the groove; as shown in fig. 7, the bottom of the fixture pressing head 19 is provided with a groove, the support roller 14 is fixed in the groove at the lower part of the fixture pressing head 19 by welding, and the support roller 14 in the groove is used for pressing the test piece 17; the lower plate 23 is provided with two probe holes, in which LVDT sensors are placed, which determine the deformation of the test piece 17 by measuring the distance the probe 22 is lowered.
In addition, the groove on the hole pressing end socket 15 is used for placing a sealing element, when the test piece 17 is sealed, the test piece 17 is sealed between the two hole pressing end sockets 15 through a heated plastic pipe, then the sealing element is pressed by the pressing piece 16, so that the sealing between the test piece 17 and the hole pressing end socket 15 is realized, and the end part of the sealed plastic pipe is located between the pressing piece 16 and the liquid injection port 152. During the experiment, the notes liquid mouth 152 of pore pressure head 15 is connected external notes liquid pipeline to through external notes liquid pipeline connection pore pressure pump, before exerting pore pressure, at first exert the confined pressure to test piece 17, then pour into high-pressure liquid into test piece 17 through the notes liquid mouth 152 of pore pressure head 15, thereby realize exerting pore pressure to test piece 17.
The working principle of the invention is as follows:
sleeving the processed test piece 17 and the two hole pressing end sockets 15 by using heated plastic pipes, blowing the plastic pipes soft by using hot air blowing, sealing the test piece 17 and the hole pressing end sockets 15, placing sealing elements in sealing grooves of the hole pressing end sockets 15, and sealing the sealing elements on the hole pressing end sockets 15 and the thermoplastic pipes by using pressing elements 16. The sealed test piece 17 is then placed on two supporting rollers 14 which clamp the fixture, the fixture pressure head 19 is placed in the upper cover plate 18, the supporting rollers 14 on the fixture pressure head 19 are pressed against the test piece 17, then the upper ring 20 containing the probe 22 is fixed on the fixture pressure head 19 by the fixing bolts 21, and the bottom of the probe 22 is inserted into the LVDT sensor hole of the lower plate 23. And then, placing a clamping fixture on a confining pressure barrel base 5, fixing the clamping fixture on the confining pressure barrel base 5 by using a bolt, hoisting a confining pressure barrel 4 to the confining pressure barrel base 5 by using hoisting equipment, sleeving the confining pressure barrel 4 outside the clamping fixture on the confining pressure barrel base 5, fixing the confining pressure barrel 4 and the confining pressure barrel base 5 together by using the bolt, pushing a trolley 7 into a rigid frame of a testing machine as shown in figure 1, aligning a concave hole at the bottom of the trolley 7 with a hydraulic shaft 9, and at the moment, superposing the confining pressure barrel base 5 and the confining pressure barrel 4 on the trolley 7 with central shafts of the trolley 7, the hydraulic shaft 9 and the rigid frame pressure head 2.
During the test, the oil hydraulic pump is started to inject oil into the pressure cavity at the bottom of the hydraulic cylinder 10, the hydraulic oil at the top of the hydraulic cylinder 10 flows back into the pressure stabilizing source, the hydraulic shaft 9 pushes the trolley 7 to move upwards, and when the confining pressure cylinder pressure head 3 contacts the rigid frame pressure head 2 and generates 0.1KN pre-tightening force, the trolley 7 stops rising. Then, starting the confining pressure pump, injecting oil into the confining pressure cavity, and discharging redundant gas in the confining pressure cavity through an exhaust hole in the confining pressure cylinder 4; and after the confining pressure cavity is filled with oil, stopping filling the oil, and closing a valve at the liquid filling port of the confining pressure cylinder base 5 and a valve at the exhaust hole of the confining pressure cylinder 4. Then starting a confining pressure pump to pressurize the confining pressure cavity, and maintaining the set confining pressure after the set confining pressure is reached; starting the pore pressure pump again, injecting liquid into the liquid injection ports 152 of the two pore pressure seal heads 15, and maintaining the set pore pressure when the test piece 17 is fully saturated and reaches the set pore pressure; and finally, heating the hydraulic oil in the confining pressure cavity to a set temperature by using a heating rod. And then starting a control recording system, loading the test piece according to the set loading rate, and recording the experimental data until the test piece 17 is damaged.
And after the test piece 17 is damaged, stopping heating, and after the liquid in the confining pressure cavity is cooled to room temperature, descending the trolley 7 to enable the axial pressure applied to the test piece 17 to reach 0.1 KN. And starting the pore pressure pump, removing the pore pressure applied on the test piece 17, and then starting the confining pressure pump to remove the confining pressure. And opening a valve at a liquid inlet of the confining pressure cylinder base 5 and a valve at an exhaust hole of the confining pressure cylinder 4, connecting an exhaust pipe connected to the exhaust hole of the confining pressure cylinder 4 to a pressure stabilizing gas station, and reversely exhausting the hydraulic oil in the confining pressure cavity into a pressure stabilizing source by using air pressure. After the hydraulic oil in the confining pressure cavity is exhausted, the trolley 7 is descended to the slide rail 8, and the trolley 7 is pushed out of the testing machine rigid frame 1. And then the confining pressure barrel 4 is disassembled, the confining pressure barrel 4 is lifted away from the trolley 7 by using hoisting equipment, and finally the test piece 17 is disassembled from the clamping fixture, so that the whole experiment process is completed.
The above description is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. Any equivalent changes and modifications that can be made by one skilled in the art without departing from the spirit and principles of the invention should fall within the protection scope of the invention.
Claims (9)
1. The utility model provides an experimental method of test rock fracture toughness under pore pressure condition, adopts the experimental apparatus of test rock fracture toughness under the pore pressure condition, and the device includes testing machine, confined pressure chamber and centre gripping anchor clamps: the testing machine comprises a rigid frame (1), wherein a confining pressure cavity is arranged in the rigid frame (1), the clamping fixture is arranged in the confining pressure cavity, a rigid frame pressure head (2) is arranged at the upper end of the rigid frame (1) of the testing machine and used for pressing the confining pressure cavity, the rigid frame (1) below the confining pressure cavity further comprises a trolley (7), slide rails (8) are arranged below the trolley (7), the number of the slide rails (8) is at least two, a hydraulic cylinder (10) is arranged on the rigid frame (1) at the inner sides of the at least two slide rails (8), a hydraulic shaft (9) is arranged in the hydraulic cylinder (10), the hydraulic cylinder (10) and the hydraulic shaft (9) are used for lifting or lowering the trolley (7), when the hydraulic cylinder (10) and the hydraulic shaft (9) are in a compression state, the trolley (7) can slide along the slide rails (8), and the hydraulic cylinder (10) is connected with an oil pressure pump; the confining pressure cavity comprises a confining pressure barrel (4), the confining pressure barrel (4) is arranged on a confining pressure barrel base (5), the confining pressure barrel (4) comprises an exhaust hole, the exhaust hole is connected with a first valve, the confining pressure barrel base (5) comprises a liquid injection hole, the liquid injection hole is connected with a second valve, the confining pressure barrel (4) and the confining pressure barrel base (5) are sealed through a sealing ring, and when liquid is injected into the confining pressure cavity, the exhaust hole is used for discharging gas in the confining pressure cavity; when liquid in the confining pressure cavity needs to be discharged, the exhaust hole is used for pumping high-pressure gas; the centre gripping anchor clamps include centre gripping base (11), are equipped with stand (12) on this centre gripping base (11), and upper cover plate (18) are fixed through four stand (12) on centre gripping base (11), and this centre gripping base (11) include spout (111), set up at least one backup pad (13) on this spout (111), test piece (17) that awaits measuring are installed to this backup pad (13) top, hypoplastron (23) pass through the bolt fastening on centre gripping base (11), set up anchor clamps pressure head (19) on upper cover plate (18), through-hole at upper cover plate (18) center is passed in this anchor clamps pressure head (19), then with test piece (17) the contact of awaiting measuring, its characterized in that: the upper ring (20) is fixed on the outer circumference of the clamp pressure head (19) through four positioning bolts, the lower plate (23) is provided with at least one probe hole, a sensor is arranged in the probe hole, the upper ring (20) is provided with a probe (22), the bottom of the probe (22) is inserted into the probe hole of the lower plate (23), and the sensor determines the deformation of the test piece (17) by measuring the descending distance of the probe (22);
the experimental method for testing the fracture toughness of the rock under the pore pressure condition comprises ①, processing the rock material into a test piece with a preset size, processing a prefabricated crack on the test piece, ②, sealing the test piece between hole pressure end sockets, placing the test piece into a clamping fixture, fixing the clamping fixture in a confining pressure cavity, ③, raising a trolley until the confining pressure cylinder is tightly attached to a rigid frame pressure head and generates a pre-tightening force of 0.1N-0.2N, filling hydraulic oil into the confining pressure cylinder, sequentially applying confining pressure and pore pressure on the test piece, heating liquid in the confining pressure cavity to a preset temperature, loading the test piece according to a set loading rate, recording experimental data until the test piece is damaged, ④, sequentially removing axial pressure, pore pressure and confining pressure on the test piece, and taking out the test piece when the liquid in the confining pressure cavity is cooled to room temperature.
2. The experimental method for testing fracture toughness of rock under pore pressure conditions as claimed in claim 1, wherein: the test piece is a cuboid test piece, the length of the test piece is not less than 76mm, the height of the test piece is half of the length, and the thickness of the test piece is 30 mm.
3. The experimental method for testing fracture toughness of rock under pore pressure conditions as claimed in claim 1, wherein: the thickness of the prefabricated crack of the test piece is not more than 1.5mm, and the length of the prefabricated crack is 0.4-0.6 times of the height of the test piece.
4. The experimental method for testing fracture toughness of rock under pore pressure conditions as claimed in claim 1, wherein: the test piece adopts the heating of thermoplastic pipe to fix between two pore pressure head, contains the sealing member in the seal groove of pore pressure head, adopts to compress tightly the piece and dies sealing member and thermoplastic pipe pressure to the realization is sealed the test piece.
5. The experimental method for testing fracture toughness of rock under pore pressure conditions as claimed in claim 1, wherein: the applied pore pressure should be less than the applied confining pressure.
6. The experimental method for testing fracture toughness of rock under pore pressure conditions as claimed in claim 1, wherein: the upper end surface of the supporting plate (13) comprises a semicircular groove, a supporting roller (14) is arranged in the groove, and the supporting roller (14) can roll in the semicircular groove of the supporting plate (13).
7. The experimental method for testing fracture toughness of rock under pore pressure conditions as claimed in claim 1, wherein: the supporting plate (13) is fixed on the sliding groove (111) of the clamping base (11) through a bolt.
8. The experimental method for testing fracture toughness of rock under pore pressure conditions as claimed in claim 1, wherein: enclose and press a section of thick bamboo base (5) including locating lever (6), enclose the bottom edge of pressing a section of thick bamboo (4) including the locating hole, when enclosing press a section of thick bamboo (4) and enclose and press a section of thick bamboo base (5) assembly together, locating lever (6) are used for lining up encloses and presses a section of thick bamboo (4) and encloses the bolt hole on pressing a section of thick bamboo base (5).
9. The experimental method for testing fracture toughness of rock under pore pressure condition as claimed in claim 4, wherein: it has notes liquid mouth (II) and liquid outlet (I) to open on pore-pressure head (15), annotate the liquid mouth with interval between the seal groove is not less than 8mm, and the test piece is sealed between two pore-pressure heads (15), through annotating liquid to annotating the liquid mouth and apply pore pressure to the test piece, the tip that the thermoplasticity was managed is located annotate the liquid mouth with position between the seal groove is so that sealed test piece (17), and does not influence and annotate the liquid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710095814.1A CN106769517B (en) | 2017-02-22 | 2017-02-22 | The experimental method of Fracture Toughness of Rocks is tested under the conditions of a kind of pore pressure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710095814.1A CN106769517B (en) | 2017-02-22 | 2017-02-22 | The experimental method of Fracture Toughness of Rocks is tested under the conditions of a kind of pore pressure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106769517A CN106769517A (en) | 2017-05-31 |
| CN106769517B true CN106769517B (en) | 2019-06-14 |
Family
ID=58957752
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710095814.1A Active CN106769517B (en) | 2017-02-22 | 2017-02-22 | The experimental method of Fracture Toughness of Rocks is tested under the conditions of a kind of pore pressure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106769517B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107451369B (en) * | 2017-08-11 | 2020-06-16 | 山东南山铝业股份有限公司 | Fracture toughness determination method and apparatus |
| CN112213226B (en) * | 2017-09-07 | 2023-04-07 | 中国石油大学(华东) | Experimental device and method for researching high-temperature reservoir fracturing transformation micro-fracturing mechanism |
| CN109870349B (en) * | 2019-03-29 | 2023-10-27 | 中国矿业大学 | High-temperature high-pressure hydraulic fracturing clamp holder and test method thereof |
| CN113899630B (en) * | 2021-12-09 | 2022-03-04 | 西南石油大学 | Dynamic and static external load temperature and pressure coupling environment hard rock multi-scale crushing parameter evaluation method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103411870A (en) * | 2013-08-02 | 2013-11-27 | 中国海洋石油总公司 | Experimental device for simulating dynamic destruction of stratum rocks |
| KR101417609B1 (en) * | 2013-03-15 | 2014-07-09 | 주식회사 포스코 | Centering unit and fracture toughness testing apparatus having thereof |
| CN104990772A (en) * | 2014-08-12 | 2015-10-21 | 中国石油大学(北京) | Base apparatus for prefabricating crack having any inclination angle in artificial specimen |
| CN105784489A (en) * | 2016-02-29 | 2016-07-20 | 辽宁工程技术大学 | Test device and method for coal body deformation under action of true triaxial stress, seepage, adsorption and desorption |
| CN106153441A (en) * | 2016-07-26 | 2016-11-23 | 西安交通大学 | The material fracture toughness test system and method being flushed with hydrogen under environment based on controllable temperature electrochemistry |
-
2017
- 2017-02-22 CN CN201710095814.1A patent/CN106769517B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101417609B1 (en) * | 2013-03-15 | 2014-07-09 | 주식회사 포스코 | Centering unit and fracture toughness testing apparatus having thereof |
| CN103411870A (en) * | 2013-08-02 | 2013-11-27 | 中国海洋石油总公司 | Experimental device for simulating dynamic destruction of stratum rocks |
| CN104990772A (en) * | 2014-08-12 | 2015-10-21 | 中国石油大学(北京) | Base apparatus for prefabricating crack having any inclination angle in artificial specimen |
| CN105784489A (en) * | 2016-02-29 | 2016-07-20 | 辽宁工程技术大学 | Test device and method for coal body deformation under action of true triaxial stress, seepage, adsorption and desorption |
| CN106153441A (en) * | 2016-07-26 | 2016-11-23 | 西安交通大学 | The material fracture toughness test system and method being flushed with hydrogen under environment based on controllable temperature electrochemistry |
Non-Patent Citations (1)
| Title |
|---|
| 砂岩Ⅰ型断裂韧度及其与强度参数的相关性研究;邓华锋等;《岩土力学》;20121231;第33卷(第12期);3585-3591 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106769517A (en) | 2017-05-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106644740B (en) | The experimental provision of Fracture Toughness of Rocks is tested under the conditions of a kind of pore pressure | |
| CN106769517B (en) | The experimental method of Fracture Toughness of Rocks is tested under the conditions of a kind of pore pressure | |
| CN107748110B (en) | Microcomputer-controlled electro-hydraulic servo rock triaxial dynamic shear seepage coupling test method | |
| CN107782634B (en) | Microcomputer-controlled electro-hydraulic servo rock triaxial dynamic shear seepage coupling test device | |
| CN108952659B (en) | Visual supercritical carbon dioxide fracturing physical simulation test method | |
| CN110595909B (en) | True triaxial test system and method for simulating deep rock mass under different temperature influences | |
| CN106437694B (en) | Coal powder discharge change monitoring device for simulating coal seam fracturing action and experimental method thereof | |
| CN102748017B (en) | Self-support fracture testing and analyzing device and method for oil-gas field development | |
| CN209875145U (en) | Oil gas well cement sheath sealing integrity testing arrangement | |
| CN101122552B (en) | Reservoir casing perforation anti-crushing simulation test method and simulation test machine | |
| CN102373919B (en) | Experimental apparatus for evaluating coalbed methane cave well completion | |
| CN201794583U (en) | Well completion evaluation experiment device for coal bed methane cave | |
| CN210775067U (en) | True triaxial test system for simulating different temperature influences of deep rock mass | |
| CN206531731U (en) | The experimental provision of Fracture Toughness of Rocks is tested under the conditions of a kind of pore pressure | |
| CN113959853A (en) | Experimental simulation device for rock stratum fracturing and radial seepage under high-temperature condition | |
| CN117723406A (en) | True three-dimensional stress seepage coupling test system and method for deep geological reservoir rock mass | |
| CN106546491B (en) | Detachable rock mass lateral load and water pressure coupling auxiliary test device | |
| CN116411959A (en) | Oil-gas well fracturing test device and method for simulating real stratum environment | |
| CN112683748B (en) | Device and method for testing dynamic permeability of coal rock in fracturing physical simulation process | |
| CN212964408U (en) | A high-efficient experimental apparatus for rock mechanics triaxial experiment | |
| CN211426111U (en) | Experimental device for non-uniform confining pressure of hydraulic simulation sleeve pipe | |
| CN112146991A (en) | A high-efficient experimental apparatus for rock mechanics triaxial experiment | |
| CN115165585A (en) | Rock triaxial mechanical parameter testing device and method under carbon dioxide contact | |
| CN114778401B (en) | Coal rock permeability measuring device and method under rock burst simulating condition | |
| CN206573511U (en) | Test the true triaxial device of thermal conductivity factor under rock temperature and stress variation |
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 |