CN103089247A - Gas pressure testing device and method of coal measure strata rich in water - Google Patents
Gas pressure testing device and method of coal measure strata rich in water Download PDFInfo
- Publication number
- CN103089247A CN103089247A CN2013100706941A CN201310070694A CN103089247A CN 103089247 A CN103089247 A CN 103089247A CN 2013100706941 A CN2013100706941 A CN 2013100706941A CN 201310070694 A CN201310070694 A CN 201310070694A CN 103089247 A CN103089247 A CN 103089247A
- Authority
- CN
- China
- Prior art keywords
- pressure
- water
- gas
- desorption tank
- valve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
Abstract
The invention relates to a gas pressure testing device and a method of coal measure strata rich in water. The method comprises a site test part and a laboratory test part. The site test part comprises that a desorption device composed of a rubber ball, a thermometer, a liquid level scale, a latex film, a pressure gage and a desorption tank is adopted after pressure of a pressure-measuring drill hole is stable, gas quantity dissolved in water in the desorption tank is desorbed in site, and meanwhile initial water temperature and water temperature when desorption is balanced are recorded, and collected water is brought back to a laboratory. The laboratory test part comprises that solubility of gas in the water collected in the site under specific water temperature condition and different gas pressure is tested, coal seam gas pressure can be inferred according to degassing amount in the site. The testing method is easy and convenient to operate, and testing cost is saved. The test of coal seam gas pressure can be practicable in the circumstance that a pressuring chamber is filled with water after hole sealing of the pressing-measuring hole is succeeded, and therefore great convenience is brought to coal seam gas pressure testing persons.
Description
Technical field
the present invention relates to a kind of equipment and method of testing gas pressure, especially be applicable in on-the-spot piezometer tube have under water condition determine gas pressure be rich in water coal measure strata gas pressure test equipment and method.
Background technology
the mining conditions of China's coal-mine is poor, in recovery process, be subject to gas, water, fire, dust, press and the impact of heat evil, wherein gas is the first killer of China's coal-mine.Present stage, the coal mine gas disaster is again with coal and Gas Outburst harmfulness maximum, and the difficulty of prevention and cure of coal and Gas Outburst is also universally acknowledged.The coal mine gas disaster is all that gas bearing capacity is higher to be caused because the gas pressure in coal seam own is larger.For effective control coal-bed gas, need understand fully that coal-bed gas is composed to deposit situation, and coal-bed gas pressure is one of major parameter of prediction Coal Seam Outburst Hazard, on-the-spot Accurate Determining coal-bed gas pressure is particularly important.
method for measuring gas pressure of coal bed be by rock gangway or coal road to the place construction drill of scheduled measurement gas pressure, form pressure measuring chamber after sealing of hole, link up pressure measuring chamber and pressure meter with piezometer tube, thereby measure the gas pressure in coal seam.If can guarantee that drilling and sealing is tightly air tight in measuring, pressure measurements is comparatively accurate, and the method for sealing of the mensuration gas pressure that China is commonly used can be divided into 5 kinds by its technique: 1. yellow mud sealing of hole; 2. light water mud sealing of hole; 3. cushion rubber-mucus sealing of hole; 4. capsule-mucus sealing of hole; 5. polyurethane foam sealing of hole.Wherein the cardinal principle of method one, two, five is to utilize solid (or liquid solidifies) thing to come the space between filling piezometer tube and drill hole wall, to stop the leakage of coal-bed gas; And method three and four refers between the solids of the two ends of closed section, inject mucus, the pressure of mucus is higher than the gas pressure of estimating, and the space between infiltration hole wall and solids, to stop the leakage of coal-bed gas.
the most coal measure stratas of China's mine have aquifer, are subject to the impact of water, and the gas pressure measurement success rate reduces greatly.Water is mainly derived from coal seam and country rock, the Sandstone Water in the country rock of coal seam especially, and hydraulic pressure is relatively high, the pressure measurement air chamber that causes holing water inlet, the pressure of measuring out is not the original gas pressure in coal seam.Be rich in determination of coal seam gas pressure under water condition for coal measure strata, domestic main employing high pressure slip-casting water-blocking method solves at present, but is subject to the impact of grouting process factor, can't fully water blocking be lived, particularly, under the aqueous conditions in coal seam own, determination of coal seam gas pressure is difficulty particularly.After the success of pressure measuring drill hole sealing of hole, in the situation of intaking in pressure measuring chamber, if judge the coal-bed gas pressure test crash, can cause serious engineering waste, and, once the gas pressure that runs into the moisture condition of pressure measuring drill hole and can't judge coal seam, the prediction of coal supply and gas outburst risk brings difficulty.
gas is slightly soluble in water, and the solubility of gas in water is subject to the impact of the factors such as temperature, pressure, water quality.Generally, be rich in mineral matter in mine water, under different quality the same terms to the different solubility of gas; Affected by ground temperature, different mines or same mine different buried depth, the water temperature difference of coal measure strata, under different gas pressures, in boring, water there are differences the solubility of gas.Therefore, include the regimen condition running into pressure measuring drill hole, can be by measuring the solubility of water to gas under site environment, in conjunction with the test result of on-the-spot water sample to gas solubility under the different gas pressures of laboratory tests, the anti-coal-bed gas pressure that pushes away, provide a kind of new method for mensuration is rich in water coal measure strata gas pressure.
Summary of the invention
can't determine the problem of coal-bed gas pressure while in order to solve in the pressure measuring drill hole be rich in the water coal measure strata, water being arranged, the invention provides a kind of water coal measure strata gas pressure test equipment and method of being rich in, this test equipment and method adopt the difference of gas solubility in water under different condition, by on-the-spot test and the anti-coal-bed gas pressure that pushes away of laboratory tests, provide a kind of new way for being rich in determination of coal seam gas pressure in the water coal measure strata, in addition, this method of testing is easy and simple to handle, saved testing cost, and in the situation that intake in pressure measuring chamber after the success of pressure measuring drill hole sealing of hole, still can practical test coal-bed gas pressure, for coal mine gas, the tester brings great convenience.
the technical solution adopted for the present invention to solve the technical problems is: this test equipment and method testing arrangement used comprises rubber ball, outlet valve, desorption tank, wire lath, pressure meter I, needle valve, pressure meter II, valve I, latex film, thermometer, Liquid level scale; The bottom of described desorption tank vertically is provided with Liquid level scale and thermometer, the upper side of desorption tank is connected with the rubber ball by outlet valve, the top, side of desorption tank also is communicated with the pressure meter I, the edge of described latex film is fixed on the upper edge edge of desorption tank, the upper can of desorption tank covers and has the through hole be connected with the external world, be distributed with wire lath in through hole, the lower side of desorption tank is connected with the side of needle valve by the valve I, the needle valve entrance is connected with piezometer tube by conduit, and the junction of needle valve and conduit is provided with the pressure meter II.
this method of testing comprises on-the-spot test and laboratory tests two parts, and its concrete steps are as follows:
1. after the sealing of hole success of gas pressure testing bore holes and pressure meter II numerical stability, open the pressure meter needle valve and find, in pressure tap, water is arranged, close at once needle valve, pressure meter II numerical value returns to raw value very soon, judges that this place hydraulic pressure is higher;
2. the desorption tank is connected with the pressure meter needle valve, latex film is divided into upper and lower two spaces by the desorption tank in the desorption tank, adopts the rubber ball desorption tank lower space gas of finding time, and closes the outlet valve between desorption tank and rubber ball, open pressure meter aciculiform valve, in piezometer tube, water enters the desorption tank;
3. in piezometer tube, water enters in desorption tank process, latex film upwards expands, and the gas of desorption tank upper space is discharged by the top pore, when the rising phenomenon appears in desorption tank pressure gauge I, close immediately the valve I between desorption tank and pressure meter needle valve, and record water temperature T 1 now;
4., after gas desorption balance in the desorption tank, the desorption tank is set level after a while,, record desorption innage and upper gas height, record this moment water temperature T 2 simultaneously, calculate gas solubility in water, complete the on-the-spot test step, gather water sample and send laboratory to be tested;
5. by the dissolution equilibrium tank of collection in worksite water sample injection experiments chamber, compensator is put into to the water bath with thermostatic control II, water bath with thermostatic control II water temperature is set to T1, compensator is connected by pressure maintaining valve with the methane steel cylinder, open methane steel cylinder and pressure maintaining valve, inject methane and be stabilized in setup pressure value P in compensator, opening water bath with thermostatic control II and mixer, being dissolved the mash gas balancing experiment;
6. after balance to be dissolved, close mixer, by on-the-spot test, desorption tank used is placed in another one water bath with thermostatic control I, water temperature is set to T2, the desorption tank is connected with compensator, open the valve II, in compensator, gas dissolving saturated aqueous solution enters in the desorption tank, carry out the operation of step 3 and step 4, can draw when pressure of methane is P the solubility of on-the-spot water sample to gas, change the methane gas pressure in the injection balance tank, repeat aforesaid operations, can draw under different methane gas pressure P conditions the solubility of on-the-spot water sample to methane;
7. survey the solubility of on-the-spot water sample to gas according to laboratory, find out on-the-spot test water to the corresponding balance methane gas of gas solubility values pressure, be the coal-bed gas pressure of this pressure measuring drill hole actual measurement.
the invention has the beneficial effects as follows, this test equipment and method adopt the difference of gas solubility in water under different condition, by on-the-spot test and the anti-coal-bed gas pressure that pushes away of laboratory tests, provide a kind of new way for being rich in determination of coal seam gas pressure in the water coal measure strata, in addition, this method of testing is easy and simple to handle, saved testing cost, and in the situation that intake in pressure measuring chamber after the success of pressure measuring drill hole sealing of hole, still can practical test coal-bed gas pressure, for coal mine gas, the tester brings great convenience.
The accompanying drawing explanation
below in conjunction with drawings and Examples, the invention will be further described.
fig. 1 is the installation site schematic diagram of used test device of the present invention.
fig. 2 is the structural principle schematic diagram of used test device of the present invention.
fig. 3 is that used test device of the present invention is along I-I sectional drawing.
fig. 4 is laboratory of the present invention used test device schematic diagram.
in figure, 1. water, 2. gas air chamber, 3. boring, 4. moisture coal body, 5. coal seam, 6. aquifer, 7. piezometer tube, 8. cement paste, 9. return pipe, 10. Grouting Pipe, 11. drill sites, 12. rubber balls, 13. outlet valve, 14. desorption tanks, 15. wire laths, 16. the pressure meter I, 17. needle valves, 18. pressure meter II, 19. the valve I, 20. latex films, 21. thermometers, 22. Liquid level scale, 23. sealings, 24. water bath with thermostatic control I, 25. the water bath with thermostatic control II, 26. compensators, 27. mixers, 28. pressure maintaining valve, 29. methane steel cylinders, 30. valve II.
The specific embodiment
in the drawings, this test equipment and method testing arrangement used comprises rubber ball 12, outlet valve 13, desorption tank 14, wire lath 15, pressure meter I 16, needle valve 17, pressure meter II 18, valve I 19, latex film 20, thermometer 21, Liquid level scale 22, the bottom of described desorption tank 14 vertically is provided with Liquid level scale 22 and thermometer 21, the upper side of desorption tank 14 is connected with rubber ball 12 by outlet valve 13, the top, side of desorption tank 14 also is communicated with pressure meter I 16, the edge of described latex film 20 is fixed on the upper edge edge of desorption tank 14, the upper can of desorption tank 14 covers and has the through hole be connected with the external world, be distributed with wire lath 15 in through hole, the lower side of desorption tank 14 is connected with the side of needle valve 17 by valve I 19, needle valve 17 entrances are connected with piezometer tube 7 by conduit, needle valve 17 is provided with pressure meter II 18 with the junction of conduit.
this method of testing comprises on-the-spot test and laboratory tests two parts, and its concrete steps are as follows:
1. after the sealing of hole success of gas pressure testing bore holes and pressure meter II 18 numerical stabilities, open pressure meter needle valve 17 and find, in pressure tap, water is arranged, close at once needle valve, pressure meter II 18 numerical value return to raw value very soon, judge that this place hydraulic pressure is higher;
2. desorption tank 14 is connected with pressure meter needle valve 17, the interior latex film 20 of desorption tank 14 is divided into upper and lower two spaces by desorption tank 14, adopt the rubber ball 12 desorption tank 14 lower space gases of finding time, close the outlet valve 13 between desorption tank 14 and rubber ball 12, open pressure meter aciculiform valve 17, the interior water of piezometer tube 7 enters desorption tank 14;
3. the interior water of piezometer tube 7 enters in desorption tank 14 processes, latex film 20 upwards expands, the gas of desorption tank 14 upper spaces is discharged by the top pore, when the rising phenomenon appears in desorption tank 14 pressure gauge I 16, close immediately the valve I 19 between desorption tank 14 and pressure meter needle valve 17, and record water temperature T 1 now;
4., after the interior gas desorption balance of desorption tank 14, desorption tank 14 is set level after a while,, record the interior liquid level of desorption tank 14 and upper gas height, record this moment water temperature T 2 simultaneously, calculate gas solubility in water, complete the on-the-spot test step, gather water sample and send laboratory to be tested;
5. by collection in worksite water sample injection experiments chamber dissolution equilibrium tank 26, compensator 26 is put into to water bath with thermostatic control II 25, water bath with thermostatic control II 25 water temperatures are set to T1, compensator 26 is connected by pressure maintaining valve 28 with methane steel cylinder 29, open methane steel cylinder 29 and pressure maintaining valve 28, to the interior injection methane of compensator 26 and be stabilized in setup pressure value P, open water bath with thermostatic control II 25 and mixer 27, dissolved the mash gas balancing experiment;
6. after balance to be dissolved, close mixer 27, by on-the-spot test, desorption tank 14 used is placed in another one water bath with thermostatic control I 24, water temperature is set to T2, desorption tank 14 is connected with compensator 26, open valve II 30, the interior gas dissolving of compensator 26 saturated aqueous solution enters in desorption tank 14, carry out the operation of step 3 and step 4, can draw when pressure of methane is P, the solubility of on-the-spot water sample to gas, change the methane gas pressure in injection balance tank 26, repeat aforesaid operations, can draw under different methane gas pressure P conditions, the solubility of on-the-spot water sample to methane,
7. survey the solubility of on-the-spot water sample to gas according to laboratory, find out on-the-spot test water to the corresponding balance methane gas of gas solubility values pressure, be the coal-bed gas pressure of this pressure measuring drill hole actual measurement.
Claims (2)
1. be rich in water coal measure strata gas pressure test equipment and method, this method of testing comprises on-the-spot test and laboratory tests two parts, it is characterized in that, concrete steps are, after the sealing of hole success of gas pressure testing bore holes and pressure meter II (18) numerical stability, open pressure meter needle valve (17) and find, in pressure tap, water is arranged, close at once needle valve, pressure meter II (18) numerical value returns to raw value very soon, judges that this place hydraulic pressure is higher, desorption tank (14) is connected with pressure meter needle valve (17), the interior latex film of desorption tank (14) (20) is divided into upper and lower two spaces by desorption tank (14), adopt rubber ball (12) desorption tank (14) the lower space gas of finding time, close the outlet valve (13) between desorption tank (14) and rubber ball (12), open pressure meter aciculiform valve (17), the interior water of piezometer tube (7) enters desorption tank (14), the interior water of piezometer tube (7) enters in desorption tank (14) process, latex film (20) upwards expands, the gas of desorption tank (14) upper space is discharged by the top pore, when the rising phenomenon appears in desorption tank (14) pressure gauge I (16), close immediately the valve I (19) between desorption tank (14) and pressure meter needle valve (17), and record water temperature T 1 now, after a while, after gas desorption balance in desorption tank (14), desorption tank (14) is set level, record the interior liquid level of desorption tank (14) and upper gas height, record this moment water temperature T 2 simultaneously, calculate gas solubility in water, complete the on-the-spot test step, gather water sample and send laboratory to be tested, by in collection in worksite water sample injection experiments chamber dissolution equilibrium tank (26), compensator (26) is put into to water bath with thermostatic control II (25), water bath with thermostatic control II (25) water temperature is set to T1, compensator (26) is connected by pressure maintaining valve (28) with methane steel cylinder (29), open methane steel cylinder (29) and pressure maintaining valve (28), inject methane and be stabilized in setup pressure value P in compensator (26), opening water bath with thermostatic control II (25) and mixer (27), being dissolved the mash gas balancing experiment, after balance to be dissolved, close mixer (27), by on-the-spot test, desorption tank (14) used is placed in another one water bath with thermostatic control I (24), water temperature is set to T2, desorption tank (14) is connected with compensator (26), open valve II (30), the interior gas dissolving of compensator (26) saturated aqueous solution enters in desorption tank (14), carry out the operation of the 3rd step and the 4th step, can draw when pressure of methane is P, the solubility of on-the-spot water sample to gas, change the methane gas pressure in injection balance tank (26), repeat aforesaid operations, can draw under different methane gas pressure P conditions, the solubility of on-the-spot water sample to methane, survey the solubility of on-the-spot water sample to gas according to laboratory, find out on-the-spot test water to the corresponding balance methane gas of gas solubility values pressure, be the coal-bed gas pressure of this pressure measuring drill hole actual measurement.
2. be rich in water coal measure strata gas pressure test equipment and method, testing arrangement used comprises rubber ball (12), outlet valve (13), desorption tank (14), wire lath (15), pressure meter I (16), needle valve (17), pressure meter II (18), valve I (19), latex film (20), thermometer (21), Liquid level scale (22), it is characterized in that, the bottom of described desorption tank (14) vertically is provided with Liquid level scale (22) and thermometer (21), the upper side of desorption tank (14) is connected with rubber ball (12) by outlet valve (13), the top, side of desorption tank (14) also is communicated with pressure meter I (16), the edge of described latex film (20) is fixed on the upper edge edge of desorption tank (14), the upper can of desorption tank (14) covers and has the through hole be connected with the external world, be distributed with wire lath (15) in through hole, the lower side of desorption tank (14) is connected with the side of needle valve (17) by valve I (19), needle valve (17) entrance is connected with piezometer tube (7) by conduit, needle valve (17) is provided with pressure meter II (18) with the junction of conduit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310070694.1A CN103089247B (en) | 2013-03-06 | 2013-03-06 | Gas pressure testing device and method of coal measure strata rich in water |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310070694.1A CN103089247B (en) | 2013-03-06 | 2013-03-06 | Gas pressure testing device and method of coal measure strata rich in water |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103089247A true CN103089247A (en) | 2013-05-08 |
| CN103089247B CN103089247B (en) | 2015-06-17 |
Family
ID=48202320
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310070694.1A Expired - Fee Related CN103089247B (en) | 2013-03-06 | 2013-03-06 | Gas pressure testing device and method of coal measure strata rich in water |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103089247B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104405358A (en) * | 2014-10-13 | 2015-03-11 | 太原理工大学 | Method for fracturing coal seam by employing high-pressure gas |
| CN106894785A (en) * | 2017-03-10 | 2017-06-27 | 河南工程学院 | Easy gushing water coal seam upward hole gas pressure measurement method |
| CN108457643A (en) * | 2018-02-05 | 2018-08-28 | 中国矿业大学 | A kind of water enchroachment (invasion) drilling gas piezometry method based on vacuum condition |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2706748Y (en) * | 2004-06-16 | 2005-06-29 | 中国矿业大学 | Device for measuring gaspressure by directly drilling and sealing hole in coal seam |
| CN101487834A (en) * | 2009-02-06 | 2009-07-22 | 煤炭科学研究总院重庆研究院 | Combined test apparatus for coal and gas burst |
| CN201857955U (en) * | 2010-04-30 | 2011-06-08 | 华北科技学院 | Multiplexing type active hole-sealing pressure measuring device |
| CN102410014A (en) * | 2011-10-31 | 2012-04-11 | 河南理工大学 | Method for testing gas pressure of water-containing surrounding rock coal seam |
-
2013
- 2013-03-06 CN CN201310070694.1A patent/CN103089247B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2706748Y (en) * | 2004-06-16 | 2005-06-29 | 中国矿业大学 | Device for measuring gaspressure by directly drilling and sealing hole in coal seam |
| CN101487834A (en) * | 2009-02-06 | 2009-07-22 | 煤炭科学研究总院重庆研究院 | Combined test apparatus for coal and gas burst |
| CN201857955U (en) * | 2010-04-30 | 2011-06-08 | 华北科技学院 | Multiplexing type active hole-sealing pressure measuring device |
| CN102410014A (en) * | 2011-10-31 | 2012-04-11 | 河南理工大学 | Method for testing gas pressure of water-containing surrounding rock coal seam |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104405358A (en) * | 2014-10-13 | 2015-03-11 | 太原理工大学 | Method for fracturing coal seam by employing high-pressure gas |
| CN106894785A (en) * | 2017-03-10 | 2017-06-27 | 河南工程学院 | Easy gushing water coal seam upward hole gas pressure measurement method |
| CN108457643A (en) * | 2018-02-05 | 2018-08-28 | 中国矿业大学 | A kind of water enchroachment (invasion) drilling gas piezometry method based on vacuum condition |
| CN108457643B (en) * | 2018-02-05 | 2020-07-31 | 中国矿业大学 | Water-invasion drilling gas pressure measuring method based on vacuum condition |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103089247B (en) | 2015-06-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN205000965U (en) | Moisture drilling gas piezometry device | |
| CN103411868B (en) | A kind of method of testing of Permeability Coefficent in Coal Seam | |
| CN102243163B (en) | Quantitative evaluation method for permeability of faults of coal mine | |
| CN102830038B (en) | Apparatus and method for rapid determination of parameters of residual gas on mining working face of underground coal mine | |
| CN101858209B (en) | Synchronous detection method of terrane crack distribution of base plate | |
| CN100514018C (en) | Pressure test method for sealing performance of salt cavern gas storage cavity | |
| CN104358561B (en) | Aqueous coal petrography descending drilling gas pressure observation system | |
| CN102012347B (en) | Method for detecting channeling condition by static gelatinization strength of cement | |
| CN104373118A (en) | Measurement method for effective extraction radius of drill hole | |
| CN103148888A (en) | High temperature and high pressure drainage dynamic evaluation system for coal bed and gas reservoir double-layer commingled production | |
| CN102253179A (en) | Simulation experimental device for coupling effects of solid-liquid-gas three phase media in coal mine stope | |
| CN104500042B (en) | Measuring method for water-containing coal and rock down drill hole gas pressure observation system | |
| CN204126636U (en) | Upward drilling pressure measuring device for water isolation | |
| US12091971B2 (en) | Tracer diffusion device, system for tracing development of water conducting fracture zone and relataed method | |
| CN104594889A (en) | Device and method for accurately measuring position of residual oil reservoir of oil well | |
| CN103089247B (en) | Gas pressure testing device and method of coal measure strata rich in water | |
| CN106401557B (en) | A kind of method of joint test coal seam gas-bearing capacity and the determining effective extraction radius that drills of gas pressure | |
| CN103161499B (en) | Division method for underground coal bed outburst and dangerous zones | |
| CN107817191A (en) | A kind of method of coal bed gas extraction validity check | |
| CN107524435A (en) | Aqueous determination of coal seam gas pressure device and assay method | |
| CN203145925U (en) | Device for quickly measuring coal seam gas pressure by upward remote drilling | |
| Mu et al. | Diffusion-hydraulic properties of grouting geological rough fractures with power-law slurry | |
| CN210347634U (en) | Coal seam gas pressure test system based on drilling sampling actual measurement | |
| Diamond et al. | The modified direct method: A solution for Obtaining accurate coal desorption Measurements | |
| CN204301779U (en) | A kind of indoor deep hole grouting multi-parameter combined measuring instrument |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150617 Termination date: 20160306 |