CN112557275A - In-situ radial testing method for coal seam permeability coefficient - Google Patents
In-situ radial testing method for coal seam permeability coefficient Download PDFInfo
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- CN112557275A CN112557275A CN202011303286.2A CN202011303286A CN112557275A CN 112557275 A CN112557275 A CN 112557275A CN 202011303286 A CN202011303286 A CN 202011303286A CN 112557275 A CN112557275 A CN 112557275A
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- 239000003245 coal Substances 0.000 title claims abstract description 66
- 230000035699 permeability Effects 0.000 title claims abstract description 33
- 238000012360 testing method Methods 0.000 title claims abstract description 22
- 238000011065 in-situ storage Methods 0.000 title claims abstract description 13
- 238000000605 extraction Methods 0.000 claims abstract description 77
- 238000007789 sealing Methods 0.000 claims abstract description 7
- 230000000149 penetrating effect Effects 0.000 claims abstract description 5
- 239000011435 rock Substances 0.000 claims abstract description 4
- 238000012544 monitoring process Methods 0.000 claims abstract description 3
- 238000005553 drilling Methods 0.000 claims description 15
- 238000010998 test method Methods 0.000 claims description 5
- 238000000034 method Methods 0.000 abstract description 6
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000009533 lab test Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000004484 Briquette Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000005065 mining Methods 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
- 238000012545 processing Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials
- G01N15/08—Investigating permeability, pore-volume, or surface area of porous materials
- G01N15/082—Investigating permeability by forcing a fluid through a sample
- G01N15/0826—Investigating permeability by forcing a fluid through a sample and measuring fluid flow rate, i.e. permeation rate or pressure change
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Abstract
The invention relates to the technical field of coal seam gas extraction, and relates to an in-situ radial testing method for coal seam gas permeability coefficient, which comprises the following steps: constructing an extraction drill hole perpendicular to a coal seam in a rock extraction roadway, wherein the radius of the extraction drill hole is r, the lower part of the coal seam is a bottom plate, an extraction pipe with one end penetrating through the bottom plate is arranged in the extraction drill hole in a matched mode, the extraction pipe is connected with the bottom plate in a sealing mode, the extraction pipe is connected with an underground extraction pipeline for negative pressure extraction, and the extraction pipeline is connected with a comprehensive parameter measuring instrument for real-time online monitoring of extraction parameters; the method can be used for testing on site, data such as gas flow, extraction flow, gas temperature, gas pressure of a borehole wall and the like can be measured on site by comprehensively considering various complex conditions on site, and the data is substituted into a derived formula to scientifically and accurately calculate the permeability coefficient of the coal seam.
Description
Technical Field
The invention relates to the technical field of coal seam gas extraction, in particular to an in-situ radial testing method for a coal seam gas permeability coefficient.
Background
With the increase of the coal mining depth, the restriction effect of coal bed gas on the safe and efficient production of a coal mine is more serious, and the gas pre-pumping is used as a fundamental measure for preventing and controlling the gas disaster of a mine, so that the safe production of the mine is ensured, and the aim of comprehensively utilizing gas resources can be fulfilled. The coal seam gas extraction efficiency is influenced by various factors, wherein the coal seam gas permeability coefficient is one of key factors influencing the gas extraction and is also a key parameter required to be measured in the gas extraction. At present, the test of the coal bed permeability mainly comprises the test of a coal sample in a laboratory, the coal sample is obtained by processing an integral coal briquette or performing secondary molding on pulverized coal, and cannot represent an in-situ coal body with a complex fracture system and structure, and the test result is difficult to guide a gas extraction project; although the field permeability coefficient test can measure the corresponding parameters of the in-situ coal body, the test result cannot accurately reflect the real seepage state due to the problems of unstable gas flowing state, variable gas pressure at the gas flowing boundary and the like. In view of this, a convenient and scientific testing method is needed to accurately measure the permeability coefficient of the coal seam and provide an important parameter basis for gas extraction design and construction.
Disclosure of Invention
The invention aims to solve the problems and provides a convenient and scientific testing method, which can comprehensively consider various complex conditions on site through a formula derived scientifically, measure data such as gas flow, extraction flow, gas temperature, gas pressure of a borehole wall and the like on site, and substitute the data into the derived formula to scientifically and accurately calculate the permeability coefficient of the coal seam.
In order to solve the problems, the technical scheme adopted by the invention is as follows:
an in-situ radial testing method for the permeability coefficient of a coal seam comprises the following steps:
1) constructing an extraction drill hole perpendicular to a coal seam in a rock extraction roadway, wherein the radius of the extraction drill hole is r, the lower part of the coal seam is a bottom plate, an extraction pipe with one end penetrating through the bottom plate is arranged in the extraction drill hole in a matched mode, the extraction pipe is connected with the bottom plate in a sealing mode, the extraction pipe is connected with an underground extraction pipeline for negative pressure extraction, and the extraction pipeline is connected with a comprehensive parameter measuring instrument for real-time online monitoring of extraction parameters;
2) constructing n constant-pressure gas supply drill holes with the diameter of 94mm on the circumference of the distance R from the center of the extraction drill hole, wherein pressure-resistant pipes are arranged in the constant-pressure gas supply drill holes in a matching manner, and the pressure-resistant pipes are connected with the bottom plate in a sealing manner;
3) connecting each pressure-resistant pipe to an air supply pipe, connecting the air supply pipe to a corresponding multi-way joint of a plurality of ways, connecting the plurality of ways with a gas source through a pressure reducing valve, and connecting the plurality of ways with a barometer;
4) opening the pressure reducing valve, reading the air supply pressure through an air pressure meter on the pressure reducing valve, adjusting the pressure reducing valve to enable the air supply pressure to reach a preset pressure value p1, and keeping the air supply pressure constant;
5) regularly observing and recording the change of the gas flow, recording each parameter after the gas flow is stable and unchanged for more than 3 days, and measuring the temperature T of the coal bed;
6) closing the pressure reducing valve, and connecting the multi-way to a downhole extraction system for extraction;
7) and substituting the measured parameters into an air permeability coefficient calculation formula to obtain the air permeability coefficient of the coal seam.
The extraction pipe in the step (1) and the pressure-resistant pipe in the step (2) are positioned in the coal seam section and are perforated pipes with holes at the periphery.
Step (2) in the constant voltage air feed drilling evenly distributed on the circumference, distance R is no longer than 5m, preferred 2-3m, and the interval between two adjacent constant voltage air feed drilling is no longer than 2m, and pi R is not less than to constant voltage air feed drilling quantity n, if R is 3m, then constant voltage air feed drilling quantity n is no less than 10.
And (3) in the step (4), the gas supply pressure p1 is greater than the original gas pressure of the coal bed and is generally 0.2MPa higher than the original pressure value.
The formula of the air permeability coefficient in the step (7) is as follows:
wherein, lambda is the permeability coefficient of the coal bed and the unit is m2/(MPa2·d)；q0Measured gas flow rate in m3S; mu is a gas viscosity coefficient with the unit of Pa.s; t is the temperature of the coal bed gas and has the unit of K; t is0Is the gas temperature in the pipeline, in units of K; r is the radius of a gas pressure fixed boundary, and the unit is m; r is0The radius of the extracted drill hole is m; pi is the circumference ratio, and the value is 3.14; h is the thickness of the coal bed and is in m; p0The gas pressure of the wall of the bore hole is also similar to the gas pressure value, Pa, of the measuring point of the underground pipeline; p1The gas pressure for a given pressure boundary is given in Pa.
The gain effect of the invention is that
The method solves the problems of distortion of laboratory test permeability state relative to field actual condition, unstable field test condition and unreliable test result and poor guidance caused by the imprecise method, can be used for field test, integrates various auxiliary means by comprehensively considering various complex conditions on the field, measures data such as gas flow, extraction flow, gas temperature, gas pressure of a drilling hole wall and the like on the field, substitutes the data into a derived formula to scientifically and accurately calculate the permeability coefficient of the coal seam, and is beneficial to mastering real extraction parameters of the coal seam and lays a foundation for improving the gas extraction efficiency of the coal seam.
Drawings
Fig. 1 is a schematic structural plan view of the present invention.
FIG. 2 is a schematic cross-sectional view of the structure of the present invention.
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings.
Referring to fig. 1 and 2, in the drawings, the serial numbers 1 are a coal seam, 2 is a top plate, 3 is a bottom plate, 4 is a constant-pressure gas supply borehole, 5 is a pressure-resistant pipe, 6 is an extraction borehole, 7 is an extraction pipe, 8 is a gas supply pipe, 9 is an extraction pipeline, 10 is a comprehensive parameter measuring instrument, 11 is a multi-way, 12 is a multi-way joint, 13 is a gas pressure gauge, 14 is a pressure reducing valve, h is a coal seam thickness, R is a circular constant-pressure boundary radius, and R is an extraction borehole radius.
An in-situ radial test method for the air permeability coefficient of coal seam includes such steps as
1) Constructing an extraction drill hole 6 with the radius r and vertical to the coal seam trend in a rock extraction roadway in the test area, and simultaneously measuring the coal seam thickness h;
2) the method comprises the following steps that a bottom plate 3 and a top plate 2 are respectively arranged below and above a coal seam 1, an extraction pipe 7 with one end penetrating through the bottom plate 3 is arranged in an extraction borehole 6 in a matched mode, the upper end of the extraction pipe 7 extends to the bottom of the extraction borehole 6, the extraction pipe 7 is connected with the bottom plate 3 in a sealing mode, the extraction pipe 7 penetrates through the bottom plate 3 and is connected with an underground extraction pipeline 9 for negative pressure extraction, the extraction pipeline 9 and a comprehensive parameter measuring instrument 10 are connected with each other to monitor extraction parameters in real time on line, and the comprehensive parameter measuring instrument 10 is a CJZ4Z gas comprehensive parameter measuring instrument;
3) constructing n constant-pressure gas supply drill holes 4 with the diameter of 94mm on the circumference of the distance R from the center of the extraction drill hole 6, arranging a pressure-resistant pipe 5 with one end penetrating through the bottom plate 3 in the constant-pressure gas supply drill holes 4 in a matching manner, enabling the upper ends of the pressure-resistant pipes 5 to reach the hole bottom of the constant-pressure gas supply drill holes 4, and enabling the pressure-resistant pipes 5 to be in sealing connection with the bottom plate 3;
4) each pressure pipe 5 is connected to an air supply pipe 8, the air supply pipe 8 is connected to a corresponding multi-way joint 12 of a multi-way 11, the multi-way 11 is connected with a gas source through a pressure reducing valve 14, and the multi-way 11 is connected with a gas pressure meter 13;
5) opening the pressure reducing valve 14, reading the air supply pressure through a barometer 13 on the pressure reducing valve 14, adjusting the pressure reducing valve 14 to enable the air supply pressure to reach a preset pressure value p1, and keeping the air supply pressure constant;
6) periodically observing and recording the change of the gas flow, and testing and recording the extraction flow q by the comprehensive parameter measuring instrument 10 after the gas flow is stable and unchanged for more than 3 days0Gas temperature T0And the gas pressure p of the borehole wall0, etcMeasuring various parameters and measuring the temperature T of the coal bed;
7) closing the pressure reducing valve 14, and connecting the multi-way pipe 11 to a downhole extraction system for extraction;
9) and substituting the measured parameters into an air permeability coefficient calculation formula to obtain the air permeability coefficient of the coal seam.
The permeability coefficient is given by
Wherein, lambda is the permeability coefficient of the coal bed and the unit is m2/(MPa2·d)；q0Measured gas flow rate in m3S; mu is a gas viscosity coefficient with the unit of Pa.s; t is the temperature of the coal bed gas and has the unit of K; t is0Is the gas temperature in the pipeline, in units of K; r is the radius of a gas pressure fixed boundary, and the unit is m; r is0The radius of the extracted drill hole is m; pi is the circumference ratio, and the value is 3.14; h is the thickness of the coal bed and is in m; p0For drilling the wallThe gas pressure of (a) is also similar to the gas pressure value, Pa, at the measuring point of the underground pipeline; p1The gas pressure for a given pressure boundary is given in Pa.
The extraction pipe 7 in the step (1) and the pressure-resistant pipe 5 in the step (2) are arranged in the coal seam section and are perforated pipes with holes on the periphery.
Constant voltage air feed drilling 4 is in evenly distributed on the circumference, distance R is no longer than 5m, preferred 2-3m, and the interval between two adjacent constant voltage air feed drilling 4 is no longer than 2m, and pi R is no less than to constant voltage air feed drilling quantity n, if R is 3m, then constant voltage air feed drilling quantity n is no less than 10.
The gas supply pressure p1 is greater than the original gas pressure of the coal seam, and is generally 0.2MPa higher than the original pressure value.
The method solves the problems of distortion of laboratory test permeability state relative to field actual condition, unstable field test condition and unreliable test result and poor guidance caused by the imprecise method, can be used for field test, integrates various auxiliary means by comprehensively considering various complex conditions on the field, measures data such as gas flow, extraction flow, gas temperature, gas pressure of a drilling hole wall and the like on the field, substitutes the data into a derived formula to scientifically and accurately calculate the permeability coefficient of the coal seam, and is beneficial to mastering real extraction parameters of the coal seam and lays a foundation for improving the gas extraction efficiency of the coal seam.
The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are merely illustrative of the principles of the invention, but that various changes and modifications may be made without departing from the spirit and scope of the invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (5)
1. An in-situ radial testing method for the permeability coefficient of a coal seam is characterized by comprising the following steps:
1) constructing an extraction drill hole perpendicular to a coal seam in a rock extraction roadway, wherein the radius of the extraction drill hole is r, the lower part of the coal seam is a bottom plate, an extraction pipe with one end penetrating through the bottom plate is arranged in the extraction drill hole in a matched mode, the extraction pipe is connected with the bottom plate in a sealing mode, the extraction pipe is connected with an underground extraction pipeline for negative pressure extraction, and the extraction pipeline is connected with a comprehensive parameter measuring instrument for real-time online monitoring of extraction parameters;
2) constructing n constant-pressure gas supply drill holes with the diameter of 94mm on the circumference of the distance R from the center of the extraction drill hole, wherein pressure-resistant pipes are arranged in the constant-pressure gas supply drill holes in a matching manner, and the pressure-resistant pipes are connected with the bottom plate in a sealing manner;
3) connecting each pressure-resistant pipe to an air supply pipe, connecting the air supply pipe to a corresponding multi-way joint of a plurality of ways, connecting the plurality of ways with a gas source through a pressure reducing valve, and connecting the plurality of ways with a barometer;
4) opening the pressure reducing valve, reading the air supply pressure through an air pressure meter on the pressure reducing valve, adjusting the pressure reducing valve to enable the air supply pressure to reach a preset pressure value p1, and keeping the air supply pressure constant;
5) regularly observing and recording the change of the gas flow, recording each parameter after the gas flow is stable and unchanged for more than 3 days, and measuring the temperature T of the coal bed;
6) closing the pressure reducing valve, and connecting the multi-way to a downhole extraction system for extraction;
7) and substituting the measured parameters into an air permeability coefficient calculation formula to obtain the air permeability coefficient of the coal seam.
2. The in-situ radial test method for the permeability coefficient of the coal seam according to claim 1, characterized by comprising the following steps: the extraction pipe in the step (1) and the pressure-resistant pipe in the step (2) are positioned in the coal seam section and are perforated pipes with holes at the periphery.
3. The in-situ radial test method for the permeability coefficient of the coal seam according to claim 1, characterized by comprising the following steps: step (2) in the constant voltage air feed drilling evenly distributed on the circumference, distance R is no longer than 5m, preferred 2-3m, and the interval between two adjacent constant voltage air feed drilling is no longer than 2m, and pi R is not less than to constant voltage air feed drilling quantity n, if R is 3m, then constant voltage air feed drilling quantity n is no less than 10.
4. The in-situ radial test method for the permeability coefficient of the coal seam according to claim 1, characterized by comprising the following steps: and (3) in the step (4), the gas supply pressure p1 is greater than the original gas pressure of the coal bed and is generally 0.2MPa higher than the original pressure value.
5. The in-situ radial test method for the permeability coefficient of the coal seam according to claim 1, characterized by comprising the following steps: the formula of the air permeability coefficient in the step (7) is as follows:
wherein, lambda is the permeability coefficient of the coal bed and the unit is m2/(MPa2·d)；q0Measured gas flow rate in m3S; mu is a gas viscosity coefficient with the unit of Pa.s; t is the temperature of the coal bed gas and has the unit of K; t is0Is the gas temperature in the pipeline, in units of K; r is the radius of a gas pressure fixed boundary, and the unit is m; r is0The radius of the extracted drill hole is m; pi is the circumference ratio, and the value is 3.14; h is the thickness of the coal bed and is in m; p0The gas pressure of the wall of the bore hole is also similar to the gas pressure value, Pa, of the measuring point of the underground pipeline; p1The gas pressure for a given pressure boundary is given in Pa.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113266315A (en) * | 2021-06-17 | 2021-08-17 | 中国矿业大学 | Method for determining permeability coefficient of coal seam |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103411868A (en) * | 2013-07-25 | 2013-11-27 | 陕西煤业化工技术研究院有限责任公司 | Measuring method for coal seam gas permeability coefficient |
| CN106124381A (en) * | 2016-06-21 | 2016-11-16 | 河南理工大学 | Hypotonic coal seam reservoirs gas free-boundary problem and the on-the-spot test method of permeability |
| CN106285599A (en) * | 2016-08-05 | 2017-01-04 | 河南能源化工集团研究院有限公司 | A kind of waterpower changing of the relative positions release anti-reflection draining coal seam gas method |
| CN106525526A (en) * | 2016-10-26 | 2017-03-22 | 山东科技大学 | Determination method of high-pressure water injection and radial gas permeability of gas-containing raw coal |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103411868A (en) * | 2013-07-25 | 2013-11-27 | 陕西煤业化工技术研究院有限责任公司 | Measuring method for coal seam gas permeability coefficient |
| CN106124381A (en) * | 2016-06-21 | 2016-11-16 | 河南理工大学 | Hypotonic coal seam reservoirs gas free-boundary problem and the on-the-spot test method of permeability |
| CN106285599A (en) * | 2016-08-05 | 2017-01-04 | 河南能源化工集团研究院有限公司 | A kind of waterpower changing of the relative positions release anti-reflection draining coal seam gas method |
| CN106525526A (en) * | 2016-10-26 | 2017-03-22 | 山东科技大学 | Determination method of high-pressure water injection and radial gas permeability of gas-containing raw coal |
Non-Patent Citations (2)
| Title |
|---|
| 屈先朝: "瓦斯抽采孔孔距及煤层透气性的测定方法", 《煤炭学报》, vol. 34, no. 11, 15 November 2009 (2009-11-15), pages 32 - 36 * |
| 陶云奇 等: "煤矿井下煤层渗透率直接测定方法研究及应用", 《煤矿安全》, vol. 49, no. 3, 31 March 2018 (2018-03-31), pages 140 - 143 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113266315A (en) * | 2021-06-17 | 2021-08-17 | 中国矿业大学 | Method for determining permeability coefficient of coal seam |
| CN113266315B (en) * | 2021-06-17 | 2022-02-08 | 中国矿业大学 | Method for determining permeability coefficient of coal seam |
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