CN106124381A - Hypotonic coal seam reservoirs gas free-boundary problem and the on-the-spot test method of permeability - Google Patents

Hypotonic coal seam reservoirs gas free-boundary problem and the on-the-spot test method of permeability Download PDF

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CN106124381A
CN106124381A CN201610460218.4A CN201610460218A CN106124381A CN 106124381 A CN106124381 A CN 106124381A CN 201610460218 A CN201610460218 A CN 201610460218A CN 106124381 A CN106124381 A CN 106124381A
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gas pumping
gas
pressure
hole
coal seam
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苏现波
李贤忠
宋金星
冯俊超
郭红玉
王乾
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Henan University of Technology
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Henan University of Technology
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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
    • 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

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Abstract

The present invention relates to a kind of hypotonic coal seam reservoirs gas free-boundary problem and the on-the-spot test method of permeability, by selecting the construction of representational white space to wear layer pressure measuring drill hole and gas pumping hole at the hypotonic coal seam reservoirs of underground coal mine, and respectively pressure measuring drill hole and gas pumping hole are carried out sealing of hole, observe and record the pressure gauge reading of pressure measuring drill hole and the gas flow reading in gas pumping hole, utilize the derivations of equation such as gas flow equation and free-boundary problem to obtain the permeability of coal seam reservoirs.The method is without processing coal sample, the particle diameter of experimental test coal body, moisture content, homogeneity, confined pressure etc. are the feature of coal seam reservoirs under time of day, the meansigma methods of the coal reservoir fracture system calculated through long-term field observation is the most accurate, a kind of theory is accurate, method the is feasible hypotonic coal seam reservoirs gas free-boundary problem of test and the new approaches of permeability can be this method provided as the reference value of the coal reservoir fracture system in the hypotonic coal seam of whole mine simultaneously.

Description

Hypotonic coal seam reservoirs gas free-boundary problem and the on-the-spot test method of permeability
Technical field
The present invention relates to free-boundary problem and permeability field tests, particularly relate to a kind of based on on-the-spot hypotonic coal storage Layer gas free-boundary problem and the method for testing of permeability.
Background technology
The concept of free-boundary problem is from proposing more than 60 year so far, and it represents when fluid flows in reservoir, fluid Barometric gradient have to be larger than a certain marginal value, flowing just can occur, and this marginal value is exactly free-boundary problem.Scholar later Research finds that gas flowing in hypotonic coal seam reservoirs there is also marginal value, and this marginal value is exactly that coal seam reservoirs gas starts pressure Power gradient.China's overwhelming majority coal seam reservoirs has the feature of " high storage is hypotonic ", and this seriously restricts China's coal-mine underground gas extraction Fast development with coal bed gas industry.Free-boundary problem determines gas fluidised form in coal seam reservoirs, affects boring around Gas diffusion and the region of non linear fluid flow through porous medium, its mensuration has great significance to instructing drilling gas extraction.Permeability is Judge the important parameter of reservoir permeability, it is thus achieved that permeability accurate, reliable is by the precondition of engineering practice activity.
There are many scholars that free-boundary problem is tested before, and have been set up the laboratory of comparative maturity Method of testing.Laboratory test starting barometric gradient is usually and first makes coal sample, and coal sample is placed in free-boundary problem test dress Test in putting, then mathematically carry out test data processing, calculating, finally give free-boundary problem.Experiment The feature of room test starting barometric gradient is: 1. experimental variable is easily-controllable, good airproof performance, the degree that becomes more meticulous high；2. experiment coal sample is big It mostly is dry raw coal, have ignored the impact of moisture, and can not directly test cherry coal；3. the confined pressure under laboratory condition, coal body are equal Matter, moisture content etc. have difference with scene；4. have ignored on-the-spot mining influence.So laboratory test starting barometric gradient method Having its limitation, the permeability obtained often can not accurately reflect on-site actual situations.
Summary of the invention
In order to solve problem above, the invention provides a kind of based on on-the-spot hypotonic coal seam reservoirs gas free-boundary problem With the method for testing of permeability, concrete the comprising the following steps of its feature:
The present invention solves that the problems referred to above are adopted the technical scheme that, it is provided that a kind of hypotonic coal seam reservoirs gas starts pressure The on-the-spot test method of power gradient and permeability, concrete comprises the following steps:
The first step: selecting representational white space at the hypotonic coal seam reservoirs of underground coal mine, described white space refers to not Have and suffer to exploit the complete hypotonic coal seam reservoirs destroyed, about without other boring interference in the range of 10 meters, in this white space This pressure measuring drill hole, as pressure measuring drill hole, is designated as C by a layer-through drilling of constructing1, pressure measuring drill hole C1Interior inclosure and pressure measuring drill hole C1Deeply Four points of aluminium-plastic pipes of degree equal length, are positioned at pressure measuring drill hole C1Circumferentially arranged with multiple ventilative on four points of interior aluminium-plastic pipe one end tube walls Hole, use colliery conventional two block up the hole-sealing technology of a note total rock section sealing of hole to pressure measuring drill hole C1Carry out sealing of hole, four points of aluminium-plastic pipes The other end at pressure measuring drill hole C1Outer reserved 30 centimetres～50 centimetres, and at the end of four points of aluminium-plastic pipes, valve and pressure are installed Table, and the reading of observed pressure table, after a period of time, manometric reading tends towards stability, and records its data, and these data are Pressure measuring drill hole C1Hypotonic coal seam reservoirs gas pressure around.
Second step: treat pressure measuring drill hole C1Pressure gauge reading stable after, with pressure measuring drill hole C1Between distance be at L Construct one and pressure measuring drill hole C1Parallel mash gas pumping drilling, is designated as C by mash gas pumping drilling2, mash gas pumping drilling C2In with Mash gas pumping drilling C2The gas pumping pipe of degree of depth equal length, is positioned at mash gas pumping drilling C2Interior gas pumping pipe one end tube wall On circumferentially arranged with multiple air-vents, use colliery conventional two block up the hole-sealing technologies of a note total rock section sealing of hole and bore gas pumping Hole C2Carrying out sealing of hole, the other end of gas pumping pipe is connected with gas pumping pumping plant, gas pumping pipe and gas pumping pumping plant Between be provided with effusion meter；Two commonly used with colliery block up the hole-sealing technology of a note to mash gas pumping drilling C2Carry out sealing of hole, and use The mode of negative pressure extraction is to mash gas pumping drilling C2Carry out gas pumping, real-time monitored record mash gas pumping drilling C2Gas-Flow Amount reading, extraction negative pressure reading and phase pressure measuring drill hole C the most in the same time1Manometric reading change.
3rd step: according to gas flow equation:
Understanding, gas flow equation when there is free-boundary problem is:
Then the computing formula of free-boundary problem is:
Along with mash gas pumping drilling C2Constantly mash gas extraction, pressure measuring drill hole C1Pressure gauge reading can constantly reduce, logical Cross measurement and obtain a series of v and p1 2-p2 2Value, then linear regression relation therebetween, obtain constant a and b, substitute into formula 3. The value of the most available hypotonic coal seam reservoirs gas free-boundary problem λ.
Wherein p0For normal atmospheric pressure, usual p0Take 101325Pa；p1For inlet pressure, i.e. pressure measuring drill hole C1Place's coal storage Layer gas pressure, is pressure measuring drill hole C herein1Pressure gauge reading, Pa；p2Bore with gas pumping for outlet pressure, i.e. normal atmosphere Hole C2The difference of extraction negative pressure, Pa；V is mash gas pumping drilling C2Gas flow speed on rib face, m/s；L is methane gas stream Through length, it is pressure measuring drill hole C herein1With mash gas pumping drilling C2Between distance；μ is methane gas dynamic viscosity, generally takes 1.107×10-5Pa·s；K is coal reservoir fracture system, m2。
Subscript or subscript in the most above-mentioned formula and symbol are distinguished as just subscript or subscript, do not represent other real The meaning on border；
4th step: according to formula 1. with formula 2., obtains computing formula based on the coal reservoir fracture system k under free-boundary problem For:
The most available for the b value substitution formula calculated in 3rd step hypotonic coal seam reservoirs based on free-boundary problem is oozed The value of rate k thoroughly.
Described pressure measuring drill hole C1Aperture be 94 millimeters, described mash gas pumping drilling C2Aperture be 94 millimeters, described pressure measurement Boring C1With mash gas pumping drilling C2Between distance L be 6 meters.
Described inlet pressure p1It is variable, at different time point inlet pressure p with flow velocity v1Value and flow velocity v value are the most not Identical, by the inlet pressure p of each timing node1Value and flow velocity v value are brought formula into and are tried to achieve the coal reservoir fracture system k of correspondence the most respectively Value, and calculate the meansigma methods obtaining coal reservoir fracture system
The meansigma methods that will calculateReference value as the coal reservoir fracture system in the hypotonic coal seam of whole mine.
Described manometric range is 0～1.6MPa.
Described second step is treated mash gas pumping drilling C2Drill after constructing, first to mash gas pumping drilling C2Carry out waterpower Punching, again to mash gas pumping drilling C after hydraulic flushing in hole completes2Carry out gas pumping.
Described hydraulic flushing in hole coal output is according to mash gas pumping drilling C2See that the length of coal section is not less than 1t/m.
The beneficial effects of the present invention is:
(1) method of testing of this invention is without processing coal sample, the particle diameter of experimental test coal body, moisture content, homogeneity, confined pressure Etc. being the feature of coal seam reservoirs under time of day, and subjects can be directly soft seam；
(2) being tested as an entirety by the coal body between import and export, what test result actually reflected is to be holed Creep into the coal seam reservoirs gas free-boundary problem under mining influence.
(3) on the basis of obtaining free-boundary problem, coal reservoir fracture system meter based on free-boundary problem has been obtained Calculating formula 4., the permeability of this coal seam reservoirs hypotonic to accurate evaluation from now on has important theory significance.
(4) free-boundary problem λ and the coal reservoir fracture system k obtained by the method more conforms to field condition, and this is right In instructing coal mine gas extraction, there is important engineering significance.
(5) test process of the method is the meansigma methods of the coal reservoir fracture system calculated through long-term field observation The most accurate, it is possible to as the reference value of the coal reservoir fracture system in the hypotonic coal seam of whole mine, to this method provide one simultaneously Plant theory is accurate, method the is feasible hypotonic coal seam reservoirs gas free-boundary problem of test and the new approaches of permeability.
Accompanying drawing explanation
Fig. 1 is the structural representation of the present invention；
Fig. 2 is the matched curve of present example one field test data；
Fig. 3 is the matched curve of present example two field test data.
Detailed description of the invention
For making the purpose of the present invention, technical scheme and beneficial effect clearer, below in conjunction with the accompanying drawings the present invention is implemented Mode is described in further detail.
Embodiment one:
As it is shown in figure 1, the invention provides the on-the-spot survey of a kind of hypotonic coal seam reservoirs gas free-boundary problem and permeability Method for testing, concrete comprises the following steps:
The first step: select representational white space, described white space to refer to not at the hypotonic coal seam reservoirs of underground coal mine 1 Have and suffer to exploit the complete hypotonic coal seam reservoirs 1 destroyed, about without other boring interference in the range of 10 meters, in this white space Through seat earth 2 layer-through drilling of constructing as pressure measuring drill hole, this pressure measuring drill hole is designated as C1, pressure measuring drill hole C1Aperture It is 94 millimeters, pressure measuring drill hole C1Interior inclosure and pressure measuring drill hole C1Four points of aluminium-plastic pipes 3 of degree of depth equal length, are positioned at pressure measuring drill hole C1In Four points of aluminium-plastic pipe 3 one end tube walls on circumferentially arranged with multiple air-vents 4 (also referred to as floral tube section), the length of described floral tube section with The thickness of hypotonic coal seam reservoirs 1 is identical, and use colliery conventional two block up the hole-sealing technology of note total rock section 5 sealing of hole to pressure measuring drill hole C1 Carrying out sealing of hole, the other end of four points of aluminium-plastic pipes 3 is at pressure measuring drill hole C1Outer reserved 30 centimetres～50 centimetres, and at four points of aluminium-plastic pipes 3 End valve 6 and Pressure gauge 7 that range is 0～1.6MPa, and the reading of observed pressure table 7 are installed, press after a period of time The reading of power table 7 tends towards stability, and records its data, and these data are pressure measuring drill hole C1Hypotonic coal seam reservoirs gas pressure around.
Second step: treat pressure measuring drill hole C1Pressure gauge 7 stable reading after, with pressure measuring drill hole C1Between distance L be 6 Construct at meter one and pressure measuring drill hole C1Parallel mash gas pumping drilling, is designated as C by mash gas pumping drilling2, mash gas pumping drilling C2 Aperture be 94 millimeters, mash gas pumping drilling C2In with mash gas pumping drilling C2The gas pumping pipe 8 of degree of depth equal length, is positioned at watt This extraction borehole C2Circumferentially arranged with multiple air-vents 4 (also referred to as floral tube section) on interior gas pumping pipe one end tube wall, use What colliery was conventional two blocks up the hole-sealing technology of note total rock section 5 sealing of hole to mash gas pumping drilling C2Carry out sealing of hole, gas pumping pipe 8 The other end is connected with gas pumping pumping plant 9, is provided with effusion meter 10 between gas pumping pipe 8 and gas pumping pumping plant 9；Use colliery Conventional two block up the hole-sealing technology of a note to mash gas pumping drilling C2Carry out sealing of hole, and use the mode of negative pressure extraction that gas is taken out Borehole C2Carrying out gas pumping, the extraction negative pressure described in the present embodiment is 54KPa, real-time monitored record mash gas pumping drilling C2Gas flow reading, extraction negative pressure reading and mutually pressure measuring drill hole C the most in the same time1Manometric reading change.
3rd step: according to gas flow equation:
Understanding, gas flow equation when there is free-boundary problem is:
Then the computing formula of free-boundary problem is:
Along with mash gas pumping drilling C2Constantly mash gas extraction, mash gas pumping drilling C2Interior gas flow speed v and pressure measuring drill hole C1 Pressure gauge reading can constantly reduce, the inlet pressure p of original coal seam reservoirs during actual measurement1, outlet pressure p2, gas pumping Boring C2The value of gas flow Q as shown in table 1, obtain a series of v and p1 2-p2 2Value, and to v and p1 2 -p2 2Value carry out line Property return, obtain matched curve as shown in Figure 2.
The measured data of the original coal seam reservoirs of table 1 and computational chart
Then constant a=4.22 × 10 are obtained according to the data of actual measurement-16, b=0.00327, by a=4.22 × 10-16, b =0.00327 substitutes into formula 3. the most available hypotonic original coal seam reservoirs gas free-boundary problem λ=0.46MPa/m.
Wherein p0For normal atmospheric pressure, usual p0Take 101325Pa；p1For inlet pressure, i.e. pressure measuring drill hole C1Place's coal storage Layer gas pressure, is pressure measuring drill hole C herein1Pressure gauge reading, Pa；p2Bore with gas pumping for outlet pressure, i.e. normal atmosphere Hole C2The difference of extraction negative pressure, Pa；V is mash gas pumping drilling C2Gas flow speed on rib face, m/s；V=Q/ π Φ l herein, Q is mash gas pumping drilling C2Gas flow, Φ is mash gas pumping drilling C2Aperture, the present embodiment takes 94 millimeters, l is watt This extraction borehole C2See the length of coal section, the present embodiment takes 8.6 meters；L is methane gas length of flow across, is pressure measuring drill hole herein C1With mash gas pumping drilling C2Between distance, the present embodiment takes 6 meters；μ is methane gas dynamic viscosity, generally take 1.107 × 10-5Pa·s；K is coal reservoir fracture system, m2。
Subscript or subscript in the most above-mentioned formula and symbol are distinguished as just subscript or subscript, do not represent other real The meaning on border；
4th step: according to formula 1. with formula 2., obtains computing formula based on the coal reservoir fracture system k under free-boundary problem For:
The b=0.00327 calculated in 3rd step is substituted into formula the most available based on free-boundary problem hypotonic Coal reservoir fracture system k=1.37 × 10-17m2。
Described inlet pressure p1It is variable, at different time point inlet pressure p with flow velocity v1Value and flow velocity v value are the most not Identical, by the inlet pressure p of each timing node1Value and flow velocity v value are brought formula into and are tried to achieve the coal reservoir fracture system k of correspondence the most respectively Value, and calculate the meansigma methods obtaining hypotonic original coal reservoir fracture system
The meansigma methods that will calculateReference value as the hypotonic original coal reservoir fracture system of whole mine.
Embodiment two:
Hypotonic coal seam reservoirs gas free-boundary problem and the on-the-spot test method of permeability after hydraulic flushing in hole, including following Step:
The step of this embodiment two is essentially identical with the step of example one, repeats the most one by one, except for the difference that at example one Second step is treated mash gas pumping drilling C2Drill after constructing, first to mash gas pumping drilling C2Carry out hydraulic flushing in hole, treat that waterpower is rushed Hole complete after again to mash gas pumping drilling C2Carry out gas pumping.Wherein hydraulic flushing in hole coal output is according to mash gas pumping drilling C2 See that the length of coal section is not less than 1t/m.
Along with mash gas pumping drilling C2Constantly mash gas extraction, mash gas pumping drilling C2Interior gas flow speed v and pressure measuring drill hole C1 Pressure gauge reading can constantly reduce, the inlet pressure p of original coal seam reservoirs during actual measurement1, outlet pressure p2, gas pumping Boring C2The value of gas flow Q as shown in table 2, obtain a series of v and p1 2-p2 2Value, and to v and p1 2-p2 2Value carry out line Property return, obtain matched curve as shown in Figure 3.
The measured data of coal seam reservoirs and computational chart after table 2 hydraulic flushing in hole
Then constant a=1.20 × 10 are obtained according to the data of actual measurement-14, b=0.00694, by a=1.20 × 10-14, b =0.00694 substitutes into hypotonic coal seam reservoirs gas free-boundary problem λ=0.12MPa/m after formula 3. the most available hydraulic flushing in hole.
Wherein p0For normal atmospheric pressure, usual p0Take 101325Pa；p1For inlet pressure, i.e. pressure measuring drill hole C1Place's coal storage Layer gas pressure, is pressure measuring drill hole C herein1Pressure gauge reading, Pa；p2Bore with gas pumping for outlet pressure, i.e. normal atmosphere Hole C2The difference of extraction negative pressure, Pa；V is mash gas pumping drilling C2Gas flow speed on rib face, m/s；V=Q/ π Φ l herein, Q is mash gas pumping drilling C2Gas flow, Φ is mash gas pumping drilling C2Aperture, the present embodiment takes 94 millimeters, l is watt This extraction borehole C2See the length of coal section, the present embodiment takes 8.6 meters；L is methane gas length of flow across, is pressure measuring drill hole herein C1With mash gas pumping drilling C2Between distance, the present embodiment takes 6 meters；μ is methane gas dynamic viscosity, generally take 1.107 × 10-5Pa·s；K is coal reservoir fracture system, m2。
The b=0.00694 calculated in 3rd step is substituted into formula the most available based on free-boundary problem hypotonic Coal reservoir fracture system k=6.24 × 10-17m2。
Described inlet pressure p1It is variable, at different time point inlet pressure p with flow velocity v1Value and flow velocity v value are the most not Identical, by the inlet pressure p of each timing node1Value and flow velocity v value are brought formula into and are tried to achieve the coal reservoir fracture system k of correspondence the most respectively Value, and calculate the meansigma methods obtaining hypotonic original coal reservoir fracture system
The meansigma methods that will calculateAs the reference value of permeability after whole mine hypotonic coal seam reservoirs hydraulic flushing in hole.
The ultimate principle of the present invention, principal character and advantages of the present invention have more than been shown and described.The technology of the industry Personnel, it should be appreciated that the present invention is not restricted to the described embodiments, simply illustrating this described in above-described embodiment and description The principle of invention, the present invention also has various changes and modifications without departing from the spirit and scope of the present invention, and these become In the range of change and improvement both fall within claimed invention.Claimed scope is by appending claims and equivalent Thing defines.

Claims (6)

  1. The most hypotonic coal seam reservoirs gas free-boundary problem and the on-the-spot test method of permeability, it is characterised in that concrete includes Following steps:
    The first step: selecting representational white space at the hypotonic coal seam reservoirs of underground coal mine, described white space refers to not meet with The complete hypotonic coal seam reservoirs destroyed to exploitation, about without other boring interference in the range of 10 meters, constructs in this white space This pressure measuring drill hole, as pressure measuring drill hole, is designated as C by one layer-through drilling1, pressure measuring drill hole C1Interior inclosure and pressure measuring drill hole C1The degree of depth etc. Four points of aluminium-plastic pipes of length, are positioned at pressure measuring drill hole C1Circumferentially arranged with multiple air-vents on four points of interior aluminium-plastic pipe one end tube walls, Use colliery conventional two block up the hole-sealing technology of a note total rock section sealing of hole to pressure measuring drill hole C1Carry out sealing of hole, four points of aluminium-plastic pipes another One end is at pressure measuring drill hole C1Outer reserved 30 centimetres～50 centimetres, and at the end of four points of aluminium-plastic pipes, valve and Pressure gauge are installed, and The reading of observed pressure table, after a period of time, manometric reading tends towards stability, and records its data, and these data are pressure measurement and bore Hole C1Hypotonic coal seam reservoirs gas pressure around；
    Second step: treat pressure measuring drill hole C1Pressure gauge reading stable after, with pressure measuring drill hole C1Between distance be at L construct One and pressure measuring drill hole C1Parallel mash gas pumping drilling, is designated as C by mash gas pumping drilling2, mash gas pumping drilling C2In and gas Extraction borehole C2The gas pumping pipe of degree of depth equal length, is positioned at mash gas pumping drilling C2Edge on interior gas pumping pipe one end tube wall Being circumferentially with multiple air-vent, use colliery conventional two block up the hole-sealing technology of a note total rock section sealing of hole to mash gas pumping drilling C2 Carrying out sealing of hole, the other end of gas pumping pipe is connected with gas pumping pumping plant, between gas pumping pipe and gas pumping pumping plant It is provided with effusion meter；Two commonly used with colliery block up the hole-sealing technology of a note to mash gas pumping drilling C2Carry out sealing of hole, and use negative pressure The mode of extraction is to mash gas pumping drilling C2Carry out gas pumping, real-time monitored record mash gas pumping drilling C2Gas flow read Number, extraction negative pressure reading and phase pressure measuring drill hole C the most in the same time1Manometric reading change；
    3rd step: according to gas flow equation:
    Understanding, gas flow equation when there is free-boundary problem is:
    V=a (p1 2-p2 2)-b ②
    Then the computing formula of free-boundary problem is:
    Along with mash gas pumping drilling C2Constantly mash gas extraction, pressure measuring drill hole C1Pressure gauge reading can constantly reduce, by survey Measure a series of v and p1 2-p2 2Value, then linear regression relation therebetween, obtain constant a and b, the formula of substitution the most just may be used Obtain the value of hypotonic coal seam reservoirs gas free-boundary problem λ；
    Wherein p0For normal atmospheric pressure, usual p0Take 101325Pa；p1For inlet pressure, i.e. pressure measuring drill hole C1Place's coal seam reservoirs gas Pressure, is pressure measuring drill hole C herein1Pressure gauge reading, Pa；p2For outlet pressure, i.e. normal atmosphere and mash gas pumping drilling C2's The difference of extraction negative pressure, Pa；V is mash gas pumping drilling C2Gas flow speed on rib face, m/s；L is that methane gas flows through length Degree, is pressure measuring drill hole C herein1With mash gas pumping drilling C2Between distance；μ is methane gas dynamic viscosity, generally takes 1.107 ×10-5Pa·s；K is coal reservoir fracture system, m2；
    Subscript or subscript in the most above-mentioned formula and symbol are distinguished as just subscript or subscript, do not represent other reality Meaning；
    4th step: according to formula 1. with formula 2., obtaining computing formula based on the coal reservoir fracture system k under free-boundary problem is:
    The most available hypotonic coal reservoir fracture system based on free-boundary problem of b value substitution formula that will calculate in 3rd step The value of k.
  2. Hypotonic coal seam reservoirs gas free-boundary problem the most according to claim 1 and the on-the-spot test method of permeability, its It is characterised by: described pressure measuring drill hole C1Aperture be 94 millimeters, described mash gas pumping drilling C2Aperture be 94 millimeters, described survey Pressure boring C1With mash gas pumping drilling C2Between distance L be 6 meters.
  3. Hypotonic coal seam reservoirs gas free-boundary problem the most according to claim 1 and the on-the-spot test method of permeability, its It is characterised by: described inlet pressure p1It is variable, at different time point inlet pressure p with flow velocity v1Value and flow velocity v value are the most not Identical, by the inlet pressure p of each timing node1Value and flow velocity v value are brought formula into and are tried to achieve the coal reservoir fracture system k of correspondence the most respectively Value, and calculate the meansigma methods obtaining coal reservoir fracture system
    The meansigma methods that will calculateReference value as the coal reservoir fracture system in the hypotonic coal seam of whole mine.
  4. Hypotonic coal seam reservoirs gas free-boundary problem the most according to claim 1 and the on-the-spot test method of permeability, its It is characterised by: described manometric range is 0～1.6MPa.
  5. Hypotonic coal seam reservoirs gas free-boundary problem the most according to claim 1 and the on-the-spot test method of permeability, its It is characterised by: described second step is treated mash gas pumping drilling C2Drill after constructing, first to mash gas pumping drilling C2Carry out waterpower Punching, again to mash gas pumping drilling C after hydraulic flushing in hole completes2Carry out gas pumping.
  6. Hypotonic coal seam reservoirs gas free-boundary problem the most according to claim 5 and the on-the-spot test method of permeability, its It is characterised by: described hydraulic flushing in hole coal output is for according to mash gas pumping drilling C2See that the length of coal section is not less than 1t/m.
CN201610460218.4A 2016-06-21 2016-06-21 Hypotonic coal seam reservoirs gas free-boundary problem and the on-the-spot test method of permeability Pending CN106124381A (en)

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CN106932328A (en) * 2017-05-16 2017-07-07 四川大学 The system and method for coal body permeability is tested using search gas
CN108507919A (en) * 2017-02-23 2018-09-07 中国石油化工股份有限公司 Shale full-hole core starts method for testing pressure under a kind of radial flow flow pattern
CN108760597A (en) * 2018-04-11 2018-11-06 河南理工大学 A kind of experimental method of evaluation coal seam reservoirs voltage-sensitive effect
CN109113705A (en) * 2018-09-06 2019-01-01 西安科技大学 A kind of coal mine underground coal bed hydraulic fracturing zone of influence Permeability Distribution determines method
CN109459371A (en) * 2018-12-25 2019-03-12 核工业北京地质研究院 A kind of rock material measuring gas permebility device and its test method
CN110175435A (en) * 2018-12-05 2019-08-27 河南理工大学 A method of dividing coal-bed gas pressure recovery curve flowing stage
CN112557275A (en) * 2020-11-19 2021-03-26 河南能源化工集团研究总院有限公司 In-situ radial testing method for coal seam permeability coefficient
CN113063711A (en) * 2021-02-25 2021-07-02 山东科技大学 Method and device for testing permeability of coal containing gas under different stress loading paths
CN113138150A (en) * 2021-04-27 2021-07-20 中国平煤神马能源化工集团有限责任公司 Transient pressure-based low-permeability coal seam in-situ permeability testing method and device
CN113295592A (en) * 2021-05-20 2021-08-24 中国石油大学(北京) Relative permeability determination system and method for low-permeability rock
CN113295594A (en) * 2021-05-20 2021-08-24 中国石油大学(北京) System and method for measuring relative permeability based on shunt model and CT scanning

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CN113295592A (en) * 2021-05-20 2021-08-24 中国石油大学(北京) Relative permeability determination system and method for low-permeability rock
CN113295594A (en) * 2021-05-20 2021-08-24 中国石油大学(北京) System and method for measuring relative permeability based on shunt model and CT scanning
CN113295592B (en) * 2021-05-20 2022-06-07 中国石油大学(北京) Relative permeability determination system and method for low-permeability rock
CN113295594B (en) * 2021-05-20 2022-07-12 中国石油大学(北京) System and method for measuring relative permeability based on shunt model and CT scanning

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