CN108896438A - Bottom hole gas bearing capacity measuring device and measurement method - Google Patents

Bottom hole gas bearing capacity measuring device and measurement method Download PDF

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Publication number
CN108896438A
CN108896438A CN201810827530.1A CN201810827530A CN108896438A CN 108896438 A CN108896438 A CN 108896438A CN 201810827530 A CN201810827530 A CN 201810827530A CN 108896438 A CN108896438 A CN 108896438A
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CN
China
Prior art keywords
air
speed change
flow speed
pressure port
gas
Prior art date
Application number
CN201810827530.1A
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Chinese (zh)
Inventor
罗永江
王法凯
梁运培
胡千庭
何将福
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重庆大学
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Application filed by 重庆大学 filed Critical 重庆大学
Priority to CN201810827530.1A priority Critical patent/CN108896438A/en
Publication of CN108896438A publication Critical patent/CN108896438A/en

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Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N7/00Analysing materials by measuring the pressure or volume of a gas or vapour
    • G01N7/14Analysing materials by measuring the pressure or volume of a gas or vapour by allowing the material to emit a gas or vapour, e.g. water vapour, and measuring a pressure or volume difference

Abstract

The invention discloses a kind of bottom hole gas bearing capacity measuring device and measurement method, which includes air-flow speed change body(5)And difference gauge(3), air-flow speed change body(5)Inside is equipped with the difference gauge with data storage function(3), difference gauge(3)The first pressure port(1)It is connected to air-flow speed change body(5)Leading portion, difference gauge(3)The second pressure port(2)It is connected to air-flow speed change body(5)Middle section.The method comprising the steps of:1, pressure differential Δ P is measured with above-mentioned measuring device;2, the density of fluid at each pressure port is calculated, and according to the sectional area at each pressure port, calculates the outburst amount of measuring point front end gas;3, the original gas bearing capacity in coal seam is pushed away by the way that the relationship of desorption of mash gas rule and time is counter.The present invention solves the problems, such as that coal sample present in existing drill hole sampling technology starts that desorption time is difficult to defining issue and coal sample is exposed to desorption of mash gas in air and loses, and drilling tool structure is simple, and measurement method is convenient.

Description

Bottom hole gas bearing capacity measuring device and measurement method
Technical field
The invention belongs to gas bearing capacity determination techniques, and in particular to one kind is applied to connect fastly in drilling drilling process with drill straight Speed measurement coal seam gas-bearing capacity.
Background technique
Coal seam gas-bearing capacity is measured, it is most important to mash gas outburst prevention and improvement etc..Currently, the measurement master of coal seam gas-bearing capacity If therefore, evaluation gas pressure, content become exploitation coal containing methane gas using the Direct Determination based on drill hole sampling Key technology.But it is exactly that coal containing methane gas sample can be exposed in air and cause a certain amount of gas that drill hole sampling technology, which has maximum drawback, The problems such as loss, makes gas parameter testing result deviation occur so as to cause that can not carry out precise measurement to coal seam gas-bearing capacity It is larger to judging the serious problems such as Coal Outburst degree of danger by accident.
Summary of the invention
Aiming at the problem that coal sample existing for the drill hole sampling technology is exposed to that desorption of mash gas loses in air, the present invention to be solved Certainly the technical issues of, is just to provide a kind of bottom hole gas bearing capacity measuring device, it can connect in down-hole drilling drilling process with drill straight Quickly measurement coal seam gas-bearing capacity avoids the bottom hole gas bearing capacity of coal containing methane gas desorption loss caused by sampling link, improves coal The accuracy of layer gas bearing capacity measurement.The present invention also provides a kind of bottom hole gas bearing capacity method for fast measuring.
The present invention provides a kind of bottom hole gas bearing capacity measuring device, and bright includes air-flow speed change body and difference gauge, air-flow speed change Body is the handle shape entity that both ends have connecting screw hole, intermediate projections, is equipped with inside air-flow speed change body with data storage function Difference gauge, the large aperture airflow channel of the first pressure port connection air-flow speed change body leading portion of difference gauge, the second pressure of difference gauge The small-bore airflow channel in hole connection air-flow speed change body middle section.
The present invention also provides a kind of bottom hole gas bearing capacity measurement methods, include the following steps:
Step 1 measures pressure differential Δ P between the first pressure port and the second sampling hole using above-mentioned measuring device;
Step 2, by Bernoulli equation, mass conservation law and pressure differential Δ P, calculate the density of fluid at each pressure port, and According to the sectional area at each pressure port, the gas emission in front of measuring point in hole section is calculated;
Step 3, by calculating the desorption of mash gas rule obtained and the relationship of time is counter pushes away the original gas bearing capacity in coal seam.
The solution have the advantages that:
Difference gauge in present invention drilled tunnel measures fluid flow, changes fluid using Venturi tube principle rule and flows shape State, Accurate Determining desorbs Gas-Flow pressure difference, and is contained by desorption of mash gas rule and the anti-original gas in coal seam that pushes away of the relationship of time Amount solves coal sample present in existing drill hole sampling technology and starts that desorption time is difficult to defining issue and coal sample is exposed to air The problem of middle desorption of mash gas loses, and drilling tool structure is simple, measurement method is convenient.
Detailed description of the invention
Detailed description of the invention of the invention is as follows:
Fig. 1 is measuring device use state diagram of the invention.
In figure:1, the first pressure port;2, the second pressure port;3, difference gauge;4, gas air-flow;5, air-flow speed change body;6, it bores Hole coal wall.
Specific embodiment
Present invention will be further explained below with reference to the attached drawings and examples:
As shown in Figure 1, measuring device of the invention includes air-flow speed change body 5 and difference gauge 3, air-flow speed change body 5 has for both ends The handle shape entity of connecting screw hole, intermediate projections is equipped with the difference gauge 3 with data storage function, differential pressure inside air-flow speed change body 5 The large aperture airflow channel of the first pressure port 1 connection 5 leading portion of air-flow speed change body of meter 3, the second pressure port 2 connection of difference gauge 3 The small-bore airflow channel in 5 middle section of air-flow speed change body.
Measuring device use state of the invention is:
As shown in Figure 1, air-flow speed change body 5 is connect with drilling rod and drill bit respectively by connecting screw hole.Air-flow speed change body 5 and drilling coal 4 flow velocity of gas air-flow is formed between wall 6 and changes channel, and leading portion is large aperture airflow channel, and middle section is small-bore airflow channel. Gas air-flow velocity at second pressure port 2 is most fast, and static pressure is minimum.First pressure port 1 and the second sampling hole 2 and 2 phase of difference gauge Even, the difference gauge 3 with data storage function automatically records pressure differential Δ P between the first pressure port 1 and the second sampling hole 2.Gas Flow velocity is maximum when air-flow 4 passes through second pressure port 2 in 5 middle section of air-flow speed change body, and air-flow speed change body is restored to change after passing through later Flow velocity before pressing.
When needing to carry out gas bearing capacity measurement to predetermined depth target coal seam, drill bit, rear termination will be terminated before the present invention Drilling rod keeps normal drilling later.
Measurement method of the invention, includes the following steps:
Step 1 measures pressure differential Δ P between the first pressure port 1 and the second sampling hole 2 using above-mentioned measuring device.
After drill bit enters coal seam, the desorption of coal seam adsorption gas, adsorption gas desorption is in air-flow speed change body 5 and drilling coal wall 6 Between formed have certain flow rate gas stream.Flow velocity changes after desorption gas air-flow flows through air-flow speed change body 5, formation office Portion's flow velocity changes section, and the first pressure port 1 is different with desorption gas flow speed at the second pressure port 2 at this time.When desorption gas flow speed most When fast, static pressure is minimum, i.e. static pressure P at the first pressure port 11Greater than static pressure P at the second pressure port 22, band data storage function Difference gauge 3 automatically record pressure differential Δ P=P1- P2
Step 2, by Bernoulli equation, mass conservation law and pressure differential Δ P, calculate the close of fluid at each pressure port Degree, and according to the sectional area at each pressure port, calculate the gas emission in front of measuring point in hole section.
According to Bernoulli Jacob's gas equation it is found that desorption gas air-flow meets the conservation of energy and mass conservation law.
Bernoulli equation:
P 1+ ρ 1 v 1 2= P 2+ ρ 2 v 2 2 (1)
Formula(1)In:
P 1For static pressure at the first pressure port 1, MPa;
P 2For static pressure at the second pressure port 2, MPa;
ρ 1For desorption gas density at the first pressure port 1, Kg/m3
ρ 2For desorption gas density at the second pressure port 2, Kg/m3
v 1 For flow velocity at the first pressure port 1, m/s;
v 2 For flow velocity at the second pressure port 2, m/s.
Mass conservation law:
ρ 1 V 1 =ρ 2 V 2 (2)
Formula(2)In:V 1 For unit length volume at the first pressure port 1, m3V 2 For unit length volume at the second pressure port 2, m3
Pressure difference calculation formula:
ΔP= P1- P2 (3)
Simultaneous solution formula(1),(2),(3), the density of fluid at each pressure port can be calculated, and according to each pressure port at Sectional area calculates the gas emission in front of measuring point in hole section.
Step 3, the relationship of the desorption of mash gas rule and time obtained by above-mentioned calculating is counter pushes away the original gas bearing capacity in coal seam.
Appropriate time is stopped in the position for needing measuring point in drilling process, implements the gas in front of the measuring point in hole section and overflows Measurement out continues to creep into forward after being measured.
The present invention solve coal sample present in existing drill hole sampling technology start desorption time be difficult to define, coal sample exposure The problem of desorption of mash gas loses in air, and drilling tool structure is simple, measurement method is convenient.

Claims (3)

1. bottom hole gas bearing capacity measuring device, it is characterized in that:Including air-flow speed change body(5)And difference gauge(3), air-flow speed change body (5)There is the handle shape entity of connecting screw hole, intermediate projections, air-flow speed change body for both ends(5)Inside stores function equipped with band data The difference gauge of energy(3), difference gauge(3)The first pressure port(1)It is connected to air-flow speed change body(5)The large aperture airflow channel of leading portion, Difference gauge(3)The second pressure port(2)It is connected to air-flow speed change body(5)The small-bore airflow channel in middle section.
2. bottom hole gas bearing capacity measuring device according to claim 1, it is characterized in that:Air-flow speed change body(5)Pass through connection Screw hole is connect with drilling rod and drill bit respectively.
3. using the bottom hole gas bearing capacity measurement method of measuring device described in claim 1, characterized in that include the following steps:
Step 1 measures pressure differential Δ P between the first pressure port and the second sampling hole using measuring device described in claim 1;
Step 2, by Bernoulli equation, mass conservation law and pressure differential Δ P, calculate the density of fluid at each pressure port, and According to the sectional area at each pressure port, the gas emission in front of measuring point in hole section is calculated;
Step 3, by calculating the desorption of mash gas rule obtained and the relationship of time is counter pushes away the original gas bearing capacity in coal seam.
CN201810827530.1A 2018-07-25 2018-07-25 Bottom hole gas bearing capacity measuring device and measurement method CN108896438A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810827530.1A CN108896438A (en) 2018-07-25 2018-07-25 Bottom hole gas bearing capacity measuring device and measurement method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810827530.1A CN108896438A (en) 2018-07-25 2018-07-25 Bottom hole gas bearing capacity measuring device and measurement method

Publications (1)

Publication Number Publication Date
CN108896438A true CN108896438A (en) 2018-11-27

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Application Number Title Priority Date Filing Date
CN201810827530.1A CN108896438A (en) 2018-07-25 2018-07-25 Bottom hole gas bearing capacity measuring device and measurement method

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2166420Y (en) * 1993-05-27 1994-05-25 武玉祥 Flow sensor
US20050188771A1 (en) * 2004-02-27 2005-09-01 Roxar Flow Measurement As Flow meter
CN1834591A (en) * 2006-04-18 2006-09-20 西安中望流量仪表有限公司 Built-in conical throttling gear
CN201348520Y (en) * 2008-12-05 2009-11-18 陕西仪新测控仪表有限公司 Concealed ring-type cone throttling device
CN102012331A (en) * 2010-11-04 2011-04-13 煤炭科学研究总院重庆研究院 Gas and pressure measuring method with anti-clogging function for gas measurement
CN102322907A (en) * 2011-05-17 2012-01-18 重庆梅安森科技股份有限公司 Integrated intelligent gas flow meter with double flow measuring heads
CN104406646A (en) * 2014-10-29 2015-03-11 水煤浆气化及煤化工国家工程研究中心 Measurement device of pulverized coal mass flow meter
CN105526979A (en) * 2015-12-31 2016-04-27 郑州光力科技股份有限公司 Gas drainage flow measurement device

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2166420Y (en) * 1993-05-27 1994-05-25 武玉祥 Flow sensor
US20050188771A1 (en) * 2004-02-27 2005-09-01 Roxar Flow Measurement As Flow meter
CN1834591A (en) * 2006-04-18 2006-09-20 西安中望流量仪表有限公司 Built-in conical throttling gear
CN201348520Y (en) * 2008-12-05 2009-11-18 陕西仪新测控仪表有限公司 Concealed ring-type cone throttling device
CN102012331A (en) * 2010-11-04 2011-04-13 煤炭科学研究总院重庆研究院 Gas and pressure measuring method with anti-clogging function for gas measurement
CN102322907A (en) * 2011-05-17 2012-01-18 重庆梅安森科技股份有限公司 Integrated intelligent gas flow meter with double flow measuring heads
CN104406646A (en) * 2014-10-29 2015-03-11 水煤浆气化及煤化工国家工程研究中心 Measurement device of pulverized coal mass flow meter
CN105526979A (en) * 2015-12-31 2016-04-27 郑州光力科技股份有限公司 Gas drainage flow measurement device

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Application publication date: 20181127