Automatic coal seam permeability testing device and method
Technical Field
The invention relates to an automatic coal seam permeability testing device and method, and belongs to the field of mine safety.
Background
Coal is the main energy source in China, and accounts for about 60 percent of the primary energy. Gas, which is an associated substance in the coal mining process, is one of the main factors that seriously threaten the safety production of coal mines. Gas disasters cause a great deal of casualties and huge property loss every year. Before coal resource exploitation, gas in a coal seam is extracted and utilized, so that not only can safe exploitation of the coal resource be guaranteed, and utilization of efficient clean energy, namely coal mine gas, be promoted, but also the atmospheric environment can be protected, and triple benefits of safety, energy and environment are realized.
The key factor for controlling the gas extraction effect is the permeability of the coal bed, which reflects the difficulty of gas passing through the coal bed under the action of pressure difference.
The traditional method for testing the permeability of the coal seam under the coal mine is very complicated, a plurality of sets of equipment are needed to complete a multi-step testing process, accordingly, a plurality of operators are needed to process the permeability, and the method runs counter to the trend of automation and intellectualization of the mining industry. In addition, a method for testing the permeability of the small coal sample in a ground laboratory is also provided, but the testing device and the method belong to simulation properties, the testing operation is carried out in an off-site environment, and due to the fact that the difference between the small coal sample and the coal seam is too large, the reality and the accuracy of the permeability obtained by the method always have certain errors with the actual situation.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention provides the automatic coal seam permeability testing device and method, which can efficiently and automatically complete the testing of the coal seam permeability, can be directly applied to the actual working condition of the underground coal mine, and has the advantages of real-time testing process and accurate testing result.
The technical scheme adopted by the invention for solving the technical problems is as follows:
an automatic coal seam permeability testing device comprises a pressure measuring pipe and an automatic testing module, wherein the automatic testing module comprises a device shell, a gas pressure gauge with data recording and transmission functions, a gas flow meter with data recording and transmission functions, a control unit, an electromagnetic flow valve and a power supply, which are arranged in the device shell; the gas pressure gauge, the gas inlet and the electromagnetic flow valve are connected through pressure pipes, the gas flow gauge, the electromagnetic flow valve and the gas outlet are also connected through pressure pipes, and the control unit is connected with the gas pressure gauge, the gas flow gauge, the electromagnetic flow valve, a power supply, an input device, a data output interface and a display screen through leads; the end of the piezometric tube is connected to the gas inlet of the device housing through a pressure tube I.
A method for testing the permeability of a coal seam by using an automatic coal seam permeability testing device comprises the following steps: step 1) constructing a cross-layer drill hole perpendicular to a tested coal seam, inserting a pressure measuring pipe into the cross-layer drill hole and sealing the drill hole; step 2) presetting the testing coal seam characteristic parameters and the drilling flow testing time through an input device; step 3) starting to automatically test the gas pressure of the coal seam, sending an instruction by the control unit, closing the electromagnetic flow valve, and gradually increasing the gas pressure in the drill hole; judging whether the gas pressure reading change is less than 0.1MPa within 24 hours, if not, continuing to execute an instruction of closing the electromagnetic flow valve, and if so, executing a step 4); step 4), the control unit sends out an instruction, opens the electromagnetic flow valve and tests the gas flow of the drilling hole; judging whether the testing time reaches the preset time, if not, continuing to execute an instruction of opening the electromagnetic flow valve, and if so, executing the step 5); and 5) integrating preset coal seam characteristic parameters, gas pressure and gas flow data by the control unit, and calculating and outputting a coal seam permeability result by using a permeability algorithm. Compared with the prior art, the automatic coal seam permeability testing device and method provided by the invention have the advantages that the automatic testing of the coal seam permeability is realized through the ingenious design and matching of the gas pressure gauge, the gas flow meter, the electromagnetic flow valve and the control unit, the measurement of the coal seam gas pressure and the drilling gas flow and the calculation of the coal seam permeability can be completed through one set of equipment, the problems of complicated steps, labor consumption and the like in the traditional technology are solved, the coal seam permeability testing efficiency is improved, and the development of the mining industry to the direction of automation and intellectualization is facilitated. The invention can be directly applied to the actual working condition of the underground coal mine, the test process is real-time, and the test result is accurate. The automatic coal bed permeability testing device is wide in application range and can adapt to permeability testing of coal beds under different occurrence conditions. In addition, the automatic coal seam permeability testing device is simple in structure, convenient to operate and low in manufacturing cost.
Drawings
The invention is further illustrated with reference to the following figures and examples.
Fig. 1 is a schematic structural diagram of an embodiment of the present invention in application.
FIG. 2 is a schematic diagram of an internal structure of an automatic test module according to an embodiment of the present invention
FIG. 3 is a flowchart of a testing method according to an embodiment of the present invention.
In the figure: 01. the device comprises a cross-layer drilling hole, 02 and a coal bed testing hole, 1, a pressure measuring pipe, 2, a pressure-resistant pipe I2, 3, a gas inlet, 4, a gas pressure gauge, 5, a gas outlet, 6, a gas flowmeter, 7, an input device, 8, a data output interface, 9, a display screen, 10, a control unit, 11, an electromagnetic flow valve, 12, a power supply, 13, a pressure-resistant pipe II, 14, a pressure-resistant pipe III, 15, a pressure-resistant pipe IV, 16, a pressure-resistant pipe V, 17, a lead I, 18, a lead II, 18, 19, a lead III, 20, a lead IV, 21, a lead V, 22, a lead VI, 23, a lead VII, 24 and a device shell.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, belong to the scope of the present invention.
Fig. 1 to 3 show schematic structural diagrams of a preferred embodiment of the present invention, and an automatic coal seam permeability testing device in fig. 1 and 2 comprises a pressure measuring tube 1 and an automatic testing module, wherein the automatic testing module comprises a device shell 24, a gas pressure gauge 4 with data recording and transmitting functions, a gas flow meter 6 with data recording and transmitting functions, a control unit 10, an electromagnetic flow valve 11 and a power supply 12, which are arranged in the device shell 24, wherein the gas pressure gauge 4 with data recording and transmitting functions and the gas flow meter 6 with data recording and transmitting functions are additionally provided with a data storage module and a data transmission module in a common digital gas pressure meter and digital gas flow meter, the data storage module is connected with a data reading module of the meter itself and then is transmitted to the control unit 10 through the data transmission module, the shell of the device shell 24 is also provided with a gas inlet 3, a gas outlet 5, an input device 7, a data output interface 8 and a display screen 9; the gas pressure gauge 4 is connected with the gas inlet 3 and the electromagnetic flow valve 11 through a pressure pipe II 13 and a pressure pipe III 14 respectively, the gas flow gauge 6 is connected with the electromagnetic flow valve 11 and the gas outlet 5 through a pressure pipe IV 15 and a pressure pipe V16 respectively, and the control unit 10 is connected with the gas pressure gauge 4, the gas flow gauge 6, the electromagnetic flow valve 11, the power supply 12, the input device 7, the data output interface 8 and the display screen 9 through a lead I17, a lead III 19, a lead II 18, a lead IV 20, a lead VI 23, a lead VII 22 and a lead V21 respectively; the tail end of the pressure measuring pipe 1 is connected with a pressure-resistant pipe I2 through a quick connector, and the pressure-resistant pipe I2 is connected to a gas inlet 3 through the quick connector.
Referring to fig. 3, the method for testing the permeability of the coal seam according to the invention comprises the following steps:
step 1) constructing a cross-layer drill hole 01 vertical to a tested coal seam 02, inserting a pressure measuring pipe 1 into the cross-layer drill hole 01 and sealing the drill hole;
step 2) presetting the testing coal seam characteristic parameters and the drilling flow testing time through the input device 7;
step 3) starting to automatically test the gas pressure of the coal seam, sending an instruction by the control unit 10, closing the electromagnetic flow valve 11, and gradually increasing the gas pressure in the cross-layer drill hole 01; judging whether the gas pressure reading change is less than 0.1MPa within 24 hours, if not, continuing to execute an instruction of closing the electromagnetic flow valve 11, and if so, executing the step 4);
step 4), the control unit 10 sends out an instruction, the electromagnetic flow valve 11 is opened, and the gas flow of the drilling hole is tested; judging whether the testing time reaches the preset time, if not, continuing to execute an instruction of opening the electromagnetic flow valve 11, and if so, executing the step 5);
and step 5), integrating preset coal seam characteristic parameters, gas pressure and gas flow data by the control unit 10, and calculating and outputting a coal seam permeability result by using a permeability algorithm.
As is known, the permeability algorithm is as follows: firstly, calculating the gas emission quantity on the coal wall of a unit area of a drill hole at the preset discharge time t
Wherein Q is the borehole gas flow obtained by testing at the moment of preset discharge time t, pi is the circumferential rate, r is a preset coal seam characteristic parameter, namely the borehole radius, and L is a preset coal seam characteristic parameter, namely the coal seamAnd (4) thickness. Further calculating the parameters
And
wherein p is the gas pressure of the coal bed obtained by the test, p
airThe alpha is the preset coal seam characteristic parameter, namely the air pressure of the test site, and the alpha is the preset coal seam characteristic parameter, namely the gas content coefficient of the coal seam.
6 judgment formulas:
the check formula is as follows: f0=ξλ
Permeability k is calculated by the formula: k is lambda/40
Selecting a judgment formula, substituting parameters omega and xi to calculate lambda; intoAnd substituting lambda and xi into a check formula to calculate F0If F is obtained by calculation0If the requirements of the used judgment formula are met, the permeability of the coal bed can be calculated by using a permeability calculation formula; if F is obtained by calculation0If the judgment formula does not meet the requirement of the used judgment formula, selecting one of the rest judgment formulas, and repeating the steps until F is obtained by calculation0And if the requirements of the used judgment formula are met, the permeability of the coal bed can be calculated by using a permeability calculation formula.
The invention has the beneficial effects that:
(1) according to the invention, through the ingenious design and matching of the gas pressure gauge 4, the gas flow gauge 6, the electromagnetic flow valve 11 and the control unit 10, the automatic testing of the coal seam permeability is realized, the measurement of the coal seam gas pressure and the drilling gas flow and the calculation of the coal seam permeability can be completed by one set of equipment, the problems of complicated steps, labor consumption and the like of the traditional technology are solved, the efficiency of the coal seam permeability testing is improved, and the development of mining industry to the direction of automation and intellectualization is facilitated.
(2) The automatic coal bed permeability testing device has wide application range and can adapt to permeability testing of coal beds under different occurrence conditions.
(3) The automatic coal seam permeability testing device is simple in structure, convenient to operate and low in manufacturing cost.
(4) The invention is directly applied to the actual working condition of the underground coal mine, the test process is real-time, and the test result is accurate.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and all simple modifications and equivalent variations of the above embodiment according to the technical spirit of the present invention are included in the protection scope of the present invention.