CN114636803A - Experimental device and method for removing hydrate blockage of natural gas pipeline by gas purging - Google Patents
Experimental device and method for removing hydrate blockage of natural gas pipeline by gas purging Download PDFInfo
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- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 174
- 239000007789 gas Substances 0.000 title claims abstract description 156
- 238000010926 purge Methods 0.000 title claims abstract description 91
- 238000000034 method Methods 0.000 title claims abstract description 40
- 239000003345 natural gas Substances 0.000 title claims abstract description 37
- 238000006243 chemical reaction Methods 0.000 claims abstract description 78
- 238000000354 decomposition reaction Methods 0.000 claims abstract description 20
- 238000001914 filtration Methods 0.000 claims abstract description 6
- 239000007788 liquid Substances 0.000 claims description 26
- 239000000243 solution Substances 0.000 claims description 16
- 238000002347 injection Methods 0.000 claims description 9
- 239000007924 injection Substances 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- 238000004140 cleaning Methods 0.000 claims description 8
- 239000008367 deionised water Substances 0.000 claims description 8
- 229910021641 deionized water Inorganic materials 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 8
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 7
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 7
- 230000036571 hydration Effects 0.000 claims description 7
- 238000006703 hydration reaction Methods 0.000 claims description 7
- 238000004817 gas chromatography Methods 0.000 claims description 6
- 230000000694 effects Effects 0.000 claims description 5
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 239000000654 additive Substances 0.000 claims description 3
- 230000000996 additive effect Effects 0.000 claims description 3
- 238000004458 analytical method Methods 0.000 claims description 3
- 230000006835 compression Effects 0.000 claims description 3
- 238000007906 compression Methods 0.000 claims description 3
- 239000001257 hydrogen Substances 0.000 claims description 3
- 229910052739 hydrogen Inorganic materials 0.000 claims description 3
- 229910052757 nitrogen Inorganic materials 0.000 claims description 3
- 239000000523 sample Substances 0.000 claims description 3
- 238000003786 synthesis reaction Methods 0.000 claims description 3
- 239000013589 supplement Substances 0.000 abstract description 2
- 238000010408 sweeping Methods 0.000 abstract description 2
- 230000001737 promoting effect Effects 0.000 abstract 1
- 230000002000 scavenging effect Effects 0.000 abstract 1
- 238000010438 heat treatment Methods 0.000 description 6
- 238000004587 chromatography analysis Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 150000004677 hydrates Chemical class 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 1
- 239000013000 chemical inhibitor Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- NMJORVOYSJLJGU-UHFFFAOYSA-N methane clathrate Chemical compound C.C.C.C.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O NMJORVOYSJLJGU-UHFFFAOYSA-N 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000004088 simulation 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
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/22—Fuels, explosives
- G01N33/222—Solid fuels, e.g. coal
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D21/00—Measuring or testing not otherwise provided for
- G01D21/02—Measuring two or more variables by means not covered by a single other subclass
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M99/00—Subject matter not provided for in other groups of this subclass
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/22—Fuels, explosives
- G01N33/225—Gaseous fuels, e.g. natural gas
Abstract
The invention discloses an experimental device and method for removing hydrate blockage of a blocked natural gas pipeline by gas purging. The experimental device can be used for researching the change laws of hydrate decomposition amount, blockage removal rate, scavenging gas consumption and the like when different gases are swept and blocked, and comprises a sweeping system, a high-pressure tubular reaction kettle and a gas collecting system, wherein two ends of the high-pressure tubular reaction kettle are sealed and are respectively provided with a filtering device, and one end of the high-pressure tubular reaction kettle is provided with a hydraulic piston for compacting a synthesized hydrate plug. The method is to prepare a hydrate plug in a high-pressure tubular reaction kettle, and then continuously introduce purge gas to unblock the hydrate plug. The gas purging can reduce the partial pressure of natural gas, and the purging gas can carry sensible heat to supplement heat required by the decomposition of the hydrate, thereby promoting the blockage removal process. The device has the advantages that the device can prepare a tight and compact hydrate plug, and the gas purging has the characteristic of high blockage removal efficiency.
Description
Technical Field
The invention relates to the technical field of natural gas pipeline flow safety guarantee, in particular to an experimental device and method for unblocking a hydrate block of a natural gas pipeline by gas purging.
Background
Natural gas is increasingly gaining attention as a relatively clean energy source in energy structures throughout the world. According to statistics, the annual consumption of natural gas in 2015-2019 in China is increased from 1931 billion cubic meters to 3100 billion cubic meters. In order to ensure the stable supply of natural gas in various regions, pipeline transportation is the most common transportation mode of natural gas. Compared with the marine transportation, the river transportation, the railway transportation and the road transportation, the pipeline transportation has the advantages of long transportation distance, large transportation capacity and the like. However, the external environment of the long-distance pipeline is complex and changeable, and the interior of the pipeline is a high-pressure environment, which provides an excellent condition for the generation of natural gas hydrate.
Gas hydrates are ice-like, non-stoichiometric compounds formed from gas molecules and water molecules. The formation of hydrates in natural gas pipelines will form blockages, leading to production stagnation. In order to avoid the damage caused by hydrate blockage, the common prevention and treatment methods mainly comprise heating, depressurization and injection of a chemical inhibitor. In addition, gas purging has also received attention from researchers as an emerging method. When the gas is blown, a large amount of heat can be carried to the blocking position of the hydrate, and the hydrate is decomposed. In addition, because the gas purging is used as a continuous process, the natural gas generated in the hydrate decomposition process can be continuously removed, so that the partial pressure of the natural gas is effectively reduced, and the continuous implementation of the hydrate decomposition is facilitated. However, at present, the change rule of the hydrate decomposition amount and the blockage removal rate in the gas purging blockage removal process is unclear, and the pipeline temperature, the pressure change rule, the optimal gas purging rate and the like in the blockage removal process are unclear, so that an experimental device and a method for removing the blockage of the natural gas pipeline by gas purging are urgently needed and are used for researching the gas purging blockage removal process.
Disclosure of Invention
The invention aims to provide an experimental device and method for evaluating the hydrate blockage removing effect of a gas purging natural gas pipeline, the device has the characteristics of easiness in operation, reliable experimental principle and the like, the simulation of the hydrate blockage removing process of the gas purging natural gas pipeline is realized, the method can be used for researching the change condition of the hydrate decomposition amount and the blockage removing speed in the gas purging process along with time, and the method has practical significance for effectively evaluating the hydrate blockage removing effect of gas purging.
In order to achieve the purpose, the invention adopts the following technical scheme:
the utility model provides an utilize gaseous experimental apparatus who removes stifled natural gas line hydrate jam that sweeps, its characterized in that, including sweeping gas cylinder, methane gas cylinder, mass flow controller, hand pump, high-pressure tube reation kettle, preceding pressure sensor of cauldron, pressure sensor behind the cauldron, temperature sensor group, thermostatic bath, vapour and liquid separator, gas desicator, back pressure valve, mass flowmeter, gas collecting tank. The methane gas cylinder is connected with the high-pressure tubular reaction kettle, and the purging gas cylinder is connected with the mass flow controller and then connected into the high-pressure tubular reaction kettle. The top of the gas-liquid separator is connected with the gas dryer through a pipeline, and the bottom of the gas-liquid separator is provided with a liquid discharge pipeline; the gas dryer is connected with a back pressure valve, the back pressure valve is connected with a mass flowmeter, and the change of the gas flow in the purging process is recorded; and a seventh stop valve is arranged on a pipeline between the mass flow meter and the gas collecting tank. The pressure sensor before the kettle is connected into the front end kettle cover of the high-pressure tubular reaction kettle through a third tee joint, and the pressure sensor after the kettle is connected into the rear end kettle cover of the high-pressure tubular reaction kettle through a fifth tee joint.
Furthermore, the pressure-resistant interval of the high-pressure tubular reaction kettle is 0.1-25 MPa, and the pipe diameter ratio is 4-8.
Further, the kettle covers at the two ends of the high-pressure tubular reaction kettle are sealed and are respectively provided with a filtering device, the front end of the high-pressure tubular reaction kettle is provided with a hydraulic piston, and liquid is injected into a cavity between the front end kettle cover and the piston through a hand pump to be compressed.
Furthermore, the temperature sensor group is equidistantly installed in the high-pressure tubular reaction kettle, and the temperature sensor probe is positioned on the central line in the high-pressure tubular reaction kettle.
Furthermore, the invention also comprises a first pressure reducing valve, a second pressure reducing valve, a first stop valve, a second stop valve, a third stop valve, a fourth stop valve, a fifth stop valve and a sixth stop valve; the first pressure reducing valve and the first stop valve are positioned on a pipeline between the purge gas cylinder and the mass flow controller; the second pressure reducing valve, the second stop valve and the third stop valve are positioned on a pipeline between the methane gas cylinder and the high-pressure tubular reaction kettle; the fourth stop valve is positioned between the hand pump and the high-pressure tubular reaction kettle, and the fifth stop valve is connected to a kettle cover at the rear end of the high-pressure tubular reaction kettle through a third tee; and the sixth stop valve is positioned on a pipeline between the high-pressure tubular reaction kettle and the gas-liquid separator.
In the device, the data acquisition unit is connected with the pressure sensor in front of the kettle, the pressure sensor behind the kettle and the temperature sensor group through signal lines, and the computer is connected with the data acquisition unit, so that the temperature and pressure data acquisition in the gas purging and blockage removing process is realized.
A method for removing hydrate blockage of a blocked natural gas pipeline by gas purging comprises the following steps:
(1) hydrate plug synthesis stage: firstly, closing a third stop valve, a fifth stop valve and a sixth stop valve, opening a kettle cover at the rear end of the high-pressure tubular reaction kettle, repeatedly cleaning by using deionized water, vacuumizing to a required vacuum degree, and sucking 10-180 mL of a prepared additive solution by using vacuum; and (3) placing the reaction kettle filled with the solution in a constant temperature tank with the temperature set to be-10-25 ℃, standing for 0.1-5 h, and balancing the temperature and the pressure. And then opening the second stop valve and the third stop valve, introducing methane gas, closing the third stop valve after gas introduction is finished, and waiting for the completion of hydrate generation. The fourth stop valve is opened and the injection liquid is compressed by a hand pump to ensure that the hydrate plug is sufficiently tight.
(2) And (3) gas purging and blockage removing stage: opening a sixth stop valve, adjusting the pressure of the backpressure valve to be 0.1-10 MPa, and then opening the first stop valve and the third stop valve to introduce purge gas; and opening a seventh stop valve, and collecting the purge gas and the hydrate decomposition gas by adopting a gas collection tank. And opening a fifth stop valve at certain intervals to collect gas phase in the kettle, and then performing gas chromatography to analyze the composition in the kettle and the collection tank. And after purging is finished, closing the first stop valve, the third stop valve and the sixth stop valve, setting the temperature of the thermostatic bath to be 25 ℃, decomposing residual hydrate, and closing the seventh stop valve. And processing the temperature, pressure and flow data acquired by the computer, and calculating data such as gas consumption, hydrate decomposition amount and unblocking rate in the gas purging and unblocking process by combining the gas chromatography analysis result, so as to evaluate the effect of the gas purging and unblocking the natural gas pipeline hydrate.
In the method, the methane injection frequency in the hydration process is 1-5 times.
In the above method, the purge gas is nitrogen or hydrogen.
In the method, the injection pressure of the purge gas is 0.2-10 MPa, and the purge rate is 0.1-10 SLM.
Compared with the prior art, the invention has the following advantages:
(1) the method can simulate the blockage of the natural gas pipeline by the hydrate, research the change rules of the hydrate decomposition amount, the blockage removal rate and the like when the gas purging is used for removing the blockage of the hydrate, evaluate the performance of the gas purging for removing the blockage and optimize the gas amount required by the gas purging.
(2) The invention adopts the hydraulic piston to compress the hydrate plug, and can ensure that the prepared hydrate plug is tight and tight enough.
(3) The gas purging blockage removing method provided by the invention starts from the thermodynamic principle of hydrate phase equilibrium, sensible heat carried by continuous gas flow can supplement heat required by hydrate decomposition, and hydrate decomposition gas is continuously removed at the same time, so that the blockage removing process is promoted, the blockage removing efficiency is improved, and the flow safety of a natural gas pipeline is effectively ensured.
Drawings
FIG. 1 is a schematic structural diagram of an experimental device for removing hydrate blockage of a natural gas pipeline by gas purging.
FIG. 2 is a sectional view of a high-pressure tubular reactor.
FIG. 3 is a diagram of four force-assisting holes on the back end cover of the high-pressure tubular reaction kettle.
In the figure: 1. a purge gas cylinder, 2, a methane gas cylinder, 3, a first pressure reducing valve, 4, a second pressure reducing valve, 5, a first stop valve, 6, a second stop valve, 7, a mass flow controller, 8, a first tee joint, 9, a third stop valve, 10, a second tee joint, 11, a hand pump, 12, a fourth stop valve, 13, a kettle front pressure sensor, 14, a high-pressure tubular reaction kettle, 14-1, a front kettle cover, 14-2, a piston, 14-3, a filtering device, 14-4, a rear kettle cover, 15, a temperature sensor group, 16, a constant temperature tank, 17, a fifth stop valve, 18, a kettle rear pressure sensor, 19, a third tee joint, 20, a fourth tee joint, 21, a sixth stop valve, 22, a gas-liquid separator, 23, a gas drier, 24, a back pressure valve, 25, a mass flow meter, 26, a seventh stop valve, 27, a gas collecting tank, 28, data, 29. a computer.
Detailed Description
The present invention will be further described with reference to the accompanying drawings and examples of the invention so as to facilitate the understanding of the invention by those skilled in the art. It is to be understood that the invention is not limited in scope to the specific embodiments, but is intended to cover various modifications within the spirit and scope of the invention as defined and defined by the appended claims, as would be apparent to one of ordinary skill in the art.
As shown in fig. 1, 2 and 3. FIG. 1 is a schematic diagram of an experimental device for removing hydrate blockage of a natural gas pipeline by gas purging. FIG. 2 is a sectional view of a high-pressure tubular reactor. FIG. 3 is a diagram of four force-assisting holes on the back end cover of the high-pressure tubular reaction kettle.
An experimental device for removing hydrate blockage of a natural gas pipeline by gas purging comprises a purging gas cylinder 1, a methane gas cylinder 2, a mass flow controller 7, a high-pressure tubular reaction kettle 14, a pressure sensor 13 in front of the kettle, a pressure sensor 18 behind the kettle, a temperature sensor group 15, a constant temperature tank 16, a gas-liquid separator 22, a gas dryer 23, a back pressure valve 24, a mass flow meter 25, a gas collecting tank 27, a data collector 28 and a computer 29. The methane gas cylinder 2 is connected with the high-pressure tubular reaction kettle 14 through a gas inlet pipeline, and the purging gas cylinder 1 is connected with the mass flow controller 7 and then connected into the high-pressure tubular reaction kettle 14. The top of the gas-liquid separator 22 is connected with a gas drier 23 through a pipeline, and the bottom of the gas-liquid separator is provided with a liquid discharge pipeline; the gas dryer 23 is connected with the back pressure valve 24, and is used for controlling the system pressure during purging, wherein the adjusting range is 0.2-10 MPa; the back pressure valve 24 is connected with the mass flow meter 25 and used for recording the gas flow change in the purging process; the line between the mass flow meter 25 and the gas collection tank 27 is provided with a seventh stop valve 26. The pressure sensor 13 before the kettle is connected to the front end of the high-pressure tubular reaction kettle 14 through a second tee joint 10, and the pressure sensor 18 after the kettle is connected to the rear end of the high-pressure tubular reaction kettle 14 through a fourth tee joint 20. The pressure sensor 13 before the kettle, the pressure sensor 18 after the kettle and the temperature sensor group 15 are respectively connected with the data acquisition unit 28 through signal lines. The high-pressure tubular reaction kettle 14 has two sealed ends and the front and rear kettle covers are respectively provided with a filtering device. The temperature sensor group 15 is equidistantly arranged on the high-pressure tubular reaction kettle 14, and the temperature sensor probe is positioned on the central line in the high-pressure tubular reaction kettle 14. The present embodiment further includes a first pressure reducing valve 3, a second pressure reducing valve 4, a first cut-off valve 5, a second cut-off valve 6, a third cut-off valve 9, a fourth cut-off valve 12, a fifth cut-off valve 17, a sixth cut-off valve 21, and a seventh cut-off valve 26; the first pressure reducing valve 3 and the first stop valve 5 are positioned on a pipeline between the purge gas cylinder 1 and the mass flow controller 7; the second pressure reducing valve 4, the second stop valve 6 and the third stop valve 9 are positioned on a pipeline between the methane gas cylinder 2 and the high-pressure tubular reaction kettle 14; the fourth stop valve 12 is positioned on a pipeline between the hand pump 11 and the high-pressure tubular reaction kettle 14, and the sixth stop valve 21 is positioned on a pipeline between the high-pressure tubular reaction kettle 14 and the gas-liquid separator 22; the seventh stop valve 26 is located on the pipe between the mass flow meter 25 and the gas collection tank 27.
A method for removing hydrate blockage of a blocked natural gas pipeline by gas purging relates to the following steps:
(1) hydrate plug synthesis stage: firstly, closing a third stop valve 9, a fifth stop valve 17 and a sixth stop valve 21, opening a rear-end kettle cover of the high-pressure tubular reaction kettle 14, repeatedly cleaning by using deionized water, vacuumizing to a required vacuum degree, and sucking 10-180 mL of a pre-prepared additive solution by using vacuum; and (3) placing the reaction kettle filled with the solution in a constant temperature tank 16 with the temperature set to be-10-25 ℃, standing for 0.1-5 h, and balancing the temperature and the pressure. And then opening the second stop valve 6 and the third stop valve 9 to introduce methane gas, closing the third stop valve 9 after the gas introduction is finished, and waiting for the generation of the hydrate to be finished. The number of methane injections is 1-5. The fourth shut-off valve 12 is opened and the liquid is injected with the hand pump 11 for compression to ensure that the hydrate plug is sufficiently tight.
(2) And (3) gas purging and blockage removing stage: opening the sixth stop valve 21, adjusting the pressure of the back pressure valve 24 to be 0.2-10 MPa, then opening the first stop valve 5 and the third stop valve 9, and introducing nitrogen or hydrogen for purging, wherein the purging rate is controlled to be 0.1-10 SLM; the seventh stop valve 26 is opened and the purge gas and the hydrate decomposition gas are collected by the gas collection tank 27. And opening a fifth stop valve 17 at certain intervals to collect gas phase in the kettle, and then performing gas chromatography to analyze the composition in the kettle and the collection tank. After purging is completed, the first stop valve 5, the third stop valve 9 and the sixth stop valve 21 are closed, the temperature of the thermostatic bath 16 is set to be 25 ℃, residual hydrate is decomposed, and the seventh stop valve 26 is closed.
(3) And (3) a data processing stage: and processing the temperature, pressure and flow data acquired by the computer, and calculating data such as gas consumption, hydrate decomposition amount and unblocking rate in the gas purging and unblocking process by combining the gas chromatography analysis result, so as to evaluate the gas purging and unblocking effect of the natural gas pipeline hydrate.
Example 1
Cleaning the reaction kettle for 3 times by using deionized water, vacuumizing to a required vacuum degree, and sucking 100mL of a pre-prepared 300ppm SDS solution in a vacuum manner; and (3) placing the reaction kettle filled with the solution in a constant temperature tank with the temperature set to be 2 ℃, and standing for 1 hour until the temperature and the pressure reach balance. Then injecting methane gas of 7.0MPa into the reaction kettle, and calculating 0.4169mol of hydrated methane after hydration is finished; injecting methane gas for the second time at 5.74MPa, wherein the content of hydrated methane is 0.2390 mol; the third injection of methane gas was 5.33MPa, the amount of hydrated methane was 0.1905mol, and the total amount of hydrated methane was 0.8464 mol. And (4) injecting liquid by using a hand pump to compact the hydrate plug. Opening a sixth stop valve, slowly adjusting the backpressure valve until the pressure in the reaction kettle is 3.6MPa, opening the first stop valve and the third stop valve, adjusting the mass flow controller to control the purging flow rate to be 1SLM, and adjusting the outlet pressure of the hydrogen gas cylinder to be 3.8 MPa; the purging time lasts for 1h, and samples are taken from the gas collecting tank and the high-pressure tubular reaction kettle every 10min for gas chromatographic analysis. And after purging is finished, closing the first stop valve, the third stop valve and the sixth stop valve, heating the thermostatic bath to 25 ℃ to decompose residual hydrate, and then closing the seventh stop valve. According to the collected temperature, pressure, flow and gas phase composition data, the total decomposition rate of the hydrate plug can be calculated to be 84.6%.
Example 2
Cleaning the reaction kettle for 3 times by using deionized water, vacuumizing to a required vacuum degree, and sucking 125mL of a pre-prepared 300ppm SDS solution in a vacuum manner; and (3) placing the reaction kettle filled with the solution in a constant temperature tank with the temperature set to be 2 ℃, and standing for 0.5h until the temperature and the pressure reach equilibrium. Then injecting methane gas of 7.8MPa into the reaction kettle, and calculating 0.4281mol of hydrated methane after hydration is finished; injecting methane gas for the second time at 7.2MPa, wherein the content of the hydrated methane is 0.3664 mol; the third injection of methane gas was 7.3MPa, the amount of hydrated methane was 0.1567mol, and the total amount of hydrated methane was 0.9512 mol. And (4) injecting liquid by using a hand pump to compact the hydrate plug. Opening a sixth stop valve, slowly adjusting the backpressure valve until the pressure in the reaction kettle is 3.6MPa, opening the first stop valve and the third stop valve, adjusting the mass flow controller to control the purging flow rate to be 0.7SLM, and adjusting the outlet pressure of the hydrogen gas cylinder to be 3.8 MPa; the purging time lasts for 1h, and samples are taken from the gas collecting tank and the high-pressure tubular reaction kettle every 10min for gas chromatographic analysis. And after purging is finished, closing the first stop valve, the third stop valve and the sixth stop valve, heating the thermostatic bath to 25 ℃ to decompose residual hydrate, and then closing the seventh stop valve. According to the collected temperature, pressure, flow and gas phase composition data, the total decomposition rate of the hydrate plug can be calculated to be 78.9%.
Example 3
Cleaning the reaction kettle for 3 times by using deionized water, vacuumizing to a required vacuum degree, and sucking 100mL of a pre-prepared 300ppm SDS solution in a vacuum manner; and (3) placing the reaction kettle filled with the solution in a constant temperature tank with the temperature set to be 2 ℃, and standing for 0.5h until the temperature and the pressure reach equilibrium. Then injecting methane gas of 8.3MPa into the reaction kettle, and calculating 0.5393mol of hydrated methane after hydration is finished; injecting methane gas for the second time at 6.1MPa, wherein the content of the hydrated methane is 0.1623 mol; the total amount of hydrated methane was 0.7016 mol. The hydrate plug is compacted by injecting liquid by a hand pump. Opening a sixth stop valve, slowly adjusting the backpressure valve until the pressure in the reaction kettle is 6.4MPa, opening the first stop valve and the third stop valve, adjusting the mass flow controller to control the purging flow rate to be 0.7SLM, and adjusting the outlet pressure of the hydrogen gas cylinder to be 6.8 MPa; the purging time lasts for 1h, and samples are taken from the gas collecting tank and the high-pressure tubular reaction kettle every 10min for gas chromatographic analysis. And after purging is finished, closing the first stop valve, the third stop valve and the sixth stop valve, heating the thermostatic bath to 25 ℃ to decompose residual hydrate, and then closing the seventh stop valve. According to the collected temperature, pressure, flow and gas phase composition data, the total decomposition rate of the hydrate plug can be calculated to be 81.3%.
Example 4
Cleaning the reaction kettle for 3 times by using deionized water, vacuumizing to a required vacuum degree, and sucking 125mL of a pre-prepared 300ppm SDS solution in a vacuum manner; and (3) placing the reaction kettle filled with the solution in a constant temperature tank with the temperature set to be 2 ℃, and standing for 1.0h until the temperature and the pressure reach equilibrium. Then injecting methane gas of 7.5MPa into the reaction kettle, and calculating 0.3942mol of hydrated methane after hydration is finished; injecting methane gas for the second time at 6.0MPa, wherein the content of hydrated methane is 0.2431 mol; injecting methane gas for the third time at 5.02MPa, wherein the content of the hydrated methane is 0.1470 mol; injecting methane gas 7.7MPa for the fourth time, wherein the content of the hydrated methane is 0.1740 mol; the total amount of hydrated methane was 0.9583 mol. And (4) injecting liquid by using a hand pump to compact the hydrate plug. Opening a sixth stop valve, slowly adjusting the back pressure valve until the pressure in the reaction kettle is 3.4MPa, opening the first stop valve and the third stop valve, adjusting the mass flow controller to control the purging flow rate to be 0.7SLM, and adjusting the outlet pressure of the nitrogen gas bottle to be 3.6 MPa; the purging time lasts for 1h, and samples are taken from the gas collecting tank and the high-pressure tubular reaction kettle every 10min for gas chromatographic analysis. And after purging is finished, closing the first stop valve, the third stop valve and the sixth stop valve, heating the thermostatic bath to 25 ℃ to decompose residual hydrate, and then closing the seventh stop valve. According to the collected temperature, pressure, flow and gas phase composition data, the total decomposition rate of the hydrate plug can be calculated to be 64.9%.
Example 5
Cleaning the reaction kettle with deionized water for 3 times, vacuumizing to a required vacuum degree, and sucking 100mL of a pre-prepared 300ppm SDS solution in a vacuum manner; and (3) placing the reaction kettle filled with the solution in a constant temperature tank with the temperature set to be 2 ℃, and standing for 1.0h until the temperature and the pressure reach equilibrium. Then injecting methane gas of 7.7MPa into the reaction kettle, and calculating 0.4815mol of hydrated methane after hydration is finished; injecting methane gas for the second time at 7.7MPa, wherein the content of the hydrated methane is 0.1320 mol; the total amount of hydrated methane was 0.6135 mol. And (4) injecting liquid by using a hand pump to compact the hydrate plug. Opening a sixth stop valve, slowly adjusting the backpressure valve until the pressure in the reaction kettle is 3.4MPa, opening the first stop valve and the third stop valve, adjusting the mass flow controller to control the purging flow rate to be 1.0SLM, and adjusting the outlet pressure of the hydrogen gas cylinder to be 3.8 MPa; the purging time lasts for 1h, and samples are taken from the gas collecting tank and the high-pressure tubular reaction kettle every 10min for gas chromatographic analysis. And after purging is finished, closing the first stop valve, the third stop valve and the sixth stop valve, heating the thermostatic bath to 25 ℃ to decompose residual hydrate, and then closing the seventh stop valve. According to the collected temperature, pressure, flow and gas phase composition data, the total decomposition rate of the hydrate plug can be calculated to be 90.0%.
Claims (10)
1. An experimental device for removing hydrate blockage of a natural gas pipeline by gas purging is characterized by comprising a purging gas cylinder (1), a methane gas cylinder (2), a mass flow controller (7), a hand pump (11), a high-pressure tubular reaction kettle (14), a pressure sensor (13) in front of the kettle, a pressure sensor (18) behind the kettle, a temperature sensor group (15), a thermostatic bath (16), a gas-liquid separator (22), a gas dryer (23), a backpressure valve (24), a mass flow meter (25) and a gas collecting tank (27); the high-pressure tubular reaction kettle (14) is arranged in the constant temperature tank (16); the methane gas cylinder (2) is connected with a high-pressure tubular reaction kettle (14), and the purge gas cylinder (1) is connected with the mass flow controller (7) and then is connected into the high-pressure tubular reaction kettle (14); the top of the gas-liquid separator (22) is connected with the gas drier (23) through a pipeline, and the bottom of the gas-liquid separator is provided with a liquid discharge pipeline; the gas dryer (23) is sequentially connected with the backpressure valve (24), the mass flow meter (25) and the gas collecting tank (27) and used for recording the gas flow change in the purging process; the pressure sensor (13) in front of the kettle is connected to a kettle cover (14-1) at the front end of the high-pressure tubular reaction kettle through a second tee joint (10), and the pressure sensor (18) behind the kettle is connected to a kettle cover (14-4) at the rear end of the high-pressure tubular reaction kettle through a fourth tee joint (20); the pressure sensor (13) in front of the kettle, the pressure sensor (18) behind the kettle and the temperature sensor group (15) are respectively connected with the data acquisition unit (28) through signal lines to acquire temperature and pressure data in the blockage removal process; the data acquisition unit (28) is connected with a computer (29); the hand pump (11) is connected with the high-pressure tubular reaction kettle (14).
2. The experimental facility for unblocking hydrate of natural gas pipeline by using gas purging as claimed in claim 1, further comprising a seventh stop valve (26) and a first tee joint (8); the seventh stop valve (26) is arranged on a pipeline between the mass flow meter (25) and the gas collecting tank (27); the purging gas cylinder (1) and the methane gas cylinder (2) are respectively connected with a first tee joint (8) and then connected with a high-pressure tubular reaction kettle (14).
3. The experimental device for unblocking hydrate of natural gas pipeline by gas purging according to claim 1, wherein the high-pressure tubular reaction kettle (14) has a pressure resistance of 0.1-25 MPa and a pipe diameter ratio of 4-8.
4. The experimental device for removing the hydrate blockage of the natural gas pipeline by using the gas purging as claimed in claim 1, wherein kettle covers at two ends of the high-pressure tubular reaction kettle (14) are sealed, a front-end kettle cover (14-1), a hydraulic piston (14-2) and a filtering device (14-3) are arranged at the front end, the filtering device (14-3) and a rear-end kettle cover (14-4) are arranged at the rear end, four force-assisting holes are formed in the rear-end kettle cover (14-4), and the cavity between the front-end kettle cover (14-1) and the piston (14-2) is filled with liquid for compression through a hand pump (11).
5. The experimental device for unblocking hydrate blockage of a natural gas pipeline by using gas purging as claimed in claim 1, wherein the temperature sensor groups (15) are equidistantly installed in the high-pressure tubular reaction kettle (14), and the temperature sensor probes are positioned on a central line in the high-pressure tubular reaction kettle (14).
6. The experimental device for unblocking hydrate blockage of a natural gas pipeline by using gas purging as claimed in claim 1, further comprising a first pressure reducing valve (3), a second pressure reducing valve (4), a first stop valve (5), a second stop valve (6), a third stop valve (9), a fourth stop valve (12), a fifth stop valve (17) and a sixth stop valve (21); the first pressure reducing valve (3) and the first stop valve (5) are positioned on a pipeline between the purge gas cylinder (1) and the mass flow controller (7); the second pressure reducing valve (4), the second stop valve (6) and the third stop valve (9) are positioned on a pipeline between the methane gas bottle (2) and the high-pressure tubular reaction kettle (14); the fourth stop valve (12) is positioned between the hand pump (11) and the high-pressure tubular reaction kettle (14), and the fifth stop valve (17) is connected to a kettle cover (14-4) at the rear end of the high-pressure tubular reaction kettle through a third tee joint (19); and the sixth stop valve (21) is positioned on a pipeline between the high-pressure tubular reaction kettle (14) and the gas-liquid separator (22).
7. A method for removing hydrate blockage of a blocked natural gas pipeline by gas purging is characterized by comprising the following steps:
(1) hydrate plug synthesis stage: firstly, closing a third stop valve (9), a fifth stop valve (17) and a sixth stop valve (21), opening a rear-end kettle cover of a high-pressure tubular reaction kettle (14), repeatedly cleaning by using deionized water, vacuumizing to a required vacuum degree, and sucking 10-180 mL of a pre-prepared additive solution by using vacuum; and (3) placing the reaction kettle filled with the solution in a constant temperature tank (16) with the temperature set to be-10-25 ℃, standing for 0.1-5 h, and balancing the temperature and the pressure. Then opening a second stop valve (6) and a third stop valve (9), introducing methane gas, closing the third stop valve (9) after the gas is introduced, and waiting for the generation of the hydrate to be finished; opening a fourth stop valve (12), and injecting liquid by using a hand pump (11) for compression to ensure that the synthesized hydrate plug is sufficiently tight;
(2) and (3) gas purging and blockage removing stage: opening a sixth stop valve (21), adjusting the pressure of a back pressure valve (24) to be 0.1-10 MPa, and then opening a first stop valve (5) and a third stop valve (9) to introduce purge gas; opening a seventh stop valve (26), and collecting the purge gas and the hydrate decomposition gas by adopting a gas collection tank (27); opening a fifth stop valve (17) at an interval of 1-120 min to collect gas in the kettle, and then performing gas chromatography to analyze the composition in the kettle and a collection tank; and after purging is finished, closing the first stop valve (5), the third stop valve (9) and the sixth stop valve (21), setting the temperature of the thermostatic bath (16) to be 25 ℃, decomposing residual hydrate, and closing the seventh stop valve (26). And processing the temperature, pressure and flow data acquired by the computer, and calculating data such as gas consumption, hydrate decomposition amount and unblocking rate in the gas purging and unblocking process by combining the gas chromatography analysis result, so as to evaluate the effect of the gas purging and unblocking the natural gas pipeline hydrate.
8. The method for unblocking hydrate of a natural gas pipeline by using gas purging as claimed in claim 7, wherein the number of times of methane injection in the hydration process is 1-5 times.
9. The method for unblocking hydrate of a natural gas pipeline according to claim 7, wherein the purge gas is nitrogen or hydrogen.
10. The method for unblocking hydrate of a natural gas pipeline by using gas purging as claimed in claim 7, wherein the injection pressure of the purging gas is 0.2-10 MPa, and the purging rate is 0.1-10 SLM.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115325431A (en) * | 2022-08-11 | 2022-11-11 | 深圳市燃气集团股份有限公司 | System and method for removing pipeline hydrate blockage through hydrogen purging in recycling mode |
| CN117402277A (en) * | 2023-12-15 | 2024-01-16 | 万华化学集团股份有限公司 | Anti-blocking process method for discharge line of ultra-high molecular weight polyethylene produced by slurry method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110305705A (en) * | 2019-07-08 | 2019-10-08 | 西南石油大学 | A kind of preparation facilities and preparation method of diagenesis class natural gas hydrate |
| CN110980734A (en) * | 2019-11-29 | 2020-04-10 | 中国科学院广州能源研究所 | Experimental device and method for hydrate method seabed carbon dioxide sequestration |
| CN112031761A (en) * | 2020-09-27 | 2020-12-04 | 西南石油大学 | Blockage removing device and method for simulating gas well hydrate blockage |
| CN112983408A (en) * | 2021-03-16 | 2021-06-18 | 西南石油大学 | Device and method for purging inert gas for preventing and controlling solid phase deposition during depressurization exploitation of hydrate |
| CN113062713A (en) * | 2021-03-04 | 2021-07-02 | 中国石油大学(华东) | Experimental device and method for simulating near-well blockage and blockage removal in natural gas hydrate exploitation |
-
2022
- 2022-02-08 CN CN202210119323.7A patent/CN114636803A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110305705A (en) * | 2019-07-08 | 2019-10-08 | 西南石油大学 | A kind of preparation facilities and preparation method of diagenesis class natural gas hydrate |
| CN110980734A (en) * | 2019-11-29 | 2020-04-10 | 中国科学院广州能源研究所 | Experimental device and method for hydrate method seabed carbon dioxide sequestration |
| CN112031761A (en) * | 2020-09-27 | 2020-12-04 | 西南石油大学 | Blockage removing device and method for simulating gas well hydrate blockage |
| CN113062713A (en) * | 2021-03-04 | 2021-07-02 | 中国石油大学(华东) | Experimental device and method for simulating near-well blockage and blockage removal in natural gas hydrate exploitation |
| CN112983408A (en) * | 2021-03-16 | 2021-06-18 | 西南石油大学 | Device and method for purging inert gas for preventing and controlling solid phase deposition during depressurization exploitation of hydrate |
Non-Patent Citations (3)
| Title |
|---|
| 李明川 等: "天然气水合物热分解实验研究", 《河南科学》 * |
| 董福海 等: "注甲醇溶液分解丙烷水合物实验模拟", 《石油化工高等学校学报》 * |
| 黄犊子 等: "水合物合成及导热系数测定", 《地球物理学报》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115325431A (en) * | 2022-08-11 | 2022-11-11 | 深圳市燃气集团股份有限公司 | System and method for removing pipeline hydrate blockage through hydrogen purging in recycling mode |
| CN117402277A (en) * | 2023-12-15 | 2024-01-16 | 万华化学集团股份有限公司 | Anti-blocking process method for discharge line of ultra-high molecular weight polyethylene produced by slurry method |
| CN117402277B (en) * | 2023-12-15 | 2024-04-09 | 万华化学集团股份有限公司 | Anti-blocking process method for discharge line of ultra-high molecular weight polyethylene produced by slurry method |
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