A kind of gas hydrate generation and decomposition test method and device
Technical field
The present invention relates to a kind of gas hydrate (Natural Gas Hydrates, NGH) method of testing, particularly about a kind of in the marine technology field gas hydrate generation and the decomposition test method and the device of one dimension sand-packed model.
Background technology
Gas hydrate are that rock gas mainly is made up of methane, so be also referred to as methane hydrate by the solid state crystallization body of rock gas and the molecular class ice of moisture shape.Have extremely strong combustion force because of containing a large amount of methane gass, can directly burn, be " combustible ice " so be commonly called as again.The energy density of gas hydrate is very high, can produce a large amount of methane gass, and the reserves of gas hydrate are very abundant, and the gas-firing hydrate only produces carbon dioxide and water, does not pollute the environment, and is a kind of rare clean energy.Gas hydrate have broad prospects and development space as a kind of potential energy, have very important effect to alleviating the lack of energy crisis that the mankind face.
At present, the method for the generation of Chang Yong detection gas hydrate and decomposition has optical means, acoustic method and electrical method etc.For example, generation and the decomposition of gas hydrate in pure water can judge that at certain pressure decline low temperature, hydrate generates the time passband in a large number to be reduced suddenly according to the variation of light passband, after this slowly heat up, decomposition of hydrate time passband rises suddenly again.But in order to simulate ocean gas hydrate, need to adopt potpourris such as water, sand, methane, opaque because of it, light passband detection method is just powerless.Other detection method, as supersonic detection method, Time Domain Reflectometry (TDR) technology and imaging (CT) technology etc., also can be intuitively, accurately, the generation and the decomposition of quantitative observation and calculating gas hydrate.But these method of testing designs are complicated, cost is higher, and can't satisfy that nucleus in the time of will reflecting gas hydrate and generate forms and the requirement of growth course, can not detect more accurately that gas hydrate generate, the basic rerum natura situation of change when decomposing.
Electric-resistivity method is measured the small volume of water compound that generates in the sediment and has successfully been applied to CO
2In-water-sediment system.But electric-resistivity method can not be used for methane-pure water-sediment system, cause that because electric-resistivity method is based on the variation of effects of ion content conductance changes, and methane is difficult to ionization in aqueous solution, and ion changes very little so is difficult to be measured.
Summary of the invention
At the problems referred to above, the purpose of this invention is to provide a kind of can monitor gas hydrate synthetic quantity size and synthetic when decomposing basis physical parameter situation of change, and nucleus forms and gas hydrate generation and the decomposition test method and the device of growth course can reflect gas hydrate and generate the time.
For achieving the above object, the present invention takes following technical scheme: a kind of gas hydrate generate and decomposition test method, it may further comprise the steps: 1) fill up sand grains in one dimension back-up sand resistivity models pipe, cover end cap, check the sealing of model pipe, then model pipe is put into a constant temperature oven; 2) inject water and methane gas to model pipe, keep temperature constant state by constant temperature oven, gas hydrate are generated gradually, and by the thermopair, pressure transducer and the electrode that are arranged on the model pipe tube wall, temperature, pressure and resistivity in the detection model pipe is worth over time respectively, detected data transmission recording storage in the data acquisition module; When 3) gas hydrate decomposed, model pipe opened model pipe by a back pressure control module, and the pressure in the model pipe slowly reduces, and gas hydrate begin to decompose gradually; Perhaps in model pipe, inject hot water, gas hydrate are decomposed gradually; 4) water and the methane gas that gas hydrate is decomposed the back generation measures by a metering module, data transmission after the metering is in data acquisition module, simultaneously in decomposable process, be worth over time by pressure, temperature and resistivity in thermopair, pressure transducer and the electrode detection model pipe, and be transferred to and carry out recording storage in the data acquisition module.
One end of described model pipe is provided with an end cap, described end cap is provided with a feed tube and a draft tube, the other end of described model pipe is provided with an outlet, is arranged at intervals with an above pressure transducer, an above thermopair and more than one electrode on the tube wall of described model pipe.
Described model pipe is a stainless steel gradient experiment tube.
A kind of gas hydrate of described method of testing of realizing generate and the decomposition proving installation, it is characterized in that: it comprises a feed flow module and an air feed module, described feed flow module is connected the generation of gas hydrate and two imports of exploitation analog module respectively with the air feed module by pipeline, described generation is arranged in the environmental simulation module with the exploitation analog module, described generation is connected a metering module by a back pressure control module, described metering module with the outlet of exploitation analog module, generate and the exploitation analog module, air feed module and feed flow module are connected to a data acquisition module.
Described generation comprises an one dimension back-up sand resistivity models pipe with the exploitation analog module, one end of described model pipe is provided with an end cap, described end cap is provided with a feed tube and a draft tube, the other end of described model pipe is provided with an outlet, is arranged at intervals with an above pressure transducer, an above thermopair and more than one electrode on the tube wall of described model pipe.
Described model pipe is a stainless steel gradient experiment tube.
Described environmental simulation module is an environment constant temperature oven, is used to adjust described generation and the environment temperature of exploiting analog module.
The present invention is owing to take above technical scheme, it has the following advantages: 1, the present invention is owing to adopted one dimension back-up sand resistivity models pipe, this model pipe is a stainless steel gradient experiment tube, and on the tube wall of model pipe, be horizontally arranged with an above pressure transducer and an above thermopair, the tube wall axially spaced-apart of model pipe is provided with more than one electrode, each pressure transducer, pressure when each position in gas hydrate generation and the decomposable process in thermopair and the electrode pair model pipe, the variation of temperature and resistivity is measured, and the numerical value of each test point is sent in the data acquisition module, therefore realized monitoring gas hydrate synthetic quantity size, with and basic physical parameter situation of change.2, the present invention is arranged on gas hydrate generation and exploitation analog module in the environmental simulation module owing to having adopted, control by model pipe internal pressure and temperature that the environmental simulation module generates and exploits in the analog module gas hydrate, the generation and the resolution of gas hydrate are controlled effectively, and by each thermopair, test in pressure transducer and the electrode pair model pipe, and with the data transmission of each test point to data acquisition module, therefore realized analyzing effectively generation and the decomposable process and the degree of uniformity thereof of gas hydrate, and the nucleus when reflecting gas hydrate and generating forms and the process of growth.3, the present invention is owing to also be provided with metering module and data acquisition module, after flowing into metering module, water that produces after making gas hydrate decompose and methane gas measure, and the data transmission of continuous data and each test point is carried out recording storage in data acquisition module, therefore further realized monitoring gas hydrate its basic physical parameter situation of change when synthesizing with decomposition.The present invention can be widely used in the various detection ranges of the generation of gas hydrate and decomposition.
Description of drawings
Fig. 1 is the synthetic and exploitation simulated experiment apparatus synoptic diagram of gas hydrate of the present invention
Fig. 2 is an one dimension back-up sand resistivity measurement model pipe structural representation of the present invention
Fig. 3 is the sectional view of Fig. 2
Embodiment
Below in conjunction with drawings and Examples the present invention is described in detail.
The inventive method may further comprise the steps:
1) in one dimension back-up sand resistivity models pipe, fills up sand grains, cover end cap, check the sealing of model pipe, then model pipe is put into a constant temperature oven;
2) inject water and methane gas to model pipe, keep temperature constant state by constant temperature oven, gas hydrate are generated gradually, and by the thermopair, pressure transducer and the electrode that are arranged on the model pipe tube wall, temperature, pressure and resistivity in the detection model pipe is worth over time respectively, detected data transmission recording storage in the data acquisition module;
When 3) gas hydrate decomposed, model pipe opened model pipe by a back pressure control module, and the pressure in the model pipe slowly reduces, and gas hydrate begin to decompose gradually; Perhaps in model pipe, inject hot water, gas hydrate are decomposed gradually;
4) water and the methane gas that gas hydrate is decomposed the back generation measures by a metering module, data transmission after the metering is in data acquisition module, simultaneously in decomposable process, be worth over time by pressure, temperature and resistivity in thermopair, pressure transducer and the electrode detection model pipe, and be transferred to and carry out recording storage in the data acquisition module.
As shown in Figure 1, proving installation of the present invention comprises that a feed flow module 1, an air feed module 2, an environmental simulation module 3, gas hydrate generate and exploitation analog module 4, a back pressure control module 5, a metering module 6 and a data acquisition module 7.Feed flow module 1 is connected the gas hydrate that are arranged in the environmental simulation module 3 with air feed module 2 by pipeline and generates and two imports of exploiting analog module 4, gas hydrate generate with the outlet of exploitation analog module 4 and are connected metering module 6 by back pressure control module 5, and metering module 6, gas hydrate generate with exploitation analog module 4, air feed module 2 and feed flow module 1 and are connected to data acquisition module 7.Wherein, environmental simulation module 3 is an environment constant temperature oven, is used to adjust gas hydrate and generates and the environment temperature of exploiting analog module 4, with the temperature environment of simulation marine bottom.
As Fig. 2, shown in Figure 3, gas hydrate of the present invention generate the one dimension back-up sand resistivity models pipe 41 that comprises a long cartridge type with exploitation analog module 4, and model pipe 41 is a stainless steel gradient experiment tube.One end of model pipe 41 is provided with an end cap 42, and end cap is provided with a feed tube 43, and feed tube 43 passes model pipe 41 tube walls and is connected with feed flow module 1, also is set side by side with a draft tube 44 with feed tube 43, and draft tube 44 is connected with air feed module 2.The other end of model pipe 41 is provided with an outlet 45.On the tube wall of model pipe 41, be arranged at intervals with the pressure transducer 46 that is used for the detector tube internal pressure more than, thermopair 47 and the more than one electrode 48 that is used for temperature in the detector tube more than, each electrode 48 inserts in the model pipe 41, and forms an electrode system.The variation of pressure, temperature and resistivity in each pressure transducer 46, thermopair 47 and 41 interior gas hydrate generations of 48 pairs of model pipe of electrode and the decomposable process when each position is measured, and measurement data is transferred to data acquisition module 7, analyze the generative process and the degree of uniformity thereof of gas hydrate, the process that the nucleus when reflecting the gas hydrate generation forms and grows.
In sum, the present invention utilizes electrolyte solution to replace pure water, because electrolyte solution has electric conductivity, therefore can make the electric-resistivity method detection application to methane-water-sediment system.And the generation of hydrate is the process of a salt discharge, when methane hydrate generates, absorb a part of pure water, concentration of electrolyte solutions is increased, conductance increases, resistance reduces, so can reflect generation and the decomposition situation and the degree of uniformity of gas hydrate in the experimentation accurately and rapidly by resistivity measurement method of the present invention, the relation of resistivity and gas hydrate saturation degree be can also further set up, thereby a kind of new method and technology provided for the experimental study of gas hydrate from now on.
The various embodiments described above only are preferred implementations of the present invention, and are every based on the changes and improvements on the technical solution of the present invention in the present technique field, should not get rid of outside protection scope of the present invention.