CN107807143B - Low-field nuclear magnetic resonance multi-probe quantitative test system and method special for hydrate - Google Patents
Low-field nuclear magnetic resonance multi-probe quantitative test system and method special for hydrate Download PDFInfo
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- CN107807143B CN107807143B CN201711235387.9A CN201711235387A CN107807143B CN 107807143 B CN107807143 B CN 107807143B CN 201711235387 A CN201711235387 A CN 201711235387A CN 107807143 B CN107807143 B CN 107807143B
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N24/00—Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects
- G01N24/08—Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects by using nuclear magnetic resonance
- G01N24/081—Making measurements of geologic samples, e.g. measurements of moisture, pH, porosity, permeability, tortuosity or viscosity
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/30—Assessment of water resources
Abstract
The invention discloses a special low-field nuclear magnetic resonance multi-probe quantitative test system and method for a hydrate, wherein the test system comprises a low-field nuclear magnetic resonance analyzer, a high-pressure probe with low confining pressure, a low-temperature and high-pressure probe without confining pressure, a normal-temperature and normal-pressure probe without confining pressure, a temperature confining pressure control module, a pore fluid supply module and an industrial personal computer.
Description
Technical Field
The invention belongs to the field of unconventional oil and gas reservoir engineering and geotechnical engineering basic physical property testing, and particularly relates to a system and a method for quantitatively testing a low-field nuclear magnetic resonance multi-probe special for a hydrate.
Background
Natural gas hydrate is widely distributed in the nature in the deep sea stratum environment and in the permafrost stratum environment, and is rich in natural gas, and is considered as an important potential alternative energy source. Natural gas hydrate decomposition weakens reservoir strength and releases significant amounts of powerful greenhouse gases, which is also considered a possible mechanism for inducing engineering geological disasters and global climate change. Therefore, the natural gas hydrate is widely focused on the world, and scientific researchers in various countries have conducted a great deal of research work from different angles, and on the basis, a plurality of natural gas hydrate trial exploitation are conducted.
However, the gas production efficiency of the natural gas hydrate test exploitation developed in the world cannot meet the requirement of the commercial exploitation at the present stage, and the requirement on the research work of the natural gas hydrate is higher, and the requirement on the measurement and research of the pore scale behavior of the hydrate sediment is more urgent. Marine hydrate deposits are typically composed of soil particles, natural gas hydrates, natural gas and water, with solid phase natural gas hydrates filling in the void spaces of the deposit, reducing the effective void space available for fluid flow, changing the spread of fluid flow channels, resulting in significant differences in the permeability of the hydrate-containing deposit under different hydrate saturation conditions and under different hydrate occurrence forms. Thus, the pore size behavior of the hydrate deposit largely determines its basic physical parameter variation. Nuclear magnetic resonance technology, computed tomography technology, scanning electron microscope technology and the like are common means for observing pore scale behaviors of hydrate sediments, and different technologies have different advantages and disadvantages and are suitable for different research conditions. Nuclear magnetic resonance technology is largely classified into high-field nuclear magnetic resonance technology and low-field nuclear magnetic resonance technology, the former has obvious limitations in the research fields of unconventional oil and gas reservoirs and geotechnical engineering due to factors such as sample size, and the latter is often used for researching the transport properties of porous medium materials such as geotechnical.
Under the condition of no natural gas hydrate, the low-field nuclear magnetic resonance qualitative and quantitative measuring device and method of the conventional rock-soil material are mature. However, the pore size behavior of the hydrate sediment is more complex than that of the conventional geotechnical material, and the corresponding measurement experiment needs to be carried out under the conditions of low temperature and high pressure, so that the existing low-field nuclear magnetic resonance measurement signal quantitative calibration methods such as mercury intrusion method and dehydration method are invalid, the low-field nuclear magnetic resonance quantitative test technology meets the unprecedented challenges in the field of natural gas hydrate research, and the corresponding experimental test method and the matched experimental test system are still deficient.
Disclosure of Invention
The invention provides a hydrate low-field nuclear magnetic resonance multi-probe quantitative test system and a method, which adopt a multi-probe combined mode to realize quantitative calibration of a hydrate sediment low-field nuclear magnetic resonance measurement signal and measurement analysis of pore scale behavior of the hydrate sediment, make up for the defects of the hydrate sediment low-field nuclear magnetic resonance quantitative test at the present stage and lay a foundation for discussing a microscopic mechanism of change of basic physical parameters of the hydrate sediment.
The invention is realized by adopting the following technical scheme:
the low-field nuclear magnetic resonance multi-probe quantitative test system special for the hydrate comprises an industrial personal computer, a low-field nuclear magnetic resonance analyzer, a temperature confining pressure control module and a pore fluid supply module, wherein the low-field nuclear magnetic resonance analyzer is connected with the industrial personal computer and is used for carrying out nuclear magnetic resonance relaxation spectrum analysis and imaging analysis on a test sample, the test precision is high and the speed is high, a normal temperature and normal pressure probe without confining pressure, a low temperature and high pressure probe without confining pressure and a low temperature and high pressure probe with confining pressure are respectively arranged on the low-field nuclear magnetic resonance analyzer according to an actual test sequence, three parallel test samples prepared by adopting the same working procedure are also respectively arranged in the three probes, and the sizes, the quality and the porosities of the three test samples are the same;
the probe can meet the sample testing requirement under the condition of normal temperature and normal pressure without confining pressure, and comprises a first low-temperature high-pressure reaction kettle and a first radio-frequency coil matched with the first low-temperature high-pressure reaction kettle, wherein the first radio-frequency coil is arranged on the outer wall of the first low-temperature high-pressure reaction kettle in a surrounding manner, and the split design is adopted, so that the sample loading and the adjustment are convenient; the probe is directly arranged on a low-field nuclear magnetic resonance analyzer without confining pressure at normal temperature and normal pressure so as to realize the analysis of a pore structure of a non-hydrate soil sample, and has no other requirements on the shape of the sample;
the low-temperature high-pressure probe without confining pressure can bear the low-temperature and high-pressure conditions required by natural gas hydrate in the experimental process, and comprises a second low-temperature high-pressure reaction kettle and a second radio-frequency coil matched with the second low-temperature high-pressure reaction kettle, wherein the second radio-frequency coil is arranged on the outer wall of the second low-temperature high-pressure reaction kettle in a surrounding manner, the split design is adopted, sample loading and adjustment are convenient, a rigid cylinder used for placing a test sample is arranged in the second low-temperature high-pressure reaction kettle, the rigid cylinder is in a stepped shaft shape and comprises a large-diameter cylinder and a diameter-reducing cylinder, the end part of the diameter-reducing cylinder is sealed, the outer wall of the large-diameter cylinder is tightly attached to the inner wall of the second low-temperature high-pressure reaction kettle, a fluorinated oil ring cavity is formed between the outer wall of the diameter-reducing cylinder and the inner wall of the second low-temperature high-pressure reaction kettle, and the test sample is arranged in the diameter-reducing cylinder; one end of the second low-temperature high-pressure reaction kettle is provided with a first end cover, the other end of the second low-temperature high-pressure reaction kettle is provided with a first fluorinated oil outlet and a first fluorinated oil inlet, the first fluorinated oil outlet, the first fluorinated oil inlet and the temperature confining pressure control module are connected through a pipeline to form a fluorinated oil circulation loop, so that circulating refrigeration fluorinated oil is filled into a fluorinated oil ring cavity, the real temperature condition of hydrate-containing sediments in the natural world can be simulated, the total volume of a natural gas hydrate system is constant in the experimental process, the experimental test result analysis is convenient, the first end cover is also provided with a first pore fluid inlet communicated with the reducing cylinder, and the first pore fluid inlet is connected with a pore fluid supply module through a pipeline;
the high-temperature high-pressure probe can bear the low-temperature high-pressure conditions required by the natural gas hydrate in the experimental process, and comprises a third low-temperature high-pressure reaction kettle and a third radio-frequency coil matched with the third low-temperature high-pressure reaction kettle, wherein the third radio-frequency coil is arranged on the outer wall of the third low-temperature high-pressure reaction kettle in a surrounding manner, the split design is adopted, the sample loading and the adjustment are convenient, a sample pore space for accommodating a test sample is arranged in the third low-temperature high-pressure reaction kettle, two ends of the third low-temperature high-pressure reaction kettle are sealed through end covers, a second pore fluid inlet and a second pore fluid outlet are respectively arranged at two ends of the third low-temperature high-pressure reaction kettle, a fluorinated oil annular cavity is formed between the sample pore space and the inner wall of the third low-temperature high-pressure reaction kettle, a second fluorinated oil inlet and a second fluorinated oil outlet are also respectively arranged on the outer wall of the third low-temperature high-pressure reaction kettle, and a flexible membrane is wrapped outside the test sample to isolate the sample pore space and the fluorinated oil annular cavity and effectively transfer the sample confining pressure; the second pore fluid inlet and the second pore fluid outlet are connected with the pore fluid supply module through pipelines to form a fluid circulation loop, and the second fluorinated oil inlet and the second fluorinated oil outlet form a low-temperature fluorinated oil circulation loop with the temperature confining pressure control module through pipelines.
Further, the temperature confining pressure control module adopts a sample temperature and sample confining pressure coupling control mode and comprises a refrigerator constant temperature box, a low-temperature circulating pump, a low-temperature fluorinated oil container, a confining pressure loading pump and a normal-temperature fluorinated oil container, wherein the low-temperature circulating pump is arranged in the refrigerator constant temperature box, one end of the low-temperature circulating pump is connected with the low-temperature fluorinated oil container, and the other end of the low-temperature circulating pump is connected with the normal-temperature fluorinated oil container through the confining pressure loading pump;
when a low-temperature high-pressure probe without confining pressure is arranged on the low-field nuclear magnetic resonance analyzer, the first fluorinated oil inlet end is connected with the connecting end of the low-temperature circulating pump and the confining pressure loading pump through a pipeline, and the first fluorinated oil outlet end is connected with the low-temperature fluorinated oil container through a pipeline;
when the pressurizing low-pressure high-pressure probe is installed on the low-field nuclear magnetic resonance analyzer, the second fluorinated oil inlet end is connected with the connecting ends of the low-temperature circulating pump and the confining pressure loading pump through a pipeline, the second fluorinated oil outlet end is connected with the low-temperature fluorinated oil container through a pipeline, the normal-temperature fluorinated oil container is connected to the low-temperature fluorinated oil circulating loop through the confining pressure loading pump and can apply confining pressure according to the requirement, namely, the annular cavity between the flexible film wrapping the test sample and the inner wall of the pressurizing low-pressure high-pressure probe is filled with fluorinated oil without nuclear magnetic signals, the fluorinated oil circulates between the annular cavity and the refrigerator incubator to refrigerate and control the temperature of the test sample, meanwhile, the confining pressure loading pump is arranged in the circulating loop, the confining pressure of the test sample is transmitted through the fluorinated oil, and the confining pressure applying function can be opened or closed according to the test requirement.
Furthermore, the pore fluid supply module comprises a high-pressure gas cylinder, a water storage container, a gas saturated water preparation container and a back pressure valve, and can be used for different natural gas hydrate synthesis methods so as to study the influence rule of the synthesis methods on pore scale behaviors of hydrate-containing sediments, wherein the water storage container and the high-pressure gas cylinder are respectively connected with the gas saturated water preparation container through connecting pipelines, the connecting pipelines are respectively provided with corresponding switching valves, a distilled water injection pump is further arranged between the water storage container and the gas saturated water preparation container, the gas saturated water preparation container is also connected with a circulating constant flow pump, and the high-pressure gas cylinder is a methane high-pressure gas cylinder;
when a low-temperature high-pressure probe without confining pressure is arranged on the low-field nuclear magnetic resonance analyzer, the gas saturated water preparation container is directly connected with the first pore fluid inlet through the circulating constant flow pump;
when the pressurizing low-temperature high-pressure probe is arranged on the low-field nuclear magnetic resonance analyzer, the inlet end of the second pore fluid is connected with the circulating constant-flow pump through a pipeline, the outlet end of the second pore fluid is connected to the gas saturated water preparation container through a back pressure valve through a pipeline, and the pore fluid supply module and the pressurizing low-temperature high-pressure probe form a fluid circulation loop.
Furthermore, the first low-temperature high-pressure reaction kettle, the second low-temperature high-pressure reaction kettle and the third low-temperature high-pressure reaction kettle are all made of non-nuclear magnetic signal materials.
Furthermore, a first temperature sensor is further arranged in the oil fluoride ring cavity of the low-temperature high-pressure probe without confining pressure, a second temperature sensor is arranged in the oil fluoride ring cavity of the low-temperature high-pressure probe without confining pressure, and the first temperature sensor and the second temperature sensor are electrically connected with the industrial control computer.
Furthermore, a pressure sensor is also arranged in the gas saturated water preparation container, and the pressure sensor is electrically connected with the industrial control computer.
Furthermore, a magnetic stirrer is also arranged in the gas saturated water preparation container and is used for promoting the dissolution of high-pressure gas in water.
Furthermore, the high-pressure gas cylinder adopts a methane high-pressure gas cylinder.
Further, the length of the test sample is 20mm-60mm, the diameter is 25.4mm, and the length of the sample can be adjusted according to experimental requirements.
Based on the test system, the invention further provides a special low-field nuclear magnetic resonance multi-probe quantitative test method for the hydrate, which comprises the following steps of:
(1) Preparing parallel soil samples:
three parallel soil samples, namely test samples, are prepared by adopting the same working procedure, and have the same size, the same quality and the same porosity, so that the pore structures of the three soil samples are ensured to be the same in a statistical sense;
(2) Measuring at normal temperature and normal pressure without confining pressure by a probe: analyzing the pore structure of the non-hydrate soil sample;
placing a soil sample in a normal temperature and normal pressure probe without confining pressure, mounting the saturated soil sample on a low-field nuclear magnetic resonance analyzer after distilling the saturated soil sample, operating the low-field nuclear magnetic resonance analyzer to obtain a T2 distribution curve, and qualitatively analyzing the pore distribution characteristics and uncalibrated porosity of the soil sample without natural gas hydrate;
(3) And (3) measuring without using a confining pressure low-temperature high-pressure probe: quantitatively calibrating and determining transverse relaxation rate;
then, a soil sample is placed in a low-temperature high-pressure probe without confining pressure, the connection relation between the soil sample and a temperature confining pressure control module and a pore fluid injection module is well connected, methane hydrate is synthesized in the soil sample, the hydrate saturation is calculated by adopting a gas quantity conservation method in the process, namely, the hydrate saturation is calculated according to the whole methane hydrate synthesized by gas, meanwhile, a low-field nuclear magnetic resonance analyzer is operated to obtain a T2 distribution curve of hydrate-containing sediments, the effective pore distribution characteristics and uncalibrated effective porosities of the soil sample containing natural gas hydrate are analyzed, the hydrate saturation is calculated by combining the uncalibrated porosities of the soil sample containing natural gas hydrate obtained in the step (2), and the hydrate saturation quantitative calibration calculated by combining the gas quantity conservation method in the step is based on the hydrate saturation determined by the low-field nuclear magnetic resonance T2 distribution curve, so that the transverse relaxation rate of the hydrate sediments used in the experiment is determined; and (4) measuring by using a confining pressure low-temperature high-pressure probe: qualitatively analyzing pore scale behavior of the hydrate-containing sediment;
placing the rest soil sample in a confining pressure adding low-temperature high-pressure probe, connecting the probe with a temperature confining pressure control module and a pore fluid injection module, setting any effective confining pressure within a range of 1MPa-10MPa, synthesizing methane hydrate in the soil sample by adopting a distilled water circulation preparation method of saturated methane gas, then manually slowly deflating to control the pressure in a gas saturated water preparation container to gradually decompose the hydrate, operating a low-field nuclear magnetic resonance analyzer to obtain T2 distribution curves of test samples at different moments in the synthesis and decomposition processes of the hydrate, and quantitatively analyzing the evolution rule of pore radius distribution curves of hydrate sediment in the synthesis and decomposition processes of the hydrate by combining the transverse relaxation rate determined in the step (3);
further, in the step (4), the influence rule of the effective confining pressure on the pore radius distribution curve of the hydrate sediment can be quantitatively analyzed by changing the effective confining pressure.
Compared with the prior art, the invention has the advantages and positive effects that:
1. the invention provides a method for quantitatively calibrating a low-field nuclear magnetic resonance measurement signal of a hydrate sediment by combining a confining pressure-adding low-temperature high-pressure probe, a confining pressure-not-adding low-temperature high-pressure probe and a confining pressure-not-adding normal-temperature normal-pressure probe, so that the integration of the calibration of the measurement signal and the test analysis of a sample is realized;
2. the confining pressure low-temperature high-pressure probe can simulate the real stratum stress and temperature conditions in the nature, and the gas saturated water circulation preparation method can simulate the real natural gas hydrate generation process in the nature in the experimental process, so that the evolution rule of pore scale behaviors such as the pore radius of the stratum containing the natural gas hydrate in the natural gas hydrate formation and exploitation processes can be researched;
3. the rigid cylinder in the low-temperature high-pressure probe without confining pressure is not deformed in the experimental process, the volume of the sample to be measured is kept constant all the time, the hydrate saturation is calculated by a pressure drop method, and the transverse relaxation rate obtained by quantitatively calibrating the low-field nuclear magnetic resonance signal by taking the hydrate saturation as a standard is more accurate and reliable;
4. the probe is convenient to use without confining pressure at normal temperature and normal pressure, and is easy to obtain a pore distribution curve of the soil sample without the natural gas hydrate, so that basic support data is provided for subsequent pore scale behavior test analysis of the soil sample with the natural gas hydrate.
Drawings
FIG. 1 is a schematic diagram of a probe structure of the normal temperature and pressure probe without confining pressure in embodiment 1 of the invention;
FIG. 2 is a schematic diagram of a low-temperature high-pressure probe without confining pressure in embodiment 1 of the invention;
FIG. 3 is a schematic diagram of a probe structure for increasing confining pressure and low temperature and high pressure in embodiment 1 of the invention;
FIG. 4 is a schematic diagram showing the connection of a low-temperature high-pressure probe without confining pressure and a test system according to embodiment 1 of the present invention;
FIG. 5 is a schematic diagram showing the connection of the probe with high confining pressure and low temperature and high pressure with the test system according to the embodiment 1 of the present invention;
FIG. 6 is a flow chart of a testing method according to embodiment 2 of the present invention.
Detailed Description
In order that the above-recited objects, features and advantages of the present invention may be more clearly understood, a further description of the invention is provided below with reference to the accompanying drawings and examples in which numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than as described herein and is not limited to the specific examples disclosed below.
The embodiment 1 of the invention relates to a special low-field nuclear magnetic resonance multi-probe quantitative test system for hydrates, which comprises an industrial personal computer, a low-field nuclear magnetic resonance analyzer, a temperature confining pressure control module and a pore fluid supply module, wherein the low-field nuclear magnetic resonance analyzer is used for carrying out nuclear magnetic resonance relaxation spectrum analysis and imaging analysis on test samples, a normal temperature probe without confining pressure, a low-temperature high-pressure probe without confining pressure and a high-temperature high-pressure probe with confining pressure are respectively arranged on the low-field nuclear magnetic resonance analyzer according to an actual test sequence, three parallel test samples prepared by adopting the same working procedure are respectively arranged in the three probes, the sizes, the masses and the porosities of the three test samples are the same, the length of the test samples is 20mm-60mm, the diameter of the test samples is 25.4mm, and the length of the test samples can be adjusted according to experimental requirements, for example, the in-situ samples are only 30mm long, and the system can be also carried for measurement.
The normal temperature and normal pressure probe without confining pressure can meet the sample test requirement under the normal temperature and normal pressure condition, as shown in figure 1, the probe comprises a first low-temperature high-pressure reaction kettle 11 and a first radio frequency coil 12 matched with the first low-temperature high-pressure reaction kettle, the first radio frequency coil 12 is arranged on the outer wall of the first low-temperature high-pressure reaction kettle 11 in a surrounding manner, and the split design is adopted, so that sample loading and adjustment are convenient; during the experiment, the probe is directly arranged on the low-field nuclear magnetic resonance analyzer without confining pressure at normal temperature and normal pressure, the analysis of the pore structure of the non-hydrate soil sample is realized through the low-field nuclear magnetic resonance analyzer, the probe has no other requirements on the shape of the test sample 1, the test can be carried out on loose sediment and consolidated core which do not contain natural gas hydrate, and the like, so that the analysis of the pore scale of the sediment containing the hydrate is conveniently provided for supporting the complete framework test data, and in addition, the test of the porosity standard sample is also convenient to calibrate and evaluate the reliability of the test result of the low-field nuclear magnetic resonance.
The low-temperature high-pressure probe without confining pressure can bear the low-temperature high-pressure conditions required by natural gas hydrate in the experimental process, referring to fig. 2, the probe comprises a second low-temperature high-pressure reaction kettle 21 and a second radio-frequency coil 22 matched with the second low-temperature high-pressure reaction kettle 21, the second radio-frequency coil is arranged on the outer wall of the second low-temperature high-pressure reaction kettle 21 in a split design, sample loading and adjustment are convenient, a rigid cylinder used for placing a test sample 1 is arranged in the second low-temperature high-pressure reaction kettle 21, the rigid cylinder is in a stepped shaft shape and comprises a large-diameter cylinder 23 and a diameter reduction cylinder 24, the end part of the diameter reduction cylinder 24 is closed, the outer wall of the large-diameter cylinder 23 is tightly attached to the inner wall of the second low-temperature high-pressure reaction kettle 21, the end face of the large-diameter cylinder 23 is flush with the end face of one end of the second low-temperature high-pressure reaction kettle 21, a fluorinated oil ring cavity 25 is formed between the outer wall of the diameter reduction cylinder 24 and the inner wall of the second low-temperature high-pressure reaction kettle, and the test sample 1 is arranged in the diameter reduction cylinder 24; the first end cover 26 is arranged at one end of the second low-temperature high-pressure reaction kettle 21, the first fluorinated oil outlet 27 and the first fluorinated oil inlet 28 are arranged at the other end of the second low-temperature high-pressure reaction kettle, the first fluorinated oil outlet 27, the first fluorinated oil inlet 28 and the temperature confining pressure control module are connected through a pipeline to form a fluorinated oil circulation loop, so that circulating refrigeration fluorinated oil is filled into a fluorinated oil ring cavity, the real temperature condition of hydrate-containing sediments in the natural world can be simulated, the total volume of a natural gas hydrate system is constant in the experimental process, the analysis of experimental test results is convenient, the first end cover 26 is further provided with a first pore fluid inlet 29 communicated with the reducing cylinder 24, and the first pore fluid inlet 29 is connected with a pore fluid supply module through a pipeline;
the confining pressure-increasing low-temperature high-pressure probe can bear low-temperature and high-pressure conditions required by natural gas hydrate in the experimental process, can simulate the real temperature and stratum stress environment of hydrate-containing sediment in the natural world, so that experimental test results are more referential, refer to fig. 3, the experimental device comprises a third low-temperature high-pressure reaction kettle 31 and a third radio-frequency coil 32 matched with the third low-temperature high-pressure reaction kettle, the third radio-frequency coil 32 is arranged on the outer wall of the third low-temperature high-pressure reaction kettle 31 in a surrounding mode, a split design is adopted, sample loading adjustment is convenient, a sample pore space 33 for accommodating a test sample 1 is arranged in the third low-temperature high-pressure reaction kettle 31, two ends of the third low-temperature high-pressure reaction kettle 31 are sealed through end covers, a second pore fluid inlet 34 and a second pore fluid outlet 35 are respectively arranged at two ends, a fluorinated oil annular cavity 36 is arranged between the sample pore space 33 and the inner wall of the third low-temperature high-pressure reaction kettle 31, a second fluorinated oil inlet 37 and a second fluorinated oil outlet 38 are respectively arranged on the outer wall of the third low-temperature high-pressure reaction kettle 31, and a flexible pore membrane 39 is wrapped outside the test sample and the sample pore space 33 is effectively transferred with the sample pore space in the shape of the sample pore space 33; the second interstitial fluid inlet 34 and the second interstitial fluid outlet 35 are connected to the interstitial fluid supply module by piping to form a fluid circulation loop, and the second fluorinated oil inlet 37 and the second fluorinated oil outlet 38 are connected to the temperature confining pressure control module by piping to form a low temperature fluorinated oil circulation loop.
In this embodiment, the temperature confining pressure control module adopts a sample temperature and sample confining pressure coupling control mode, as shown in fig. 4 and 5, the temperature confining pressure control module includes a refrigerator incubator 4, a low temperature circulating pump 5, a low temperature fluorinated oil container 6, a confining pressure loading pump 7 and a normal temperature fluorinated oil container 8, the low temperature circulating pump 5 is arranged in the refrigerator incubator 4, one end of the low temperature circulating pump 5 is connected with the low temperature fluorinated oil container 6, and the other end is connected with the normal temperature fluorinated oil container 8 through the confining pressure loading pump 7; when the low-temperature high-pressure probe without confining pressure is arranged on the low-field nuclear magnetic resonance analyzer, referring to fig. 5, the first fluorinated oil inlet 28 end is connected with the connecting end of the low-temperature circulating pump 5 and the confining pressure loading pump 7 through a pipeline, and the first fluorinated oil outlet 27 end is connected with the low-temperature fluorinated oil container 6 through a pipeline;
when the pressurizing low-pressure high-pressure probe is installed on the low-field nuclear magnetic resonance analyzer, referring to fig. 5, the second fluorinated oil inlet 37 end is connected with the connection ends of the low-temperature circulating pump 5 and the confining pressure loading pump 7 through a pipeline, the second fluorinated oil outlet 38 end is connected with the low-temperature fluorinated oil container 6 through a pipeline, the normal-temperature fluorinated oil container 8 is connected to the low-temperature fluorinated oil circulating loop through the confining pressure loading pump 7, confining pressure can be applied according to the requirement, namely, the fluorinated oil ring cavity 36 between the outer side of the flexible membrane 39 wrapping the test sample and the inner wall of the pressurizing low-pressure high-pressure probe is filled with fluorinated oil without nuclear magnetic signals, the fluorinated oil circulates between the ring cavity and the refrigerator constant temperature box to refrigerate and control the temperature of the test sample, and meanwhile, by arranging the confining pressure loading pump 7 in the circulating loop, the confining pressure applying function can be started or closed according to the test requirement through the fluorinated oil transmission test sample confining pressure.
The temperature and pressure stabilizing control module can meet the temperature and pressure conditions required by the generation and decomposition of natural gas hydrate for the temperature and confining pressure control range, and the problem that nuclear magnetic signals are affected due to the fact that the outside of a sample tube absorbs water and freezes caused by an air compressor and a long-pipeline drying agent required by an air cooling mode can be effectively avoided by innovatively adopting a low-temperature fluorinated oil circulation cooling mode; the fluorinated oil without nuclear magnetic signal interference is used as a temperature medium, so that the continuous working time is long; the refrigerator incubator with ultralow temperature of minus 60 ℃ can provide a stable cold source, can rapidly reduce the temperature of a sample and keep the sample stable, and has the sample temperature control range of minus 20 ℃ to normal temperature and the temperature control precision of 0.1 ℃; the upper limit of the confining pressure of the sample is 20MPa.
With continued reference to fig. 4 and 5, the pore fluid supply module includes a high-pressure gas cylinder 13, a water storage container 14, a gas saturated water preparation container 15 and a back pressure valve 16, which can be used by different natural gas hydrate synthesis methods to study the influence rule of the synthesis method on pore scale behavior of hydrate-containing sediment, the water storage container 14 and the high-pressure gas cylinder 13 are respectively connected with the gas saturated water preparation container 15 through connecting pipelines, corresponding switching valves are respectively arranged on the connecting pipelines, a distilled water injection pump 17 is further arranged between the water storage container 14 and the gas saturated water preparation container, the gas saturated water preparation container 15 is further connected with a circulation constant flow pump 18, a magnetic stirrer 19 is further arranged in the gas saturated water preparation container, which is used for promoting the dissolution of high-pressure gas in water, and the rotating speed is adjustable between 0rpm and 2000 rpm; the high-pressure air bottle 13 is a methane high-pressure air bottle, the gas saturated water preparation container 15 is made of stainless steel, the inner diameter is 100mm, the height is 200mm, the effective volume is 2261ml, the pressure resistance is 25MPa, the water storage container is made of glass, the effective volume is 1000ml, the upper limit of the injection fluid flow of the circulating constant-flow 18 pump is 50ml/min, and the pressure resistance is 25MPa; the control accuracy of the back pressure valve 16 is + -0.1 MPa, using different components in the pore fluid supply module according to different natural gas hydrate synthesis methods;
for example, when the low-temperature high-pressure probe without confining pressure is installed on the low-field nuclear magnetic resonance analyzer 10, referring to fig. 4, the gas-saturated water preparation vessel 15 is directly connected to the first pore fluid inlet 29 through the circulation constant-flow pump 18; when the pressurized low-temperature high-pressure probe is installed on the low-field nuclear magnetic resonance analyzer 10, as shown in fig. 5, the second pore fluid inlet 34 is connected to the circulation constant-flow pump 18 through a pipeline, the second pore fluid outlet 35 is connected to the gas saturated water preparation container 15 through the back pressure valve 16 through a pipeline, and the pore fluid supply module and the pressurized low-temperature high-pressure probe form a fluid circulation loop.
In addition, in this embodiment, the first low-temperature high-pressure reaction kettle 11, the second low-temperature high-pressure reaction kettle 21 and the third low-temperature high-pressure reaction kettle 31 are all made of non-nuclear magnetic signal materials, the upper limit of the pressure resistance of the reaction kettle is 30MPa, the reaction kettle can normally work under the condition of 40 ℃ below zero to room temperature, a first temperature sensor A is further arranged in the fluorinated oil ring cavity 25 without the confining pressure low-temperature high-pressure probe, a second temperature sensor B is arranged in the fluorinated oil ring cavity 36 with the confining pressure low-temperature high-pressure probe, a pressure sensor is further arranged in the gas saturated water preparation container 15, and the first temperature sensor A, the second temperature sensor B and the pressure sensor are all electrically connected with an industrial control computer so as to acquire temperature, pressure and other data in the experimental process.
The low-field nuclear magnetic resonance analyzer and the industrial personal computer in the embodiment all adopt the existing equipment of the production of Suzhou New Yoghurt company, for example, the low-field nuclear magnetic resonance analyzer can adopt MesoMR23-060H-I type equipment, can perform nuclear magnetic resonance relaxation spectrum analysis and imaging analysis on a test sample, are mainly used for obtaining transverse relaxation time T2 data of the sample, have high test precision and high speed, can characterize the porosity, pore size distribution, bound water, permeability and the like of the test sample, and the industrial personal computer mainly realizes automatic control of a test system, automatic data recording, subsequent result analysis and the like.
Based on the above-mentioned test system, the invention further provides a method for quantitatively testing a plurality of probes for low-field nuclear magnetic resonance special for hydrates, as shown in fig. 6, comprising the following steps:
(1) Preparing parallel soil samples:
three parallel soil samples, namely test samples, are prepared by adopting the same working procedure, and have the same size, the same quality and the same porosity, so that the pore structures of the three soil samples are ensured to be the same in a statistical sense;
(2) Measuring at normal temperature and normal pressure without confining pressure by a probe: analyzing the pore structure of the non-hydrate soil sample;
placing a soil sample in a normal temperature and normal pressure probe without confining pressure, mounting the saturated soil sample on a low-field nuclear magnetic resonance analyzer after distilling the saturated soil sample, operating the low-field nuclear magnetic resonance analyzer to obtain a T2 distribution curve, and qualitatively analyzing the pore distribution characteristics and uncalibrated porosity of the soil sample without natural gas hydrate;
(3) And (3) measuring without using a confining pressure low-temperature high-pressure probe: quantitatively calibrating and determining transverse relaxation rate;
firstly injecting methane gas with a set volume into the soil sample according to the saturation degree of the hydrate to be synthesized, then injecting pure water or salt water to increase the pore pressure of the soil sample, and repeatedly supplementing water and pressurizing until the pore pressure is not obviously reduced (usually less than 0.2 MPa) along with the synthesis of the hydrate, wherein all methane gas is considered to be synthesized into methane hydrate, the saturation degree of the hydrate is calculated by adopting a gas quantity conservation method, namely, the molecular formula CH of the methane hydrate is combined after all methane gas is synthesized into the hydrate 4 ·N h H 2 O calculates the saturation of the hydrate; meanwhile, a low-field nuclear magnetic resonance analyzer is operated to obtain a T2 distribution curve of hydrate-containing sediment, and the effective pore distribution characteristics and uncalibrated effective porosity of a natural gas-containing hydrate soil sample are analyzed;
calculating the saturation of the hydrate by combining the uncalibrated porosity of the soil sample without the natural gas hydrate obtained in the step (2), and quantitatively calibrating the saturation of the hydrate by combining the saturation of the hydrate calculated by the gas quantity conservation method in the step, which is determined based on a low-field nuclear magnetic resonance T2 distribution curve, so as to determine the transverse relaxation rate of hydrate sediment used in the experiment;
(4) And (3) measuring by using a confining pressure low-temperature high-pressure probe: qualitatively analyzing pore scale behavior of the hydrate-containing sediment;
placing the rest soil sample in a confining pressure adding low-temperature high-pressure probe, connecting the probe with a temperature confining pressure control module and a pore fluid injection module, setting any effective confining pressure within a range of 1MPa-10MPa, synthesizing methane hydrate in the soil sample by adopting a distilled water circulation preparation method of saturated methane gas, slowly deflating to control the pressure in a gas saturated water preparation container to gradually decompose the hydrate, operating a low-field nuclear magnetic resonance analyzer to obtain T2 distribution curves of test samples at different moments in the synthesis and decomposition processes of the hydrate, and quantitatively analyzing evolution rules of pore radius distribution curves of hydrate sediment in the synthesis and decomposition processes of the hydrate by combining the transverse relaxation rate determined in the step (3);
in addition, the effective confining pressure is changed within the range of 1MPa-10MPa to repeat the step (4), and the method can be used for quantitatively analyzing the influence rule of the effective confining pressure on the pore radius distribution curve of the hydrate sediment.
The quantitative calibration of the low-field nuclear magnetic resonance measurement signal of the hydrate-containing sediment and the measurement and analysis of the pore dimension behavior of the hydrate-containing sediment are integrated by adopting a multi-probe combined mode, so that the study of the pore dimension behavior characteristic of the hydrate-containing sediment is facilitated, a foundation is laid for the study of a microscopic mechanism of the change of basic physical property parameters of the hydrate-containing sediment, and the method has wide practical and application values.
The present invention is not limited to the above-mentioned embodiments, and any equivalent embodiments which can be changed or modified by the technical content disclosed above can be applied to other fields, but any simple modification, equivalent changes and modification made to the above-mentioned embodiments according to the technical substance of the present invention without departing from the technical content of the present invention still belong to the protection scope of the technical solution of the present invention.
Claims (10)
1. The system is characterized by comprising an industrial personal computer, a low-field nuclear magnetic resonance analyzer, a temperature confining pressure control module and a pore fluid supply module, wherein the low-field nuclear magnetic resonance analyzer is connected with the industrial personal computer and is used for carrying out nuclear magnetic resonance relaxation spectrum analysis and imaging analysis on a test sample, a normal temperature and normal pressure probe without confining pressure, a low temperature and high pressure probe without confining pressure and a high temperature and high pressure probe with confining pressure are respectively arranged on the low-field nuclear magnetic resonance analyzer according to an actual test sequence, three test samples prepared by adopting the same working procedure are also respectively arranged in the three probes, and the sizes, the qualities and the porosities of the three test samples are the same;
the non-confining pressure normal temperature and normal pressure probe comprises a first low-temperature high-pressure reaction kettle and a first radio frequency coil matched with the first low-temperature high-pressure reaction kettle, wherein the first radio frequency coil is arranged on the outer wall of the first low-temperature high-pressure reaction kettle in a surrounding mode, and the non-confining pressure normal temperature and normal pressure probe is directly arranged on a low-field nuclear magnetic resonance analyzer so as to realize the analysis of a pore structure of a non-hydrate soil sample;
the low-temperature high-pressure probe without confining pressure comprises a second low-temperature high-pressure reaction kettle and a second radio-frequency coil matched with the second low-temperature high-pressure reaction kettle, the second radio-frequency coil is arranged on the outer wall of the second low-temperature high-pressure reaction kettle in a surrounding mode, a rigid cylinder used for placing a test sample is arranged in the second low-temperature high-pressure reaction kettle, the rigid cylinder is in a stepped shaft shape and comprises a large-diameter cylinder and a diameter-reducing cylinder, the end portion of the diameter-reducing cylinder is sealed, the outer wall of the large-diameter cylinder is tightly attached to the inner wall of the second low-temperature high-pressure reaction kettle, a fluorine oil ring cavity is formed between the outer wall of the diameter-reducing cylinder and the inner wall of the second low-temperature high-pressure reaction kettle, and the test sample is arranged in the diameter-reducing cylinder; one end of the second low-temperature high-pressure reaction kettle is provided with a first end cover, the other end of the second low-temperature high-pressure reaction kettle is provided with a first fluorinated oil outlet and a first fluorinated oil inlet, the first fluorinated oil outlet and the first fluorinated oil inlet are connected with the temperature confining pressure control module through a pipeline to form a circulating loop, the first end cover is also provided with a first pore fluid inlet communicated with the reducing cylinder, and the first pore fluid inlet is connected with the pore fluid supply module through a pipeline;
the high-temperature high-pressure probe comprises a third low-temperature high-pressure reaction kettle and a third radio-frequency coil matched with the third low-temperature high-pressure reaction kettle, the third radio-frequency coil is arranged on the outer wall of the third low-temperature high-pressure reaction kettle in a surrounding mode, a sample pore space for containing a test sample is arranged in the third low-temperature high-pressure reaction kettle, two ends of the third low-temperature high-pressure reaction kettle are sealed through end covers, a second pore fluid inlet and a second pore fluid outlet are respectively arranged at two ends of the third low-temperature high-pressure reaction kettle, a fluorinated oil annular cavity is formed between the sample pore space and the inner wall of the third low-temperature high-pressure reaction kettle, a second fluorinated oil inlet and a second fluorinated oil outlet are respectively arranged on the outer wall of the third low-temperature high-pressure reaction kettle, and a flexible membrane is wrapped outside the test sample to isolate the sample pore space and the fluorinated oil annular cavity and effectively transmit the sample confining pressure; the second pore fluid inlet and the second pore fluid outlet are connected with the pore fluid supply module through pipelines to form a fluid circulation loop, and the second fluorinated oil inlet and the second fluorinated oil outlet form a low-temperature fluorinated oil circulation loop with the temperature confining pressure control module through pipelines.
2. The test system of claim 1, wherein: the temperature confining pressure control module comprises a refrigerator constant temperature box, a low-temperature circulating pump, a low-temperature fluorinated oil container, a confining pressure loading pump and a normal-temperature fluorinated oil container, wherein the low-temperature circulating pump is arranged in the refrigerator constant temperature box, one end of the low-temperature circulating pump is connected with the low-temperature fluorinated oil container, and the other end of the low-temperature circulating pump is connected with the normal-temperature fluorinated oil container through the confining pressure loading pump;
when a low-temperature high-pressure probe without confining pressure is arranged on the low-field nuclear magnetic resonance analyzer, the first fluorinated oil inlet end is connected with the connecting end of the low-temperature circulating pump and the confining pressure loading pump through a pipeline, and the first fluorinated oil outlet end is connected with the low-temperature fluorinated oil container through a pipeline;
when the pressurizing low-pressure high-pressure probe is arranged on the low-field nuclear magnetic resonance analyzer, the second fluorinated oil inlet end is connected with the connecting ends of the low-temperature circulating pump and the confining pressure loading pump through a pipeline, the second fluorinated oil outlet end is connected with the low-temperature fluorinated oil container through a pipeline, and the normal-temperature fluorinated oil container is connected to the low-temperature fluorinated oil circulating loop through the confining pressure loading pump.
3. The test system according to claim 1 or 2, wherein: the pore fluid supply module comprises a high-pressure gas cylinder, a water storage container, a gas saturated water preparation container and a back pressure valve, wherein the water storage container and the high-pressure gas cylinder are respectively connected with the gas saturated water preparation container through connecting pipelines, corresponding switching valves are respectively arranged on the connecting pipelines, a distilled water injection pump is further arranged between the water storage container and the gas saturated water preparation container, and the gas saturated water preparation container is further connected with a circulating constant flow pump;
when a low-temperature high-pressure probe without confining pressure is arranged on the low-field nuclear magnetic resonance analyzer, the gas saturated water preparation container is directly connected with the first pore fluid inlet through the circulating constant flow pump;
when the pressurizing low-temperature high-pressure probe is arranged on the low-field nuclear magnetic resonance analyzer, the inlet end of the second pore fluid is connected with the circulating constant-flow pump through a pipeline, the outlet end of the second pore fluid is connected to the gas saturated water preparation container through a back pressure valve through a pipeline, and the pore fluid supply module and the pressurizing low-temperature high-pressure probe form a fluid circulation loop.
4. A test system according to claim 3, wherein: the first low-temperature high-pressure reaction kettle, the second low-temperature high-pressure reaction kettle and the third low-temperature high-pressure reaction kettle are all made of non-nuclear magnetic signal materials.
5. The test system of claim 4, wherein: the first temperature sensor is arranged in the oil fluoride ring cavity of the non-confining pressure low-temperature high-pressure probe, the second temperature sensor is arranged in the oil fluoride ring cavity of the confining pressure low-temperature high-pressure probe, and the first temperature sensor and the second temperature sensor are electrically connected with the industrial control computer.
6. The test system of claim 5, wherein: the gas saturated water preparation container is also provided with a pressure sensor, and the pressure sensor is electrically connected with the industrial control computer.
7. The test system of claim 6, wherein: and a magnetic stirrer is also arranged in the gas saturated water preparation container.
8. The test system of claim 7, wherein: the high-pressure gas cylinder adopts a methane high-pressure gas cylinder.
9. A method for quantitatively testing a hydrate-specific low-field nuclear magnetic resonance multi-probe based on a test system according to any one of claims 1 to 8, characterized by comprising the steps of:
(1) Preparing parallel soil samples:
three parallel soil samples, namely test samples, are prepared by adopting the same working procedure, wherein the three soil samples have the same size, the same quality and the same porosity;
(2) Measuring at normal temperature and normal pressure without confining pressure by a probe: analyzing the pore structure of the non-hydrate soil sample;
placing a soil sample in a normal temperature and normal pressure probe without confining pressure, mounting the saturated soil sample on a low-field nuclear magnetic resonance analyzer after distilling the saturated soil sample, operating the low-field nuclear magnetic resonance analyzer to obtain a T2 distribution curve of the low-field nuclear magnetic resonance analyzer, and analyzing the pore distribution characteristics and uncalibrated porosity of the soil sample without natural gas hydrate;
(3) And (3) measuring without using a confining pressure low-temperature high-pressure probe: quantitatively calibrating and determining transverse relaxation rate;
then, a soil sample is placed in a low-temperature high-pressure probe without confining pressure, the connection relation between the soil sample and a temperature confining pressure control module and the connection relation between the soil sample and a pore fluid injection module are well connected, methane hydrate is synthesized in the soil sample, and the saturation of the hydrate is calculated by adopting a gas quantity conservation method in the process; meanwhile, a T2 distribution curve of the hydrate-containing sediment obtained by a low-field nuclear magnetic resonance analyzer is operated, and the effective pore distribution characteristics and uncalibrated effective porosity of a natural gas-containing hydrate soil sample are analyzed;
calculating the hydrate saturation of the synthesized methane hydrate in the step according to the uncalibrated porosity of the soil sample without the natural gas hydrate obtained in the step (2), and determining the transverse relaxation rate of hydrate sediment used in the experiment by combining the hydrate saturation calculated by adopting a gas quantity conservation method;
(4) And (3) measuring by using a confining pressure low-temperature high-pressure probe: qualitatively analyzing pore scale behavior of the hydrate-containing sediment;
and (3) placing the rest soil sample in a confining pressure adding low-temperature high-pressure probe, connecting the probe with a temperature confining pressure control module and a pore fluid injection module, synthesizing methane hydrate in the soil sample by adopting a saturated methane distilled water circulation preparation method according to the set effective confining pressure, gradually decomposing the hydrate by controlling the pressure in a gas saturated water preparation container, operating a low-field nuclear magnetic resonance analyzer to obtain T2 distribution curves of test samples at different moments in the synthesis and decomposition processes of the hydrate, and quantitatively analyzing the evolution law of pore radius distribution curves of hydrate sediment in the synthesis and decomposition processes of the hydrate by combining the transverse relaxation rate determined in the step (3).
10. The test method according to claim 9, wherein: in the step (4), the influence rule of the effective confining pressure on the pore radius distribution curve of the hydrate sediment can be quantitatively analyzed by changing the effective confining pressure.
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Families Citing this family (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| CN111380789A (en) * | 2018-12-29 | 2020-07-07 | 中国石油大学(北京) | Device and method for measuring permeability of combustible ice |
| CN111380791A (en) * | 2018-12-29 | 2020-07-07 | 中国石油大学(北京) | System and method for measuring permeability of combustible ice under temperature control condition |
| CN110031785B (en) * | 2019-04-29 | 2021-04-06 | 江苏麦格迈医学科技有限公司 | Temperature-variable portable probe for nuclear magnetic resonance detection |
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| CN111289553B (en) * | 2020-03-05 | 2021-02-26 | 青岛海洋地质研究所 | Device and method for analyzing mechanical properties of hydrate sediments based on low-field nuclear magnetic analysis |
| CN111589393B (en) * | 2020-05-26 | 2020-12-29 | 中国科学院西北生态环境资源研究院 | Natural gas hydrate experiment reaction kettle device suitable for low-field nuclear magnetic resonance |
| CN111678938B (en) * | 2020-07-17 | 2021-08-24 | 中南大学 | Multi-field coupling rock-soil nuclear magnetic resonance online monitoring system |
| CN112485282B (en) * | 2020-11-03 | 2022-05-03 | 中国地质大学（武汉） | Measuring system and method for soil-water characteristic curve of gas hydrate-containing sediment |
| CN112540098B (en) * | 2020-12-02 | 2022-07-05 | 中国地质大学（北京） | Device and method for measuring phase equilibrium condition of gas hydrate in sediment |
| CN112505085B (en) * | 2021-02-05 | 2021-04-09 | 西南石油大学 | Method for measuring porosity effective stress coefficient based on nuclear magnetic resonance |
| CN112986309A (en) * | 2021-04-01 | 2021-06-18 | 中海石油(中国)有限公司 | Method for measuring porosity of coal seam by using rock debris crushed coal sample |
| CN115201246B (en) * | 2022-07-29 | 2024-04-12 | 青岛海洋地质研究所 | Low-temperature control device and method for hydrate decomposition nuclear magnetic resonance experiment |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102495090A (en) * | 2011-11-24 | 2012-06-13 | 大连理工大学 | Device and method for low-temperature high-pressure nuclear magnetic resonance imaging of natural gas hydrate |
| CN104677806A (en) * | 2015-03-24 | 2015-06-03 | 苏州纽迈电子科技有限公司 | Nuclear magnetic resonance low-temperature pore analysis system |
| CN106153662A (en) * | 2016-06-17 | 2016-11-23 | 北京大学 | The measuring method of rock core stress sensitivity |
| CN207557144U (en) * | 2017-11-30 | 2018-06-29 | 青岛海洋地质研究所 | The special low-field nuclear magnetic resonance Multi probe quantitative testing system of hydrate |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7688071B2 (en) * | 2007-01-31 | 2010-03-30 | Schlumberger Technology Corporation | NMR measurement of wax appearance in fluids |
| GB2489005B (en) * | 2011-03-15 | 2015-11-25 | Schlumberger Holdings | Examination of porosity by NMR and intrusion porosimetry |
-
2017
- 2017-11-30 CN CN201711235387.9A patent/CN107807143B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102495090A (en) * | 2011-11-24 | 2012-06-13 | 大连理工大学 | Device and method for low-temperature high-pressure nuclear magnetic resonance imaging of natural gas hydrate |
| CN104677806A (en) * | 2015-03-24 | 2015-06-03 | 苏州纽迈电子科技有限公司 | Nuclear magnetic resonance low-temperature pore analysis system |
| CN106153662A (en) * | 2016-06-17 | 2016-11-23 | 北京大学 | The measuring method of rock core stress sensitivity |
| CN207557144U (en) * | 2017-11-30 | 2018-06-29 | 青岛海洋地质研究所 | The special low-field nuclear magnetic resonance Multi probe quantitative testing system of hydrate |
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