98 results about "Transverse Relaxation Time" patented technology

A method for separating liquid-like (T2e) from solid-like (T2G) 1H NMR transverse relaxation times in porous media uses novel pulse sequences together with a 1H NMR spectrometer optimized for geological core samples. The method is applied to obtain 1D T2 distributions and 2D T1-T2 maps in organic-rich chalks for quantification of liquid-like signal (micropore fluids, meso-macropore fluids, fluids dissolved in organic matter, and clay-bound water) and solid-like signal (kerogen, bitumen, and clay hydroxyls). The novel pulse sequences comprise a solid-echo, which detects more solid-like signal than an FID. The method is used for fluid typing in micro / meso-macro pores, clay mineral identification, determination of kerogen content, and quantification of solvent-extracted bitumen versus bitumen expelled from kerogen due to swelling from dissolved hydrocarbons. The method is used to quantify the asphaltene, resin, aromatic, and / or saturate content of bitumen in the rock.

The invention provides a nuclear magnetic resonance and image intelligent bimodal unfrozen water dynamic identification method and system, and belongs to the technical field of frozen soil engineering and geophysical exploration, and the method comprises the steps: sealing a frozen soil sample in a nuclear magnetic sample tube, and achieving the gradient cooling of the sample in a preset low temperature range through temperature control; scanning by using a nuclear magnetic resonance technology to obtain transverse relaxation time T2 spectrums and nuclear magnetic images of the frozen soil sample at different temperature nodes; after image preprocessing is carried out on the nuclear magnetic image, a temperature-signal intensity curve in the nuclear magnetic image is automatically extracted by utilizing an image recognition technology; carrying out integral calculation on a liquid water signal in the T2 spectrum, and dynamically calculating the content of the unfrozen water at each temperature based on a nuclear magnetic signal intensity formula; according to the method, a pore-fracture co-evolution matrix is constructed, accurate analysis of unfrozen water dynamic and pore evolution in the freezing and thawing process is realized, the method is suitable for hydrothermal coupling characteristic analysis of Qinghai-Tibet soil in a complex freezing and thawing environment, and reliable technical support is provided for stability evaluation of frozen soil engineering.

The invention relates to a magnetic resonance imaging method and device and a storage medium, and the method comprises the steps: scanning a target region through employing a first magnetic resonance sequence, setting a plurality of echo times, and collecting a plurality of spin echo images; recording a plurality of echo times and corresponding dispersion sensitivity coefficients according to the first magnetic resonance sequence; scanning the target area by using the second magnetic resonance sequence to obtain an apparent dispersion coefficient; and according to the plurality of spin echo images, the plurality of echo times, the dispersion sensitivity coefficient and the apparent dispersion coefficient, fitting to obtain a transverse relaxation time constant quantitative image for correcting the dispersion influence. According to the method and the device, the problem of dispersion when a magnetic resonance transverse relaxation time constant quantitative image is obtained through a variable echo time spin echo method in the prior art is solved, and the beneficial effect of effectively improving the quantitative accuracy is achieved.

In a method for quantitative detection of parameters in MRI, first and second spoiled gradient echo images and at least one multi-echo steady-state first / second magnetization image are acquired; based on the extended phase graph theory, signal equations are obtained corresponding to the first and second spoiled gradient echo images, the at least one multi-echo steady-state first magnetization image and the at least one multi-echo steady-state second magnetization image; based on the signal equations of the first and second spoiled gradient echo images, the signal equation of the at least one multi-echo steady-state first magnetization image and the signal equation of the at least one multi-echo steady-state second magnetization image, a spoiled gradient echo proton density map, a multi-echo steady-state proton density map, a longitudinal relaxation time map and a transverse relaxation time map of the target tissue are obtained.

The invention belongs to the technical field of geophysical exploration, and relates to an underground water magnetic resonance longitudinal relaxation time detection method, which comprises the following steps: laying a magnetic resonance detection coil on the ground, fixing a short emission time, changing a current amplitude, emitting a plurality of short pulses, and collecting a short pulse observation signal generated by each short pulse; fixing a long emission time, re-emitting a series of long pulses with different current amplitudes, and collecting a long pulse observation signal generated by each long pulse; inverting the short pulse observation signal to obtain water content and transverse relaxation time distribution of underground water at different depths; and taking the water content and the transverse relaxation time distribution of the underground water at different depths as prior data of Bayesian inversion, and analyzing the long pulse observation signal by adopting Bayesian inversion to obtain longitudinal relaxation time distribution. According to the invention, a complex excitation sequence form is not needed, and a longitudinal relaxation signal of a short relaxation sample with a fast attenuation speed can be captured. The method is suitable for a high-power scene of field ground magnetic resonance detection.

The invention discloses a lithogenous phase classification-based nuclear magnetic well logging particle size parameter inversion method, which comprises the following steps of S1, carrying out nuclear magnetic resonance and particle size analysis test experiments to obtain a saturated water T2 spectrum accumulation curve and a particle size accumulation curve; s2, drawing a transverse relaxation time T2-particle size relation curve, performing scale range division on the particle size, and obtaining a relational expression I of the transverse relaxation time T2 and the particle size in each scale range; s3, diagenetic lithofacies types of the target area are divided; s4, by taking the diagenetic lithofacies type as a constraint, optimizing the relational expression 1 to obtain a relational expression 2 between the transverse relaxation time T2 and the particle size under different diagenetic lithofacies types and different scale ranges; establishing a standard for identifying diagenetic lithofacies of the logging curve; and S5, obtaining a logging curve of the target wellbore profile, identifying diagenetic lithofacies of the target wellbore profile, and obtaining continuous granularity parameters of the target wellbore profile in combination with second inversion of the relational expression. According to the method, the particle size distribution on the wellbore section can be accurately and quantitatively inverted by using nuclear magnetic logging.

The invention provides a transformer oil degradation detection method and device, a terminal and a computer storage medium, and the method comprises the steps: transmitting corresponding test radio frequency magnetic field pulse sequences to a transformer oil circulation pipeline based on a preset test magnetic field intensity group, so as to obtain corresponding test echo chain signals; performing inverse Laplace transformation on each test echo chain signal, and calculating each corresponding test transverse relaxation time distribution spectrum; acquiring a reference transverse relaxation time distribution spectrum corresponding to each test transverse relaxation time distribution spectrum; and respectively calculating the deviation value of each test transverse relaxation time distribution spectrum relative to the corresponding reference transverse relaxation time distribution spectrum, and obtaining the deterioration degree of the transformer oil in the transformer oil circulation pipeline based on each deviation value so as to realize online detection of the deterioration condition of the transformer oil.

The invention provides a method and device for determining the gas content of a deep coal rock gas reservoir and a readable storage medium, and belongs to the technical field of oil-gas exploration. The method comprises the following steps: acquiring a substrate transverse relaxation time spectrum of a dried reservoir rock sample, transverse relaxation time spectrums before adsorption equilibrium at different pressure points and transverse relaxation time spectrums after adsorption equilibrium at different pressure points; based on the substrate transverse relaxation time spectrum, the transverse relaxation time spectrums before adsorption equilibrium at different pressure points and the transverse relaxation time spectrums after adsorption equilibrium at different pressure points, transverse relaxation time correction spectrums after adsorption equilibrium at different pressure points are determined; obtaining actual free gas volumes under different pressure points and actual adsorption gas volumes under different pressure points; and constructing a gas content determination model for outputting the gas content of the deep coal and rock gas reservoir to be detected. By redefining the T2 cut-off values of the adsorption gas and the free gas, the adsorption gas amount and the free gas amount are accurately calculated, and the calculation precision of the gas content of the reservoir can be improved.

The invention relates to the technical field of oil and gas field development, in particular to a method for converting transverse relaxation time distribution into capillary force distribution. According to the method, the correction coefficient for converting the high-pressure mercury injection pore throat radius into the transverse relaxation time is provided, then the conversion coefficient is obtained through linear interpolation and volume proportion weighting, the method for converting transverse relaxation time distribution into capillary force distribution is established, and technical reference is provided for researching the microstructure and properties of a reservoir.

An objective of the present invention is to provide a binder composition for non-aqueous secondary battery electrodes that makes it possible to reduce the internal resistance of a non-aqueous secondary battery. The present invention is a binder composition for non-aqueous secondary battery electrodes that contains a particulate polymer, wherein, when a least square method is used to waveform-separate a free induction decay curve of transverse relaxation of 1H measured by a pulse NMR solid echo method into two curves derived from two components, component A and component B, in ascending order of a transverse relaxation time T2, the component fraction αA of the A component of the particulate polymer is 1.0%-10.0%.

The present invention relates to the technical field of oil and gas field development, and specifically relates to a method for converting the transverse relaxation time distribution into the capillary pressure distribution. The present invention proposes a correction coefficient for converting the high-pressure mercury intrusion pore throat radius into the transverse relaxation time, and then obtains the conversion coefficient by using linear interpolation and volume ratio weighting, and establishes a method for converting the transverse relaxation time distribution into the capillary pressure distribution, providing a technical reference for studying the microscopic structure and properties of reservoirs.

The invention discloses a method, system and equipment for determining the emulsification effect of a middle-phase microemulsion based on nuclear magnetic resonance, a medium and a product, and relates to the technical field of oil exploitation, and the method comprises the following steps: carrying out baseline correction, noise removal, normalization processing and Laplace inverse transformation on a spin echo intensity signal; obtaining an effective diffusion coefficient-effective transverse relaxation time combined distribution diagram, projecting the effective diffusion coefficient-effective transverse relaxation time combined distribution diagram in an effective diffusion coefficient direction, and solving by adopting a multi-peak Gaussian fitting model and a least square method according to the effective diffusion coefficients of different components to obtain an effective diffusion coefficient range; and integrating the effective diffusion coefficient-effective transverse relaxation time combined distribution diagram within the effective diffusion coefficient range so as to determine an effective transverse relaxation time distribution curve, obtaining a simulated oil peak area in a bicontinuous phase and a simulated oil peak area in an oil phase through integration, and calculating the emulsification effect of the middle-phase microemulsion. According to the method, the accuracy of calculating the emulsification effect of the to-be-detected middle-phase microemulsion can be improved.

This invention discloses a method and system for testing rock pore size distribution curves based on nuclear magnetic resonance (NMR) technology. The method includes: preprocessing the rock sample to be tested and obtaining the porosity and transverse relaxation time curves of the sample at room temperature and low temperature; obtaining the measured value of unfrozen water content by the ratio of low-temperature to room-temperature porosity, serving as an objective benchmark for verifying theoretical results; converting the room-temperature relaxation curve into a cumulative pore size distribution curve, fitting and extracting pore characteristic parameters, and substituting relevant characteristic parameters into a theoretical model to calculate the theoretical value of unfrozen water content; iteratively optimizing the transverse surface relaxation rate to ensure the deviation between the theoretical and measured values ​​meets accuracy requirements; establishing a precise correspondence between relaxation time and pore radius; and outputting the final pore size distribution curve. Each step is interconnected and mutually supportive, forming a complete logical closed loop. This provides reliable technical support for characterizing rock pore structure.

The invention relates to the technical field of power equipment operation inspection, in particular to a nuclear magnetic resonance transverse relaxation time spectrum-based composite insulator aging evaluation method, which comprises the following steps of: measuring a composite insulator sample by using a nuclear magnetic resonance spectrometer to obtain a transverse relaxation time distribution T2 spectral line of the sample, and extracting key characteristic parameters; and establishing a mapping relation model of the characteristic parameters and the aging degree, calculating an aging index, and realizing evaluation of the aging degree of the composite insulator and judgment of aging factors. According to the method, starting from the change of the microstructure of the material, the aging degree is represented through the nuclear magnetic resonance signal, the signal abnormity at the initial stage of aging can be detected when the appearance of the insulator has no obvious change, and an earlier basis is provided for formulating a maintenance strategy.

This disclosure provides a nuclear magnetic resonance (NMR) analysis method for establishing the chemical composition and condensed-state structure of fluorine-containing materials and its application. The method includes: placing fluorine-containing materials under different operating conditions in a single-sided NMR spectrometer; under a single-sided inhomogeneous magnetic field environment; presetting parameters for a spin echo pulse sequence; using the spin echo pulse sequence to excite fluorine and hydrogen nuclei in the fluorine-containing material to obtain coupled NMR signals of fluorine and hydrogen nuclei; determining echo peak data from the coupled NMR signals according to the preset parameters; processing the echo peak data according to the structural characteristics of the fluorine-containing material to obtain relaxation spectrum fingerprint data; performing data transformation on the relaxation spectrum fingerprint data to obtain transverse relaxation time data; and establishing a relaxation spectrum fingerprint database and a transverse relaxation time database of the coupling of fluorine and hydrogen nuclei in the fluorine-containing material based on the relaxation spectrum fingerprint data and transverse relaxation time data under different operating conditions.

The invention discloses a method, a system and equipment for determining saturation of liquid in a porous medium. The method for determining the saturation degree of the liquid in the porous medium comprises the following steps: determining the type of the porous medium according to the pore size distribution condition of the porous medium; if the porous medium is a single-scale porous medium, respectively obtaining a first nuclear magnetic resonance relaxation spectrum and a second nuclear magnetic resonance relaxation spectrum of the liquid in the porous medium when the liquid in the porous medium is in a saturated state and an unsaturated state; and obtaining the saturation of the liquid in the porous medium according to the first nuclear magnetic resonance relaxation spectrum, the second nuclear magnetic resonance relaxation spectrum and the bulk phase transverse relaxation time of the liquid. By adopting the method and the device, the liquid saturation condition in the porous medium can be better determined, and the method and the device are further suitable for analyzing the occurrence and transportation process of porous multiphase system fluids with complex pore sizes and phase state distribution conditions.

The present invention provides a full-aperture pore structure characterization method and device driven by multidimensional data, the method comprising: obtaining a target tight reservoir rock sample; subjecting the target tight reservoir rock sample to brine saturation treatment and a first nuclear magnetic resonance measurement to obtain the brine-saturated rock sample and the transverse relaxation time under brine saturation; subjecting the brine-saturated rock sample to high-pressure mercury injection and nitrogen adsorption to obtain high-pressure mercury injection and gas adsorption experimental data; calibrating the transverse relaxation time under brine saturation based on a full-aperture cumulative pore volume frequency distribution curve to obtain a transverse relaxation time pore size distribution curve based on nuclear magnetic resonance; subjecting the target tight reservoir rock sample to constant-rate mercury injection treatment to obtain a pore size distribution curve based on constant-rate mercury injection; determining the overlapping position of the transverse relaxation time pore size distribution curve based on nuclear magnetic resonance and the pore size distribution curve based on constant-rate mercury injection, and using the overlapping position as a joining point; and determining the full-aperture distribution range of the target tight reservoir.

The present application discloses a method, device and computing equipment for determining the lower limit of effective reservoir physical properties. The method includes: obtaining a first transverse relaxation time spectrum of any measurement point obtained by performing nuclear magnetic resonance logging on the target formation; calculating the first effective porosity of the measurement point based on the first transverse relaxation time spectrum of the measurement point; extracting the second transverse relaxation time spectrum of the invading mud from the first transverse relaxation time spectrum of the measurement point, and calculating the second effective porosity of the measurement point based on the second transverse relaxation time spectrum; establishing a first intersection diagram of the first effective porosity and the second effective porosity based on the first effective porosity and the second effective porosity of different measurement points; determining the inflection point of the first intersection diagram, and using the first effective porosity corresponding to the inflection point as the lower limit of the effective porosity of the target formation. This solution can improve the accuracy of determining the lower limit of effective reservoir physical properties, lower the data threshold, and improve the efficiency of determining the lower limit of effective reservoir physical properties.

The invention discloses a full-scale characterization method and system for a microscopic pore throat structure of a glutenite reservoir. According to the method, interpolation processing is performed on the pore throat radius of the mercury injection test by using the transverse relaxation time obtained by the nuclear magnetic resonance test, and then linear fitting is performed, so that the transverse relaxation time of the nuclear magnetic resonance test is converted into the pore throat radius of the glutenite, and the obtained pore throat radius data is finer and higher in accuracy; and moreover, small pore throat radius distribution into which mercury cannot enter can be obtained, so that full-scale characterization of the pore throat structure of the glutenite reservoir is realized. Segmented fitting is carried out according to the modal category of the glutenite reservoir, the pore throat structure distribution condition of the glutenite reservoir can be represented more finely, the pore throat structure of the glutenite reservoir can be described by using the method, and the applicability of oil and gas development is improved.

The application provides a nuclear magnetic resonance and image intelligent dual-mode unfrozen water dynamic identification method and system, and belongs to the technical field of frozen soil engineering and geophysical exploration, and comprises the following steps: sealing a frozen soil sample in a nuclear magnetic sample tube, and realizing gradient cooling of the sample in a preset low temperature range through temperature control; scanning and acquiring a transverse relaxation time T2 spectrum and a nuclear magnetic image of the frozen soil sample at different temperature nodes by using a nuclear magnetic resonance technology; automatically extracting a temperature-signal intensity curve in the nuclear magnetic image by using an image recognition technology after image preprocessing of the nuclear magnetic image; performing integral calculation on liquid water signals in the T2 spectrum, and dynamically calculating the content of unfrozen water at each temperature based on a nuclear magnetic signal intensity formula; and constructing a pore-fracture collaborative evolution matrix, so that accurate analysis of the dynamic unfrozen water and pore evolution in a freezing and thawing process is realized, the water-heat coupling characteristics of Qinghai-Tibet soil under a complex freezing and thawing environment are analyzed, and reliable technical support is provided for stability evaluation of frozen soil engineering.

The invention discloses a nondestructive detection method, equipment, medium and product for the quality of Chinese wolfberry puree, and relates to the field of food detection.The method comprises the steps that the transverse relaxation time of Chinese wolfberry puree to be detected is determined through a low-field nuclear magnetic resonance analyzer, fitting is conducted through inverse Laplace transformation, and a first characteristic peak, a second characteristic peak and a third characteristic peak are obtained; determining a corresponding peak area proportion; when the transverse relaxation time is less than the set relaxation time and the proportion of the main peak signal is greater than the set proportion, determining that the to-be-detected Chinese wolfberry primary pulp is 100% pure Chinese wolfberry primary pulp; and carrying out weighted geometric averaging on the transverse relaxation time of the to-be-detected wolfberry puree to obtain weighted geometric average relaxation time, and determining the total sugar content, the total acid content and the total moisture content of the to-be-detected wolfberry puree by combining the first peak area proportion, the second peak area proportion and the third peak area proportion and utilizing the quality prediction model. According to the invention, rapid, nondestructive and on-line detection of the quality of the wolfberry puree can be realized.

The embodiment of the present invention relates to the technical field of downhole temperature correction, and discloses a downhole T2 spectrum temperature correction method and calculation device. The embodiment of the present invention obtains a second T2 spectrum by fitting a first T2 spectrum of a target layer according to a Gaussian distribution model, performs temperature correction of the transverse relaxation time on the characteristic points of the second T2 spectrum according to a first temperature correction formula to obtain a third T2 spectrum, then corrects the first nuclear magnetic total porosity of the target layer according to the second temperature correction formula to obtain a second nuclear magnetic total porosity at ground temperature, normalizes the third T2 spectrum to obtain a fourth T2 spectrum, and finally performs temperature correction of the porosity component of the fourth T2 spectrum according to the second nuclear magnetic total porosity to obtain a fifth T2 spectrum, thereby achieving temperature correction of nuclear magnetic data measured in a downhole high-temperature environment, thereby making the nuclear magnetic data measured in a downhole high-temperature environment suitable for an evaluation model established at normal ground temperature.

The invention provides a method and a system for determining diamond nitrogen vacancy color center intrinsic transverse relaxation time. The method comprises the following steps: acquiring a transverse relaxation time calibration value of a standard nitrogen vacancy color center diamond sample; respectively measuring the first transverse relaxation time and the second transverse relaxation time of the standard nitrogen vacancy color center diamond sample and the nitrogen vacancy color center diamond sample to be detected under the action of the non-uniform external magnetic field on the detection platform; according to the transverse relaxation time calibration value and the first transverse relaxation time, calculating the transverse relaxation time deviation of the standard nitrogen vacancy color center diamond sample under the action of the non-uniform external magnetic field; and according to the transverse relaxation time deviation and the second transverse relaxation time, calculating the intrinsic transverse relaxation time of the nitrogen vacancy color center diamond sample to be measured. According to the method and the system, an ultrahigh-uniformity static magnetic field environment with extremely high cost is not needed, the detection method is high in robustness, and the calibration accuracy of the to-be-detected sample in a complex or non-ideal experimental environment can be remarkably improved.

The present invention belongs to the field of geophysical exploration technology and is a method for detecting the longitudinal relaxation time of groundwater using magnetic resonance. The method comprises: laying a magnetic resonance detection coil on the ground, fixing a short emission time, varying the current amplitude to emit multiple short pulses, and collecting the short pulse observation signal generated by each short pulse; fixing a long emission time, re-emitting a series of long pulses with different current amplitudes, and collecting the long pulse observation signal generated by each long pulse; inverting the short pulse observation signal to obtain the water content and transverse relaxation time distribution of groundwater at different depths; using the water content and transverse relaxation time distribution of groundwater at different depths as prior data for Bayesian inversion, and employing Bayesian inversion to analyze the long pulse observation signal to obtain the longitudinal relaxation time distribution. The present invention can capture the longitudinal relaxation signal of samples with fast decay rates and short relaxation without the need for complex excitation sequences. The method is suitable for high-power scenarios in field ground magnetic resonance detection.

The invention provides a method and a device for determining pore size distribution of a reservoir core. Dividing a to-be-detected target rock core into a first layer and a second layer, and carrying out nuclear magnetic resonance testing on the to-be-detected rock core to obtain a first corresponding relation between the transverse relaxation time in the first layer and the nuclear magnetic resonance signal intensity and a second corresponding relation between the transverse relaxation time in the second layer and the nuclear magnetic resonance signal intensity; acquiring a third corresponding relation between the diameter of the mesoporous throat in the first layer and the content of the crude oil through a laser confocal microscope; according to the first corresponding relation and the third corresponding relation, performing fitting processing on parameters in a target relational expression between the transverse relaxation time and the pore throat diameter to obtain the target relational expression; and determining the distribution information of the pore throat diameter in the second layer according to the target relational expression, the second corresponding relation and the nuclear magnetic resonance signal intensity in the second layer. On the basis of the method, the accuracy of pore size characterization in the oil reservoir is improved on the premise that the rock core is not damaged.

The invention discloses a low-field NMR relaxation time rapid measurement method, and the method comprises the steps: designing an IR-bSSFP pulse sequence which comprises a 180-degree reversal pulse and an excitation pulse sequence, and enabling the flip angle of a radio frequency excitation pulse in the excitation pulse sequence to be a pseudo-random flip angle; the radio-frequency phases of the adjacent radio-frequency excitation pulses are linearly changed by a fixed phase increment; based on the IR-bSSFP pulse sequence, obtaining a component MRF signal sequence of a measured object, and simulating a magnetization vector evolution process to obtain a dictionary matrix; matching the component MRF signal with a dictionary matrix pattern in combination with a smooth constraint term to obtain corresponding longitudinal relaxation time and transverse relaxation time; the invention also discloses low-field NMR relaxation time rapid measurement equipment, which comprises a pulse sequence construction module, a dictionary generation module and a mode matching module. Multi-parameter information can be obtained through single scanning, the measurement time is remarkably shortened, the experiment complexity is reduced, and the precision and repeatability of a measurement result are improved.

This specification provides a method and device for determining the pore size distribution of reservoir cores. The target core to be tested is divided into a first layer and a second layer, and a nuclear magnetic resonance test is performed on the target core to be tested to obtain a first correspondence between the transverse relaxation time and the nuclear magnetic resonance signal intensity in the first layer, and a second correspondence between the transverse relaxation time and the nuclear magnetic resonance signal intensity in the second layer; a third correspondence between the pore throat diameter and the crude oil content in the first layer is obtained through a laser confocal microscope; based on the first and third correspondences, the parameters in the target relationship between the transverse relaxation time and the pore throat diameter are fitted to obtain the target relationship; based on the target relationship, the second correspondence, and the nuclear magnetic resonance signal intensity in the second layer, the distribution information of the pore throat diameter in the second layer is determined. Based on the above method, it is possible to improve the accuracy of pore size characterization in oil reservoirs without destroying the core.

The invention relates to the technical field of rock physical analysis in oil-gas exploration and development, and particularly provides a shale full-size pore structure characterization method which comprises the following steps: acquiring high-pressure mercury injection experimental data and nuclear magnetic resonance experimental data of a shale sample, dividing a pore system of the shale sample into a small pore section and a large pore section by an inflection point of fractal dimension, respectively fitting the pore throat radius of the small pore section and the pore throat radius of the large pore section with the transverse relaxation time to obtain two groups of conversion coefficients, respectively inverting the pore diameter distribution curve of the small pore section and the pore diameter distribution curve of the large pore section by utilizing the two groups of conversion coefficients, and carrying out segmented integration according to the intersection point of the two curves to characterize the full pore diameter distribution of the shale sample. According to the method, a fractal inflection point division pore system is introduced, deep structure information is excavated by utilizing a fractal theory, segmentation fitting is carried out, and the technical problems that a traditional HPMI-NMR conjoint analysis method is insufficient in precision under the conditions of large displacement pressure, low mercury injection saturation and strong heterogeneity are solved.

The present invention discloses a method for characterizing wood cell wall stiffness based on low-field nuclear magnetic resonance. When the wood sample is dried, the wood sample is taken out at regular intervals for weighing and low-field nuclear magnetic resonance scanning. The complete relaxation signal intensity of the wood sample is collected by using an MSE-CPMG pulse sequence, thereby obtaining the moisture content and free induction decay curve of the wood sample. The transverse relaxation time T of the wood sample is calculated by a data inversion algorithm combining Gaussian fitting and exponential fitting. 21 , transverse relaxation time integral peak area A1. The characterization method of the present invention is non-destructive, continuous and has high measurement accuracy.

The invention relates to the technical field of geological exploration, in particular to a dessert interval determination method and device, a storage medium and a computer program.The method comprises the steps that distribution information of one-dimensional nuclear magnetic transverse relaxation time T2 and distribution information of longitudinal relaxation time T1 of rock samples of different depths of a continental facies shale oil and gas reservoir are obtained, sorting the distribution information of the transverse relaxation time T2 and the distribution information of the longitudinal relaxation time T1 of each rock sample along the corresponding depth of each rock sample to obtain pore size distribution information and oil-water distribution information of the continental facies shale oil and gas reservoir; and determining the sweet spot interval of the continental facies shale oil and gas reservoir according to the pore size distribution information and the oil-water distribution information. According to the method and the device, the oil content conditions of the reservoirs can be compared more visually, and the dividing efficiency and accuracy of the dessert layer sections are improved.