14 results about "T2 value" patented technology

A method and device for determining oil-water relative permeability information of a medium-high permeability reservoir, relating to the technical field of oil and gas reservoir development. The method comprises: acquiring nuclear magnetic resonance T2 spectrum information of a medium-high permeability reservoir in multiple states (101); determining pore distribution and oil phase distribution on the basis of the nuclear magnetic resonance T2 spectrum information in multiple states (102); using the pore distribution and the oil phase distribution of the medium-high permeability reservoir, combined with the wettability type of a core of the medium-high permeability reservoir, to divide movable oil-water space in the nuclear magnetic resonance T2 spectrum information in multiple states (103); on the basis of the nuclear magnetic resonance T2 spectrum information of the medium-high permeability reservoir in multiple states, determining a correspondence between the normalized saturation of the movable oil-water space and a T2 value (104); and on the basis of the correspondence between the normalized saturation of the movable oil-water space and the T2 value, determining an oil-phase relative permeability curve and a water-phase relative permeability curve of the medium-high permeability reservoir (105).

The invention relates to the technical field of tobacco leaf detection, in particular to a tobacco leaf oil content quantitative characterization method. The method comprises the following steps: measuring state information of protons in a tobacco leaf sample by using low-field nuclear magnetic resonance to obtain a spin-spin relaxation time T2 spectrum and a spin-lattice relaxation time T1 spectrum, and generating a T1-T2 two-dimensional spectrogram; determining peak positions of low-activity protons and medium-activity protons in the T1-T2 two-dimensional spectrogram to obtain T2 values of the low-activity protons and the medium-activity protons, and solving an average T2 value of the low-activity protons and the medium-activity protons of the plurality of groups of tobacco leaf samples; on the spin-spin relaxation time T2 spectrum of the tobacco leaf sample to be detected, the low-activity proton peak intensity and the medium-activity proton peak intensity of the tobacco leaf sample to be detected at the average T2 value are obtained, and the ratio of the low-activity proton peak intensity to the medium-activity proton peak intensity serves as the oil content quantitative value of the tobacco leaf sample to be detected. According to the method, nondestructive testing of the tobacco leaf raw material oil content is realized by utilizing a low-field nuclear magnetic technology, and quantitative characterization of the tobacco leaf raw material oil content is realized by combining the T1-T2 two-dimensional spectrogram.

The invention discloses a method for researching an MOF (Metal Organic Framework) synthesis process by utilizing a low-field nuclear magnetic imaging device, and belongs to the technical field of material synthesis process analysis. The method comprises the following steps: firstly, preparing a metal source solution and an organic ligand solution; one of the solutions is selected for low-field nuclear magnetic resonance relaxation time measurement, and imaging sequence parameters are optimized; mixing the two solutions, and immediately putting the mixed solution into a low-field nuclear magnetic imaging device; and carrying out continuous relaxation time weighted imaging and layered relaxation time measurement on the reaction process by using the optimized imaging sequence. The lossless, in-situ, visual and quantitative monitoring of the metal-organic framework material in the nucleation, growth and sedimentation process is realized by analyzing the change of image signal intensity in time and space and the change trend of relaxation time (such as T2 value) of different liquid layers along with time. According to the method, required equipment is simple, operation is convenient and fast, and an innovative research means is provided for deeply understanding the MOF synthesis mechanism and optimizing the synthesis process.

This application relates to the field of reservoir exploration technology, specifically to a method, device, storage medium, and electronic equipment for quantitative characterization of pore size across all scales, including: performing nuclear magnetic resonance analysis on the shale to be tested, obtaining the nuclear magnetic resonance T2 spectrum of the shale to be tested, and establishing a cumulative T2 probability curve; according to the formula r c =CT2 yields the pore size r corresponding to the T2 value with the same cumulative content. c Where C is the conversion coefficient; a cumulative pore size probability curve is established based on the pore size value and the corresponding cumulative content. This application can solve the problem of unclear pore size distribution in continental shale at all scales due to strong heterogeneity, and achieve quantitative characterization of pore size at all scales while avoiding damage to the shale under test.

The invention discloses a multi-parameter magnetic resonance quantitative imaging method and system, and relates to the technical field of MRI (magnetic resonance imaging), and the method comprises the steps: employing a multi-overlap echo sequence XMOLED, carrying out the simulation of magnetic resonance simulation software, and generating a simulation XMOLED image, constructing a simulation data set composed of a large number of paired simulation XMOLED images, simulation T2, T2 * and an apparent diffusion coefficient (ADC) quantitative graph, and training a deep learning neural network used for reconstruction of the magnetic resonance parameter quantitative graph; sequence parameters are configured on a magnetic resonance imaging instrument, an XMOLED signal of an actual imaging object is collected, and an XMOLED image of the actual imaging object is obtained through signal processing; and inputting the XMOLED image of the actual imaging object into the trained magnetic resonance parameter quantitative graph reconstruction network for reconstruction to obtain T2, T2 * and ADC quantitative graphs of the actual imaging object. According to the method, T2, T2 * and ADC quantitative diagrams can be obtained at the same time only through single-sequence XMOLED collection, the problem that scanning time is prolonged due to multi-sequence combined imaging is solved, and rapid and accurate multi-parameter quantitative magnetic resonance imaging is achieved.

The application discloses an infant brain T2 weighted magnetic resonance imaging optimization method based on a fast spin echo sequence. First, T1, T2 and PD quantitative imaging of the infant brain from 0 to 24 months old is collected to obtain T1, T2 and PD values of the infant brain white matter and gray matter regions, and according to the relationship characteristics of the infant brain white matter T2 value and the gray matter T2 value, the infant is divided into different month groups. Then, based on the 3D T2 weighted imaging of the variable flip angle fast spin echo sequence, the signal intensity of the infant brain white matter and gray matter under different refocusing flip angle chains is calculated through an extended phase graph algorithm, and the best flip angle chain design scheme of each group is determined with the maximum white matter / gray matter contrast as the target. The application fills the blank of the infant brain T2 weighted imaging optimization, formulates the best flip angle chain optimization scheme of different month groups, and thus significantly improves the contrast of the infant brain T2 weighted imaging.

The invention discloses a method and a device for determining oil-water relative permeability information of a medium-high permeability reservoir, and relates to the technical field of oil and gas reservoir development, the method comprises the following steps: acquiring nuclear magnetic resonance T2 spectrum information of the medium-high permeability reservoir in multiple states; determining pore distribution and oil phase distribution according to the nuclear magnetic resonance T2 spectrum information in multiple states; dividing an oil-water movable space in multi-state nuclear magnetic resonance T2 spectrum information by utilizing pore distribution and oil phase distribution of the medium-high permeability reservoir and combining a wetting type of a core of the medium-high permeability reservoir; according to the nuclear magnetic resonance T2 spectrum information of the medium-high permeability reservoir in multiple states, the corresponding relation between the normalized saturation of the oil-water movable space and the T2 value is determined; and determining an oil-phase relative permeability curve and a water-phase relative permeability curve of the medium-high permeability reservoir according to the corresponding relationship between the normalized saturation of the oil-water movable space and the T2 value. The problem that the oil-water flow rule cannot be considered when the existing relative permeability curve is determined can be solved.

A validation technique for quality assurance of quantitative MRI methods compares the measured magnetic properties of a phantom over a range of T1 and T2 values ​​measured by a clinically feasible acceleration protocol with predicted values ​​for that magnetic properties calculated from a set of reference T1 and T2 values ​​measured on the phantom. The prediction is based on the relationship between the values ​​from the acceleration protocol and the values ​​from reference measurements obtained by repeated scanning of one or more phantoms.

The present invention belongs to the technical field of oil and gas reservoir evaluation and development research, and discloses a method for calculating the T2 cutoff value based on saturation nuclear magnetic resonance experiment: obtaining the saturation / imposed water nuclear magnetic resonance T2 spectrum curve of a tight sandstone sample; determining the T2 cutoff value based on the saturation / imposed water nuclear magnetic resonance cumulative porosity curve, which is recorded as T 2‑Cutoff ; Obtain the saturated NMR T2 spectrum logT2-logφ intersection curve, and the T2 value corresponding to the inflection point of the curve is recorded as T 2‑Log ; Determine T 2‑Log and T 2‑Cutoff The mathematical relationship between the two is used to establish a T2 cutoff value calculation model based on saturated nuclear magnetic resonance experiments. The present invention only requires performing a nuclear magnetic resonance experiment on a saturated water sample and calculating the T2 cutoff value by mathematically processing the T2 spectrum. This method has the advantages of being economical, simple, efficient, and highly practical.

The invention relates to the field of nuclear magnetic resonance imaging, and particularly discloses a phantom for nuclear magnetic resonance T1 rho sequence and T2 mapping sequence and a manufacturing method thereof, the phantom is a set of phantom composed of nine sub-phantoms, and each sub-phantom comprises the following raw materials: 0-0.4 g of proteoglycan powder, 0.1-0.7 g of agarose powder, 0-0.01 g of a preservative and 20 ml of double distilled water. The invention provides a phantom for a nuclear magnetic resonance T1 rho sequence and a nuclear magnetic resonance T2 mapping sequence and a manufacturing method of the phantom, a series of phantom with different proteoglycan and agarose concentrations are constructed, and a tool is provided for calibration of a T1 rho value and a T2 value between different magnetic resonance scanning devices.

The application discloses a kind of optimization nuclear magnetic resonance well logging parameter method, system, storage medium and electronic equipment, the method comprises the following steps: obtaining T2 value and corresponding amplitude value of nuclear magnetic resonance well logging different time points to obtain T2 spectrum;By searching the T2 spectrum, T2 cutoff value that meets preset condition is obtained;Based on each T2 value and the T2 cutoff value, the denoising coefficient distribution is obtained by calculation;Based on each T2 value and the denoising coefficient distribution, the T2 spectrum after denoising is obtained by second calculation formula.The method provided by the application uses the T2 spectrum after accurate denoising to calculate porosity, movable fluid volume and permeability, improves the accuracy and effectiveness of reservoir parameter evaluation, and is beneficial to the drilling of oil well.

The embodiment of the invention provides a nuclear magnetic resonance logging T2 spectrum borehole expanding correction method and device, equipment and a medium. The method comprises the steps that a slurry filtrate T2 value is determined according to the morphological change relation of a borehole diameter curve and a nuclear magnetic resonance logging T2 spectrum; re-inverting the measured echo string based on the T2 value of the slurry filtrate, and calculating the porosity Pmf of the slurry filtrate; calculating a corrected echo string of the slurry filtrate according to the T2 value of the slurry filtrate and the porosity Pmf of the slurry filtrate; and performing inversion on the corrected echo string, and calculating the corrected T2 spectrum of the mud filtrate. In the embodiment of the invention, the T2 value and the porosity of the slurry filtrate are determined by utilizing the change relationship between the hole diameter curve and the nuclear magnetic resonance logging T2 spectrum, and the T2 spectrum is corrected to eliminate the influence of the slurry filtrate, so that a more accurate T2 spectrum is provided for logging interpretation personnel to be used for interpretation and evaluation of a logging reservoir, and the interpretation and evaluation precision of nuclear magnetic logging is improved.

The invention discloses a shale reservoir fluid fluidity and productivity characterization method, device and equipment and a medium, and relates to the technical field of oil and gas field exploration and development, nuclear magnetic resonance T1-T2 experimental measurement and inversion are performed on a core sample to obtain a nuclear magnetic resonance T1-T2 spectrum, and the T1 value and T2 value of each spectrum peak in the nuclear magnetic resonance T1-T2 spectrum are determined; constructing an inversion objective function based on the T1 value and the T2 value by using a nuclear magnetic resonance relaxation theory model, and solving the objective function to obtain the optimal translational diffusion correlation time of each spectrum peak; determining a fluid type corresponding to each spectrum peak based on the optimal translation diffusion correlation time; calculating the average translational diffusion correlation time and saturation of each single-phase fluid; carrying out shale reservoir fluid fluidity characterization on the core sample by utilizing the average translational diffusion correlation time of each single-phase fluid; the productivity index is calculated, shale reservoir productivity characterization is carried out on the core sample, and rapid, accurate and non-destructive characterization of the oil phase and water phase flowability and productivity of the shale reservoir is achieved.

The present invention discloses a method for characterizing the full-aperture pore size of shale based on a gravimetric method and combined NMR measurement. The method comprises: plotting a curve of the pore distribution frequency of a rock sample versus pore diameter; calculating the water-saturated porosity of the rock sample based on the weight of the rock sample after drying and the weight of the rock sample after saturation; converting the nuclear magnetic resonance signal of the nuclear magnetic resonance T2 spectrum of the rock sample after saturation into porosity components based on the water-saturated porosity of the rock sample; plotting a curve of the porosity components and the cumulative porosity value of the rock sample after saturation versus relaxation time T2 based on the porosity components; calculating a spatiotemporal conversion coefficient between the NMR relaxation time T2 value and pore size; and plotting a full-aperture pore size result diagram of the rock sample after saturation based on the curve of the porosity components and the cumulative porosity value of the rock sample after saturation versus relaxation time T2 based on the spatiotemporal conversion coefficient. The multiple combined measurement methods eliminate the phenomenon of pore size measurement range overlap, and the obtained full-aperture pore size result is more accurate.