14 results about "Synthetic seismogram" patented technology

The present application relates to oil and gas geophysical exploration technology field, specifically disclose a kind of tight sandstone gas reservoir fluid mobility gradient attribute prediction method and system, the method includes constructing fluid mobility term's reflection coefficient expression, and deduce the formula for calculating fluid mobility using dispersion attribute, construct and frequency and seismic wave incidence angle related fluid mobility gradient attribute;Establish double-pore petrophysical model, generate synthetic seismogram, apply frequency-variable AVO inversion to the synthetic seismogram, extract bulk modulus dispersion attribute and shear modulus dispersion attribute;Fluid mobility changing with frequency and incidence angle is calculated, based on gradient attribute calculation formula and fluid mobility, fluid mobility gradient attribute is calculated.The present application makes full use of the response of the seismic wave dispersion and attenuation caused by permeability and gas saturation, constructs the seismic gradient attribute and calculation method of fluid mobility, realizes the high-precision prediction of fluid mobility by applying the elastic and dispersion petrophysical information of seismic signal.

The present invention provides a method for correcting acoustic wave curves under the condition of complex borehole diameter enlargement, including: Step 1, analyzing the relationship among formation intervals, lithology and borehole diameter enlargement; Step 2, analyzing the relationship between acoustic wave curves and borehole diameter enlargement, and finding wells and formation intervals with small borehole diameter enlargement as correction references; Step 3, confirming the range of abnormal influence of borehole diameter enlargement on acoustic waves and the correction amount of acoustic wave curves; Step 4, correcting the acoustic wave abnormal area, and comprehensively judging the rationality of the correction by using three methods, namely, the correlation between synthetic seismogram and seismic data, the correlation between seismic trace gather and forward modeling trace gather, and the consistency of calibration of multi-well standard reflection layers. The method for correcting acoustic wave curves under the condition of complex borehole diameter enlargement has strong operability, clear and reliable verification means, improves the reliability of acoustic wave curve correction under the condition of complex borehole diameter enlargement, and ensures the solid foundation for seismic reservoir prediction and seismic reservoir description research.

The invention belongs to the technical field of oil-gas exploration, and provides a method for predicting the minimum horizontal principal stress of a shale gas reservoir. Comprising the following steps: performing multi-term optimization on an original shot record to obtain a pre-stack OVT gather and post-stack time migration data; after the pre-stack OVT gathers are stacked, performing energy compensation and de-noising processing to obtain a sub-azimuth pre-stack gather satisfying inversion; calculating a correlation coefficient, extracting wavelet and reflection coefficient convolution to obtain a synthetic seismic record, and comparing to obtain a calibration result time-depth relationship; interpreting the top and the bottom of the shale reservoir to obtain a horizon interpretation result; preprocessing logging data and calculating shear wave velocity and anisotropy parameters; and Young modulus, a Poisson ratio curve and a fracture density curve are calculated, a low-frequency model is constructed, and inversion is carried out to obtain related parameters. And calculating a vertical principal stress logging curve, and introducing AVF inversion to obtain vertical principal stress. The minimum horizontal principal stress is solved, and the shale reservoir crustal stress characteristics are evaluated. According to the method, more accurate and efficient minimum horizontal principal stress prediction is realized.

The application provides a stratum overlap line identification method based on a NEWS system and a storage medium. The identification method comprises the following steps: collecting logging data of all wells in a study area, and performing single-well geology comprehensive interpretation on a target well section in the study area; performing synthetic seismogram calibration on the target well section in the study area, and determining an accurate position of a target layer; establishing a reservoir development mode and a main control factor of the target layer through multi-well stratum correlation analysis; and comprehensively identifying and depicting an overlap boundary through fine structure interpretation. The application provides a stratum overlap line identification method and process based on the NEWS system, which can improve the description precision of the overlap line, and can also fully utilize the geophysical software product with independent intellectual property rights to improve the stratum overlap line identification efficiency.

The application discloses a kind of wideband seismic result data vertical resolution quantitative evaluation method, S1: determining the main frequency and frequency width of the target layer in seismic result data;S2: according to the main frequency of target layer, build wideband zero-phase wavelet;S3: according to the frequency width of target layer, band-pass filter is carried out to wideband zero-phase wavelet, and form band-limited zero-phase pseudo seismic source wavelet;S4: build wedge formation model;S5: using band-limited zero-phase pseudo seismic source wavelet and wedge formation model carries out wave field forward modeling, generates synthetic seismogram profile;S6: from seismic wavelet and seismic record two aspects, carry out seismic vertical resolution analysis.The present application can be used for marine natural gas hydrate and oil and gas seismic data, because the influence of frequency width is considered, the vertical resolution of seismic wavelet and seismic record can be accurately quantitatively evaluated.Provide resolution index for seismic exploration effect evaluation, also provide method means for carrying out the main influencing factor and law of seismic vertical resolution.

The present application provides a kind of quick broadband controllable seismic source viscoelasticity forward method, the quick broadband controllable seismic source viscoelasticity forward method includes: step 1: in controllable seismic source exciting point position loading pulse vertical force source function;Step 2: calculate the viscoelasticity equation Green function of controllable seismic source exciting point position;Step 3: according to the convolution broadband controllable seismic source function and viscoelasticity equation Green function generates the controllable seismic source record of the position excitation;Step 4: according to observation system, linear combination single shot synthetic seismogram, form combined shot controllable seismic source synthetic seismogram.The quick broadband controllable seismic source viscoelasticity forward method effectively reduces the calculation cost of long time record broadband viscoelasticity forward simulation, realizes high efficiency broadband controllable seismic source viscoelasticity forward simulation.The present application realizes controllable seismic source high-precision high-efficiency seismic simulation under complex geological conditions, provides important tool for controllable seismic source observation system design and analysis.

A method is described for reservoir structure characterization including obtaining well logs and seismic data; performing facies classification and stratigraphic sequencing on the well logs to identify a plurality of layers; estimating wavelets from the seismic data and using the wavelets to tie synthetic seismograms from well logs to the seismic data; determining a mean value for each elastic property in each layer of the well logs and assigning the mean value to each layer to generate blocky well logs; using the wavelets to attempt to tie synthetic seismograms from the blocky well logs to the seismic data; defining facies-dependent properties based on the blocky well logs; performing global optimization using the facies-dependent properties and the seismic data to find thicknesses of the layers across the volume of interest; and mapping the reservoir structure based on the global optimization to generate a graphical representation of the reservoir structure.

The application discloses a well-seismic error analysis method of depth domain seismic data, an electronic device and a medium. The method comprises the following steps: obtaining full-area time domain seismic data, depth domain seismic data, drilled well logging curve data and drilled well layered data; obtaining a time domain synthetic seismogram based on the time domain seismic data and the drilled well logging curve data; obtaining time domain seismic data wave group characteristic information corresponding to a target layer section according to the time domain synthetic seismogram; identifying the time domain seismic data wave group characteristic information on the depth domain seismic data, and reading corresponding underwater true vertical depth; obtaining well-up true vertical depth according to the drilled well layered data and the depth domain seismic data; and obtaining well-seismic error of the depth domain seismic data according to the underwater true vertical depth and the well-up true vertical depth. In this way, reliable well-seismic error can be obtained.

The present application relates to a kind of river channel sand body identification method and system, comprising: based on well seismic data and field outcrop data, the well-to-well velocity model of river channel sand body is established;Synthetic seismogram is formed by forward modeling to well-to-well velocity model, and the similarity of synthetic seismogram and the reflection characteristics of actual seismic record of river channel sand body is compared and analyzed, to predict the actual reservoir distribution of river channel sand body.The coincidence rate of the development of target sand body to be drilled predicted by the present application and actual drilling is high, at the same time, by comparing the reflection characteristics of synthetic seismogram and actual seismic, the possible lithology combination and distribution of target layer can also be obtained.The present application is fast, efficient, simple to operate, suitable for accurate prediction of reservoir in exploration stage, reservoir evaluation stage and early development stage, and can be widely applied in the field of oil exploration and development technology.

A direct well-tie method for depth-domain logging and seismic data, including: removing null and outlier values from logging velocity data and logging density data to obtain valid logging velocity data and valid logging density data; calculating a logging reflection coefficient; estimating an initial zero-phase depth-domain seismic wavelet from seismic section; making a depth-domain synthetic seismogram; interpolating the depth-domain seismogram at the logging location; performing cross-correlating operation between the depth-domain synthetic seismogram and the interpolated depth-domain seismogram at the logging location; estimating a depth-domain seismic wavelet; updating the depth-domain synthetic seismogram; generating a corresponding depth deviation point set; subjecting elements in the set to interpolation to obtain a depth calibration curve; subjecting the depth calibration curve and depth axis to addition to obtain depth axis; generating a logging depth-seismic depth corresponding relationship and a depth-domain seismic wavelet.

A method is described for seismic inversion with uncertainty quantification including performing low frequency Markov Chain Monte Carlo (MCMC) processes on rock physics models to generate low frequency models (LFMs) of rock properties and training a deep neural network using the low frequency models and synthetic seismograms to generate a trained neural network. Given a seismic dataset, the trained neural network can generate a high frequency rock property model and then broad-band MCMC processes can be performed on the high frequency rock property model for uncertainty quantification. The method is executed by a computer system.

Certain aspects of the disclosure provide a method that comprises filtering a greyscale image with a seismic spectrum to produce an image footprint; grouping a masked image into object anomalies; smoothing the object anomalies to produce a synthetic geo-feature type image; imposing at least one of the image footprint or the synthetic geo-feature type image onto an initial velocity model to generate a final velocity model; and generating a synthetic seismic image from the final velocity model.

The present application relates to a kind of reservoir lithology boundary quantitative prediction method and system based on sand body mechanism model forward, it includes: the sand body mechanism model of typical well tie line is determined, the sedimentary microfacies type of target sand body is included, the development scale of different sedimentary microfacies and the combination relationship possibly existing in sedimentary microfacies is clear;Using well logging curve, petrophysical crossplot determines the petrophysical parameter corresponding to different sedimentary microfacies type, all drilled well information is simplified into single well sand body mechanism model, and the calibration relationship between actual seismic response and forward synthetic seismogram is obtained by seismic forward analysis;Establish the reservoir model of thickness and sedimentary microfacies combination multi-parameter variable, so that it can cover the various reservoir development conditions possibly in target sand body, set the reservoir parameter range corresponding to reservoir boundary, attribute threshold value corresponding to reservoir boundary is predicted according to calibration relationship;According to attribute threshold value, reservoir boundary is circled, and development horizontal well optimization is guided.The present application can be applied in oilfield development field.

The invention discloses a fluid saturation crack seismic wave scattering modeling method based on a virtual stress method, and belongs to the field of geophysical exploration. According to the technical scheme, a linearization fluid mechanics equation is used for describing fluid movement in a fracture, a Green function basic solution of a plane strain elastic wave problem is deduced, a boundary integral equation of fracture scattering is established in combination with a virtual stress method, numerical simulation is achieved, and a synthetic seismic map and a wave field snapshot are obtained. Compared with the prior art, the boundary element method is used for carrying out numerical simulation, so that the influence of viscous fluid saturation cracks in an infinite stratum on seismic wave dispersion and attenuation can be reflected more truly, and the limitation of finite volume numerical rock sample simulation is avoided; besides, a fluid mechanics equation is used for replacing a traditional method that a pore medium equation is used for describing the flowing behavior of fluid in the crack, the essence of physical problems is restored, and calculation errors caused by using a non-fluid equation to describe fluid dynamics behaviors are avoided. The method can be applied to the fields of geophysical exploration, petroleum logging engineering detection, underground complex environment monitoring and the like.