131 results about "Seismic processing" patented technology

Embodiments use seismic processing methods that account for the spatial variability of surface wave velocities. Embodiments analyze surface wave properties by rapidly characterizing spatial variability of the surface waves in the seismic survey data (302). Filtering criteria are formed using the spatial variability of the surface waves (204). The filtering criteria can then be used to remove at least a portion of the surface waves from the seismic data (206, 319). The rapid characterization involves estimating a local group velocity of the surface waves by cross-correlation of the analytic signals (302).

A method and visualization apparatus for spectral analysis of time-and-space varying signals enables high resolution investigation of 3D seismic data for the exploration of oil and gas. The method extrapolates multi-resolution short windows into an average long window then computes its FFT. Extrapolation uses the continuity relationship between data inside and outside of short windows. Applications of the method are illustrated with graphical screen 3D volume displays of amplitude spectra, dip and azimuth, curvature and faults (figure below). Aside from high resolution these displays improve the productivity of a seismic interpreter.

The invention belongs to seismic data processing in petroleum geophysical exploration and geological engineering survey, and relates to near-surface velocity modeling and static correction in seismic exploration aiming at research and development of a shallow velocity model required for combined post static correction in a detector chamber of single-point high-density seism. A method for establishing a near-surface velocity model in high-density seismic static correction processing comprises the following steps of: supposing that the near-surface velocity is linearly increased along with the depth, calculating refracted wave velocity of different geophone offset from the travel time difference of primary waves of adjacent detection points of the high-density seism according to the physical property of the primary wave of the near-surface velocity field, establishing a near-surface ramp velocity field parameter according to the relationship between the geophone offset and the refracted wave, and further establishing the near-surface velocity model which can be directly used for static correction quantity calculation in seismic processing and also can be used as an initial model for tomographic inversion of near-surface velocity. The method has high calculation speed, and does not depend on the change of the initial position caused by a seismic focus.

This invention relates to mapping the hydrocarbon reservoir characteristics by mapping the reservoir formations that display dynamic elastic nonlinearity responses to the seismic signals. The main reason of this nonlinear behavior in the reservoir rocks is their bulk rock property: the porosity, fractures, differential pressure and pore saturation. To map these bulk rock properties, the interaction of the two seismic waves as they propagate through elastically nonlinear rocks is recorded. Two compressional seismic signals are transmitted from the surface. Seismic reflection data using surface or borehole detectors are recorded. One of the transmitted signals is a conventional swept frequency and the other is a mono-frequency signal. During the propagation of these two signals through the elastically nonlinear reservoir rocks, there is an interaction between the two signals. The sum and difference frequencies of the two primary seismic signals that were transmitted from the surface are created. These new frequencies constitute an "interaction' wave that travels along with the two primary waves. In this invention, the "interaction' signal created by the two seismic waves as they propagate through the reservoir rocks is separated from the primary signals and used to map the reservoir rocks that exhibit elastic nonlinearity due their bulk rock properties. The cross-correlation of the recorded data with the swept frequency signal provides a conventional seismic data set that is used for normal 2-D or 3-D seismic processing. The cross-correlation of the recorded data with the summed and differenced signals provides two sets of data that represent the seismic reflected image from the subsurface nonlinear formations.

According to a preferred aspect of the instant invention, there is provided herein a system and method for improving the computational efficiency of the DMO transformation that has many uses in the seismic processing arts. More particularly, the instant inventor has conceived and invented a faster method of calculating a log-stretch DMO transformation that utilizes multiple independent time windows, each with its own starting and ending time. A particularly preferred usage of the improved DMO method is as an element of a multiple attenuation program such as SRME.

A method of constructing a basis of functions intended for the building of approximations of one-way or two-way seismic traveltime versus offset functions. The method is characterized by the combination of the following steps of (a) creating a distribution of reference one-way or two-way traveltime versus offset functions by traveltime modelling in a set of velocity models representing possible velocity distributions, (b) obtaining new reference functions by modifying these reference traveltime functions by applying an operator to them, (c) selecting a set of discrete offsets to make these new reference functions discrete, (d) arranging these discrete functions in columns to form a matrix, (e) applying a singular value decomposition to this matrix, with singular values sorted in decreasing order, to express its columns as linear combinations of the columns of an orthogonal matrix, and (f) building the basis functions by interpolating the columns of the orthogonal matrix.

There is provided herein a New system arid method of local attribute match filtering which operates in the local attribute domain via the use of complex wavelet transform technology. This approach is adaptable to address various noise types in seismic data and, more particularly, is well suited to reduce the noise in geophone data as long as an associated hydrophone signal is relatively noise-free.

The optimized design method of geological geophysical model based three-dimensional seismological observation system includes the following steps: A). creating geological geophysical model; B). designing two kinds of several kinds of observation systems with three-dimentional geological data acquisition; C). adopting imaginary spectrum method and combinatino of three-dimensional wave equation numerical analog and three-dimensional geophysical model analog two methods of implement data acquisitino work; D). using common-reflection point as basis, making depth deviation treatment of acquired data before superposition to obtain several kinds of imaging results of seismic treatment; and E). making comprehensive comparison and evaluation of imaging quality of said imaging results and defining one optimum seismic imaging result. The invention is extensive in application range, can obtain good effect for making seismic exploration of petroleum and natural gas.

According to a preferred aspect of the instant invention, there is provided herein a system and method for improving the computational efficiency of the DMO transformation that has many uses in the seismic processing arts. More particularly, the instant inventor has conceived and invented a faster method of calculating a log-stretch DMO transformation that utilizes multiple independent time windows, each with its own starting and ending time. A particularly preferred usage of the improved DMO method is as an element of a multiple attenuation program such as SRME.

Computing device, computer instructions and method for processing input seismic data d. The method includes receiving the input seismic data d recorded in a data domain, solving a linear inversion problem constrained by input seismic data d to obtain a model domain and its energy, wherein the linear inversion problem is dependent on sparseness weights that are simultaneously a function of both time and frequency, reverse transforming the model domain energy to the data domain, and generating an image of a surveyed subsurface based on the reverse transformed model domain energy.

The invention belongs to the technical field of sandstone-type uranium deposit exploration, and particularly discloses a sand body reorganization method in sandstone-type uranium deposit exploration. The method includes the following steps that (1) pure wave data of a seismic processing section are collected; (2) logging data of a drilling well nearby the seismic section are collected, and the abnormal contrast value of density and the abnormal contrast value of sound waves are calculated; (3) moving average processing is conducted on density data and sound wave data; (4) a seismic inversion calculation initial model is established through the density data, the sound wave data and the logging data after moving average processing in the step (3); (5) inversion calculation is carried out on wave impedance data of the seismic section through an inversion method based on the model, and the wave impedance data of the seismic section are acquired; (6) sand bodies in a sandstone-type uranium deposit area are determined according to the wave impedance data acquired in the step (5). By means of the sand body reorganization method in sandstone-type uranium deposit exploration, the development condition and the distribution feature of the sand bodies in sandstone-type uranium deposit exploration can be recognized accurately, rapidly and economically.

A method of assessing acquisition errors in seismic images in a seismic data volume. The method includes selecting a seismic attribute in a seismic data volume and then stacking seismic quality image measurements taken along the selected attribute. The stacked measurements are then related on the basis of any vertical correlation and any vertically correlated feature is identified as a cobweb. Any identified cobwebs are removed from the seismic data volume.

The invention provides a variable-offset VSP data time difference correction method and belongs to the field of earthquake data processing. The method includes the following steps: (1) decompiling acquired original variable-offset VSP data so that three-component wave field data is obtained; (2) inputting a shallow replacement speed V<replacement> and an earthquake processing base level elevation Z<base level>, which are used in processing of ground earthquake data of an area which a VSP observation well is in; (3) picking up first-arrival times of direct waves on vertical components z of offsets so that time-depth data T<0> (n, L<K>) is obtained; (4) calculating a time difference in a single offset; (5) calculating inter-offset time differences; (6) correcting a total time difference; (7) analyzing correction error; (8)ending. The method improves the original wave field quality of the variable-offset VSP data and provides accurate basic data for further effective application of the variable-offset VSP data.

The present invention relates to the technical field of seismic data processing, and in particular to a seismic data edge preserving smoothing method based on structural features, which performs targeted sub-region de-noising treatment based on the structural information of seismic data and the similarity information of the pre-filtering process. In addition to the random noise removal, the method effectively protects the boundary information of seismic data. The edge preserving smoothing method includes steps of smoothing the seismic data, decomposing the matrix to obtain the structure tensor of the seismic data, and completing the structural feature analysis of the seismic data; using the conventional de-noising method to filter the seismic data and obtaining the local similarity coefficient; building a guide filtering equation; and performing multiple de-noising iterations and other steps.

The invention relates to a beam orientation principle based suppression method for random noise in seismic single-shot records. Different time and space random noise in the single-shot records has randomness, and a beam orientation method is utilized to realize superposition of the random noise in different times and spaces. Strengthening of effective signals and weakening of the random noise are realized. The problem that the effective signals in the single-shot records are difficult to distinguish due to the fact that signal to noise ratio of single-shot random-noise seismic records is low is solved. For original single-shot data, different paths and the same path are different in random noise at different moments but identical in effective signal, and strengthening of signals in the single-shot records and superposition of the random noise in different times and spaces are realized by the aid of the beam orientation principle, so that the random noise in the single-shot records is lowered, the signal to noise ratio of the single-shot records is increased, quality of the original single-shot data is improved, and excellent seismic data are provided for subsequent seismic processing. The method can widely adapt to explosive source and controllable seismic-focus seismic exploration.

A seismic processing method to solve an eikonal equation to determine a travel time (t) of a sound wave between a seismic source at a first set of coordinates (x2,y2, z2) and a point underground at a second set of coordinates (x,y,z), comprising determining a distance between the seismic source and the point underground; obtaining a propagation time between the seismic source and the point underground; calculating a velocity variable (v) as a ration of the distance between the seismic source and the underground point divided by the propagation time between the seismic source and the point underground; and extrapolating on the velocity variable to obtain a travel time.

The invention relates to a method of seismic data processing, wherein the data includes a set of seismic traces, with each trace including a signal that has been recorded by a sensor after having been propagated in a subsurface area, with the signal being defined by an amplitude as a function of time, including the steps of:migration of data according to an initial time-velocity model,picking in the time-migrated data one or more event(s) corresponding to one or more subsurface reflector(s) so as to obtain facets locally approximating the event,kinematic demigration of the facets plotted so as to obtain simplified seismic data in the form of a set of facets and a set of attributes associated with the facets.

The invention relates to a method for improving a seismic processing signal to noise ratio and resolution ratio for geophysical exploration seismic data processing, comprising: determining the apparent velocity of the surface wave according to a single shot record; carrying out small time window and space window division on the single-shot seismic record data; carrying out linear energy dip angle scanning on the divided space window; selecting the dig angle of the strongest linear energy; when the speed corresponding to the line of the maximum value of the amplitude quadratic sum is between the maximum apparent velocity and the minimum apparent velocity of the surface wave, attenuating because of determining as the surface wave; and otherwise, carrying no attenuation because of determining as the effective signal. The linear energy scanning method favorably separates the surface wave and the effective signal, and then the surface wave is attenuated to protect the effective signal; meanwhile, the purpose of improving the signal to noise ratio and the resolution ratio in the seismic data processing can be realized; and surface wave attenuation performance is improved.

A method for identification and prediction of a fore-land basin extremely-thick conglomerate body belongs to the technical filed of petroleum and natural gas exploration and development. The method comprises the following steps: the step 1) determining electrical characteristics of a gravel layer; the step 2) determining the characteristics of gravel layer seismic horizon and seismic facies; the steps 3) carrying out electrical profile and earthquake depth profile superposition; and the step 4) carrying out gravel layer lithology and lithofacies space identification. The beneficial effects of the method are that gravel layer distribution range, lithology and lithofacies vertical and horizontal distribution rules and the like, which restrict fore-land basin oil and gas exploration and development at each geological time in the fore-land basin can be determined; speed traps caused by the gravel layers can be eliminated to the maximum degree; the earthquake processing imaging speed is allowed to be more accurate; seismic data quality reaches a new level; entrapment implement precision is improved greatly; and well exploration success rate can be further improved.

A method of processing seismic data using a seismic energy propagation model of the subsurface is disclosed. The method assigns seismic source, seismic receiver, and reflection point locations to the propagation model; identifies a plurality of alternative raypaths consistent with the propagation model that originate at said seismic source location, reflect at said reflection point location, and terminate at said seismic receiver location; selects a raypath from the plurality of alternative raypaths having a shortest ray length, and utilizes the selected raypath in subsequent seismic processing.

A method for obtaining enhanced seismic data and optimized inverted reflectivities includes computing statistical well characterizations based upon band-limited well reflectivities for a subsurface region. Sets of processed seismic data are computed by applying differing processing sequences to seismic data corresponding to the subsurface region. Inverted reflectivities are computed by inverting the sets of processed seismic data. Statistical seismic characterizations are computed based upon the inverted reflectivities. Statistical difference measurements (SDMs) are computed between the statistical well and seismic characterizations. An optimal processing sequence is selected based upon the computed SDMs. Enhanced seismic data is obtained by processing the seismic data corresponding to thesubsurface region. An optimal seismic inversion algorithm is obtained based upon the computed SDMs. The seismic data is inverted using the optimal seismic inversion algorithm to produce a set of optimized inverted reflectivities.

A seismic processing method of the migration type, comprising the steps of:linearly combining downgoing waves generated at a plurality of shotpoints, and also upgoing waves recorded by a plurality of seismic sensors;notionally propagating the composite waves as obtained in this way in order to obtain migrated downgoing and upgoing waves for different depths; anddetermining at a plurality of depths at least one characteristic of the subsoil as a function of the upgoing and downgoing waves propagated in this way;the downgoing (resp. upgoing) composite waves being calculated by a linear combination of downgoing (resp. upgoing) waves in which said downgoing (resp. upgoing) waves are weighted by the coefficients of a spatial modulation matrix which is a function of the positions of the shotpoints.

The invention discloses a method for extracting a converted wave angle channel set for improving the speed and precision of calculating the converted wave incidence angle in the earthquake process. A channel set, the converted wave speed and aeolotropy parameters of a converted wave are utilized for calculating the speed, the aeolotropy parameters of a longitudinal wave, the longitudinal shot-geophone distance corresponding to the converted wave shot-geophone distance, the converted wave travel time of the aero shot-geophone distance, the longitudinal wave travel time and the interlayer longitudinal wave speed, wherein the channel set is formed through longitudinal wave incidence converted wave data and transverse wave reflection converted wave data, the amplitude of the channel set changes along with the offset distance, and the normal difference of the channel set is corrected. The converted wave incidence angle theta is calculated according to the longitudinal wave time difference equation and the interlayer longitudinal wave speed, and the incidence angle of each sampling point is calculated, wherein each sampling point is placed on the angle channel of the incidence angle. The process is carried out repeatedly for all sampling points to obtain the converted wave angle channel set. According to the method, the calculation is easy to conduct, and the speed and precision of extracting the converted wave angle channel set can be improved.

Implementations of various technologies for processing seismic data. In one implementation, the seismic data may be processed by creating a fictitious source-receiver line connecting a source with a receiver location of interest, projecting one or more receiver locations adjacent the receiver location of interest onto the fictitious source-receiver line and decomposing seismic data on the receiver locations disposed on the fictitious source-receiver line into up-going wavefields and down-going wavefields.

The invention discloses a seismic processing multi-core heterogeneous parallel mode adaptive matching general computation module. According to the model, a corresponding multi-core heterogeneous parallel algorithm is designed by analyzing the multi-core heterogeneous parallel calculation target problem; the parallel algorithm is interpreted into a parallel function based on different software and hardware architectures through an interpreting system, in addition, a software and hardware general parameter base of the current system is referred, and the system processing efficiency is improved; by aiming at different multi-core heterogeneous software and hardware interfaces, developers realize corresponding parallel program programming; parallel programs are compiled into machine languages through a corresponding compiler, and are operated on the corresponding multi-core heterogeneous software and hardware architectures. The computation module provided by the invention has the advantages that the development difficulty of the developers is simplified, and in addition, the portability and the expandability of the model are improved through expanding and updating a multi-core heterogeneous general parameter base and an algorithm base.

The invention relates to a method for processing relevant / stack data in seismic prospecting, comprising the following steps: (1) hybrid algorithm combining fast Fourier transform algorithm and Hartley transform characteristics; (2) segmentation and summation in the FTT-Hartly hybrid algorithm; (3) threading arrangement of multi-core and multi-CPU parallel processing, wherein testing through an IBM 3755 server (4-core) leads to the following indicators: when no noise control is loaded, 2 milliseconds for sampling rate, 24 seconds for scanning signal, 32 seconds for seismic acquisition; when 8-second record length is obtained after the relevance / stack computation is carried out, time is no more than 3 seconds in case of processing 4000 courses and the time is no more than 4 seconds in case of processing 8000 courses; when noise control part is loaded(segmentation weight stack), time for computing 8000 courses ( record length of each course is different from the record length of the previous course) is no more than 7 seconds.

Seismic processing method, in which, in order to eliminate multiple reflections on seismic data, seismic data are migrated in time or in depth (110) arid the data thus migrated are processed to determine an approximation of multiple reflections to be subtracted from, seismic data (120 to 160).

There is a method of seismic data processing that includes receiving seismic data that includes a set of seismic traces, each trace including a signal recorded by a sensor after having been propagated in a subsurface area; migrating the seismic data according to a first velocity model; picking from the time-migrated seismic data one or more events corresponding to one or more subsurface reflectors so as to obtain a set of facets locally approximating the event; kinematic demigrating the picked set of facets so as to obtain simplified seismic data that includes the set of facets and a set of attributes associated with the set of facets; migrating the set of facets based on a second velocity model; and updating the initial velocity model based on an alignment of migrated points within the set of facets.