Abstract: Hydrocarbon exploration and extraction can be facilitated by determining fault surfaces from fault attribute volumes. For example, a system described herein can receive a fault attribute volume for faults in a subterranean formation determined using seismic data. The fault attribute volume may include multiple traces with trace locations. The system can determine a set of fault samples for each trace location. Each fault sample can include fault attributes such as a depth value, an amplitude value, and a vertical thickness value. The system can determine additional fault attributes such as a dip value and an azimuth value for each fault sample of each trace location. The system can determine fault surfaces for the faults using the fault samples and fault attributes. The system can then output the fault surfaces for use in a hydrocarbon extraction operation.

Abstract: Systems and methods for generating an interference prediction for a target well are disclosed herein. A computing system generates a plurality of interference metrics for a plurality of interference events. For each well, the computing system generates a graph based representation of the well and its neighboring wells. The computing system generates a predictive model using a graph-based model by generating a training data set and learning, by the graph-based model, an interference value for each interference event based on the training data set. The computing system receives, from a client device, a request to generate an interference prediction for a target well. The computing system generates, via the predictive model, an interference metric based on the one or more metrics associated with the target well.

Abstract: A system for searching for underground entities in ground of an area, including a search probe configured to generate and deliver an acoustic signal into the ground of the area, wherein the acoustic signal uses a low frequency signal so that wavelengths of the acoustic signal are between 0.01-500 times the depth to the sought underground entity, two or more sensors positioned on the ground at about an equal distance from the search probe at different angles, an analysis device that receives measurements from the two or more sensors in the form of a measured echo signal responsive to the delivered acoustic signal, wherein said analysis device designates pairs of sensors and subtracts their echo signals to identify a difference indicating the existence of an underground entity.

Abstract: A method of detecting an event within a wellbore includes obtaining a sample data set, determining a plurality of frequency domain features of the sample data set, comparing the plurality of frequency domain features with an event signature, determining that the plurality of frequency domain features matches the thresholds, ranges, or both of the event signature, and determining the presence of the event within the wellbore based on determining that the plurality of frequency domain features match the thresholds, ranges, or both of the event signature. The sample data set is a sample of an acoustic signal originating within a wellbore including a fluid. The sample data set is representative of the acoustic signal across a frequency spectrum. The event signature includes a plurality of thresholds, ranges, or both corresponding to the plurality of frequency domain features.

Abstract: A method for spectral analysis of seismic data obtains imaged seismic data and generates orthogonally shifted imaged seismic data gathers. The orthogonally shifted imaged seismic data gathers are processed to generate a spectrally processed imaged seismic data. Alternatively, the imaged seismic data are obtained using a spectral processing filter that is a function of a magnitude of a total wavenumber of the imaged seismic data in three dimensions and a spatially variable velocity function.

Abstract: Device, medium and method for generating a multidimensional image of a subsurface of the earth. The method includes receiving data related to the subsurface of the earth; generating an ensemble of realizations associated with the subsurface based on the received data; applying wavelet re-parameterization to spatial properties of the members of the ensemble to calculate a set of wavelet coefficients; reconstructing the spatial properties of the ensemble based on a subset of the wavelet coefficients; applying a forward simulator to the reconstructed spatial properties of the ensemble for estimating one or more physical parameters of the subsurface; applying an ensemble-based optimization method to update the subset of the wavelet coefficients; and generating multidimensional image of the subsurface based on the updated subset of the wavelet coefficients.

Abstract: A method for using microseismic data during an injection or perforation event includes injecting fluid or perforating a well to create cracks in the formation. Microseismic data is obtained from the formation and forward modelling source parameter estimations are performed using a full moment tensor space source model and a double-couple source model. Likelihoods of the microseismic data are calculated for each model type by forward modelling synthetic data from a sampled source parameter probability distribution derived from each estimation, and by comparing the synthetic data with the microseismic data. The likelihoods are marginalized over prior probabilities for the source models, and Bayesian inference converts the likelihoods and prior probabilities to posterior probabilities. The posterior probabilities for the full tensor space and double-couple source models are compared to reveal whether an event is a fracture opening, fracture closing, or a slip on a fault plane.

Abstract: The present disclosure discloses a fracture AVO inversion method for a fractured medium, wherein, said method includes: acquiring seismic data from the fractured medium; obtaining a reflection coefficient of the fractured medium, by an AVO inversion for the seismic data based on a newly-built equation. The present disclosure also provides a fracture AVO inversion apparatus and device for a fractured medium. The present invention can flexibly and accurately obtain properties of a fractured medium with impedance contrast (rock properties of the host media plus properties of thee fracture).

Abstract: A method is described for high-resolution seismic imaging of complex subsurface volumes using a two-stage least-squares reverse time migration with two objective functions. A traveltime misfit objective function enables long-wavelength imaging and an amplitude misfit objective function enables short-wavelength imaging. The method may be executed by a computer system.

Abstract: Methods and apparatus for characterizing a subterranean formation traversed by a wellbore including collecting data from the formation using a tool wherein the tool collects data to form an azimuthal image, characterizing a section of the formation comprising data and images acquired in a high angle wellbore section or horizontal wellbore section using a parametric model, and performing an inversion using apparent densities and volumetric photoelectric factor images to build a formation model wherein the inversion is tailored for high angle wellbore sections and/or horizontal wellbore sections.

Abstract: A method includes the steps of receiving a wavefield generated by reflections in a subsurface region and recorded by a plurality of seismic receivers and compensating the recorded wavefield for amplitude attenuation. The method further includes modelling a propagation of a source wavefield forward in time, from an initial time-state to a final time-state through an earth model that is representative of the subsurface region, wherein the modelling includes phase and amplitude effects of attenuation and modelling a propagation of the compensated recorded wavefield backward in time from a final time-state to an earlier time-state through the earth model, wherein the subsurface region has an absorption characteristic that dampens the recorded wavefield wherein the modelling includes phase and amplitude effects of attenuation.

Abstract: Time lapse or 4D seismic data are corrected for geologic overburden and seismic recording system effects. The data from a survey at one time of interest is processed within a selected frequency band and the reservoir level is normalized by the overburden. The results are used to extract reservoir amplitudes from the data of that same survey. Frequencies where overburden signal-to-noise ratios vary dramatically between time lapse surveys may then be avoided in processing of data from the area of interest.

Abstract: Methods and systems for separating P-S wave field data are described. Slowness values for the PP mode and the PS mode are estimated and are, typically, unequal based on aliased and/or irregularly sampled data. A calculation, in the space-time domain, based on a matrix of equations, generates separated P-wave and S-wave data. The separated P-wave data and S-wave data are output for further imaging.

Abstract: Apparatus and methods for characterizing the physical state of a barrier installed in a borehole traversing a formation including locating an ultrasonic tool with a plurality of spaced receivers and a transmitter at a location in the borehole, activating the ultrasonic tool to form ultrasonic waveforms, wherein the spaced receivers record the ultrasonic waveforms, aligning the transmitter and the spaced receivers, wherein the ultrasonic waveforms comprise propagated Lamb modes, processing the ultrasonic waveforms to obtain a first amplitude dispersion plot of attenuation as a function of frequency and first phase dispersion plot of phase velocity as a function of frequency, processing attenuation dispersions to identify discontinuities, and relating the discontinuities to barrier wavespeeds.

Abstract: A method for locating diffractors in subsurface formations includes actuating at least two seismic energy sources at spaced apart locations. Seismic energy is detected in the formations resulting from actuation of the two sources. Signals corresponding to the detected seismic energy are processed to remove components related to direct arrivals from each source. Arrival times of seismic energy in the signals corresponding to energy diffracted from at least one diffractor are identified. The at least one is located diffractor in a plane using the identified arrival times.

Abstract: A system and method of characterizing properties of a medium from a non-linear interaction are include generating, by first and second acoustic sources disposed on a surface of the medium on a first line, first and second acoustic waves. The first and second acoustic sources are controllable such that trajectories of the first and second acoustic waves intersect in a mixing zone within the medium. The method further includes receiving, by a receiver positioned in a plane containing the first and second acoustic sources, a third acoustic wave generated by a non-linear mixing process from the first and second acoustic waves in the mixing zone; and creating a first two-dimensional image of non-linear properties or a first ratio of compressional velocity and shear velocity, or both, of the medium in a first plane generally perpendicular to the surface and containing the first line, based on the received third acoustic wave.

Abstract: Methods and devices for seismic data processing deblend seismic data gathered using simultaneous source acquisition by applying two different deblending techniques. The second deblending technique is applied to residual data obtained after applying the first deblending technique. At least one of these first and second deblending techniques uses a signal-to-noise map.

Abstract: Seismic stratigraphic features may be enhanced using orientation vectors. In one example, a process includes converting a seismic attribute section from a spatial domain to a spatial-frequency domain using a Fourier transform. For each filter in an orientation filter array, the seismic attribute section is convolved with a filter in the spatial-frequency domain. The convolution result is converted back to the spatial domain by inverse Fourier transform. For each point in the seismic section an orientation filter having a response with a maximum energy is found and the orientation is associated with the corresponding energy and the corresponding point.

Abstract: A technique includes receiving seismic data acquired in a seismic survey. The technique includes determining a geophysical trend of trace amplitudes indicated by the seismic data based on non-linear regression and performing quality control analysis on the seismic data based on the determined trend.

Abstract: The invention concerns a method of acquiring vibroseismic data concerning a zone of the subsoil. This method comprises the following steps: —operating a vibroseismic source so that it transmits a first vibroseismic signal having a first amplitude (101, 201), —operating the source so that it transmits a second vibroseismic signal having a second amplitude different from the first amplitude (103, 203), —recording first data corresponding to the first signal after propagation in the medium to be explored (102, 202), —recording second data corresponding to the second signal after propagation in the medium to be explored (104, 204). The method supplies information for filtering the surface waves (ground roll).

Abstract: A method and apparatus for correcting an input seismic trace. The method includes receiving the input seismic trace and creating a t by Q gather using the input seismic trace, where t represents traveltime, Q represents absorption parameter, and the t by Q gather has traveltime as the vertical axis and a ratio of t and Q as the horizontal axis. The ratio of t and Q is referred to as R. The method further includes applying an interpolation algorithm to the t by Q gather to derive a corrected input seismic trace.

Abstract: A microseismic monitoring system includes a seismic sensor positioned proximate to a wellbore traversing a formation; an orientation source producing an orientation shot; a hydraulic apparatus operationally connected with the formation to produce a fracture in the formation; a computer control system operationally connected with a database of known spectral attributes for event categories; and a computer readable medium that carries instructions executable by the computer control system that, when executed: receive data from the seismic sensor; select an event of interest from the data received; determine a spectral estimate of the selected event of interest; compare the determined spectral estimate of the selected event of interest to the known spectral estimates; and select from the data received by the seismic source the orientation shot for orientation of the seismic sensor.

Abstract: A method and apparatus for a method for generating an estimated value of absorption parameter Q(t). In one embodiment, the method includes receiving an input seismic trace, applying a time variant Fourier transform to the input seismic trace to generate a time variant amplitude spectrum of the input seismic trace, dividing the natural logarithm of the time variant amplitude spectrum by ??f, and performing a power series approximation to the result with an index starting from one to generate an estimated value of R(t). R(t) is a ratio between traveltime t and the absorption parameter Q(t). The method further includes dividing t by R(t) to generate the estimated value of the absorption parameter Q(t).

Abstract: A seismic wave source and sensing system coupled to the surface of an elastic wave propagation medium has a seismic wave source transducer having a preferred axis of vibration oriented horizontally on the surface of the elastic wave propagation medium. A seismic wave sensing transducer has a preferred axis of vibration response oriented horizontally on the surface of said elastic wave propagation medium such that said sensing transducer is capable of detecting dynamic particle motions and displacements of SH waves. An arrangement of the source and sensing transducers is provided on the surface of the elastic wave propagation medium. A recording system capable of acquiring and storing reflected SH wave signals detected by the sensing transducer, wherein the recorded signals represent reflections from contrasting physical properties within the elastic wave propagation medium to provide preferential detection of elongate subsurface targets such as utility pipes, conduits, and other similar object.

Abstract: Method for reconstructing subsurface Q models (110) from seismic data (10) by performing ray-based (60), centroid frequency shift (50) Q tomography. The seismic source waveform's amplitude spectrum is approximated by a frequency-weighted exponential function of frequency (40), having two parameters to adjust to fit the frequency shift data, thereby providing a better fit to various asymmetric source amplitude spectra. Box constraints may be used in the optimization routine, and a multi-index active-set method used in velocity tomography is a preferred technique for implementing the box constraints (100).

Abstract: A method, system and a computer readable medium to compute geometric reflectivity enhancement (GRE) distributions based on seismic data are disclosed. The GRE distributions may be derived from absolute values of a seismic trace amplitude and a quadrature signal obtained by computing the Hilbert transform of the seismic trace amplitude. The derived GRE distributions preserve zero crossings and peaks of the seismic amplitude data.

Abstract: Time lapse or 4D seismic data are corrected for geologic overburden and seismic recording system effects. The data from a survey at one time of interest is processed within a selected frequency band and the reservoir level is normalized by the overburden. The results are used to extract reservoir amplitudes from the data of that same survey. Frequencies where overburden signal-to-noise ratios vary dramatically between time lapse surveys may then be avoided in processing of data from the area of interest.

Abstract: A method and system of detecting and mapping a subsurface hydrocarbon reservoir includes acquiring seismic data having a plurality of components, applying a data transform to the seismic data to obtain seismic data spectral component maxima and maxima profiles, and recording the maxima or maxima profile in a form for display.

Abstract: A system and method of acquiring and processing full elastic waveform data from a vertical-force source comprises providing seismic waves into the earth from the vertical-force source, sensing reflections of the seismic waves at multi-component geophones placed along the surface of the earth, and processing the reflections of the seismic waves to generate full elastic waveform data.

Abstract: A method for spectrally conditioning surface seismic data. In one implementation, the method may include correcting surface seismic data for distortions due to anomalous spectral amplitudes, thereby generating a first set of corrected data; correcting the first set of corrected data for deterministic distortions, thereby generating a second set of corrected data; correcting the second set of corrected data for spectral distortions due to the seismic waves traveling through the near-surface, thereby generating a third set of corrected data; and correcting the third set of corrected data for spectral distortions due to the seismic waves traveling through deeper strata.

Abstract: A method for locating origin time, origin location and source mechanism of seismic events occurring in a selected volume of subsurface formations includes calculating a travel time from each possible origin location to each of a plurality of seismic receivers disposed above the volume in a selected pattern. A signal amplitude is measured by each receiver for each possible origin time at each possible origin location. The signal amplitude is determined from the continuously recorded data by calculating travel time delays for each possible origin location and origin time. The deviatoric moment tensors are determined from the signal amplitudes by moment tensor inversion restricted to deviatoric moment tensors. A norm for each deviatoric moment tensor is generated. An origin time, origin position and source mechanism of a seismic event is determined wherein any norm exceeds a selected threshold.

Abstract: Method for reconstructing subsurface Q models (110) from seismic data (10) by performing ray-based (60), centroid frequency shift (50) Q tomography. The seismic source waveform's amplitude spectrum is approximated by a frequency-weighted exponential function of frequency (40), having two parameters to adjust to fit the frequency shift data, thereby providing a better fit to various asymmetric source amplitude spectra. Box constraints may be used in the optimization routine, and a multi-index active-set method used in velocity tomography is a preferred technique for implementing the box constraints (100).

Abstract: A system and method monitor a hydrocarbon reservoir for drainage in volumetric three dimensions. Monitoring between wells is imperative for optimum reservoir management and is achieved by mapping the hydrocarbon fluid pathways in a producing reservoir. Unlike conventional 4D or time-lapse reflection seismic imaging systems that use a controlled active seismic source and records reflected seismic energy at receivers, the system and method exploit the minute vibrations, or micro-earthquakes generated in the reservoir layers that are induced by fluid movement. These microseisms are detected as the fluids move in the reservoir.

Abstract: A system and method of acquiring and processing full elastic waveform data from a vertical-force source comprises providing seismic waves into the earth from the vertical-force source, sensing reflections of the seismic waves at multi-component geophones placed along the surface of the earth, and processing the reflections of the seismic waves to generate full elastic waveform data.

Abstract: Method for deriving a reservoir property change data volume from time shifts used to time-align 4D seismic survey data (31). The time alignment is performed on at least one angle stack of 4D data to determine a time-shift data volume (32). When multiple angle stacks are used, the time shifts are corrected to zero offset. A running time window is defined, and within each window the time shifts are best fit to a straight-line function of time (depth), one angle stack at a time (33). The slopes from the straight line fits from different angle stacks are averaged at each voxel in the data volume, which yields a reservoir properties (??/?) data volume (34). This data volume may be filtered with a low-pass filter to improve signal-to-noise (35). The resulting data volume may be merged with the 4D data volume to expand its bandwidth (36), or it may be converted into a reservoir saturation and pressure change data volume (38) using a rock-physics model (37).

Abstract: A technique includes receiving seismic data acquired in a seismic survey. The technique includes determining a geophysical trend of trace amplitudes indicated by the seismic data based on non-linear regression and performing quality control analysis on the seismic data based on the determined trend.

Abstract: A technique includes receiving seismic data acquired in a seismic survey and performing quality control analysis on a given trace indicated by the seismic data. The quality control analysis includes selectively accepting or rejecting the given trace based on a median trend of other trace amplitudes determined from traces associated with sensor positions near a sensor position associated with the given trace.

Abstract: Method for evaluating fluid pressures in an underground zone by means of seismic and well data. The zone studied is divided into several time analysis intervals. For each of these intervals, a pre-stack stratigraphic inversion of the seismic data is then carried out using geological a priori information, and a lithoseismic facies cube is determined by lithoseismic analysis. Then, for each facies, relations connecting the seismic impedances of wells to differential pressures in wells are determined in each analysis interval. Finally, a differential pressure cube is determined using the previous relations, as well as a confining pressure cube, in order to determine the fluid pressures in the subsoil by simple difference between these two cubes. Application: petroleum sphere for the detection of overpressure zones during drilling for example.

Abstract: Methods of processing seismic data to remove unwanted noise from meaningful reflection signals are provided for. The methods comprise the steps of assembling seismic data into common geometry gathers in an offset-time domain without correcting the data for normal moveout. The amplitude data are then transformed from the offset-time domain to the time-slowness domain using a limited Radon transformation. That is, the Radon transformation is applied within defined slowness limits pmin and pmax, where pmin is a predetermined minimum slowness and pmax is a predetermined maximum slowness. A corrective filter is then applied to the transformed data enhance the primary reflection signal content of the data and to eliminate unwanted noise events. After filtering, the enhanced signal content is inverse transformed from the time-slowness domain back to the offset-time domain using an inverse Radon transformation.

Abstract: A passive method for exploring a region below the surface of the earth. The method comprises using a single sensor located in turn at a plurality of locations to obtain seismic data obtained by recording ambient seismic interface waves in a frequency range whose lower limit is greater than 0 Hz, and whose upper limit is less than or equal to substantially 1 Hz. The data are processed so as to obtain a measure of the energy in a frequency band within the frequency range. For example, the seismic data may be filtered and may be subjected to amplitude normalization before being transformed into the frequency domain. The energy measure may then be calculated by integrating the spectrum in the frequency domain over a desired frequency range. The resulting calculated energy provides information about the region of the earth being explored.

Abstract: Improved methods of processing seismic data which comprise amplitude data assembled in the offset-time domain in which primary reflection signals and noise overlap are provided for. The methods include the step of enhancing the separation between primary reflection signals and coherent noise by transforming the assembled data from the offset-time domain to the time-slowness domain. More specifically, the assembled amplitude data are transformed from the offset-time domain to the time-slowness domain using a Radon transformation according to an index j of the slowness set and a sampling variable ?p; wherein j = p max - p min + 1 ? ? µ ? ? sec ? / ? m ? ? ? p , ?p is from about 0.5 to about 4.0 ?sec/m, pmax is a predetermined maximum slowness, and pmin is a predetermined minimum slowness. Alternately, an offset weighting factor xn is applied to the assembled amplitude data, wherein 0<n<1, and the amplitude data are transformed with a Radon transformation.

Abstract: A method and system of processing seismic data includes acquiring three-component seismic data and combining horizontal components of the three-component seismic data to obtain a merged horizontal component. Frequency spectra are determined for the acquired three-component seismic data. A ratio of a vertical component of the seismic data to the merged horizontal component is determined. A V/H integration-measure is obtained from the integration of the area bounded by a selected minimum-amplitude value and the amplitude values greater than the selected minimum-amplitude value and the V/H integration-measure is stored in a form for display.

Abstract: A method of characterizing a fractured reservoir in a field includes measuring seismic reflection coefficient of the fractured reservoir as a function of angle of incidence and azimuth, predicting seismic reflection coefficient of the fractured reservoir as a function of angle of incidence and azimuth using an elastic stiffness tensor and an elastic compliance tensor of the fractured reservoir, determining components of an excess compliance tensor due to the presence of fractures in the fractured reservoir by matching the predicted seismic reflection coefficient to the measured seismic reflection coefficient, and characterizing one or more properties of the fractured reservoir using the excess compliance tensor.

Abstract: A method for seismic event mapping includes transforming seismic signals recorded at selected positions into a domain of possible spatial positions of a source of seismic events. An origin in spatial position and time of at least one seismic event is determined from space and time distribution of at least one attribute of the transformed seismic data.

Abstract: A method for the quantitative characterization of a seabed sediment composition and a seabed's layered subbottom structure from at least one normal-incidence, single-channel reflection acoustic amplitude time series seismogram is disclosed. The method detects a plurality of reflections from subbottom interfaces in said seismograms, determines the traveltime, the polarity and the reflectivity of each detected reflection, determines the intrinsic attenuation of the sediment layer between pairs of adjacent reflections, and determines the acoustic properties, layer thicknesses and material properties of the seabed's layered subbottom structure as a function of said traveltimes, polarities and reflectivities of the detected reflections and said intrinsic attenuation of the sediment layer between pairs of adjacent reflections. A forward model describing the physical relationship between the material properties and the acoustic properties of seabed sediments is also disclosed.

Abstract: Resonance scattering analysis of at least 3-component (3-C) VSP data detects heterogeneities in the proximity of a borehole. A method for seismic exploration of a pre-determined volume of the earth for assessing features of the volume using at least 3-C VSP data generated for the volume comprises: computing a resonance spectra indicating resonance scattering of the at least 3-C VSP data; and determining a lateral continuity of said features in accordance with the resonance spectra. Zero amplitude in a resonance spectrum indicates definite polarization of the direct pressure wave into the ray direction and very weak lateral heterogeneity along the path of the direct wave. High amplitudes in a resonance spectrum are observed if energy of the direct wave is observed on the horizontal components due to scattering at small-scale lateral heterogeneities near the receiver. Peak frequency provides information on the size and location of the scattering structure.

Abstract: A method, apparatus and computer-readable medium for evaluating an earth formation includes making measurements with a logging tool having a first depth of investigation in a borehole in the earth formation. A first dip of the formation is estimated using multi-component measurements. The estimated dip is compared with a second dip measurement in the borehole. The results of the comparison are stored on a tangible medium.

Abstract: A method for spectrally conditioning surface seismic data. In one implementation, the method may include correcting surface seismic data for distortions due to anomalous spectral amplitudes, thereby generating a first set of corrected data; correcting the first set of corrected data for deterministic distortions, thereby generating a second set of corrected data; correcting the second set of corrected data for spectral distortions due to the seismic waves traveling through the near-surface, thereby generating a third set of corrected data; and correcting the third set of corrected data for spectral distortions due to the seismic waves traveling through deeper strata.

Abstract: To generate an absorption parameter model, estimated values of an effective absorption parameter are received, where the estimated effective absorption parameter values represent absorption encountered by a seismic wave in a subterranean structure. Based on the estimated effective absorption parameter values, an absorption parameter model is generated that varies absorption parameter values along at least one dimension of the subterranean structure.

Abstract: A method and system of processing seismic data includes acquiring three-component seismic data and combining horizontal components of the three-component seismic data to obtain a merged horizontal component. Frequency spectra are determined for the acquired three-component seismic data. A ratio of a vertical component of the seismic data to the merged horizontal component is determined. A V/H integration-measure is obtained from the integration of the area bounded by a selected minimum-amplitude value and the amplitude values greater than the selected minimum-amplitude value and the V/H integration-measure is stored in a form for display.