Abstract: The invention relates to processing seismic data that includes signals from at least two sources and typically three or four sources where source separation is necessary for geophysical analysis. Specifically, the present invention is an analytical technique that quickly creates a more accurate source signature delivered by analysis of the source generated data contamination present in the separated data. The technique is to invert a segment of the data using a seed source signature and compute an error that reflects the generated data contamination observed in the separated source data. The source signature is iteratively revised as the segment is continually inverted with the goal of finding the optimal source signature that provides the lowest computed error. The source signature that provides the lowest error is, or is very close to, the true source signature and is then used in the separation process for the entire composite data set.

Abstract: A method and system for processing synchronous array seismic data includes acquiring synchronous passive seismic data from a plurality of sensors to obtain synchronized array measurements. A reverse-time data process is applied to the synchronized array measurements to obtain a plurality of dynamic particle parameters associated with subsurface locations. These dynamic particle parameters are stored in a form for display. Maximum values of the dynamic particle parameters may be interpreted as reservoir locations. The dynamic particle parameters may be particle displacement values, particle velocity values, particle acceleration values or particle pressure values. The sensors may be three-component sensors. Zero-phase frequency filtering of different ranges of interest may be applied. The data may be resampled to facilitate efficient data processing.

Abstract: A method and system for processing synchronous array seismic data includes acquiring synchronous passive seismic data from a plurality of sensors to obtain synchronized array measurements. A reverse-time data process is applied to the synchronized array measurements to obtain a plurality of dynamic particle parameters associated with subsurface locations. These dynamic particle parameters are stored in a form for display. Maximum values of the dynamic particle parameters may be interpreted as reservoir locations. The dynamic particle parameters may be particle displacement values, particle velocity values, particle acceleration values or particle pressure values. The sensors may be three-component sensors. Zero-phase frequency filtering of different ranges of interest may be applied. The data may be resampled to facilitate efficient data processing.

Abstract: A merged particle velocity signal is generated by combining a recorded vertical particle velocity signal, scaled in an upper frequency range using a time-dependent arrival angle as determined by cross-ghosting analysis, with a simulated particle velocity signal, calculated in a lower frequency range from a recorded pressure signal using a time-varying filter based on the time-dependent arrival angle. Combined pressure and vertical particle velocity signals are generated from the recorded pressure and merged particle velocity signals.

Abstract: A method of processing seismic data representing a physical system, the method comprising a difference between first and second seismic data representing the system in first and second states, respectively, and inverting the difference in accordance with a parameterized model of the physical system to obtain changes in the parameters of the model.

Abstract: A system for transmitting telemetry data between an underground structure and a location above the underground structure includes a network of receiving devices within the underground structure which gathers telemetry data from a data transmitter located within the underground structure. An underground broadcasting station in communication with the network of receiving devices includes an underground processing device for converting the telemetry data into an encoded impactor signal and a seismic generator in contact with the underground structure and driven by the encoded impactor signal to broadcast an encoded seismic signal through an adjacent earthen formation. The system includes a receiving station having a seismic sensor and a processing device. The seismic sensor is in contact with the earthen formation at a remote location substantially above the underground structure.

Abstract: The technologies described herein include systems and methods for performing a first seismic survey and performing a second seismic survey after a predetermined amount of time has lapsed between the first seismic survey and the second seismic survey. The shot times and the shot positions of the second seismic survey may be substantially the same as the shot times and the shot positions of the first seismic survey. After performing the seismic surveys, seismic data generated by the first seismic survey may be processed to generate a first image, and seismic data generated by the second seismic survey may be processed to generate a second image. After generating the first and second images, a difference between the first image and the second image may be computed to generate a time lapse difference image.

Abstract: A method for generating a synthetic seismogram. In one implementation, a ray tracing may be performed on a subsurface. The ray tracing may generate a plurality of rays. A first seismic wavefront may be reconstructed by triangulating a first plurality of control points that correspond to the plurality of rays. Each control point may represent an end point of a ray at the first seismic wavefront. The plurality of rays may be propagated to a second seismic wavefront. The second seismic wavefront may have a hole associated with at least one missing ray at the second seismic wavefront. A plurality of points on a circle may be defined that correspond to a second plurality of control points defining the hole. The second seismic wavefront may be reconstructed based on the plurality of points on the circle.

Abstract: A method of locating subsurface hydrocarbon reservoirs includes acquiring seismic data, extracting seismic data attributes from the seismic data, calculating exemplar data group probability density function values using distribution values associated with the seismic attributes and applying Bayesian inversion to determine the likelihood of subsurface hydrocarbons.

Abstract: A method and system for processing synchronous array seismic data includes acquiring synchronous passive seismic data from a plurality of sensors to obtain synchronized array measurements. A reverse-time data process is applied to the synchronized array measurements to obtain a plurality of dynamic particle parameters associated with subsurface locations. These dynamic particle parameters are stored in a form for display. Maximum values of the dynamic particle parameters may be interpreted as reservoir locations. The dynamic particle parameters may be particle displacement values, particle velocity values, particle acceleration values or particle pressure values. The sensors may be three-component sensors. Zero-phase frequency filtering of different ranges of interest may be applied. The data may be resampled to facilitate efficient data processing.

Abstract: A method and system for processing synchronous array seismic data includes acquiring synchronous passive seismic data from a plurality of sensors to obtain synchronized array measurements. A reverse-time data propagation process is applied to the synchronized array measurements to obtain a plurality of dynamic particle parameters associated with subsurface locations. Imaging conditions are applied to the dynamic particle parameters to obtain image values associated with subsurface energy source locations.

Abstract: A method for mapping a property of a subsurface reservoir includes determining a value of at least one reservoir property from measurements obtained from a well drilled through the reservoir. A relationship is determined between the at least one property of the reservoir and at least one seismic attribute and at least one electromagnetic survey attribute at a geodetic position of the well. A value of the at least one reservoir property is determined at at least one other geodetic position from a value of the at least one seismic attribute, a value of the at least one electromagnetic survey attribute at the at least one other geodetic position, and from the determined relationship.

Abstract: Seismic visibility analysis of selected subsurface structures is employed to determine surface locations offering high visibility of target events. These locations can then be used as a basis for acquiring additional seismic survey data and/or selecting existing traces for re-migration with more sophisticated migration methods. With either usage, the newly migrated data is expected to offer enhanced images of the target event. In some embodiments, the visibility determination includes using a wave equation based propagator to find, for each of multiple simulated shots, a reflection wavefield from the target event in a seismic model; and to calculate, for each of multiple receiver positions, a contribution signal from each reflection wavefield. The visibility determination further includes converting each contribution signal into a source-receiver visibility value. Because data acquisition and/or re-migration is limited to the selected region, the imaging effort for the target event is significantly reduced.

Abstract: A downhole acoustic logging tool is used for generating a guided borehole wave that propagates into the formation as a body wave, reflects from an interface and is converted back into a guided borehole wave. Guided borehole waves resulting from reflection of the body wave are used to image a reflector.

Abstract: To determine fault transmissivity in a subterranean reservoir, fault structures in the subterranean reservoir are identified, and elastic impedance data is computed from well log data and seismic data. Normalization parameters that have a predetermined orientation with respect to the identified fault structures are computed, and elastic impedance flux values are normalized with respect to the normalization parameters, where the normalized elastic impedance flux values are indicative of transmissivities of fault structures in the subterranean structure.

Abstract: Geophysical data representing at least first and second overlapping geophysical spaces may be aggregated. A first set of geophysical data representing the first geophysical space and a second set of geophysical data representing the second geophysical space may be obtained. The second set of geophysical data may be separate and discrete from the first set of geophysical data. The first set of geophysical data may be transformed from a first parametric domain to a third parametric domain, while the second set of geophysical data may be transformed from a second parametric domain to the third parametric domain. The first set of geophysical data may be fused with the second set of geophysical data in the third parametric domain to create a fused set of geophysical data. The fused set of geophysical data may be transformed from the third parametric domain to a fourth parametric domain.

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: A measured pressure field, a measured vertical velocity field, and two measured orthogonal horizontal velocity fields are obtained. A programmable computer is used to perform the following. A scaling factor is determined from water acoustic impedance, the measured pressure field, and the horizontal velocity fields. One of the measured pressure field and measured vertical velocity field is combined with one of the measured vertical velocity field scaled by the scaling factor and the measured pressure field scaled by the scaling factor, generating one of up-going and down-going pressure and velocity wavefields.

Abstract: A system and method approximate a set of wave equations describing the propagation of seismic waves of one or more frequencies through a seismic volume of interest. In one embodiment, a ray-based initial beam solution is determined that describes the propagation of seismic waves at a first frequency through the seismic volume of interest as a set of one or more beams. Based on the ray-based initial beam solution, a refined finite-element beam solution is determined that describes the propagation of the seismic waves at the first frequency through the seismic volume of interest by approximating the two-way wave equation with a one-way wave equation.

Abstract: A method and system for determining the location of miners trapped in an underground mine that includes recording a reference seismic signature for each of a plurality of underground base stations in the mine in advance of an emergency. The reference seismic signatures are created by generating first a seismic signal with a high signal-to-noise ratio at each base station, monitoring the signal with a permanent array of surface seismic sensors, and recording each unique signature on a central computer. In the event of an emergency, trapped miners can generate a second seismic signal at any of the underground base stations which can be easily identified with the central computer by using the pre-recorded reference seismic signature to overcome a weak signal-to-noise ratio.

Abstract: Fast anisotropy axis values are determined for each bin in seismic data binned by azimuth. A fast azimuth gather is determined within each bin in the seismic data from the fast anisotropy axis values. The earth's subsurface is imaged, using the fast azimuth gathers.

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: Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture are described. According to one embodiment, an earth analysis method includes engaging a device with the earth, analyzing the earth in a single substantially lineal direction using the device during the engaging, and providing information regarding a subsurface feature of the earth using the analysis.

Abstract: According to a preferred aspect of the instant invention, there is provided herein a system and method for imaging complex subsurface geologic structures such as salt dome flanks using VSP data. In the preferred arrangement, a receiver wave field will be downward continued through a salt flood model and a source wave field will be upward continued through a sediment flood model until they “meet” at the subsurface locations of the VSP receivers. The source and receiver wave fields will be cross correlated as an imaging condition at each depth interval.

Abstract: The invention relates to a method for seismic exploration, comprising the steps of controlling a plurality of sources so that they emit a plurality of seismic waves in a subsurface zone to be explored, each source successively occupying a plurality of emitter positions, producing for each emission a signal representative of the emission, and recording the position of the source and the instant at which the emission starts, continuously recording by means of seismic sensors the composite signals reflected by the medium in response to said emissions, and carrying out shot point migration, on the one hand, from a reflected wave field constituted of said composite signals and respective sensor positions, and on the other hand, from an incident wave field constituted of signals representative of the emissions, source positions and start emission instants, so as to obtain a seismic image.

Abstract: To process measurement data representing a subterranean structure, a derivative of the measurement data collected by at least one survey receiver is computed, with respect to frequency. A response representing the subterranean structure is then computed based on the derivative of the measurement data, where the response contains an air-wave component that has been suppressed due to computing the derivative of the measurement data relative to at least another component that is sensitive to the subterranean structure.

Abstract: One or more methods and systems for processing seismic data to improve resolution of seismic images are provided. In one or more embodiments the method can include constructing a plurality of ray path traces. Each ray path trace can have a first portion for a first vertical location and a second portion for a second vertical location. An impinging angle for each ray path trace is held constant for the first vertical location and the second vertical location.

Abstract: A method for estimating internal multiples in seismic data. The method includes selecting a subset from a set of regularly sampled seismic data based on a low-discrepancy point set. The method may then include integrating one or more depth integrals of the inverse-scattering internal multiple prediction (ISIMP) algorithm over each data point in the subset. After integrating the depth integrals, the method may then include integrating a function of the integrated depth integrals using a quasi-Monte Carlo (QMC) integration over the subset, thereby generating an estimate of the internal multiples.

Abstract: Provided is an apparatus of imaging a subsurface of a target area. The apparatus includes: an observed wavefield acquiring unit configured to acquire an observed wavefield for a target area based on seismic data; a parameter storage configured to store a characteristic parameter for the target area; a modeled wavefield creator configured to create a modeled wavefield corresponding to the observed wavefield using the characteristic parameter stored in the parameter storage; an energy calculator configured to calculate accumulated energies of the observed wavefield and the modeled wavefield, wherein the accumulated energies are defined as energies accumulated over time with respect to the observed wavefield and the modeled wavefield; and a parameter updating unit configured to update the characteristic parameter stored in the parameter storage such that a difference between the accumulated energy of the observed wavefield and the accumulated energy of the modeled wavefield is minimized.

Abstract: Methods and systems are described for measuring effects of a hydraulic fracturing process. The techniques can utilizes cross-well seismic technology, such as used in Schlumberger's DeepLook-CS tools and service, or in some case surface to borehole or borehole to surface seismic technology. The downhole seismic sources at known locations can be conventional sources or can be other types of equipment operating at known locations such as perforation guns. The source is activated or swept creating energy which is transmitted through the formation. The energy is recorded at the receiver array and processed to yield a tomographic image indicating changes in the subterranean formation resulting from the hydraulic fracturing process. The process can be performed pre and post hydraulic fracture stimulation to generate a difference image of propped fractures in the reservoir.

Abstract: A method is disclosed that uses (a) source-receiver reciprocity and (b) a method such as ISR DMO (U.S. Patent Application Publication No. 2006/0098529) that allows reconstruction of densely sampled gathers at arbitrary surface locations, to efficiently predict multiple reflections, either surface related or interbed multiples, in seismic data. For each reconstructed gather and each output (field) trace, two traces are extracted corresponding to the field source and receiver positions of the output trace, then they are convolved and the convolution result is added (summed) to that obtained by applying this procedure to previously reconstructed gathers. The efficiency results from the fact that the convolutions are performed by looping over all traces for each “bounce” point, with the outer loop being over bounce points. Once all the reconstructed gathers are processed, multiple predictions are obtained for the whole survey by conventional means.

Abstract: Seismic data are obtained for each seismic source activation in a marine streamer and for each frequency, after being transformed to a spectral domain. An iterative conjugate gradient scheme, using a physically-based preconditioner, is applied to the transformed seismic data, to provide a least squares solution to a normal set of equations for a deghosting system of equations. The solution is inverse-transformed back to a space-time domain to provide deghosted seismic data.

Abstract: A method of imaging the Earth's subsurface using passive seismic emissions includes detecting seismic signals originating from within the Earth's subsurface over a selected time period using an array of seismic sensors deployed proximate the Earth's surface. Hypocenters of seismic events in the subsurface are determined from the detected signals. Seismic signals detected at selected ones of the seismic sensors are cross-correlated to signals detected at other selected ones of the seismic sensors. The cross-correlated signals are processed to obtain a reflectivity series at a geodetic position of the selected one of the seismic sensors. A spatial distribution of at least one seismic property in the subsurface is determined using the determined hypocenters and the reflectivity series.

Abstract: Methods and related systems are described relating to processing subsurface sonic and seismic data. The described techniques use anisotropy estimates derived from a walkaway VSP to calibrate elastic properties derived from sonic logs. An empirical relationship between the sonic derived anisotropy parameters is modified until the upscaled elastic properties from the sonic log data best matches the anisotropy parameters measured with the walkway VSP. The result is a set of elastic constants consistent with the walkaway VSP measurements.

Abstract: A method for seismic event mapping includes selecting a plurality of subvolumes representing possible locations of origin of a seismic event in the Earth's subsurface. For each subvolume a plurality of possible directions of motion of subsurface formations is selected. For each subvolume and each possible direction of motion, polarity correction is applied to seismic signals recorded at a plurality of positions proximate a volume of the Earth's subsurface to be evaluated. The polarity correction is based on the direction of motion and the position of each seismic sensor with respect to the subvolume. The recorded, polarity corrected seismic signal recordings are time aligned. The time aligned recordings are summed. A most likely direction of motion and subvolume position are determined based on a selected attribute of the summed, time aligned seismic signals.

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: The present invention relates to producing a quality control measure for use during data acquisition and/or data processing of, preferably, seismic data. While or after obtaining the data, a surface consistent decomposition of the data is performed. From the surface consistent decomposition, one may compute a decomposed logarithmic spectra, and from the decomposed logarithmic spectra, one may compute one or more residua. An error attribute based on the one or more residua can be formulated, analyzed, and output. The error attribute can be used as a quality control measure or the analysis result can be used to produce a quality control measure.

Abstract: A technique includes determining at least one parameter that characterizes a seismic survey in which multiple interfering seismic sources are fired and seismic sensors sense energy that is produced by the seismic sources. The determination of the parameter(s) includes optimizing the seismic survey for separation of the sensed energy according to the seismic sources.

Abstract: The invention provides a system, method and downhole tool for stimulating a borehole of wells in reservoir. The invention allows a user to determine the type of stimulation adequate to promote production in a reservoir, and apply one or more treatments to each individual well by activating one or more modules comprised in the downhole tools. Furthermore, the tool comprises sensors that collect information in real-time of the state of the reservoir. The data collected is processed and newly acquired data is compared with previously acquired data to assess the development of production and further plan treatment strategies to optimize production.

Abstract: A method of processing geophysical signals obtained by monitoring the response of the earth to an source using a plurality of receivers is described including the evaluation of sums or integrals of functions of weighted signal values over a one or multidimensional domain such that the domain is split into a plurality of simplices and the signal values are interpolated across the simplices using a non-linear approximation of the function, the approximation including signals and gradients of the signals, and the evaluated sums or integrals are used to obtain a representation of characteristics of the earth.

Abstract: An adaptive signal separation is provided that isolates signal data and listening data from multiple continuous overlapping seismic signals.

Abstract: The methods described herein are conceptually similar to classical migration/imaging for surface seismic data. However, instead of using computed (estimated) Green's functions in the imaging process, the instant invention utilizes measured (near-exact) Green's functions from VSP data to image the surface seismic data. Although the instant invention is best utilized where the velocity profile is approximately 1D (i.e., v(z)), the methods disclosed herein can also be extended to instances where there are some lateral velocity variations. Under these conditions, the instant invention allows for imaging surface seismic data and ‘self-imaging’ VSP data without first having to estimate a velocity model. The measurements obtained from the VSP data can also be used as a tool for calibrating computed Green's functions and migration operators.

Abstract: Method for velocity model building and analysis using wavefield-coordinates reflection operators in wave-equation migration or reverse-time migration.

Abstract: Originating from a novel and an exact algebraic formula for the impulse response of a plane acoustic reflector at zero offset due to a point acoustic source the present invention provides a method for computing an exact impulse response of a plane acoustic reflector at zero offset due to a point acoustic source; and originating from the method, methods for testing and validating algorithms for numerical modeling of seismic reflection, seismic migration and seismic inversion; a method for testing the efficacy of ray-theoretical solution for a given source-reflector configuration; another method for computing zero-offset reflection response of a circular reflector at its central axis; yet another method for validating an interpretation of a reflector as a planar structure; still yet another method for estimating the seismic source-time function when the zero-offset reflection response of a plane reflector is given.

Abstract: There is provided herein a system and method of acquiring, processing, and imaging transient Controlled Source ElectroMagnetic (t-CSEM) data in ways that are similar to those used for seismic data. In particular, the instant invention exploits the time-distance characteristics of t-CSEM data to permit the design and execution of t-CSEM surveys for optimal subsequent processing and imaging. The instant invention illustrates how to correct t-CSEM data traces for attenuation and dispersion, so that their characteristics are more like those of seismic data and can be processed using algorithms familiar to the seismic processor. The resulting t-CSEM images, particularly if combined with corresponding seismic images, may be used to infer the location of hydrocarbon reservoirs.

Abstract: A technique includes determining a change in an elastic property of a region of interest at a second time relative to a first time based on a flow simulation model. The technique includes scaling the determined change in the elastic property based on data acquired in a seismic survey.

Abstract: Methods of processing seismic data to remove unwanted noise from meaningful reflection signals are provided for. Assembled seismic data are transformed from the offset-time domain to the time-slowness domain using a Radon transformation. Preferably, the Radon transformation is applied within defined slowness limits pmin and pmax that will preserve coherent noise, and according to an index j of the slowness set and a sampling variable ?p; wherein j = p ma ? ? x - p m ? ? i ? ? n + 1 ? ?sec ? / ? m ? ? ? p , ?p is from about 0.5 to about 4.0 ?sec/m. The coherent noise content of the transformed data is then enhanced, and the primary reflection signal content diminished by filtering at least a subset of the transformed data.

Abstract: Embodiments of a machine, program product and computer implemented method to perform a process of picking an initial first arrival from at least one trace of the plurality of seismic traces and a process of refining the initial first arrival pick based upon a comparison of the initial first arrival pick with first arrival pick of adjacent traces is disclosed. Such embodiments perform the steps of: centering a main time window around each of the plurality of possible first arrivals for the seismic traces, setting a start of the time window to zero, transforming the plurality traces into a plurality of peak spike traces; dividing the main window into a plurality of sub-windows; comparing each of the plurality of peak spikes in the sub-window, determining the first arrivals, and determining if the first arrival is a desired pick.

Abstract: This invention discloses methods of processing data using a computer to separate out geophysical exploration response at receivers corresponding to one source among many sources by determining at least one spatio-temporal variant directional propagation attribute of the responses at receivers corresponding to the one source and by decomposition or filtering process using the determined attribute.