Abstract: Various optical fiber-based seismic monitoring system embodiments include a light source that drives an optical fiber positioned within a borehole. At least one light sensor analyzes Rayleigh backscattered light to obtain an acoustic signal for each of multiple points along the borehole. One or more processors operate to determine microseismic event direction, distance, and/or intensity based at least in part on phase information of said acoustic signals. The acoustic signal cross-correlations, semblances, or phase-sensitive similarity measures can be determined as a function of scanning direction to accurately determine the relevant microseismic event information. The optical fiber may be positioned in the cemented annulus of a cased borehole having a shape that extends along more than one dimension (e.g., an L-shaped borehole).

Abstract: A method of modelling a subterranean region of the Earth at a first location comprises the steps of: providing geological data; selecting a plurality of facies; providing a distribution of rock physics probability with spatial dependencies; approximating the rock physics probability at the first location with at least one distribution per facies utilizing the spatial dependencies in the rock physics probability distribution; and performing a Bayesian inversion at the first location using the approximation of the rock physics probability distribution. The method may also employ a window comprising the first location and at least one further location.

Abstract: Self-consistency and/or differences between volume images and interpreted spatial/volumetric context may be exploited for improving seismic imaging and estimation of attributes of geobodies, in accordance with one or more embodiments. Exemplary embodiments allow exploitation of positional and/or shape discrepancies and/or similarities of geobodies in image volumes associated with a geologic model of a geologic volume of interest to improve the accuracy of the geologic model and/or the image volumes. Constraints associated with the geologic volume of interest may be determined and/or utilized to confirm and/or specify dependencies between attributes that are potentially associated with individual geobodies.

Abstract: A technique includes performing reverse time imaging to determine an image in a region of interest. The reverse time imaging includes modeling a pressure wavefield and a gradient wavefield in the region of interest based at least in part on particle motion data and pressure data acquired by sensors in response to energy being produced by at least one source.

Abstract: A technique includes processing seismic data indicative of samples of at least one measured seismic signal in a processor-based machine to, in an iterative process, determine basis functions, which represent a constructed seismic signal. The technique includes in each iteration of the iterative process, selecting another basis function of the plurality of basis functions. The selecting includes based at least in part on the samples and a current version of the constructed seismic signal, determining a cost function; and interpreting the cost function based at least in part on a predicted energy distribution of the constructed seismic signal to select the basis function.

Abstract: The invention relates to seismic surveying where complex geologies are likely to create data that is confusing or ambiguous for a conventional matrix of acquisition source points and receiver locations. With some understanding of the geological substructure, the acquisition source points and receiver locations that optimize the imaging may be found by using a reciprocal two-way wave equation propagation method coupled with the best geologic model available. With this, the acquisition source points and receiver locations that optimize the imaging may be used in seismic survey to better resolve the substructure and avoid the inclusion of data that obscures understanding of the substructure.

Abstract: A beam tomography computer implemented method and system for generating improved seismic images and earth models without dependence on reflector structure is disclosed. Recorded seismic data is transformed into data beams which are compared to forward modeled beams using an earth model having a velocity model to compute raypaths and a seismic image to specify the reflectors. The tomographic updates to the earth model and velocity model are based on misalignments between the data beams and the same beams forward modeled from the velocity model and the seismic image. The updated earth model and seismic image better describe the true propagation of the beams through the earth.

Abstract: Methods for fracture characterization of unconventional formations are provided. Synthetic seismic fracture responses can be generated based on the derived fracture parameters. The synthetic seismic fracture responses may then be used to derive optimum seismic data acquisition geometry for fracture characterization. These methods of determining the seismic data acquisition geometry are advantageous over conventional methods in that these methods are more reliable and cheaper than existing empirical methods, particularly as applied to fractured unconventional formations. Moreover, these methods allow fracture parameters to be derived from limited but common well log data. Certain embodiments additionally contemplate determining the presence of gas filled fractures. These characterizations and evaluations of unconventional formations are useful for, among other things, determining optimal producing intervals and optimal drilling locations. These methods can eliminate the use of costly image logs and core data.

Abstract: The present invention relates to a method for determining a lithology map. The method comprises receiving a geophysical attribute image comprising a plurality of points associated with geophysical attribute value, and receiving first information data representing a plurality of zones in the image, each point of the image being contained in a zone. For at least one point of the image, computing a uniform value associated with said point based on the geophysical attribute value and distributions values of the geophysical attribute values. The method further comprises receiving second information data representing geological probability value for a plurality of facies associated with the points of the image, and for at least one point of the image, determining a facies in the plurality facies based on the computed uniform value and the geological probabilities associated with said point.

Abstract: A system and method for estimating seismic anisotropy of subsurface formations with high resolution. A method for determining anisotropy parameters of subsurface formations includes generating a synthetic reflectivity gather from a vertical well log. Times of a surface seismic gather are adjusted to those of the synthetic gather. Low-cut filtering is applied to the surface seismic gather. Anisotropy parameters are generated as a difference of the filtered seismic gather and the synthetic gather. An anisotropy value is assigned to each of plurality of layers of a formation based on the generated anisotropy parameters.

Abstract: A method can include receiving data that characterizes anisotropy of a formation; receiving a model that models one or more planes of weakness in an anisotropic formation; and, based at least in part on the model and the data, outputting information germane to stability of a bore in an anisotropic formation.

Abstract: A method for analyzing seismic data by generating a post-migration common image gather in a dip angle domain from measured seismic data; detecting concave features related to reflection events in the common image gather and apexes; filtering out part of the concave features in the common image gather in a vicinity of the detected apexes; applying a hybrid Radon transform to the filtered common image gather to separate residues of the concave features from other image features related to diffraction events; and applying an inverse hybrid Radon transform to an image containing the separated features related to diffraction events to obtain a transformed common image gather in the dip angle domain.

Abstract: A technique includes modeling interpolated seismic measurements as a random process characterized by seismic measurements acquired at a set of sensor locations and an interpolation error. The technique includes determining the interpolated seismic measurements based at least in part on a minimization of the interpolation error.

Abstract: Disclosed is a method for determining seismic event data from indications of seismic noise, the method including receiving seismic trace data from a plurality of locations, and providing a virtual trace value (ERvirtual) as seismic event data for a virtual trace location from the seismic trace data. A system and computer program product for determining seismic event data is also disclosed.

Abstract: Method for using seismic data from earthquakes to address the low frequency lacuna problem in traditional hydrocarbon exploration methods. Seismometers with frequency response down to about 1 Hz are placed over a target subsurface region in an array with spacing suitable for hydrocarbon exploration (21). Data are collected over a long (weeks or months) time period (22). Segments of the data (44) are identified with known events from earthquake catalogs (43). Those data segments are analyzed using techniques such as traveltime delay measurements (307) or receiver function calculations (46) and then are combined with one or more other types of geophysical data acquired from the target region, using joint inversion (308-310) in some embodiments of the method, to infer physical features of the subsurface indicative of hydrocarbon potential or lack thereof (26).

Abstract: A method for characterizing ultrasound scatterers in a medium comprises receiving ultrasound data representing a region of interest comprising a plurality of scatterers in a medium, the plurality of scatterers including aggregates of the scatterers. The ultrasound data is modeled data using an effective medium theory combined with the structure factor model, the structure factor model defining the spatial organization and concentration of the aggregates. The modeled ultrasound data is compared to theoretical data obtained with the effective medium theory combined with the structure factor model. From the comparison, dimensional data of the aggregates of the scatterers and the volume concentration of scatterers in the medium is determined.

Abstract: A method of subsurface imaging is disclosed, the method involving using input data relating to the geometry of a fracture in a subsurface medium, mechanical properties of the medium and in-situ stress states in the medium, to model the behavior of the fracture and obtain predicted information relating to deformation of the fracture. The predicted information is then used to constrain the interpretation of measured microseismic data caused by movement of the fracture to determine characteristics of the movement and/or failure of the fracture.

Abstract: The invention is a method for inferring the saturation and pressure change of a reservoir by combining the information from 4D (time-lapse) seismic and time lag data volumes (7) derived from the 4D seismic, well logs (4), and reservoir simulation results (when simulator results are available) and featuring one or more 4D well ties (1) for a quantitative 4D interpretation. The inventive method uses model-based inversion incorporating rock physics (2) at well locations (5), and is statistical-based (6) away from wells. The method thus allows integration (8) of rock physics model and reservoir simulation and honors 4D seismic change.

Abstract: A programmable computer is used to perform the following. 3D seismic data sets, corresponding to each azimuth in seismic data obtained from a multi-azimuth marine seismic survey, are migrated in grids oriented with the corresponding azimuth. Acquisition geometry is stored for each trace in the seismic data sets for each azimuth. Residual analysis, based on the corresponding azimuth, is performed on each of the migrated data sets, generating residuals and reflectors for each azimuth. The residuals and reflectors generated for each azimuth are rotated and merged on a master grid. Reflection tomographic inversion is applied iteratively to the rotated and merged residuals and reflectors to update a velocity model using the acquisition geometry as based on the master grid. The earth's subsurface is imaged using the updated velocity model.

Abstract: A computer system and a computer-implemented method for analyzing input data from a geological volume of interest in a subterranean formation. The method includes processing the input data using a first subterranean interpretation model, the first subterranean interpretation model being configured to provide first output data that are representative of characteristics of the geological volume of interest. The method further includes processing the input data using a second subterranean interpretation model, the second subterranean interpretation model being configured to provide second output data that are representative of the characteristics of the geological volume of interest. The method further includes determining a relationship between the first output data and the second output data, and transforming the second output data into the first output data using the relationship to obtain a transformed second output data.

Abstract: A method for mapping a fracture network that includes determining a source of at least one seismic event from features in recorded seismic signals exceeding a selected amplitude (“visible seismic event”). The signals are generated by a plurality of seismic receivers disposed proximate a volume of subsurface to be evaluated. The signals are electrical or optical and represent seismic amplitude. A source mechanism of the at least one visible seismic event is determined. A fracture size and orientation are determined from the source mechanism. Seismic events are determined from the signals from features less than the selected amplitude (“invisible seismic events”) using a stacking procedure. A source mechanism for the invisible seismic events is determined by matched filtering. At least one fracture is defined from the invisible seismic events. A fracture network model is generated by combining the fracture determined from the visible seismic event with the fracture determined from the invisible seismic events.

Abstract: In various embodiments, the present disclosure describes methods for processing seismic data to concurrently produce a velocity model and a depth image. Various embodiments of the methods include: a) acquiring seismic data; b) generating a shallow velocity model from the seismic data; c) generating a stacking velocity model using the shallow velocity model as a guide; d) generating an initial interval velocity model from the stacking velocity model; and e) generating an initial depth image using the initial interval velocity model. The methods also include iterative improvement of the initial depth image and the initial interval velocity model to produce improved depth images and improved interval velocity models. Improvement of the depth images and the interval velocity models is evaluated by using a congruency test.

Abstract: A method can include providing spatial data for a base case of a subsurface geologic formation; providing spatial data for a simulation case of the subsurface geologic formation; performing box counting for the spatial data for the base case; performing box counting for the spatial data for the simulation case; based on the box counting for the spatial data for the base case, determining a fractal dimension for the base case; based on the box counting for the spatial data for the simulation case, determining a fractal dimension for the simulation case; comparing the simulation case to the base case based at least in part on the fractal dimensions; and, based on the comparing, adjusting one or more simulation parameters to generate spatial data for an additional simulation case of the subsurface geologic formation. Various other apparatuses, systems, methods, etc., are also disclosed.

Abstract: A method and apparatus for constructing a velocity model of a subsurface of the earth, is disclosed herein. Seismic data may be received. A first velocity model of the subsurface may be constructed using the seismic data. The subsurface may have one or more salt bodies. A second velocity model of the subsurface without the salt bodies may be constructed using the seismic data. A set of attributes induced by the salt bodies may be determined based on the first velocity model and the second velocity model. A stiffness tensor change between the first velocity model and the second velocity model may be calculated based on the set of attributes induced by the salt bodies. The first velocity model may be updated based on the stiffness tensor change.

Abstract: Disclosed is a method for determining seismic event data from indications of seismic noise, the method including receiving seismic trace data from a plurality of locations, and providing a virtual trace value (ERvirtual) as seismic event data for a virtual trace location from the seismic trace data. A system and computer program product for determining seismic event data is also disclosed.

Abstract: A technique includes a method and apparatus for simultaneous joint inversion of surface wave and refraction data to identify near surface geophysical and geological properties.

Abstract: A technique includes modeling interpolated seismic measurements as a random process characterized by seismic measurements acquired at a set of sensor locations and an interpolation error. The technique includes determining the interpolated seismic measurements based at least in part on a minimization of the interpolation error.

Abstract: Self-consistency and/or differences between volume images and interpreted spatial/volumetric context may be exploited for improving seismic imaging and estimation of attributes of geobodies, in accordance with one or more embodiments. Exemplary embodiments allow exploitation of positional and/or shape discrepancies and/or similarities of geobodies in image volumes associated with a geologic model of a geologic volume of interest to improve the accuracy of the geologic model and/or the image volumes. Constraints associated with the geologic volume of interest may be determined and/or utilized to confirm and/or specify dependencies between attributes that are potentially associated with individual geobodies.

Abstract: An improved method for analyzing seismic data to obtain elastic attributes is disclosed. In one embodiment, a reflectivity series is determined for at least one seismic trace of seismic data obtained for a subterranean formation, where the reflectivity series includes anisotropy properties of a formation. One or more synthetic seismic traces are obtained by convolving the reflectivity series with a source wavelet. The one or more synthetic seismic traces are inverted to obtain elastic parameters estimates. According to one aspect, the data inputs are angle-azimuth stacks. According to another aspect, the data inputs are azimuthal Fourier coefficients un, vn.

Abstract: Methods and systems for determining a presence and saturation of clathrates are provided. One method includes identifying a potential zone of clathrates based on observed seismic data, the observed seismic data including an observed signal amplitude at the potential zone of clathrates, and assigning subsurface sediment types within and around the potential zone of clathrates. The method includes creating one or more lithologic type logs based on the interpreted subsurface sediment types, and creating from each of the one or more lithologic type logs a plurality of synthetic logs including compressional velocity at a plurality of possible clathrate saturation levels. The method includes matching expected signals from one of the plurality of synthetic logs to the observed signals in the observed seismic data to determine a best-fit match synthetic log to the observed seismic data, thereby determining a clathrate saturation level from among the plurality of possible clathrate saturation levels.

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: Method, system, and computer program product for tracing seismic sections to convert to digital format are provided. The method includes: receiving a scan of a seismic section having multiple overlapping traces measured at spot points; splitting the traces into segments; associating the segments with appropriate baselines; estimating the traces between segments using logical rules; and deriving amplitudes of the traces.

Abstract: The invention relates to acquiring seismic data in either land or marine environments, but typically marine environments where a pulse-type source is fired in a distinctive composite pulse like a distinctive rumble. In a preferred embodiment, a number of pulse-type seismic sources, sometimes called an array, are fired in a distinctive composite pulse to be able to identify within the returning wavefield the energy resulting from the composite pulse. Firing the pulse-type sources creates an identifiable signature so that two or more marine seismic acquisition systems with source arrays can be acquiring seismic data concurrently and the peak energy delivered into the water will be less, which will reduce the irritation of seismic data acquisition to marine life.

Abstract: A method of developing a velocity model for processing a seismic dataset is implemented at a computer system having a processor and memory. The method includes: deriving a first velocity model from the seismic dataset; building a basin model based on the first velocity model and interpretation of the seismic dataset; validating the basin model using calibration data; deriving a second velocity model from the validated basin model; and updating the first velocity model based, at least in part, on the second velocity model.

Abstract: A system and method may, based on a 3D seismic data set seed point, execute a seed picking algorithm, using the first point for picking a set of second points from the data set, setting each of the points in the set of second points as the first point and repeating the algorithm. An iteration number or other attribute may be assigned to the points, the iteration number corresponding to the number of times the algorithm repeated to process the point. The attribute or a number of attributes may be displayed as a visual characteristic for each point. An iterative process may be applied to a set of seismic data points, starting at a seed data point and finding a set of next iteration seed points from among the set of points neighboring the seed point, continuing only with next iteration seed points, and recording for each of a set of data points the number of points that are found by the process when the point is used as a seed data point.

Abstract: A method for processing seismic data. The method includes performing a plurality of stochastic simulations for one or more rock model parameters to generate one or more anisotropic parameters for a subsurface area of the earth. The method then derives one or more joint multi-dimensional probability density functions for the anisotropic parameters. Using the joint multi-dimensional probability density functions and measured well log data, the method computes one or more posterior probability density functions. The method then includes deriving one or more anisotropic profiles from the posterior probability density functions and generating a seismic image from the anisotropic profiles.

Abstract: An improved method for analyzing seismic data to obtain elastic attributes is disclosed. In one embodiment, a reflectivity series is determined for at least one seismic trace of seismic data obtained for a subterranean formation, where the reflectivity series includes anisotropy properties of a formation. One or more synthetic seismic traces are obtained by convolving the reflectivity series with a source wavelet. The one or more synthetic seismic traces are inverted to obtain elastic parameters estimates. According to one aspect, the data inputs are angle-azimuth stacks. According to another aspect, the data inputs are azimuthal Fourier coefficients, un, vn.

Abstract: Noise may be filtered or attenuated from seismic data by building a four-dimensional volume using the acquired seismic data and then applying a random noise attenuation filter to the four-dimensional volume. The dimensions of the four-dimensional volume may include a trace number dimension, a time dimension, a shot number dimension, and a cable number dimension. The random noise attenuation filter may filter portions of the acquired seismic data if the seismic data is not correlated with respect to other seismic data in the four dimensional volume.

Abstract: Methods and apparatus that use microseismic event data, stress data, seismic data, and rock properties to predict the hydrocarbon production success of a well location are disclosed. An example method generates a hydrocarbon production function based on information associated with at least a first well location, obtains information associated with a second well location, and calculates the hydrocarbon production function using the information associated with the second well location to predict the hydrocarbon production of the second well location.

Abstract: A computer-implemented method, system, and article of manufacture for generating images of a subsurface region are disclosed. The method includes obtaining seismic data and an earth model related to the subsurface region, forward propagating a source wavefield through the earth model for a limited time range dependent on a first travel time and a second travel time, backward propagating a receiver wavefield through the earth model for the limited time range dependent on the first travel time and the second travel time, and applying an imaging condition to the forward propagated source wavefield and backward propagated receiver wavefield to generate images related to the subsurface region. The first travel time is a length of time taken by seismic energy to travel from a seismic source to an image point in the subsurface region and the second travel time is a length of time taken by seismic energy to travel from a seismic receiver to the image point in the subsurface region.

Abstract: It is described a method of interpolating and extrapolating seismic recordings, including the steps of deriving particle velocity related data from seismic recordings obtained by at least one streamer carrying a plurality of multi-component receivers and using the particle velocity related data to replace higher derivatives of pressure data in an expansion series.

Abstract: Method for estimating a model of seismic velocity in a subsurface region from seismic data (31) recorded on 3-component instruments. The method measures the apparent incidence angle (32) of a seismic wave observed at a surface as a function of wave frequency. This apparent angle is converted to an effective velocity as a function of frequency (33), which is then inverted (34) to obtain a subsurface velocity model.

Abstract: An approach for seismic data analysis is provided. In accordance with embodiments of this approach, parallel regions within a volume of seismic data are modeled. Residual regions within the volumetric data set are identified, where the residual regions comprise those regions not modeled as parallel regions. The residual regions or a graphic derived from the residual regions are displayed for review.

Abstract: A profile is produced based on measured survey data, where the profile contains indications corresponding to refraction events at different depths in a subterranean structure. Based on the profile and a critical angle model that correlates different concentrations of a given material to respective critical angles, a quantity of the given material in a subterranean structure at a particular depth is determined.

Abstract: A walkaway VSP survey is carried out using a receiver array. First arrivals to a plurality of receivers are picked and used to estimate a normal-moveout (NMO) velocity. Using the NMO velocity and vertical velocities estimated from the VSP data, two anisotropy parameters are estimated for each of the layers. The anisotropy parameters may then be used to process surface seismic data to give a stacked image in true depth and for the interpretation purposes. For multi-azimuthal walkaway or 3D VSP data, we determine two VTI parameters ? and ? for multi-azimuth vertical planes. Then we determine five anisotropic interval parameters that describe P-wave kinematics for orthorhombic layers. These orthorhombic parameters may then be used to process surface seismic data to give a stacked image in true depth and for the interpretation purposes.

Abstract: Methods of analyzing velocity models include defining velocity anomaly models for a subsurface region under study. The velocity anomaly model is overlain on a seismic stack image to produce a hybrid velocity/amplitude model. Regions in which stack amplitudes are coincident with velocity anomalies may be interpreted as representing structures of interest. In an embodiment, clathrate deposits are identified using the hybrid model. In an embodiment, geobodies are identified, and velocity anomalies are constrained by the geobodies for revising migration models.

Abstract: Methods of analyzing velocity models include defining velocity anomaly models for a subsurface region under study. The velocity anomaly model is overlain on a seismic stack image to produce a hybrid velocity/amplitude model. Regions in which stack amplitudes are coincident with velocity anomalies may be interpreted as representing structures of interest. In an embodiment, clathrate deposits are identified using the hybrid model. In an embodiment, geobodies are identified, and velocity anomalies are constrained by the geobodies for revising migration models.

Abstract: Full wavefield images are produced for a target within a geologic volume of interest from which seismic information has been acquired. The images are generated by generating Green's functions for wavefields propagating from a location at or near the target to the surface without requiring imaging of the entire geologic volume of interest.

Abstract: A method for verifying the accuracy of a wave velocity model. The method may include generating an extended image using the wave velocity model, operating on the extended image using an annihilator, where the extended images represent a geophysical field, and determining if the extended image obeys at least one physical characteristic. In the event that the extended image does not obey at least one physical characteristic the method may include recreating or altering the wave velocity model accordingly.

Abstract: A system, method and computer program product for seismic imaging implements a seismic imaging algorithm utilizing Reverse Time Migration technique requiring large communication bandwidth and low latency to convert a parallel problem into one solved using massive domain partitioning. Since in RTM, both the forward and reverse wave propagation is iteratively calculated on time step increments, the method implements methods that includes partitioning memory between computation and intermediate results to optimize an RTM computation. The methods make maximum use of the memory to either eliminate storing the snapshot wavefield data to disk, or hide all or a significant portion of the disk I/O time. Furthermore, the schemes can provide the flexibility to vary a number of iterations (step size) for each snapshot to be kept in the memory. If any of the given conditions changes during the process, maximum usage of the available memory is ensured.