Abstract: Disclosed are advantageous designs for highly-sparse seabed acquisition for imaging geological structure and/or monitoring reservoir production using sea surface reflections. The highly-sparse geometry designs may be adapted for imaging techniques using the primary and higher orders of sea surface reflection and may advantageously allow for the use of significantly fewer sensors than conventional seabed acquisition. The highly-sparse geometry designs may be relevant to 3D imaging, as well as 4D (“time-lapse”) imaging (where the fourth dimension is time). In accordance with embodiments of the invention, geophysical sensors may be arranged on a seabed to form an array of cells. Each cell in the array may have an interior region that contains no geophysical sensors and may be sufficiently large in area such that a 500 meter diameter circle may be inscribed therein.

Abstract: A pig has a body of resiliently compressible material extending along a central longitudinal axis. At least one strain gauge is embedded in the material of the body. The or each strain gauge extends transversely with respect to the central longitudinal axis and is arranged to deflect and elongate longitudinally with longitudinal deflection of a forward end of the body.

Abstract: A method is described for seismic imaging including determination of reservoir stresses. The method may include the use of elastic full waveform inversion (FWI), 3rd-order elasticity, and finite-difference strain calculations. The method may be executed by a computer system.

Abstract: Translational data in a first direction is measured by particle motion sensors contained in an elongated housing of a sensor device provided at an earth surface. The particle motion sensors are spaced apart along a second, different direction along a longitudinal axis of the elongated housing. Rotation data around a third direction is computed based at least in part on computing a gradient of the translational data with respect to the second direction.

Abstract: The presently disclosed technology relates to an arrangement for seismic acquisition where the spacing between adjacent pairs of receiver and sources lines is not all the same. Some receiver and/or source lines and/or receiver and/or source spacings are larger and some are smaller to provide a higher quality wavefield reconstruction when covering a larger total area or for a similar total area of seismic data acquisition, while providing a wavefield that is optimally sampled by the receivers and sources so that the wavefield reconstruction is suitable for subsurface imaging needs.

Abstract: The present disclosure is directed to a MEMS-based rotation sensor for use in seismic data acquisition and sensor units having same. The MEMS-based rotation sensor includes a substrate, an anchor disposed on the substrate and a proof mass coupled to the anchor via a plurality of flexural springs. The proof mass has a first electrode coupled to and extending therefrom. A second electrode is fixed to the substrate, and one of the first and second electrodes is configured to receive an actuation signal, and another of the first and second electrodes is configured to generate an electrical signal having an amplitude corresponding with a degree of angular movement of the first electrode relative to the second electrode. The MEMS-based rotation sensor further includes closed loop circuitry configured to receive the electrical signal and provide the actuation signal. Related methods for using the MEMS-based rotation sensor in seismic data acquisition are also described.

Abstract: Provided is an interferometer for inspecting a test sample. The interferometer includes: a light source for providing a light beam; a beam splitting element, splitting the light beam into first and second incident light, wherein the first incident light is reflected by the test sample into first reflection light; a reflecting element, reflecting the second incident light into second reflection light; an optical detection element, receiving the first and the second reflection light into an interference signal; and a signal processing module, coupled to the optical detection element, for performing spatial differential calculation on the interference signal to generate a demodulation image of the test sample.

Abstract: An electrically passive device and method for in-situ acoustic emission, and/or releasing, sampling and/or measuring of a fluid or various material(s) is provided. The device may provide a robust timing mechanism to release, sample and/or perform measurements on a predefined schedule, and, in various embodiments, emits an acoustic signal sequence(s) that may be used for triangulation of the device position within, for example, a hydrocarbon reservoir or a living body.

Abstract: Apparatus and methods for acquiring seismic data using a seabed seismic data cable positioned on a seabed are described, including correcting for the effect of one or more sensor non-linear motions, which improves accuracy of seismic data. One or multiple non-linear movements of the sensor may be corrected for. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: An electrically passive device and method for in-situ acoustic emission, and/or releasing, sampling and/or measuring of a fluid or various material(s) is provided. The device may provide a robust timing mechanism to release, sample and/or perform measurements on a predefined schedule, and, in various embodiments, emits an acoustic signal sequence(s) that may be used for triangulation of the device position within, for example, a hydrocarbon reservoir or a living body.

Abstract: Rotation data and translational data are received. A calibration operator is determined based on the rotation data and translational data, where the calibration operator is useable to relatively calibrate the rotation data and the translation of data.

Abstract: A method for spatial sampling of a seismic wavefield at the bottom of a water layer at an effective spatial sampling denser than the physical layout of the sensors. The sensors comprise a sensing element for vertical particle motion and a sensing element for rotational motion around a horizontal axis. Stress and wavefield conditions allow the rotational sensing element to yield the transverse horizontal gradient of the vertical particle motion wavefield, used in ordinate and slope sampling to yield improved transverse spatial sampling of the vertical particle motion wavefield.

Abstract: Method and system for improving azimuth distribution. The system includes plural streamers towed by a streamer vessel; a central source towed by the streamer vessel; first and second front sources located in front of the plural streamers along a traveling direction of the streamer vessel; and first and second tail sources located behind of the plural streamers along the traveling direction. The offset distance between the first and second tail sources, along a cross-line direction, is larger than an offset distance between the first and second front sources.

Abstract: An electrically passive device and method for in-situ acoustic emission, and/or releasing, sampling and/or measuring of a fluid or various material(s) is provided. The device may provide a robust timing mechanism to release, sample and/or perform measurements on a predefined schedule, and, in various embodiments, emits an acoustic signal sequence(s) that may be used for triangulation of the device position within, for example, a hydrocarbon reservoir or a living body.

Abstract: In one embodiment, a method of processing seismic data using a single triaxial geophone is disclosed, where the method comprises acts of calibrating the single triaxial geophone sensor to determine a position and an orientation relative to a surrounding environment, configuring the single triaxial geophone sensor to receive seismic data from the surrounding environment along three orthogonal axes, measuring, with the single triaxial geophone sensor, a plurality of time series of seismic data from the surrounding environment for the three orthogonal axes, storing, with a computer system coupled to the single triaxial geophone sensor, the time series of seismic data from the surrounding environment for the three orthogonal axes, and processing, with the computer system, the time series of seismic data to identify a plurality of seismic waves of different polarizations.

Abstract: Translational data acquired by at least one translational survey sensor is received, and rotation data is received. A representation of wavefield velocity based on the translational data and the rotation data is determined.

Abstract: Computing device, computer instructions and method for deghosting seismic data related to a subsurface of a body of water. The method includes receiving seismic data recorded by seismic receivers that are towed by a vessel, wherein the seismic data is recorded in a time-space domain and the seismic receivers are located at different depths (zr) in the body of water; modeling the seismic data in a shot or common midpoint domain as a function of linear operators that re-ghost the receiver to derive a model; using the derived model to remove the receiver ghost from the seismic data to obtain deghosted seismic data; and generating a final image of the subsurface based on the deghosted seismic data.

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: A borehole seismic acquisition system is described with a plurality of sensors arranged so as to identify within the data measured by the pressure sensors P- and S-wave related signals converted at the boundary of the borehole into pressure waves, the sensors being best arranged in groups or clusters sensitive to pressure gradients in one or more directions.

Abstract: A method for seismic surveying includes disposing a plurality of seismic sensors in a selected pattern above an area of the Earth's subsurface to be evaluated. A seismic energy source is repeatedly actuated proximate the seismic sensors. Signals generated by the seismic sensors, indexed in time with respect to each actuation of the seismic energy source are recorded. The recorded signals are processed to generate an image corresponding to at least one point in the subsurface. The processing includes stacking recordings from each sensor for a plurality of actuations of the source and beam steering a response of the seismic sensors such that the at least one point is equivalent to a focal point of a response of the plurality of sensors.

Abstract: A sensor assembly has first sensors spaced apart along a first direction, and second sensors oriented in a second direction generally orthogonal to the first direction. Differencing of outputs of the first sensors is performed, and differencing of outputs of the second sensors is performed. A signal output is produced by combining the differenced outputs of the first sensors and the differenced outputs of the second sensors, where the signal output represents a seismic response of a subterranean structure.

Abstract: The present invention concerns a method and an antenna for active and/or passive seismic survey, such as a particular geometric layout of a plurality of vibration sensors, each one of adequate sensitivity, to be used with signal correlation in seismic surveys with or without an artificial wave source. In particular, the invention concerns a specific geometric layout of four vibration sensors, set along an alignment at positions, with one position chosen so that the antenna covers the desired wavelength interval. The sum of the signal correlations of all possible sensor couples allows a uniform sampling of all the spatial wavelengths that such an antenna defines, producing an accurate measure of the elastic and anelastic parameters of the subsoil and of the vibrational modes of a construction with the minimum possible number of sensors and minimum physical dimensions.

Abstract: A vibration sensor system for contacting the surface of a solid medium for detecting horizontally polarized shear waves and compressional waves. At least two contact points interface between a vibration sensor array and the solid medium to provide uninterrupted contact with the medium during detection of dynamic motions in the medium. A single vibration sensor is mounted on at least two adjacent contact points to convert detected dynamic motions to corresponding electrical signals. The single vibration sensor mounted on the two adjacent contact points forms a sub-array. The vibration sensor system has at least two sub-arrays. A conditioning and combining member treats sensor electrical signals from at least two sub-arrays to form a composite output signal for the system.

Abstract: A subterranean survey system includes a sensor string having a communications link and a plurality of survey sensors connected to the communications link. The sensor string has a loop connection to provide communications redundancy, and the survey sensors are used to detect signals affected by a subterranean structure. A first router is connected to the sensor string, and a transport network is connected to the first router. The first router communicates data from the survey sensors over the transport network.

Abstract: A method and apparatus for generating a seismic source signal are provided for generating energy in the form of a plurality of time sequence vibratory signals, the vibratory signals being partitioned as a function of time and/or frequency, wherein each of the plurality of signals comprises a distinguishing signature. The partitioned vibratory signals are emitted into a terrain of interest as seismic source signals for conducting a seismic survey.

Abstract: A method for processing geophysical data. The method includes applying a first interferometry on an estimate of a direct ground roll between a receiver location and one or more boundary source locations and an estimate of a direct ground roll between one or more boundary receiver locations and each boundary source location to generate an interferometric estimate of a direct ground roll between the receiver location and each boundary receiver location. The method then includes applying a second interferometry on geophysical data between the source location and each boundary receiver location and the interferometric estimate of the direct ground roll between the receiver location and each boundary receiver location to generate an interferometric estimate of a direct and scattered ground roll between the source location and the receiver location.

Abstract: Described herein is a land seismic data acquisition system comprising a central processing unit; a cabled network connected to the central processing unit comprising a plurality of acquisition lines each comprising: electronic units assembled in series along a telemetry cable and each associated with at least one seismic sensor, the units processing signals transmitted by the sensor(s); intermediate modules assembled in series along the telemetry cable and each associated with at least one of the electronic units, each intermediate module providing power supply and synchronization of the electronic unit(s) wherewith it is associated; wherein each electronic unit is associated with at least two intermediate modules including at least one upstream and at least one downstream from the electronic unit along the telemetry cable, and comprises synchronization means independent from the cabled network, bidirectional and autonomous power supply means, bidirectional storage means of the signals processed by the electr

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 sensor assembly has first sensors spaced apart along a first direction, and second sensors oriented in a second direction generally orthogonal to the first direction. Differencing of outputs of the first sensors is performed, and differencing of outputs of the second sensors is performed. A signal output is produced by combining the differenced outputs of the first sensors and the differenced outputs of the second sensors, where the signal output represents a seismic response of a subterranean structure.

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: To perform seismic surveying, a plurality of sensor assemblies are provided, where each of multiple ones of the plurality of sensor assemblies has a seismic sensor and a divergence sensor, and where the divergence sensor is used to measure noise. In addition, the plurality of sensor assemblies are arranged in a layout designed to acquire seismic signals in a target sampling pattern, where the layout is independent of provision of sensor assemblies for noise acquisition.

Abstract: A receiver point arrangement is deployed having one or more receiver lines, each receiver line having receivers with substantially uniform inline spacing. A seismic source is triggered at each source point in an arrangement of source points along one or more source lines, each source line having source points with substantially uniform crossline spacing. Seismic data traces are collected, each trace having an associated midpoint. A perturbation pattern is applied to at least one of the receiver point arrangement and the source point arrangement to distribute the midpoints evenly within a bin having dimensions of half the receiver inline spacing and half the source crossline spacing across multiple locations within that bin.

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: A method for seismic surveying includes disposing a plurality of seismic sensors in a selected pattern above an area of the Earth's subsurface to be evaluated. A seismic energy source is repeatedly actuated proximate the seismic sensors. Signals generated by the seismic sensors, indexed in time with respect to each actuation of the seismic energy source are recorded. The recorded signals are processed to generate an image corresponding to at least one point in the subsurface. The processing includes stacking recordings from each sensor for a plurality of actuations of the source and beam steering a response of the seismic sensors such that the at least one point is equivalent to a focal point of a response of the plurality of sensors.

Abstract: A method for analyzing seismic data from a formation. The method may first receive two-dimensional (2-D) seismic data of a formation comprising a number of individual seismic lines acquired over an exploration area and having a large interline spacing. The 2-D seismic data may then be preprocessed to enhance diffracted energy. For each respective hypothetical diffractor location, the method may then search for coherent diffraction arrivals on nearby 2-D seismic lines consistent with the respective hypothetical diffractor location. The method may then store information regarding identified diffractor locations. The method may then create a map based on the identified diffractor locations, wherein the map illustrates areas of high diffraction. The map may then be displayed on a display, wherein the map is useable to assess the formation.

Abstract: Method for determining acceptability of sensor locations used to perform a seismic survey. In one implementation, the method includes obtaining a first set of reference data, generating a first output trace from a second set of reference data estimated from the first set of reference data at a plurality of planned sensor locations, generating a second output trace from a third set of reference data estimated at a plurality of actual sensor locations and comparing the second output trace with the first output trace to determine whether the variation between the second output trace and the first output trace is less than a predetermined value.

Abstract: Methods and systems for estimating one or more orientation parameters of a seismic apparatus are described. One method comprises initiating an acoustic signal from an acoustic transmitter in a marine seismic spread comprising a streamer, the streamer having at least two nodes separated by a fixed distance; measuring a first and a second difference in acoustic arrival times at the nodes for the acoustic signal; and using change in the second difference from the first difference to estimate orientation of the streamer. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: The specification discloses a system and related method for installing seismic sensors in shallow, low-angle boreholes for obtaining conventional three-dimensional and four-dimensional seismic surveys. Installing seismic sensors in shallow, low-angle boreholes removes the sensing devices from surface anomalies that may affect seismic sensing performance. Moreover, installation of the seismic devices in this manner may be done in environmentally sensitive areas without undue environmental impact.

Abstract: A method for estimating near-surface material properties in the vicinity of a locally dense group of seismic receivers is disclosed. The method includes receiving seismic data that has been measured by a locally dense group of seismic receivers. Local derivatives of the wavefield are estimated such that the derivatives are centered at a single location preferably using the Lax-Wendroff correction. Physical relationships between the estimated derivatives including the free surface condition and wave equations are used to estimate near-surface material properties in the vicinity of the receiver group. Another embodiment of the invention is disclosed wherein the physical relationships used to estimate material properties are derived from the physics of plane waves arriving at the receiver group, and the group of receivers does not include any buried receivers.

Abstract: A system and method of creating a filter for use with locally dense seismic data is disclosed. The method includes obtaining survey geometry characteristics from a locally dense seismic survey. A filter is designed which uses spatial derivatives of the wavefield of order between (1) and the maximum order of spatial derivatives of the wavefield that can be estimated within a group. The filter can be designed so as to separate up/down going components, p/s components, or both up/down and p/s components. Partial derivatives in space and time of the wavefield can be calculated, using, for example, a taylor series expansion as an approximation. The seismic data is filtered by combining estimated near surface material properties, the seismic data, and the calculated partial derivatives.

Abstract: Seismic detection apparatus comprising seismic detection means capable of detecting a plurality of seismic components over a defined tetrahedral volume is provided. The seismic detection means comprises four three-component geophones. Seismic data acquired by the geophones is processed to separate P-wave components from S-wave components. The geophones are spaced apart by distances smaller than the wavelength of the detected seismic components. The apparatus may be used on surface or in a marine environment or transition zone. A method of processing seismic data is also provided comprising acquiring seismic data relating to a wavefield over a selected volume of acquisition, and measuring the curl and divergence of the wavefield from the seismic data, to thereby identify seismic components within the seismic data. Additionally, an apparatus and method for hydrocarbon exploration is disclosed for using three or more seismic receivers placed in a plane and spaced closely to each other.

Abstract: The invention is a method for determining the orientation of a multi-component receiver where the preferred embodiment of the method makes use of an approximation of the relative bearing angle provided by a relative bearing sensor. The method comprises the steps of scanning various angles around the approximated relative bearing angle provided by the relative bearing sensor and for each scanned angle rotating the data into the true earth frame using a given scanned angle and measuring the polarization angle of the rotated data in the horizontal plane and calculating a weighted sum of the differences between the source azimuth and the estimated azimuth from the polarization.

Abstract: The specification discloses a system and related method for installing seismic sensors in shallow, low-angle boreholes for obtaining conventional three-dimensional and four-dimensional seismic surveys. Installing seismic sensors in shallow, low-angle boreholes removes the sensing devices from surface anomalies that may affect seismic sensing performance. Moreover, installation of the seismic devices in this manner may be done in environmentally sensitive areas without undue environmental impact.

Abstract: A method for estimating near-surface material properties in the vicinity of a locally dense group of seismic receivers is disclosed. The method includes receiving seismic data that has been measured by a locally dense group of seismic receivers. Local derivatives of the wavefield are estimated such that the derivatives are centered at a single location preferably using the Lax-Wendroff correction. Physical relationships between the estimated derivatives including the free surface condition and wave equations are used to estimate near-surface material properties in the vicinity of the receiver group.

Abstract: A system for, and method of, orienting seismic energy sources and seismic energy receivers to substantially separate a compressional wave from a vertical shear wave. The method includes reflecting a seismic energy from a subsurface interface to produce a reflected seismic energy wave that has a compressional energy and vertical shear energy associated therewith. A first seismic energy receiver is oriented such that it is aligned with an angle of emergence of the reflected seismic energy wave to thereby maximize the vertical shear energy received by a second seismic energy receiver.

Abstract: Method intended for absolute preserved amplitude processing of data obtained by seismic prospecting known as VSP.

Abstract: A system and method of creating a filter for use with locally dense seismic data is disclosed. The method includes obtaining survey geometry characteristics from a locally dense seismic survey. A filter is designed which uses spatial derivatives of the wavefield of order between (1) and the maximum order of spatial derivatives of the wavefield that can be estimated within a group. The filter can be designed so as to separate up/down going components, p/s components, or both up/down and p/s components. Partial derivatives in space and time of the wavefield can be calculated, using, for example, a taylor series expansion as an approximation. The seismic data is filtered by combining estimated near surface material properties, the seismic data, and the calculated partial derivatives.

Abstract: A system and method for periodically providing information about subsurface formations in a marine environment using a non-towed seismic signal source (3) and a static array of seismic signal receivers (4) is disclosed. The seismic signal source (3) comprises a support frame (10) and a line (7) attaching the support frame to a stationary platform (2), wherein the line (7) restrains the support frame (10) in a position that is static in relation to the formation (8). The seismic signal source (3) includes eight air guns (12) attached to the support frame (10) such that the air guns (12) are discharged to provide a tapered, heavy centered, point source seismic signal at a specific location relative to the formation (8) that is reflected to the static array of seismic signal receivers (4) such that changes in the formation characteristics may be observed over time.

Abstract: The method consists in building a common midpoint gather of seismic traces of which the CMP point is said given point, subjecting the traces of this gather to dynamic and/or static corrections, and characterized in that the gather associated with the given point (A) is built by recording four CMP sub-gathers associated with said given point along four angular directions (1 to 4) passing through said given point, and dynamic and/or static corrections are applied to each of the four CMP sub-gathers in order to determine, for each sub-gather, a value of the curvature and/or the velocity optimizing the energy of the trace stack of the corrected sub-gather concerned, the four values thus obtained representing the components of the stacking velocity field desired for each of the reflector elements corresponding to the given point, and characterized by a vertical propagation time t0 with reflection for zero offset.Application in particular to the exploration of a medium with a complex tectonics.

Abstract: A method for performing a seismic survey with even fold. An inline direction and a crossline direction are selected. Seismic signals are generated at a plurality of source locations positioned along one or more source lines. The source locations are substantially equally spaced, and the source lines are substantially parallel to each other. Seismic signals are detected at a plurality of receiver locations positioned along a plurality of receiver paths having longitudinal axes parallel to the inline direction, and substantially equally spaced in each receiver path. Each receiver path is positioned along its axis, and extends in a regular pattern on both sides of the axis. The axes are substantially parallel to each other. A desired fold, F.sub.i, is determined in the inline direction, and a desired fold, F.sub.x, is determined in the crossline direction. A number of receiver channels, NC.sub.i, per receiver path in the inline direction, a spacing, RI.sub.