Abstract: A technique includes obtaining seismic data acquired by seismic sensors of a composite seismic signal that is produced by the firings of multiple seismic sources. The technique includes modeling the seismic data as being a function of models for the sources and linear operators and defining desired constraints on the models. The technique includes simultaneously determining the models based on the modeling and the desired constraints. The datasets are generated based on the determined models. Each dataset is indicative of a component of the composite seismic signal and is attributable to a different one of the seismic sources.

Abstract: A method for evaluating subsurface formations includes deploying at least two intersecting seismic transducer lines above an area of the subsurface to be surveyed. Each line includes spaced apart seismic transmitters on one side of the intersection and spaced apart seismic receivers on the other side. On each line, one of the transmitters is actuated and signals are detected at one of the receivers. The foregoing is repeated for each of the remaining receivers. The foregoing is then repeated for each of the remaining transmitters on each line. The detected signals are processed to enhance both specular and non-specular seismic events in the subsurface. The enhanced events may be stored and/or displayed.

Abstract: A system for communication through subterranean structures underneath a surface comprises at least one exploration tool adapted to penetrate into the underground, at least one transmitter, at least one receiver, and signal transfer means for transmitting signals between the exploration tool and a recording unit arranged overground, where at least one of the transmitter or receiver is integrated in the exploration tool. The exploration tool is a device which is able to penetrate into the underground in order to bring equipment into the underground independent of any existing or new wells.

Abstract: The invention relates to a process for two separate seismic crews to work in proximity to one another that would otherwise require expensive time sharing where one crew is a conventional seismic acquisition system and the other is a phase encoded seismic acquisition system. Typically, each recording system would receive seismic energy from the other that neither data set would be very useful. The invention primarily envisions some collaboration between the crews where each adjusts its sweeps to comprise a different time duration so that the energy the other crew's sources are distinguishable in the data set and easily eliminated therefrom. Distinctions may be further enhanced when the two crews use construct their sweeps so that each crew has a distinctly different start frequency and a distinctly different end frequency.

Abstract: A system and method of mapping underground utilities and other subsurface objects involves one or more of acquiring utility location data using a number of different detectors and sensors, processing the multiple detector/sensor output data to produce mapping data, storing the mapping data in a database, and providing access to and use of the stored mapping data by subscribing users on a usage fee basis.

Abstract: A measurement method for a granular compaction pile 10 using a crosshole seismic test. The measurement method includes forming first to fifth measurement holes around the granular compaction pile, injecting grouting material into the first to fifth measurement holes and inserting casings into the first to fifth measurement holes, respectively, and installing an oscillator and a detector of a crosshole seismic tester in the first to fifth holes and detecting a velocity of a shearing wave, thereby measuring a diameter of the granular compaction pile according to a construction depth thereof. The shape and the diameter of the granular compaction pile are easily checked without causing damage to the granular compaction pile.

Abstract: A method for generating a synthetic seismogram. In one implementation, the method may include generating a first seismogram in a tau-p domain for a wavefront that moves through an overburden to an upper boundary of a reservoir. The first seismogram is based on a common shot point gather. The method may further include generating a second seismogram in the tau-p domain for the wavefront moving from the upper boundary to a lower boundary of the reservoir and reflected back up to the upper boundary; generating a third seismogram in the tau-p domain for the wavefront moving from the upper boundary of the reservoir through the overburden; and adding the first seismogram in the tau-p domain, the second seismogram in the tau-p domain, and the third seismogram in the tau-p domain.

Abstract: In various embodiments, seismic receivers may detect seismic energy and transmit digital signals representative of the seismic energy to an S-line interface module (SLIM) and/or a smart antenna module (SAM) for collection. A SLIM may be used to connect two or more seismic receivers together. A SAM may include a memory medium for storing digital signals from seismic receivers (e.g., received directly from the seismic receivers or received through a connection to a SLIM) and a wireless transmitter to transmit data stored on the memory medium. The SAM may further include a Global Positioning System (GPS) receiver for receiving and storing timestamps, clock data, and/or positional data relative to the seismic receivers. The timestamps, clock data, and/or positional data may be transmitted along with the digital signal data to an external source (e.g., a laptop) for analysis to detect characteristics of subterranean formations.

Abstract: A system and method of processing seismic data obtained using a surface-based receiver configured to measure vertical movement of the Earth includes retrieving seismic data from a storage device, the seismic data comprising P-P data and shear mode data. The P-P data and shear mode data were both received at a surface-based receiver configured to measure vertical movement of the Earth to generate the seismic data. The system and method further include processing the seismic data to extract the shear mode data and generating a shear mode image based on the extracted shear mode data.

Abstract: There is provided a method of seismic acquisition that utilizes a bank of restricted-bandwidth swept-frequency sub-band sources as a seismic source. Each seismic source will cover a restricted sub-band of frequencies, with all the sources taken together covering the full frequency range. Adjacent frequency bands may partially overlap, but non-adjacent frequency bands should not. The sources may be divided into two or more groups, with no sources covering adjacent frequency bands being placed in the same group. The sources within a group can then be separated by bandpass filtering or by conventional simultaneous source-separation techniques. The source groups may be operated simultaneously but separated in space, and the individual sources themselves may each operate independently, on a sweep schedule customized for that particular source.

Abstract: The maximum output of a seismic source array may be reduced by activating the individual seismic sources within these seismic source array in a pattern that is extended in time rather than by the presently employed conventional simultaneous activation of a large number of individual seismic sources. Methods are disclosed which take data shot with patterned sources and may use a sparse inversion method to create data with the about same image quality as that of conventional sources. In this manner the output of the maximum impulse of a seismic source array may be reduced by an amplitude factor of about 10 in the examples shown here, corresponding to a reduction of about 20 dB while maintaining virtually the same seismic image quality. The disclosed methods may be used in combination with any simultaneous sourcing technique. In addition, the disclosed methods may be used with a plurality of source arrays.

Abstract: A seismic sensor module includes sensing elements arranged in a plurality of axes to detect seismic signals in a plurality of respective directions, and a processor to receive data from the sensing elements and to determine inclinations of the axes with respect to a particular orientation. The determined inclinations are used to combine the data received from the sensing elements to derive tilt-corrected seismic data for the particular orientation.

Abstract: An apparatus and system for acquiring seismic data over a loose surface is disclosed. The apparatus includes a housing capable of moving on the loose surface with an opening configured at a bottom surface of the housing. The apparatus further includes a seismic sensing unit configured within the housing at an angle with respect to a horizontal plane. The horizontal plane may be the bottom surface of the housing. The seismic sensing unit is operable to retractably move within the housing towards and away from the opening. In response to the seismic sensing unit moving towards the opening, the seismic sensing unit establishes contact with the loose surface for acquiring the seismic data.

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 seismic cable for use in land applications is described. The cable includes seismic sensors for measuring seismic signals reflected from subterranean or subsea formations. The cable may be deployed in trenches dug in the survey region to provide adequate sensor coupling to ground. Sensor units may be inline with the cable and may further be disposed in slim casings, thus facilitating handling and deployment.

Abstract: Data acquisition modules and systems including batteries with integrated data storage. The battery with integrated data storage can be selectively removed from the data acquisition module. This allows for reduced logistical effort associated with data retrieval and battery charging. For instance, the entire data acquisition module need not be transported to a central location for data recovery and charging, but rather the removable battery with integrated storage may be removed and transported. Also facilitated is extended surveys in that the battery or storage module may be replaced, such that survey design limitations such as storage capacity or battery life may be eliminated.

Abstract: Implementations of various technologies for a method for processing seismic data. A first portion of a record of pre-stack seismic data may be displayed in a three-dimensional XYZ (3-D XYZ) space. A selection may be received of a second portion of the record of the pre-stack seismic data within the first portion. One or more attributes may be determined that define the second portion. One or more regions may be identified within the record of the pre-stack seismic data having the attributes that define the second portion.

Abstract: The method for exploring desired characteristics of a subsurface sector, having at least one resonant frequency, is based on selectively transmitting suitable narrowband energy waves into the subsurface sector, thereby producing narrowband signals reflected off the subsurface sector. The transmitted narrowband energy waves can be selectively and optimally adjusted in real time so as to provide optimum illumination of the desired characteristics from the explored sector.

Abstract: The disclosure identifies method and apparatus for seismic exploration which may be used to provide improved positioning of land-based seismic sources in an array. Also described are methods which make use of the improved positioning to allow, in some examples, improved direction or distribution of the energy beam resulting from actuation of the sources. Some methods make use of the described techniques to steer the energy beam; and in some cases at each source or a distribution location, multiple shots will be taken to distribute the beam in multiple orientations relative to the central source point.

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

Abstract: A method and system are disclosed for performing seismic surveys using a seismic vibrator, which generates a sweep signal (1,21) with enhanced low frequency content by generating a combination of a linear and nonlinear sweep and wherein the nonlinear sweep snonl(t) as a function of time (t) is calculated by a predetermined algorithm.

Abstract: A system and method of mapping underground utilities and other subsurface objects involves one or more of acquiring utility location data using a number of different detectors and sensors, processing the multiple detector/sensor output data to produce mapping data, storing the mapping data in a database, and providing access to and use of the stored mapping data by subscribing users on a usage fee basis.

Abstract: The present disclosure relates to a method and system for finding and physically altering underground targets. Multiple nodes are dispersed into the ground and determine their spatial orientation using seismic waves, and then operate as an array to locate and properly time kinetic pulses to focus seismic waves on the target.

Abstract: A method for seismic data acquisition includes deploying a seismic energy source at a selected position above an area of the Earth's subsurface to be evaluated. A substantially zero offset sensor is disposed proximate the seismic energy source. A plurality of seismic sensors is deployed proximate the area. At selected times the seismic energy source is actuated. Signals detected by the seismic sensors and the substantially zero offset sensor are recorded. The substantially zero offset sensor signal recording is performed for a sufficient time to detect seismic energy reflected from the subsurface.

Abstract: A seismic energy source includes a base plate and a block fixedly coupled in a frame. The base plate is configured for contact with a part of the Earth's subsurface to be seismically energized. The frame has a first electromagnet associated therewith. A second electromagnet is disposed in a travelling reaction mass, which is movably disposed in the frame between the first electromagnet assembly and the top block. The reaction mass includes at least a third electromagnet associated therewith.

Abstract: This patent delineates methods for quantifying and mitigating dip-induced azimuthal AVO effects in seismic fracture detection using Azimuthal AVO analysis by accurately accounting for the divergence correction and azimuthal dependence of the reflection angle. Solutions are provided for three cases: (1) dipping isotropic reservoirs; (2) anisotropic reservoirs with fractures aligned in arbitrary direction; and (3) anisotropic reservoirs where vertical fractures are aligned perpendicular to the dip direction.

Abstract: A method of analysing the dynamic behaviour of fracture networks in a seismic volume is provided. The method includes providing a plurality of seismic time lapse vintages of the same geological volume; identifying and parameterising fractures within fracture networks of each vintage; determining one or more distributions of fracture parameters for the fracture networks of each vintage; and identifying changes to the fracture networks by comparing corresponding distributions across the vintages.

Abstract: A method for generating a synthetic seismogram. In one implementation, the method may include generating a first seismogram in a tau-p domain for a wavefront that moves through an overburden to an upper boundary of a reservoir. The first seismogram is based on a common shot point gather. The method may further include generating a second seismogram in the tau-p domain for the wavefront moving from the upper boundary to a lower boundary of the reservoir and reflected back up to the upper boundary; generating a third seismogram in the tau-p domain for the wavefront moving from the upper boundary of the reservoir through the overburden; and adding the first seismogram in the tau-p domain, the second seismogram in the tau-p domain, and the third seismogram in the tau-p domain.

Abstract: The disclosure identifies method and apparatus for seismic exploration which may be used to provide improved positioning of land-based seismic sources in an array. Also described are methods which make use of the improved positioning to allow, in some examples, improved direction or distribution of the energy beam resulting from actuation of the sources. Some methods make use of the described techniques to steer the energy beam; and in some cases at each source or a distribution location, multiple shots will be taken to distribute the beam in multiple orientations relative to the central source point.

Abstract: Method for subsurface exploration. In one implementation, the method may include receiving a gamma value at a subsurface interface, wherein the gamma value is a ratio of Vp/Vs at the subsurface interface. Vp is the average P wave velocity and Vs is the average S wave velocity. The method may further include receiving a converted wave reflection coefficient at the subsurface interface. The converted wave reflection coefficient is a function of a density contrast at the subsurface interface and a shear velocity contrast at the subsurface interface. The method may further include determining a P wave incident angle such that the converted wave reflection coefficient is a function of substantially only the density contrast at the P wave incident angle. The P wave incident angle is referred to herein as ?. The method may further include calculating the density contrast based on the converted wave reflection coefficient at ?.

Abstract: A method for data processing includes transforming measurement data acquired in the time domain during an oilfield operation into a second domain to produce transformed data; identifying distortions in the transformed data; removing the distortions from the transformed data; and transforming back from the second domain to the time domain to produce cleaned-up data. The transforming measurement data may use a Fourier transform or a wavelet transform. The method may further include compressing the cleaned-up data or reconstructing signals from the cleaned-up data. A method for data processing includes decomposing measurement data, which are acquired in an oilfield operation, using a low pass filter to produce a first dataset; decomposing the measurement data using a high pass filter to produce a second dataset; removing distortions from the second dataset to yield a corrected second dataset; and reconstructing a corrected dataset from the first dataset and the corrected second dataset.

Abstract: A seismic exploration method and unit comprised of continuous recording, self-contained wireless seismometer units or pods. The self-contained unit may include a tilt meter, a compass and a mechanically gimbaled clock platform. Upon retrieval, seismic data recorded by the unit can be extracted and the unit can be charged, tested, re-synchronized, and operation can be re-initiated without the need to open the unit's case. The unit may include an additional geophone to mechanically vibrate the unit to gauge the degree of coupling between the unit and the earth. The unit may correct seismic data for the effects of crystal aging arising from the clock. Deployment location of the unit may be determined tracking linear and angular acceleration from an initial position. The unit may utilize multiple geophones angularly oriented to one another in order to redundantly measure seismic activity in a particular plane.

Abstract: The invention relates to oil-gas engineering, in particular to maintaining wells in the oil-gas industry and, more specifically the hydraulic fracturing seismic monitoring. A first method is carried out when a pulse amplitude is sufficient for opening a strike-slip fractures around a crack, wherein said crack is detectable with the aid of traditional means for passively recording seismic waves produced by acoustical events related to the opening of strike-slip fractures and by interpreting the position of the thus obtained events in the form of the events adjacent to the crack.

Abstract: The method for exploring desired characteristics of a subsurface sector, having at least one resonant frequency, is based on selectively transmitting suitable narrowband energy waves into the subsurface sector, thereby producing narrowband signals reflected off the subsurface sector. The transmitted narrowband energy waves can be selectively and optimally adjusted in real time so as to provide optimum illumination of the desired characteristics from the explored sector.

Abstract: A technique includes operating a seismic vibrator, including driving the seismic vibrator at different frequencies and driving forces. The technique includes monitoring a parameter affected by the operation of the seismic vibrator during the frequency sweep and based at least in part on the monitored parameter, determining a maximum driving force profile for the seismic vibrator.

Abstract: The invention relates to a method for fracture plane reconstruction in a three-dimensional set (20) of values, comprising the steps of providing a computer with the three-dimensional set, display by the computer of a succession of plane sections (10) of the three-dimensional set, selection by the user of points of the fracture plane over some of these sections during their display; and reconstruction by the computer of the fracture plane from the selected points.

Abstract: Seismic data may be imaged using or recognizing substantially only primary reflections. Imaging seismic data may include for example integrating a plurality of seismic data points that have substantially similar arrival directions, for example, to a modeled primary ray. Seismic data points may be imaged that for example substantially meet a set of predetermined conditions, for example, conditions substantially unique to primaries, which may include for example arrival direction and angle of reflection.

Abstract: According to a preferred aspect of the instant invention, there is provided herein a system and method for using both a temporal zone of seismic data and conditioned amplitude spectra thereof to determine the underlying layer sequence. The instant invention is suitable both for determining layer positions and layer impedance magnitudes, that best describes the geologic sequence sampled by a band limited seismic source wavelet as reflected from the zone.

Abstract: A seismic exploration method and unit comprised of continuous recording, self-contained wireless seismometer units or pods. The self-contained unit may include a tilt meter, a compass and a mechanically gimbaled clock platform. Upon retrieval, seismic data recorded by the unit can be extracted and the unit can be charged, tested, re-synchronized, and operation can be re-initiated without the need to open the unit's case. The unit may include an additional geophone to mechanically vibrate the unit to gauge the degree of coupling between the unit and the earth. The unit may correct seismic data for the effects of crystal aging arising from the clock. Deployment location of the unit may be determined tracking linear and angular acceleration from an initial position. The unit may utilize multiple geophones angularly oriented to one another in order to redundantly measure seismic activity in a particular plane.

Abstract: Solutions to the problem of reversing seismic fault movements are formulated using a model based on elasticity theory, and using finite element and boundary element methods for generating a solution. The solution involves defining slip vectors from known formations in the fault and applying a space constraint restriction to traction values on the fault surface. The method may be applied in either 2D or 3D applications. The method is computationally fast enough to allow interactive fault reversal, and permits experimentation with various unfaulting scenarios so that a geologically acceptable solution is provided.

Abstract: A method of imaging in an underground formation one or more steep-sloping geologic interfaces, which are not necessarily in a plane, by forming with primary reflectors, which are not necessarily in a plane, dihedra giving rise to prismatic seismic reflections (double reflections). The geometry of the steep-sloping interface is determined from choosing seismic records of one or more events corresponding to prismatic reflections for different source-pickup pairs of an acquisition device. A new reflection tomography technique is used, wherein introduction of specific constraints guarantees the convergence of the algorithm. The velocity distribution in the geologic formation and/or the geometry of the interface(s) between the sedimentary layers can be known otherwise or determined by means of the method. The method can apply to a formation comprising several different sloping interfaces.

Abstract: A seismic sensor includes a seismic energy detector having a case configured to be affixed to the ground. A portion of the case above the ground surface is exposed. An energy distributing shield is affixed directly to the exposed portion of the case. A method for seismic data acquisition includes affixing a plurality of spaced apart seismic sensors to the ground surface. Each of the sensors includes a shield affixed directly to an exposed portion of the sensor. The shield is made from an energy distributing material. At selected times a seismic energy source is actuated. Signals generated by each of the seismic sensors are recorded individually.

Abstract: A system and method of mapping underground utilities and other subsurface objects involves one or more of acquiring utility location data using a number of different detectors and sensors, processing the multiple detector/sensor output data to produce mapping data, storing the mapping data in a database, and providing access to and use of the stored mapping data by subscribing users on a usage fee basis.

Abstract: This invention is a method of separating induced microseismicity signals from seismic signals acquired within active seismic monitoring operations carried out in underground zones under development which has application for monitoring of underground hydrocarbon or fluid storage reservoirs. Seismic records are formed from signals emitted by one or more seismic sources controlled by orthogonal signals. In this case, the signals are processed to separate the respective contributions of the at least one seismic source to the signals received and to reconstruct the seismograms equivalent to those that would be obtained by actuating the at least one seismic source separately.

Abstract: A method of investigating a reservoir region in a subsurface formation by a time-lapse seismic survey. The subsurface formation comprises a further formation region adjacent to the reservoir region. Data are obtained from a time-lapse seismic survey and includes seismic data of the subsurface formation at a first point in time and a later point in time. The seismic data is processed to obtain a seismic representation of change in a predetermined seismic parameter in the further formation region, whereby the seismic parameter is dependent on stress. The seismic representation of change in the seismic parameter in the further formation region is interpreted for an indication of changes of stress distribution in the further formation region, and a property of the reservoir region is derived using the indication of change of stress distribution in the further formation region.

Abstract: The combination of a portable article and a security system. The security system has a flexible element/tether with a length. The flexible element/tether is connected between the portable article and a support to confine movement of the portable article within a range dictated by the length of the flexible element/tether. The flexible element/tether has a flexible core and a protective layer over the core. The protective layer is made at least partially from a material that is resistant to being cut to thereby avoid severance of the flexible core.

Abstract: A Method for Interpreting Seismic Data Using Duplex Waves is described. Whereas substantially horizontal boundaries are readily identified using conventional processing methods based on primary reflections, it has been difficult or impossible to use such methods for locating substantially vertical events or boundaries. The method of the present invention uses secondary reflections to locate substantially vertical events by gathering common source or receiver traces for processing. Wave fields of these gathers are continued downward to the level of the base boundary, then at each discrete depth level, a seismic image of sub-vertical events is formed. The downward-continued gathers correspond to the travel time of the wave from when it left the source or the receiver point, was reflected from the base boundary, and arrived to the corresponding point of the discrete level of wave-field continuation.

Abstract: An electromechanical device for generating elastic waves in a material medium such as the subsoil in a frequency range where the wavelengths of the waves generated are great in view of the dimensions of the device, and method of implementation. The device comprises one or more vibrators which are buried in the medium, associated with a control system. Each vibrator comprises at least one inertia mass (1), several plates (2, 3) providing mechanical coupling with the medium, electromechanical transducers (4, 5) connecting inertia masses (1) to plates (2, 3). A control system (7) applies to the various transducers (4, 5) respective control signals so that the resulting elastic wavefield generated in the medium by the device is preferentially oriented in one or more directions.

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 is disclosed for processing seismic data. The method includes prestack depth migrating the seismic data to generate common image gathers using an initial velocity-depth model. Horizons in the migrated seismic data are selected. Residual migration velocity analysis in the depth-offset domain is performed with respect to each selected horizon, and the velocity-depth model is updated based on the residual migration velocity analysis.