Abstract: A marine seismic data acquisition system includes a streamer spread including plural streamers; a first set of front sources configured to generate seismic waves; a streamer vessel towing the streamer spread and the first set of the front sources, in front of the streamer spread along an inline direction X; a second set of top sources configured to generate additional seismic waves; and first and second source vessels towing the second set of top sources directly above or below the streamer spread. A number NT of the top sources is larger than a number NF of the front sources.

Abstract: A sensing system and a sensing signal measuring method thereof are provided. The sensing system includes a signal source, a connecting device, a frequency sweep circuit, and a controller. In the method, the signal source is activated to generate a specific signal. The controller controls the frequency sweep circuit to switch a frequency band of a frequency sweep signal to a first frequency band corresponding to each of a plurality of types of multi-point sensors. The controller receives a sensor signal of each multi-point sensor through the connecting device, where the sensor signal is a variation of a measurement signal output by each multi-point sensor in response to the specific signal and the frequency sweep signal. The controller executes an adaptive algorithm on the sensor signal to construct a correspondence between an eigenvalue of each multi-point sensor and a location of the first frequency band, and records the correspondence.

Abstract: A method for estimating a far field seismic energy source signature includes using detected near field seismic signals corresponding to actuation of each one of a plurality of seismic energy sources in an array of seismic energy sources. The near field seismic signals are detected at two spaced apart locations in the near field of each seismic energy source, the at least two spaced apart locations being arranged such that a direction of propagation of the detected near field seismic signals is determinable from the detected near field signals. A notional source signature for each seismic energy source and a notional ghost for each seismic energy source using the detected near field seismic signals. A far field signature is determined for the plurality of seismic energy sources using the determined notional source signature and notional ghost signature from each seismic energy source.

Abstract: Methods and systems for seismic data acquisition in a survey area use compressed sensing and take into consideration operational limitations. The operational limitations may be related to the equipment used for the survey, the topography of the surveyed area or limitations that otherwise optimize the survey path.

Abstract: A method of seismic acquisition using a dispersed-source array (DSA) comprising two or more sources. The method comprises determining, for each of the two or more sources of the DSA, an individual spectrally-banded waveform. For each of the two or more sources, a primary waveform is formed by repeating the individual spectrally-banded waveform. For each of the two or more sources, a secondary waveform is formed based on the primary waveform. The secondary waveform is spectrally shifted relative to the primary waveform such that secondary waveforms of any two of the two or more sources are spectrally non-overlapping. The blending operator based on the secondary waveform of each of the two or more sources is provided to the DSA. The method also includes performing deblended-data reconstruction of acquired seismic data using one or more properties of the blending operators of the two or more sources.

Abstract: A method, apparatus and computer program product for secure communication includes receiving a message for transmission from a transmitting node to a receiving node. The message is split into a plurality of channels and each channel receives an identical copy of the message. Noise data is added to each version of the message. The noise data is different for a respective copy of the message than any other version of the message thus producing a plurality of ciphers each for a respective channel. The ciphers are transmitted via the respective channels from the transmitting node to the receiving node.

Abstract: A system is described that comprises a plurality of sensor nodes and at least one remote server, wherein each sensor node of the plurality of sensor nodes and the at least one remote server are communicatively coupled, wherein the plurality of sensor nodes receive at least one acoustic signal, process the at least one acoustic signal to detect one or more transient events, classify the one or more transient events as an event type, and determine geometry information and timing information of the one or more transient events. The system comprises at least one of the plurality of sensor nodes and the at least one remote server identifying the source of the one or more transient events.

Abstract: A notional source signature of a bubble may be determined. For example, a method for determining a notional source signature of a bubble can include estimating a position of a bubble created by actuation of an impulsive source. A notional source signature of the bubble can be determined based on the estimate.

Abstract: Seismic data obtained from a seismic survey conducted of a subterranean region is received. The seismic data includes multiple frequency components, having a frequency bandwidth. A target, to-be-picked horizon is identified by displaying well data on the seismic section and correlating the seismic reflector with layer tops in the well data. A horizon represents a seismic reflector between two geological layers in the subterranean region. A single frequency that gives rise to a predetermined continuity along the target horizon is determined from the frequency bandwidth of the seismic data. The seismic data is filtered to mono-frequency volumes. The mono-frequency seismic volumes include a single frequency component. A horizon is picked corresponding to the target horizon based on the mono-frequency volumes. The identified horizon corresponding to the target horizon is output for determining geological features of the subterranean region based on the identified horizon.

Abstract: A method for wavefield separation of sonic data is provided. The method comprises estimating direct phases of waveforms of sonic data observed with two or more sensors by using cross-correlation of waveform traces at adjacent sensor locations, removing the direct phases from the observed waveforms, and extracting event signals from the waveforms after removing the direct phases.

Abstract: Methods and systems for performing multiple pulse LIDAR measurements are presented herein. In one aspect, each LIDAR measurement beam illuminates a location in a three dimensional environment with a sequence of multiple pulses of illumination light. Light reflected from the location is detected by a photosensitive detector of the LIDAR system during a measurement window having a duration that is greater than or equal to the time of flight of light from the LIDAR system out to the programmed range of the LIDAR system, and back. The pulses in a measurement pulse sequence can vary in magnitude and duration. Furthermore, the delay between pulses and the number of pulses in each measurement pulse sequence can also be varied. In some embodiments, the multi-pulse illumination beam is encoded and the return measurement pulse sequence is decoded to distinguish the measurement pulse sequence from exogenous signals.

Abstract: A method of estimating a velocity of a geological layer includes a. providing a first, initial model including an interval velocity associated with a subsurface location and an uncertainty associated with the interval velocity; b. providing data including an actual or approximated root-mean-square (RMS) velocity associated with a subsurface location and an uncertainty associated with the RMS velocity; and c. estimating a second model including an interval velocity associated with a subsurface location and an uncertainty associated with the interval velocity, based on the interval velocity and the uncertainty of the first model, and the RMS velocity and the uncertainty of the data.

Abstract: Sweep signals for vibrators used to generate seismic signals for seismic surveys are described. By selecting a certain amount of one or more odd order harmonic components to be included in the sweep signal, the amplitude of the seismic signal generated by the vibrator can be increased.

Abstract: A measure of structural growth of subsurface geological formations layers or intervals is obtained to investigate and analyze layer structure development history. The measure or indication can be considered a structural growth index (SGI) and is used to evaluate for possible presence of hydrocarbons in the layers or strata in a structure of concern. The structural growth measure or index for a given geologic interval of interest is defined as the ratio of the layer thickness difference measured at two selected locations, one at a structural high and the other at a structural low of layer or interval, over the larger number of the paired-thickness measurements. The structural growth measure is determined for a series of sequentially layered geologic formations of interest and displays of determined measures are formed as functions of geologic time for the formations. Based on the structural growth measure, the geologic growth history of the given oil field structure is revealed quantitatively.

Abstract: Marine surveys carried out with multiple source arrays comprising three or more sources are discussed. Each source of a multiple source array is an array of source elements, such as air guns. The sources of a multiple source array may be arranged in particular type of configuration that is effectively maintained while the survey vessel travels a sail line. The sources of the multiple source array are activated to acoustically illuminate a subterranean formation with acoustic signals. Two or more sources of a multiple source array may be activated to create blended seismic data. Methods to deblend, source deghost, and attenuate noise in the blended seismic data obtained by using a multiple source array are also discussed.

Abstract: Improved methods of gather high fidelity vibratory seismic surveys for ZenSeis® systems wherein at least one optimal phase encoding schemes for surveys having 2-8 vibratory sources are disclosed. These encoding schemes can be hard coded into the source controller and will allow for quality data to be obtained on each survey. Further, the data will also have the best separation during inversion processing steps, leading to an optimal seismic survey.

Abstract: A sequence generator implemented on a processor that generates a sequence of signals applies a feedback shift register with feedback. A feedback loop connects at least a first and a second shift register element to last shift register element to a first shift register element of the shift register and includes at least one two-input n-state switching functions that is characterized by non-associative switching functions or switching tables. The sequence generator may be part of a scrambler, an autonomous sequence generator, a hash code generator, a communication device, and a data storage device.

Abstract: A method for attenuating noise in seismic data signals is described wherein seismic signals are transmitted using a pseudo-random frequency sweep signal. Noise is then attenuated from the resulting, acquired seismic data on pre-phase subtraction basis, e.g., before correlating or de-convolving the acquired seismic data. In this way, repetitions associated with, for example, diversity stacking techniques can be avoided.

Abstract: An embodiment of the invention includes simultaneous drive signals whose respective phase angle offset(s) varies over a portion or duration of the simultaneous sweeps. Other embodiments are discussed herein.

Abstract: The present disclosure is direct to method of performing measurements while drilling in an earth formation. The method may include estimating a location of a seismic reflector using signals from one or more of seismic sensors located at a plurality of locations in a borehole and the drilling depth of the one or more seismic sensors in a borehole. The signals may include information about times when the seismic sensors detect a direct wave and a reflected wave. The method may include storing the information in a memory using a processor.

Abstract: A method of performing a seismic sweep includes forming a composite force profile; constructing a target seismic frequency sweep using the composite force profile; and operating a seismic source using the constructed target frequency seismic sweep.

Abstract: A device, medium and method for de-blending seismic data associated with a subsurface of the earth. The method includes receiving blended seismic data, wherein the blended seismic data includes traces having energies from two or more different shots that partially overlap; applying an apex-shifted radon transform (ASRT) to the blended seismic data to transform it from a first domain to a second domain; applying a mute processing for removing all shots except a first shot in the second domain; applying a reverse ASRT to the given shot to obtain the first shot in the first domain; and generating an image of the subsurface based on the first shot in the first domain. The procedure may be iteratively repeated to separate all shots.

Abstract: An apparatus uses a steered ultrasound beam to assess microstructure of the cervix revealed by backscatter power variation at a range of angles and depth. Analysis of a distribution of power loss at different angles and depths referenced to the structure of the cervix may be used to characterize cervical tissue.

Abstract: A technique includes generating vibroseis sweeps for a vibroseis survey to produce seismic data acquired in response to seismic signals produced by the sweeps. The generation of the vibroseis sweeps including temporally arranging the sweeps into time-overlapping groups. The technique includes regulating a timing of the groups relative to each other based on a slip time. The technique also includes regulating a timing of the sweeps of each group such that consecutive sweep firings of each group are spaced apart by a time substantially less than the slip time.

Abstract: In an embodiment a semiconductor device correlates a received signal with a known pattern. A correlation output is used as a basis for forming a confidence reference level. The confidence reference level and the correlation output are compared to identify a peak in the received signal indicating that a present signal state of the received signal contains the known pattern.

Abstract: The invention relates to processing seismic data that includes signals from at least two sources and typically three or four sources where source separation is necessary for geophysical analysis. Specifically, the present invention is a process for correcting data prior to inversion where the correction is provided to correct for the filtering effect of the earth. The earth is a non-homogenous seismic propagator that causes distortions of wavelets of seismic energy related to the source and receiver azimuth and offset that makes the identification of source specific data within the composite data harder to identify. Computing an earth response and correcting for the effects of the earth on the wavelets provides for more resolution and more clarity in the resulting data and better geophysical interpretation.

Abstract: Computer software, computer and method for generating with a computing device a desired pilot signal for driving a vibratory source to generate seismic waves. The method includes steps for compressing a pilot signal in a force domain and also compressing a mass displacement in a displacement domain. The resulting desired pilot signal boosts the low-frequency end of the vibratory source.

Abstract: A method for seismic prospecting that includes a step of deploying plural vibratory sources on the ground; a step of receiving at each vibratory source a corresponding pilot signal for driving the vibratory source; a step of asynchronously actuating the vibratory sources to generate seismic waves into the ground; and a step of continuously recording seismic signals produced by the seismic waves. Pilot signals for the plural vibratory sources are obtained by spectrally shaping starting sequences into continuous pseudorandom sequences that are weakly correlated over a predetermined time interval.

Abstract: The present invention relates to an apparatus for use in geophysical surveying. Geophysical surveying typically involves stimulating an area of interest with a seismic source and detecting the response in a sensor array. The application describes a fibre optic distributed sensing apparatus having a source (112) of electromagnetic radiation for repeatedly launching interrogating electromagnetic radiation into an optic fibre (104) deployed in said of area interest, a sampling detector (116) for sampling radiation back-scattered from the fibre; and a processor (108) arranged to process the back-scattered radiation to provide, for each of a plurality of longitudinal sensing portions of optic fibre, an indication of any incident acoustic signals affecting that sensing portion. The sampling detector is arranged to acquire a plurality of diversity samples for each said longitudinal sensing portion.

Abstract: A device, medium and method for de-blending seismic data associated with a subsurface of the earth. The method includes a step of receiving seismic data “d” recorded with one or more land receivers, wherein the seismic data includes shot recordings generated by plural sources that are simultaneously actuated; a step of forming either a continuous receiver trace or trace segments from the received seismic data; a step of selecting plural overlapping spatial blocks that cover the surface shot locations; a step of assigning the shot recordings to the plural overlapping spatial blocks; a step of applying a mathematical technique to the recordings to determine de-blended data; and a step of generating an image of the subsurface based on the de-blended data.

Abstract: Computer software, computer and method for generating with a computing device a desired pilot signal for driving a vibratory source to generate seismic waves. The method includes steps for compressing a pilot signal in a force domain and also compressing a mass displacement in a displacement domain. The resulting desired pilot signal boosts the low-frequency end of the vibratory source.

Abstract: A method for seismic prospecting that includes a step of deploying plural vibratory sources on the ground; a step of receiving at each vibratory source a corresponding pilot signal for driving the vibratory source; a step of asynchronously actuating the vibratory sources to generate seismic waves into the ground; and a step of continuously recording seismic signals produced by the seismic waves. Pilot signals for the plural vibratory sources are obtained by spectrally shaping starting sequences into continuous pseudorandom sequences that are weakly correlated over a predetermined time interval.

Abstract: The invention relates to processing seismic data that includes signals from at least two sources and typically three or four sources where source separation is necessary for geophysical analysis. Specifically, the present invention is a process for correcting data prior to inversion where the correction is provided to correct for the filtering effect of the earth. The earth is a non-homogenous seismic propagator that causes distortions of wavelets of seismic energy related to the source and receiver azimuth and offset that makes the identification of source specific data within the composite data harder to identify. Computing an earth response and correcting for the effects of the earth on the wavelets provides for more resolution and more clarity in the resulting data and better geophysical interpretation.

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

Abstract: An embodiment includes determining whether first and second seismic sources are ready to perform seismic sweeps.

Abstract: A method for the emplacement of a sensor in soil for sensing seismic activity comprising in one embodiment the steps of creating a borepath in the soil, the borepath having opposing ends and a diameter, inserting a longitudinal housing and a grout pipe into the borepath extending from one of said opposing ends to the other, the longitudinal housing having the sensor encapsulated within, the grout pipe having one end and a grouting end, pulling the grout pipe longitudinally within the borepath by the one end to position the grouting end between the opposing ends within the borepath, and conducting a grout through the grout pipe into the borepath at the grouting end to encase the longitudinal housing within the borepath thereby facilitating emplacement of a sensor in soil for sensing seismic activity. The grout preferably selected so to acoustically match the longitudinal housing to the soil.

Abstract: The invention relates to the acquisition of seismic data using many seismic sources simultaneously or where the sources are emitting in an overlapping time frame but where it is desired to separate the data traces into source separated data traces. The key is having each seismic source emit a distinctive pattern of seismic energy that may all be discerned in the shot records of all of the seismic receivers. Distinctive patterns are preferably based on time/frequency pattern that is distinctive like an easily recognized song, but may include other subtle, but recognizable features such a phase differences, ancillary noise emissions, and physical properties of the vibes such a the weight and shape of the pad and the reaction mass and the performance of the hydraulic system and prime energy source.

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

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

Abstract: A method of directional drilling which comprises an intelligent non-invasive ultrasonic sensors that can detect the approaching of an existing well and then can stop and redirect the directional drilling to prevent collisions with preexisting wells.

Abstract: A method and apparatus for pre-inversion noise attenuation of seismic data. The method can generally comprise: (a) acquiring seismic data including receiver data corresponding to vibratory signals simultaneously generated by the multiple sources and detected by at least one of the receivers at a location remote from the sources and source data corresponding to the vibratory signals detected at a location in proximity to the sources; (b) attenuating noise present within at least a portion of the receiver data to generate corrected receiver data; and (c) inverting the corrected receiver data with the source data to separate the vibratory signals.

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 technique includes modeling a fundamental component of a vibroseis sweep that is injected into the earth based on a ground force measurement and a reference sweep. The technique includes determining an operator to compensate seismic data acquired in response to the injected vibroseis sweep based at least in part on the reference sweep and the fundamental component, and the technique includes applying the operator to the seismic data.

Abstract: A method for generating seismic energy for subsurface surveying includes operating a first seismic vibrator and operating at least a second seismic vibrator substantially contemporaneously with the operating the first seismic vibrator. A driver signal to each of the first and the at least a second seismic vibrators that are substantially uncorrelated with each other.

Abstract: Methods for improving the range and resolution of simultaneous multiple vibratory source seismic system including ZENSEIS™ are provided.

Abstract: A technique includes generating vibroseis sweeps for a vibroseis survey to produce seismic data acquired in response to seismic signals produced by the sweeps. The generation of the vibroseis sweeps including temporally arranging the sweeps into time-overlapping groups. The technique includes regulating a timing of the groups relative to each other based on a slip time. The technique also includes regulating a timing of the sweeps of each group such that consecutive sweep firings of each group are spaced apart by a time substantially less than the slip time.

Abstract: The present invention provides a seismic surveying method in which vibrators in a first vibrator group are actuated at time T0 and vibrators in a second vibrator group are actuated at time T1, where T0<T1<T0+S1+L and S1 is the sweep time of the first group and L is the listening time. This method enables the time required to complete a seismic survey to be reduced. In other embodiments, vibrators in the first vibrator group may be actuated at time T2, where T1<T2<T1+S2+L and S2 is the sweep time of the first group, and vibrators in the second vibrator group at time T3 where T2<T3<T2+S1+L and T3?T2?T1?T0. Such embodiments providing that by appropriately combining the shot records noise may be eliminated.

Abstract: The invention relates to a method of determining impulse responses from a medium (2) in relation to the transmission of waves between different points (T1-TN). The inventive method consists in: transmitting waves in the medium by generating, at each point j, signals ei(t) each comprising n elementary signals with respective frequencies which are spaced apart in pairs by an interval ?f and which are different from the frequencies of the elementary signals corresponding to the other points; receiving signals rj(t) at points j after the transmission of the aforementioned waves in the medium; and calculating each impulse response hij(t) from a correlation signal between signal ei(t) transmitted at point i and signal rj(t) received at point j.

Abstract: A method of performing a 3-D seismic survey operation using (i) a plurality of vibroseis sources, and (ii) an array of seismic sensors arranged within a survey area wherein each vibroseis source emits a distinctive acoustic signal and each seismic sensor of the array is in a continuous state of readiness to detect reflected acoustic signals, the method comprising: (a) assigning vibroseis points (VPs) to each of the vibroseis sources; (b) independently moving each vibroseis source to assigned vibroseis point (VPs) where the vibroseis source emits its distinctive acoustic signal independently in time of the emission of the distinctive acoustic signals of the other vibroseis sources at their assigned vibroseis points (VPs); (c) recording the emission time of the distinctive acoustic signal by each vibroseis source at its assigned VPs together with the geographic position of the assigned VPs; (d) continuously listening for reflected acoustic signals using the array of seismic sensors and recording a time domain r

Abstract: A method for determining presence of seismic events in seismic signals includes determining presence of at least one seismic event in seismic signals corresponding to each of a plurality of seismic sensors. A correlation window is selected for each of the plurality of seismic signals. Each correlation window has a selected time interval including an arrival time of the at least one seismic event in each seismic signal. Each window is correlated to the respective seismic signal between a first selected time and a second selected time. Presence of at least one other seismic event in the seismic signals from a result of the correlating.