| Patent application number | Description | Published |
|---|
| 20090010101 | Seismic streamer having longitudinally symmetrically sensitive sensors to reduce effects of longitudinally traveling waves - A seismic streamer includes a jacket and at least one seismic sensor disposed in a sensor holder inside the jacket. The at least one sensor is oriented inside the sensor holder such that a response of the at least one sensor is substantially longitudinally symmetric. | 01-08-2009 |
| 20090147621 | Method of attenuating noise in marine seismic streamers utilizing varied sensor spacing and position-dependent band-pass filters - The invention comprises a system for attenuating noise in seismic signals detected in a marine seismic streamer. In a particular implementation the system may comprise seismic detectors positioned in the streamer and interconnected to form a plurality of wavenumber filters, with each of the wavenumber filters attenuating signals within a range of wavenumbers. The output signals from the wavenumber filters are operatively connected to a plurality of band-pass filters, and the output signals of the band-pass filters are combined by summation means. The range of wavenumbers attenuated by the wavenumber filters and the passbands of the band-pass filters are selected so that in the output signal of the summation means, signals within a selected frequency range of interest propagating along the cable within a selected velocity range are attenuated and signals within the selected frequency range of interest having a velocity range outside the selected velocity range are preserved. | 06-11-2009 |
| 20100008184 | Method for aquiring and processing marine seismic data to extract and constructively use the up-going and down-going wave-fields emitted by the source(s) - A method for acquisition and processing of marine seismic signals to extract up-going and down- going wave-fields from a seismic energy source includes deploying at least two marine seismic energy sources at different depths in a body of water. These seismic energy sources are actuated with known time delays that are varied from shot record to shot record. Seismic signals from sources deployed at different depths are recorded simultaneously. Seismic energy corresponding to each of the sources is extracted from the recorded seismic signals. Up-going and down-going wave-fields are extracted from the sources deployed at different depths using the extracted seismic energy therefrom. A method includes the separated up-going and down-going wave-fields are propagated to a water surface or a common reference, the up-going or the down-going wave-field is 180 degree phase shifted, and the signals from these modified up-going and down-going wave-fields are summed. | 01-14-2010 |
| 20100165792 | Marine seismic streamer cable with noise suppressing sensor support - A seismic streamer includes at least one elongated strength member. The seismic streamer further includes a substantially rigid sensor holder coupled to the strength member and fixed in position relative to the strength member. The streamer includes at least one particle motion sensor coupled to the sensor holder and fixed in position relative to the sensor holder. | 07-01-2010 |
| 20110242937 | Method for separating up and down propagating pressure and vertical velocity fields from pressure and three-axial motion sensors in towed streamers - A measured pressure field, a measured vertical velocity field, and two measured orthogonal horizontal velocity fields are obtained. A programmable computer is used to perform the following. A scaling factor is determined from water acoustic impedance, the measured pressure field, and the horizontal velocity fields. One of the measured pressure field and measured vertical velocity field is combined with one of the measured vertical velocity field scaled by the scaling factor and the measured pressure field scaled by the scaling factor, generating one of up-going and down-going pressure and velocity wavefields. | 10-06-2011 |
| 20120002502 | Methods for gathering marine geophysical data - In a first embodiment the invention comprises a method for gathering geophysical data, including towing geophysical data gathering equipment behind a survey vessel in a body of water, said equipment including an array of sensor streamers extending behind said vessel, and determining a geodetic location of a streamer steering reference point at a forward end of the sensor streamers and a reference direction. At least one sensor streamer included in said array of sensor streamers is laterally deflected in response to the determined geodetic location of said streamer steering reference point and the determined reference direction. | 01-05-2012 |
| 20120026829 | Method for wave decomposition using multi-component motion sensors - Three-axis velocity data, obtained along with pressure data in a marine seismic survey, are rotated to a ray direction. Plane wave decomposition is applied in the ray direction to the rotated velocity data. The pressure data and the velocity data are combined to generate at least one of up-going and down-going wave fields. The at least one of up-going and down-going wave fields are used in a time-space domain to image the earth's subsurface. | 02-02-2012 |
| 20120033526 | Wavefield deghosting of seismic data recorded using multiple seismic sources at different water depths - Seismic data are acquired by actuating a first source at a first time and one or more additional seismic sources each with their own characteristic times with respect to a time of signal recording, the sources substantially collocated and at different depths. A first wavefield is determined that would occur if the first source were actuated at a selected time with respect to an initiation time of the recordings and being time adjusted for the water depth. One or more additional wavefields are determined that would occur if the one or more additional sources were each actuated at said selected time with respect to said initiation time, and being time adjusted for water depths of the one or more additional sources. The first wavefield and the one or more additional wavefields are combined to determine a deghosted source wavefield corresponding to actuation of a single seismic energy source. | 02-09-2012 |
| 20120259553 | Method for eliminating spectral constraints of acquisition system and earth filtering effects - Recorded seismic data are represented as a convolution of operators representing a reflectivity series of the earth and a seismic wavelet. The recorded seismic wavelet is represented as a convolution of operators representing a receiver ghost, a source ghost, a ghost-free source system response, an earth filter response, and a receiver system response. The operator representing the receiver ghost is removed from the convolution representing the seismic wavelet. The operator representing the source ghost is removed from the convolution representing the seismic wavelet. The operator representing the ghost-free source response is removed from the convolution representing the seismic wavelet. The operator representing the earth filter response is removed from the convolution representing the seismic wavelet. The operator representing the seismic wavelet is removed from the convolution representing the recorded seismic data. | 10-11-2012 |
| 20120307591 | METHODS AND APPARATUS FOR SEISMIC EXPLORATION USING PRESSURE CHANGES CAUSED BY SEA-SURFACE VARIATIONS - Disclosed are apparatus and methods for seismic exploration using pressure changes caused by sea-surface variations as a low-frequency seismic energy source. One embodiment relates to a method which obtains dual wave-fields measured below a sea surface. The measured dual wave-fields are decomposed into a down-going wave-field and an up-going wave-field at a selected observation level. Seismic images are then generated using the down-going and up-going wave-fields. Other embodiments, aspects, and features are also disclosed. | 12-06-2012 |
| 20130088235 | Method for Acquiring and Processing Marine Seismic Data to Extract and Constructively use the Up-Going and Down-Going Wave-fields Emitted by the Source(s) - A method for acquisition and processing of marine seismic signals to extract up-going and down- going wave-fields from a seismic energy source includes deploying at least two marine seismic energy sources at different depths in a body of water. These seismic energy sources are actuated with known time delays that are varied from shot record to shot record. Seismic signals from sources deployed at different depths are recorded simultaneously, Seismic energy corresponding to each of the sources is extracted from the recorded seismic signals. Up-going and down-going wave-fields are extracted from the sources deployed at different depths using the extracted seismic energy therefrom. A method includes the separated up-going and down-going wave-fields are propagated to a water surface or a common reference, the up-going or the down-going wave-field is 180 degree phase shifted, and the signals from these modified up-going and down-going wave-fields are summed. | 04-11-2013 |
| 20130088938 | SUBSURFACE IMAGING SYSTEMS AND METHODS WITH MULTI-SOURCE SURVEY COMPONENT SEGREGATION AND REDETERMINATION - A disclosed subsurface imaging method begins by obtaining initial signals from a geophysical survey that has been acquired with multiple geophysical energy sources actuated in a plurality of firing sequences, each sequence having a known time delay between the firing times of each source. The initial signals are grouped into gathers of signals acquired from multiple firing sequences. For each gather, initial estimates of the first and second source wave fields are determined. Quieted signals for the first source are then generated to represent the initial signals minus a current estimate of the second source wave field. A coherent energy separation operation is applied to the quieted signals to obtain a refined estimate for the first source wave field. | 04-11-2013 |
| 20130092469 | SYSTEMS AND METHODS FOR PRODUCING DIRECTED SEISMIC WAVES IN WATER - A disclosed seismic source assembly includes a body having a cavity and a seismic source positioned in the cavity. The cavity is in fluid communication with the water via an aperture oriented in a first direction. One or more surfaces of the body define a water contact significantly larger than an area of the aperture and on a side opposite the first direction. A described method includes forming a source assembly by: providing a cavity having an aperture for transmitting seismic waves; rigidly attaching a base to a side of the cavity opposite the aperture, where a transverse area of the base is significantly larger than an area of the aperture; and positioning a seismic source in the cavity. The source assembly is submerged in the water and triggered. | 04-18-2013 |
| 20130201791 | METHOD AND SYSTEM FOR DETERMINING SOURCE SIGNATURES AFTER SOURCE GHOST REMOVAL - Seismic data are acquired using a seismic source comprising a plurality of seismic sub-sources disposed in a body of water at a plurality of depths and activated with different time delays. Far-field signatures are determined for the plurality of seismic sub-sources at each of the plurality of depths. A composite ghost-free far-field signature of the seismic source is determined from the far-field signatures for the plurality of seismic sub-sources at each of the plurality of depths and different time delays. A source response is removed from the seismic data using the far-field signatures of the seismic source | 08-08-2013 |
| 20130322205 | Seismic Surveying Techniques with Illumination Areas Identifiable from Primary and Higher-Order Reflections - Techniques are disclosed relating to determining or executing a survey pattern for a marine seismic survey vessel. The survey pattern may be determined based on a determined subsurface illumination area. The subsurface illumination area may be identifiable from primary reflections and higher-order reflections detected by sensors disposed in a sensor streamer configuration that may be towed behind the survey vessel. The sensor streamer configuration may include a plurality of streamers. | 12-05-2013 |
| 20130325427 | METHODS AND SYSTEMS FOR COMPUTING NOTIONAL SOURCE SIGNATURES FROM NEAR-FIELD MEASUREMENTS AND MODELED NOTIONAL SIGNATURES - Methods and systems for computing notional source signatures from modeled notional signatures and measured near-field signatures are described. Modeled near-field signatures are calculated from the modeled notional signatures. Low weights are assigned to parts of a source pressure wavefield spectrum where signatures are less reliable and higher weights are assigned to parts of the source pressure wavefield spectrum where signatures are more reliable. The part of the spectrum where both sets of signatures are reliable can be used for quality control and for comparing the measured near-field signatures to modeled near-field signatures. When there are uncertainties in the input parameters to the modeling, the input parameters can be scaled to minimize the differences between measured and modeled near-field signatures. Resultant near-field signatures are computed by a weighted summation of the modeled and measured near-field signatures, and notional source signatures are calculated from the resultant near-field signatures. | 12-05-2013 |
| 20140269170 | Method for Optimizing the Design of Multiple-Source Arrays Used in Marine Seismic Surveys - A method and apparatus for determining marine seismic source configurations which produce a minimum error after the process of combining the wave fields to eliminate the responses of sources including the source ghost operated at multiple depths, without separating these wave fields, is disclosed. In one embodiment, a method includes simulating, on a computer system, the performing of a seismic survey for one or more source configurations. An error term is calculated for each configuration simulated. Based on the calculated error terms, a configuration having the smallest error among those simulated may be determined. | 09-18-2014 |
| 20140269182 | SYSTEMS AND METHODS FOR REMOVING ACQUISITION RELATED EFFECTS FROM SEISMIC DATA - Systems and methods for operating a seismic source to attenuate shot generated noise, or residual energy from previous activation of the source, in recorded seismic data are described. In one aspect, methods operate a single seismic source towed through a body of water along a survey track. As the survey vessel travels along the survey track, the source is activated at the end of randomly selected time delays, resulting in attenuation of shot generated noise. The method also attenuates other forms of coherent noise that align from shot to shot. | 09-18-2014 |
| 20140340983 | TIME-EFFICIENT TESTS TO DETECT AIR GUN FAULTS - Techniques are disclosed relating to testing of seismic air guns, for example via bubble tests. According to some embodiments of these techniques, a firing sequence for testing the air guns may be determined that reduces the amount of interaction between firings. Further, firing time delays may also be determined in order to further reduce the interactions. Accordingly, a test of an array of air guns may be completed relatively quickly. | 11-20-2014 |
| 20150085609 | METHODS FOR GATHERING MARINE GEOPHYSICAL DATA - In a first embodiment the invention comprises a method for gathering geophysical data, including towing geophysical data gathering equipment behind a survey vessel in a body of water, said equipment including an array of sensor streamers extending behind said vessel, and determining a geodetic location of a streamer steering reference point at a forward end of the sensor streamers and a reference direction. At least one sensor streamer included in said array of sensor streamers is laterally deflected in response to the determined geodetic location of said streamer steering reference point and the determined reference direction. | 03-26-2015 |
| 20150293241 | SEISMIC DATA ACQUISITION - A method for seismic data acquisition can include near-continuously recording seismic data received from a number of seismic receivers and triggering a plurality of source elements, based upon time and not based upon position, at a predefined sequence of times relative to a start of a near-continuous recording. | 10-15-2015 |
| 20150293242 | SEISMIC DATA PROCESSING - A method for seismic data processing can include obtaining seismic data acquired based upon trigger times and not based upon positions of triggered source elements. The seismic data can include near-continuously recorded seismic data in split records. The split records can be spliced together into a single near-continuous record to produce a trace with seismic data from a single acquired line. The seismic data can be processed by performing a spatial shift for each of a number of time samples to correct for motion of a number of seismic receivers. | 10-15-2015 |
| 20160047928 | METHODS AND SYSTEMS OF WAVEFIELD SEPARATION APPLIED TO NEAR-CONTINUOUSLY RECORDED WAVEFIELDS - Wavefield separation methods and systems that adjust near-continuous pressure and particle motion wavefields based on distance moved along a vessel track by the sensors when the wavefields were measured are disclosed. Methods and systems correct for the motion of the receivers in towed streamer seismic data in order to obtain a wavefield with approximately stationary-receiver locations. Wavefield separation may then be applied to the wavefield with approximately stationary-receiver locations. | 02-18-2016 |
| 20160047929 | METHODS AND SYSTEMS THAT COMBINE WAVEFIELDS ASSOCIATED WITH GENERALIZED SOURCE ACTIVATION TIMES AND NEAR-CONTINUOUSLY RECORDED SEISMIC DATA - Systems and methods to correct source responses and perform source deghosting of a pressure or particle motion wavefield recorded using near-continuous recording of seismic data along a vessel track with generalize source activation times. The methods and systems receive a near-continuously recorded seismic data and generate a near-continuous wavefield for approximately stationary-receiver locations. Time windows of different temporal lengths are applied to traces of the near-continuous wavefield in approximately stationary-receiver locations in order to compute common-receiver gathers. The common-receiver gathers are corrected source wavefield response and source ghost effects and are combined in weighted sums to generate broadband seismic data. | 02-18-2016 |
| 20160047930 | Method For Acquiring and Processing Marine Seismic Data to Extract and Constructively Use the Up-Going and Down-Going Wave-fields Emitted by the Source - A method for marine seismic surveying includes separating up-going and down-going wavefields from seismic energy emitted by at least one marine seismic energy source. The separated up-going and down-going wavefields are propagated from the at least one marine seismic energy source to at least one of a water surface and a common reference depth. One of the up-going and down-going wavefields is phase shifted 180 degrees. The propagated, phase shifted up-going and down-going wavefields are summed. | 02-18-2016 |
