Abstract: A marine source element is configured to generate seismic waves. The source element includes a body and a source actuator attached to the body and configured to generate the seismic waves. The body is autonomous from a vessel towing streamers along a pre-plot line associated with a seismic survey.
Type:
Grant
Filed:
May 16, 2016
Date of Patent:
November 6, 2018
Assignee:
CGG SERVICES SAS
Inventors:
Herve Richer De Forges, Karine Desrues, Risto Siliqi
Abstract: A method for removing ocean bottom and/or geology related contamination. The method includes receiving first measurements corresponding to first seismic sensors mounted on a first source array; receiving second measurements corresponding to second seismic sensors mounted away from the first source array; processing the second measurements to determine a contamination model related to the ocean bottom and geology; removing the contamination model from the first measurements to obtain cleaned data; and calculating a source signature of the first source array based on the cleaned data.
Type:
Grant
Filed:
July 21, 2016
Date of Patent:
October 23, 2018
Assignee:
CGG SERVICES SAS
Inventors:
Yoong Ern Lee, Chris Davison, Gordon Poole
Abstract: A system and method for performing seismic exploration with multiple acquisition systems is disclosed. The method includes configuring a first seismic source located outside of an exclusion zone and configuring a second seismic source located inside of the exclusion zone. The method further includes obtaining a first seismic dataset corresponding to a first seismic signal emitted by the first seismic source and obtaining a second seismic dataset corresponding to a second seismic signal emitted by the second seismic source. The method further includes combining the first and second datasets to create a complete dataset covering a survey area and creating a seismic image of a subsurface of the survey area.
Type:
Grant
Filed:
December 5, 2014
Date of Patent:
October 16, 2018
Assignee:
CGG SERVICES SAS
Inventors:
Cécile Berron, Philippe Herrmann, Julien Cotton, Eric Forgues, John J. Sallas
Abstract: There is a method for generating a final image of a subsurface of the earth. The method includes receiving measured seismic data d of the subsurface; selecting an objective function E that is function of a reflectivity r of the subsurface; and calculating, in a processor, the reflectivity r based on the measured seismic data d, the objective function E, simulated data {tilde over (d)}, a modeling operator M from a reverse time demigration (RTDM) process and an imaging operator MT from a reverse time migration (RTM) process.
Abstract: A system and method for generating simultaneous plural frequencies in seismic exploration is disclosed. The method includes configuring a seismic source to emit a seismic signal that includes multiple frequencies emitted substantially simultaneously. The method additionally includes identifying a plurality of frequencies to include in the seismic signal and determining an amplitude of the seismic signal. The method further includes obtaining a seismic dataset corresponding to the seismic signal emitted by the seismic source and creating a seismic image of a subsurface of a seismic survey area.
Abstract: Seismic data recorded on an ocean bottom node (OBN) is used to determine observed direct arrival times at the OBN from a set of seismic source shots having a time span that is only a portion of an entire span time for a shot line. The observed direct arrival times for each shot in the set of seismic source shots are compared statistically with a plurality of predicted direct arrival times for each shot in the set of seismic source shots to derive a statistical measure of differences across all shots. Each predicted direct arrival time is associated with a unique proposed position of the OBN. The unique proposed position that minimizes the statistical measure of differences between the observed direct arrival times and the predicted direct arrival times is selected for each shot in the set of shots as a corrected OBN position.
Abstract: A system and method for discontinuous spectrum emission in seismic exploration is disclosed. The method may include determining a minimum frequency to be emitted by a seismic source in a frequency spectrum. The method may further include selecting a maximum frequency to be emitted by the seismic source in the frequency spectrum. The method may include identifying a portion of the spectrum between the minimum frequency and the maximum frequency where a reduced signal will be emitted by the seismic source. The method may finally include emitting, by the seismic source, a seismic signal according to the frequency spectrum and the identified portion of the frequency spectrum with the reduced signal.
Abstract: A passive, automatic cable winding system is coupled by a cable to a seismic source or streamer and automatically adjusts a payout of the cable connecting the seismic source or streamer to a float. The passive, automatic cable winding system includes a tensioning system configured so that when the seismic source or streamer is deployed during a seismic survey the water exerts force on the seismic source or streamer and the passive, automatic cable winding system pays out the cable so that the seismic source or streamer is at the desired depth for the seismic survey. When the seismic source or streamer is pulled out of the water during recovery, the passive, automatic winding system reduces the length of the cable between the float and the seismic source or streamer, and thus reduces the chances of the cable becoming tangled during recovery.
Abstract: A sweep generator is employed to generate a sweep to be used by a seismic vibrator device for generating a desired target output spectrum, wherein the frequency sweep is designed so as to comply with one or more constraints imposed by the seismic vibrator device and/or imposed by the environment in which the device is to be used. In one embodiment, a sweep generator determines a sweep for achieving a desired target output spectrum by a given seismic vibrator device in compliance with at least a pump flow constraint imposed by the seismic vibrator device. In another embodiment, a sweep generator determines a sweep for achieving a desired target output spectrum by a given seismic vibrator device in compliance with all of multiple operational constraints of the seismic vibrator device, such as both mass displacement and pump flow constraints. Environmental constraints may also be accounted for in certain embodiments.
Abstract: An electromagnetic (EM) receiver system for measuring EM signals. The EM receiver system includes a platform; a coil for measuring EM signals; and first to third suspension mechanisms located between the platform and the coil so that the coil oscillates relative to the platform, and the first to third suspension mechanisms attenuate motion induced noise introduced by towing the receiver system above ground.
Abstract: A method for estimating a fracability index for a geological location includes determining a fabric metric and a mineralogical composition metric for a geological sample extracted from a geological location and estimating a fracability index for the geological location from the fabric metric and the mineralogical composition metric. The fabric metric may be a grain related measurement such as grain size or angularity, or a pore-space related measurement such as pore area, diameter, aspect ratio, and circumference, or statistics associated with such measurements. In certain embodiments, determining the mineralogical composition metric includes detecting a prevalence of at least one organic proxy within the geological sample such as vanadium, iron, uranium, thorium, copper, sulfur, zinc, chromium, nickel, cobalt, lead and molybdenum. Determining the mineralogical composition metric may also include detecting a prevalence of one, two, or all of siliciclastics, carbonate and clay.
Abstract: An underwater base handles an autonomous underwater vehicle. The underwater a support structure to be hooked to a cable, a storing part configured to store the AUVs, an inlet part located above the storing part and configured to control access of the plural AUVs to the storing part, and a control part configured to control a movement of the inlet part relative to the support structure. The control part is further configured to wirelessly guide the AUVs while approaching the inlet part.
Abstract: Seismic source modules are combined into seismic source strings that are grouped into seismic source arrays. The seismic source array includes a plurality of seismic source strings arranged in parallel and towed behind a seismic source vessel. Each seismic source string includes a plurality of seismic source modules coupled in series along the seismic source string. Each seismic source module includes a protective cage, at least one seismic source disposed within the protective cage and decoupled from the protective cage and a pair of couplers in communication with the protective cage. The seismic source string also includes a plurality of tethers attached to couplers between adjacent pairs of seismic source modules in the series of seismic source modules.
Type:
Grant
Filed:
December 15, 2015
Date of Patent:
July 10, 2018
Assignee:
CGG SERVICES SAS
Inventors:
Florian Josse, Herve Richer De Forges, Junya Konno
Abstract: Computing device, computer instructions and method for jointly deghosting first and second 3-dimensional (3D) seismic vintages of a same subsurface. The method includes receiving the first 3D vintage; receiving the second 3D vintage, wherein the second 3D vintage is taken later in time than the first 3D vintage, over the same subsurface; jointly deghosting the first and second 3D vintages based on a common ghost-free model U0, a first vintage ghost-free model Ub, and a second vintage ghost-free model Um; and generating an image of the subsurface indicative of changes between the first and second 3D vintages based on the common ghost-free model U0.
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: A device and method for calculating electrical properties of a surveyed underground formation. The method includes selecting a waveform having multiple current transition rates; placing a time-domain electromagnetic (TEM) system above the underground formation while generating with a transmitter a transient primary magnetic field during an on-time period and no magnetic field during a following off-time period, due to the waveform; and recording with a receiver magnetic related data generated by the earth as a result of the transient primary magnetic field. The receiver records the magnetic related data during the on-time period using plural on-time gates sampling.
Abstract: System and method for calculating a pre-plot for a marine seismic acquisition system. The method includes receiving as input a first number of streamer vessels and a second number of source vessels; receiving a geometry of an area to be surveyed; receiving a set of naturally different regions and/or humanly set targets for the area to be surveyed; calculating a first sailing path for a streamer vessel of the first number of streamer vessels; calculating a second sailing path for a source vessel of the second number of source vessels, based on the set of naturally different regions and/or humanly set targets; and entering the pre-plot into a navigation system of the streamer vessel and the source vessel so that the streamer and source vessels dynamically change an offset distance between them, while sailing during a seismic survey, based on the naturally different regions and/or humanly set targets.
Abstract: An electromagnetic (EM) receiver system for measuring EM signals. The EM receiver system includes a frame; a first EM receiver attached to the frame and configured to measure the EM signals within a first frequency range; and a second EM receiver attached to the frame and configured to measure the EM signals within a second frequency range. Corresponding axes of the first and second EM receivers are substantially parallel to each other.
Abstract: An electromagnetic (EM) receiver system for measuring EM signals. The EM receiver system includes a survey EM transmitter for generating survey EM signals within a first frequency range; a tracking EM transmitter for generating tracking signals within a second frequency range; and a receiver section including a receiver that measures both the survey EM signals and the tracking signals.
Abstract: Methods and systems for separating multiple events from primary events in noisy seismic data are described. Multiples are predicted and then the predictions are improved by least-square matching filtering in the space and time domain. An adaptive curvelet domain separation (ACDS) is then performed and the ACDS equation is solved with an iterative soft-thresholding technique. Further processing can be added to compensate for prediction inaccuracy or variable/excessive seismic data noise by dividing the seismic data into predetermined bands and processing each band independently.