Patent classifications
G01V2210/21
System and method for spatially imaging and characterizing properties of rock formations using specular and non-specular beamforming
A method for imaging non-specular seismic events as well as correlating non-specular events with physically measurable quantites in a volume of Earth's subsurface. Includes entering as input to a computer signals detected by a plurality of seismic sensors disposed above and/or within the volume in response to actuation of at least one seismic energy source above and/or within the volume. Parameter analysis is performed to populate the initial model with point-wise, best-fit wavefront travel-time approximations. Imaging is performed to obtain undifferentiated specular and non-specular representations of the volume. Specular boundaries are mapped using the imaged volume and using the boundaries to form a model of specular components of the volume. Beamforming is used to characterize seismic attributes associated with specular and non-specular reflections as separate and differentiated data sets.
Mapping wave slowness using multi-mode semblance processing techniques
Techniques for calculating and visually presenting multiple acoustic modes that have different formation slowness are disclosed herein. The techniques include methods for receiving time-domain waveforms from adjacent formations in a borehole, processing each of the time-domain waveforms to generate frequency-domain spectrums, selecting frequency and slowness values, and predicting travel time of a mode associated with the slowness value. In some aspects, the method further includes steps for calculating a semblance difference of the frequency-domain spectrums based on the frequency value, the slowness value and the predicted travel time. Systems and computer-readable media are also provided.
Quality control and preconditioning of seismic data
Various implementations directed to quality control and preconditioning of seismic data are provided. In one implementation, a method may include receiving particle motion data from particle motion sensors disposed on seismic streamers. The method may also include performing quality control (QC) processing on the particle motion data. The method may further include performing preconditioning processing on the QC-processed particle motion data. The method may additionally include attenuating noise in the preconditioning-processed particle motion data.
ISO-FREQUENCY RATIO LOGS
Disclosed are methods, systems, and computer-readable medium to perform operations including: spectrally decomposing seismic data associated with a target subsurface area into a plurality of iso-frequency volumes; selecting a low-frequency volume and a high-frequency volume from the plurality of iso-frequency volumes; dividing the low-frequency volume by the high-frequency volume to generate a frequency ratio volume for the target subsurface area; establishing a time-depth relationship in the target subsurface area; extracting, based on the time-depth relationship and the frequency ratio volume, an iso-frequency ratio log in the target subsurface area; and using the iso-frequency ratio log to identify a subsurface gas reservoir in the target subsurface area.
Method of high-resolution amplitude-preserving seismic imaging for subsurface reflectivity model
The present disclosure provides a method of high-resolution amplitude-preserving seismic imaging for a subsurface reflectivity model, including: performing reverse time migration (RTM) to obtain an initial imaging result, performing Born forward modeling on the initial imaging result to obtain seismic simulation data, and performing RTM on the seismic simulation data to obtain a second imaging result; performing curvelet transformation on the two imaging results, performing pointwise estimation in a curvelet domain, and using a Wiener solution that matches two curvelet coefficients as a solution of a matched filter; and applying the estimated matched filter to the initial imaging result to obtain a high-resolution amplitude-preserving seismic imaging result.
ENHANCEMENT OF SEISMIC DATA
Methods, systems, and computer-readable medium to perform operations including: generating a first time-frequency spectrum of a first seismic trace from an original seismic dataset; generating a second time-frequency spectrum of a second seismic trace from an enhanced seismic dataset, where the second seismic trace corresponds to the first seismic trace; and re-combining an amplitude spectrum of the first time-frequency spectrum and a phase spectrum of the second time-frequency spectrum to generate a third time-frequency spectrum of an output trace that corresponds to the first and second seismic traces.
Frequency based method for reducing the effect of multiples in seismic data
Disclosed are methods, systems, and computer-readable medium to perform operations including: decomposing the seismic data into a plurality of sub-volumes, each sub-volume associated with a respective one of the plurality of frequency components; identifying a portion of the seismic data that includes one or more multiples, the multiples being seismic data associated with multiply reflected seismic energy; identifying, based on the plurality of sub-volumes, the one or more multiples within the portion of the seismic data; and determining, from the plurality of frequency components, a single frequency that gives rise to a predetermined continuity along a primary reflector affected by the one or more multiples.
Estimation of formation and/or downhole component properties using electromagnetic acoustic sensing
A method is provided of inspecting a nested multi-layer structure including a first and second electrically conductive layer and a third layer disposed behind the second conductive layer. The method includes deploying a sensor device including an electromagnetic acoustic transducer to a borehole location proximate to the structure, generating a drive signal including a plurality of frequencies, applying an electrical current signal to the sensor device based on the drive signal and inducing currents in the first conductive layer that induce currents generating acoustic signals having the plurality of frequencies, detecting a first set of resonant frequencies based on received electromagnetic signals, detecting a second set of resonant frequencies based on received acoustic signals, estimating a property of the first and/or the second conductive layer based on the first set of resonant frequencies, and estimating a property of the third layer based on the second set of resonant frequencies.
METHOD AND SYSTEM FOR ESTIMATING THICKNESS OF DEEP RESERVOIRS
A method for estimating a thickness of a deep reservoir may include obtaining seismic data relating to the deep reservoir. The method may include performing spectral decomposition to obtain one or more frequency components from the seismic data. The method may include identifying a number of mono-frequency horizons corresponding to high frequencies in the seismic data, determining whether the deep reservoir is a thin reservoir based on the number of mono-frequency horizons, and estimating the thickness of the deep reservoir when the deep reservoir is determined to be the thin reservoir.
Method of high-resolution amplitude-preserving seismic imaging for subsurface reflectivity model
The present disclosure provides a method of high-resolution amplitude-preserving seismic imaging for a subsurface reflectivity model, including: performing reverse time migration (RTM) to obtain an initial imaging result, performing Born forward modeling on the initial imaging result to obtain seismic simulation data, and performing RTM on the seismic simulation data to obtain a second imaging result; performing curvelet transformation on the two imaging results, performing pointwise estimation in a curvelet domain, and using a Wiener solution that matches two curvelet coefficients as a solution of a matched filter; and applying the estimated matched filter to the initial imaging result to obtain a high-resolution amplitude-preserving seismic imaging result.