Patent classifications
G01V1/362
Real-time processing and control of DAS VSP surveys
A system for processing DAS VSP surveys in real-time is provided. The system includes a DAS data collection system coupled to at least one optical fiber at least partially positioned within a wellbore and configured to repeatedly activate a seismic source of energy. The system further includes an information processing system connected to the DAS data collection system. A seismic dataset is received from the DAS data collection system. The seismic dataset includes a plurality of seismic data records. Two or more of the plurality of seismic data records are combined into a stack. A quality metric indicative of a desired signal-to-noise ratio or incoherence of the stack is determined for each processed seismic dataset collected from a repeated source. Instructions are sent to the DAS data collection system to stop activating the seismic source, in response to determining that the quality metric has reached a predefined threshold.
System and method for automatically correlating geologic tops
A system and method are provided for automatically correlating geologic tops. The system receives well logs from different well bores and each of the picks is added to a priority queue ordered by each pick's quality measure. User selected picks are assigned the highest level of quality measure. The system performs correlation by selecting a window of well log data about a pick selected from the top of the priority queue and then finding the best optimal match with a corresponding window in a neighboring wellbore.
BEAMFORM PROCESSING FOR SONIC IMAGING USING MONOPOLE AND DIPOLE SOURCES
Embodiments provide for a method that utilizes the azimuthally spaced receivers of a sonic logging tool. Signals from monopole and dipole sources are reflected from the geologic interfaces and recorded by arrays of receivers of the same tool. For the incident P-waves from the monopole source, phase arrival times for the azimuthal receivers are compensated for stacking using properties of wave propagation in the borehole, and for the incident SH-waves from the dipole source, signs of waveforms for the receivers are changed for specified azimuths.
METHOD, APPARATUS, AND SYSTEM FOR IDENTIFYING SURFACE LOCATIONS CORRESPONDING TO SUBSURFACE GEOHAZARDS BASED ON FREQUENCY RATIOS AMONG SEISMIC TRACE SIGNALS
A method and apparatus of locating subsurface geohazards in a geographical area that includes: receiving a plurality of seismic trace signals in the geographical area based on a shot gather from a seismic shot source; isolating and stacking the plurality of seismic trace signals to generate a windowed trace signal associated with refraction traces from the seismic shot source; transforming the windowed trace signal to a frequency domain; calculating a low frequency to high frequency ratio for the transformed trace signal; outputting the calculated ratio to a two-dimensional array representing the geographical area at a source location and at a mean receiver location; repeating the steps for a plurality of other shot gathers in the geographical area; and multiplying each source location ratio with one or more mean receiver location ratios on the two-dimensional array to generate a final frequency ratio map.
Picking seismic stacking velocity based on structures in a subterranean formation
Systems and methods for picking seismic stacking velocity based on structures in a subterranean formation include: receiving seismic data representing a subterranean formation; generating semblance spectrums from the seismic data representing the subterranean formation; smoothing the semblance spectrums; and picking stacking velocities based on the smoothed semblance spectrums.
Detection and Removal of Delayed Seismic Travel Times Produced by Velocity Inversions
In seismic imaging, accurate velocity functions (velocity model) defining seismic velocity as a function of depth in the earth are required. The velocity model is obtained as a result of seismic surveying. Delayed travel times in near surface refraction seismic surveys, an effect known as shingling, can result from an anomalous condition, seismic velocity decreasing with depth. Inclusion of such delayed travel times in a tomographic process for seismic imaging would otherwise cause large errors in determination of a seismic velocity model for seismic imaging of subsurface features. At locations (source-receiver offset) in the survey where the shingling occurs, the velocity inversions are identified. The undesirable effects the delayed travel times caused by the velocity inversions are removed from the survey dataset.
SYSTEM AND METHOD FOR REDUCING STATICS IN SEISMIC IMAGING
The present embodiments describe a system and method for generating one or more predictive models to reduce the static interference present in seismic reflection studies. The system can include a user device and a server. The method proceeds with gathering historical data, generating synthetic data, generating a predictive model based on those data sets, and applying that model to a current set of a data to calculate a seismic reflection of a geological space.
Non-Linear Solution to Seismic Data Conditioning Using Trained Dictionaries
Techniques to reduce noise in seismic data by receiving a set of seismic data comprising a plurality of input volumes each inclusive of positional data and at least one additional attribute related to the seismic data, selecting a first input volume of the plurality of input volumes having a first additional attribute related to the seismic data, and generating a pilot volume by selecting a range of input volumes of the plurality of input volumes and stacking input volumes of the range of input volumes with the first input volume. Additionally, generating a trained dictionary based upon transformation of the pilot volume, transforming the first input volume into transformed data, imposing a sparse condition on the transformed data utilizing the trained dictionary to generate sparsified data, and inverse transforming the sparsified data to generate an output data volume as a portion of a set of modified seismic data.
SEISMIC DATA PROCESSING METHOD FOR RESOLVING THE NEAR-SURFACE IN THE PRESENCE OF VELOCITY INVERSIONS
A method for weathered layer correction of seismic data includes identifying arrival times in the seismic data corresponding to a weathered layer velocity gradient. A velocity model of the weathered layer is generated using the arrival times. The seismic data are time adjusted using the velocity model.
Systems and methods to enhance 3-D prestack seismic data based on non-linear beamforming in the cross-spread domain
The disclosure provides systems and methods to enhance pre-stack data for seismic data analysis by: sorting the reflection seismic data acquired from cross-spread gathers into sets of data sections; performing data enhancement on the sets of data sections to generate enhanced traces by: (i) applying forward normal-moveout (NMO) corrections such that arrival times of primary reflection events become more flat, (ii) estimating beamforming parameters including a nonlinear traveltime surface and a summation aperture, (iii) generating enhanced traces that combine contributions from original traces in the sets of data sections, and (iv) applying inverse NMO corrections to the enhanced traces such that temporal rearrangements due to the forward NMO corrections are undone.