10 results about "Apparent velocity" patented technology

The invention discloses a VSP wellbore wave suppression method for improving U-Net based on physical constraints, which comprises the following steps: introducing apparent velocity constraints of an F-K transform domain, constructing physical constraint conditions, simultaneously realizing time sequence feature extraction and prediction of wellbore waves in combination with a GRU network, and learning a mapping relation between a noise image and a clean image by using the network so as to improve the suppression efficiency of the wellbore waves. The details and the structure of a noise image are accurately restored through a training network, the difference between a real de-noised image and network output is minimized so as to achieve the purpose of image de-noising, the model retains effective signals through a residual learning mechanism, and meanwhile precise suppression of shaft wave noise is achieved. The method provided by the invention can accurately identify and effectively suppress wellbore waves and reflected waves thereof in a complex VSP wave field, significantly improve the signal-to-noise ratio, reduce residual noise, improve data processing efficiency while improving data quality, provide technical support for high-precision seismic imaging under a complex geological condition, and have a wide application prospect. And meanwhile, a feasible solution is provided for popularization and application in an actual work area.

Data obtained from synthetic aperture radar "SAR" image acquisition apparatus on a satellite, operating in orbit around Earth, is processed to form looks at a target area on Earth at different points in time. Dense optical flow is computed to identify apparent motion between successive looks and to determine apparent velocity for at least some pixels between successive looks. The apparent velocity is converted into actual velocity by correction for the relative motion between the platform and the target. A 2D velocity map of motion in the target area may be generated.

This invention relates to a method and apparatus for designing seismic data acquisition trace spacing. The method includes: determining different first apparent velocities of effective waves and different second apparent velocities of interfering waves based on raw single-shot data; determining a first frequency corresponding to a first preset minimum energy value for each effective wave and a second frequency corresponding to a second preset minimum energy value for each interfering wave; determining a first candidate maximum wavenumber for each effective wave that does not produce spatial aliasing based on the first frequency and the first apparent velocity, and determining a second candidate maximum wavenumber for each interfering wave that does not produce spatial aliasing based on the second frequency and the second apparent velocity; determining a target maximum wavenumber from the first and second candidate maximum wavenumbers, and then determining the seismic data acquisition trace spacing for the target work area; and designing a trace spacing that can balance exploration costs and technical requirements using old single-shot data, saving costs and fully utilizing the value of old data.

The present invention discloses a VSP borehole wave suppression method based on improving U-Net with physical constraints. By introducing apparent velocity constraints in the F-K transform domain, physical constraint conditions are constructed. At the same time, combined with the GRU network, the temporal feature extraction and prediction of borehole waves are realized, and the mapping relationship between the noise image and the clean image is learned by the network. By training the network, the details and structure of the noise image are accurately restored, and the difference between the real denoised image and the network output is minimized to achieve the purpose of image denoising. The model retains the effective signal through the residual learning mechanism and simultaneously achieves precise suppression of borehole wave noise. The method of the present invention can accurately identify and effectively suppress borehole waves and their reflected waves in a complex VSP wavefield, significantly improve the signal-to-noise ratio, reduce the residual noise, improve the data processing efficiency while improving the data quality, provide technical support for high-precision seismic imaging under complex geological conditions, and provide a feasible solution for the popularization and application in the actual work area.

The present invention discloses a method for attenuating coherent noise in three-dimensional prestack seismic records, comprising the following steps: 1) performing wavelet transform on each seismic record in a three-dimensional prestack seismic data volume to decompose the three-dimensional prestack seismic data volume into frequency-divided seismic data volumes with different wavelet orders; 2) determining the wavelet order W of the frequency-divided seismic data volume and the apparent velocity scanning range of the coherent noise in this wavelet order according to the frequency and apparent velocity of the coherent noise; 3) determining the direction of coherent noise for each sample point of each trace according to the apparent velocity scanning of the coherent noise; 4) predicting the amplitude value of the coherent noise for each sample point of each trace along the direction of coherent noise and performing attenuation processing on the coherent noise; 5) performing the same processing on each sample point within the processing time range of each shot and each trace to obtain the result after coherent noise attenuation, and performing wavelet transform reconstruction on the result after coherent noise attenuation to obtain the seismic record. The coherent noise attenuation method of the present invention provides good protection for effective signals.

The invention relates to a karst detection multi-parameter joint interpretation method based on environmental noise and application. The method comprises the following steps of: 1, acquiring an environmental noise signal by adopting a three-component broadband digital seismograph and a two-dimensional array observation system; 2, a Capon F-K (Force-Wave Domain) analysis algorithm is adopted to carry out calculation, so that a frequency-surface wave phase velocity curve of each two-dimensional array can be obtained; 3, calculating and obtaining a frequency spectrum curve and an H / V spectrum ratio curve of two horizontal components and vertical components of each detection point of each two-dimensional array by adopting an independently researched and developed MATLAB (Matrix Laboratory) program; 4, respectively drawing a surface wave phase velocity (or surface wave horizon velocity) profile map, a frequency spectrum profile map and an H / V spectrum ratio profile map by adopting an independently researched and developed MATLAB (Matrix Laboratory) program; and 5, performing multi-parameter joint interpretation on karst detection by using parameters such as surface wave phase velocity (or surface wave apparent velocity), frequency spectrum and H / V spectrum ratio. The multi-parameter joint interpretation method is used for multi-parameter joint interpretation of karst detection, reliability and accuracy of interpretation results can be improved, potential risk sources are found in advance for engineering construction, and major construction accidents are avoided.

The invention discloses a surface wave apparent velocity analysis method and device based on deep learning, equipment and a storage medium, and the method comprises the steps: extracting part of seismic data as a data set, and taking the seismic data which is not extracted as to-be-processed data; analyzing the data set to obtain a corresponding apparent velocity label; the data set and the corresponding apparent velocity label are converted to a t-v domain through RT transformation; the converted data set is preprocessed; according to a preprocessing result, extracting a part of the data set as a training set, and taking the remaining data set as a verification set; constructing a deep neural network, and training a U-net model; converting the to-be-processed data to a t-v domain through RT conversion; using the U-net model to predict the data to be processed; a prediction result is converted to a t-x domain through inverse RT transformation; converting the t-x domain prediction result into apparent velocity information; and performing surface wave suppression on the surface wave apparent velocity result. The method is well suitable for surface wave analysis work of seismic data of different terrains, the manual workload is reduced, and the analysis efficiency and the analysis result accuracy are improved.

This invention belongs to the field of seismic data processing technology for petroleum exploration, specifically relating to a pre-stack time migration denoising method and apparatus. The denoising method includes the following steps: (1) processing seismic data to obtain a pre-stack time migration profile, and selecting a stable wave impedance interface for the work area on the pre-stack time migration profile; (2) performing geological correction on the pre-stack time migration profile based on the stable wave impedance interface for the work area to obtain a geologically corrected profile; (3) performing F-K filtering on the geologically corrected profile to obtain an F-K filtered profile; (4) performing wave impedance interface inverse correction on the F-K filtered profile to obtain the final profile. The pre-stack time migration denoising method of this invention adopts the concept of "geological correction," combined with F-K filtering to effectively suppress migration noise. It features a simple and easy-to-draw time window, a small apparent velocity range that is easy to control, and improved operational efficiency. The denoised profile exhibits good amplitude preservation, greatly improving profile quality.

This application discloses a method, apparatus, and computer equipment for detecting anomalous first arrival times, belonging to the field of oil and gas exploration technology. The method includes: acquiring seismic data from seismic traces, the seismic data including multiple first arrival times; preprocessing the first arrival times to obtain second arrival times; acquiring global features corresponding to the seismic data, determining a first anomalous first arrival time and reference seismic data based on the global features within the second arrival time, the global features including apparent velocity; dividing the reference seismic data into data segments, determining the local features corresponding to the data segments, and determining a second anomalous first arrival time within the second arrival time based on the local features. This method, by preprocessing the first arrival times to obtain the second arrival time, can improve the accuracy of the determined arrival time; and by determining the first and second anomalous first arrival times within the second arrival time, it can improve the accuracy and reliability of the determined anomalous first arrival times.

The present invention belongs to the field of seismic exploration technology and discloses a method for correcting the deviation of the actual excitation point from the center in a radial arrangement test, comprising collecting the coordinates of the actual excitation point; collecting the apparent velocity of the first arrival wave of the receiving point; collecting the coordinates of the receiving point; calculating the distance from the actual excitation point to each receiving point on the concentric circle; calculating the difference between the distance from the actual excitation point to each receiving point on the concentric circle and the distance from the theoretical excitation point to each receiving point on the concentric circle; calculating the correction amount of the first arrival wave of each receiving point on the concentric circle; and applying the correction amount to correct the deviation of the actual excitation point from the center in the radial arrangement test. The method of the present invention is simple and lays a good foundation for subsequent data analysis. The present invention is suitable for correcting the deviation of the actual excitation point from the center in a radial arrangement test.